The prevention and solutions for the reactor agitator imbalance problem can be considered and implemented in the following aspects:

Preventive measures

1. Optimization at the design stage:
   
• In the design stage of the stirrer, the structure, material, weight distribution and other factors of the stirrer should be fully considered to ensure that the stirrer has good dynamic balance performance.
  
• Reasonably design the blade shape, quantity and angle of the agitator to reduce the vortex and turbulence generated during the mixing process, improve the mixing efficiency and reduce vibration.
  
2. Control of installation process:
   
• Strictly follow the installation specification for the installation and commissioning of the stirrer to ensure that the coaxiality, parallelism and perpendicularity of the stirrer and the reactor meet the requirements.
  
• During the installation process, each part of the stirrer is carefully inspected and tested to ensure that there is no damage or defect.
  
3. Formulation of operation specification:
   
• Formulate detailed operation specification and safety operation specification to clarify the operation method, precautions and emergency treatment measures of the agitator.
  
• Train the operators to ensure that they understand the structure, working principle and operating regulations of the agitator and can operate the agitator correctly and safely.
  
4. Regular maintenance and inspection:
   
• Formulate a regular maintenance and inspection plan, and carry out regular inspection and maintenance of the agitator and its accessories, including cleaning, lubrication and tightening.
  
• Regularly check the bearings, seals and other wear parts of the agitator and replace worn or damaged parts in time.
  

Solution

1. Adjust the clearance between agitator blade and kettle body:
   
• If the gap between the agitator blades and the kettle body is improper, adjustments should be made to ensure that the gap is reasonable. Too much or too little clearance may result in uneven mixing or vibration.
  
2. Re-perform dynamic balance test:
   
• If the agitator is experiencing imbalance problems, the dynamic balance test should be redone. Adjust the agitator's center of gravity position by adding or subtracting counterweights, etc., to bring it into balance.
  
3. Replacement of worn parts:
   
• If the bearings, seals and other parts of the agitator are badly worn or damaged, they should be replaced with new ones. Damage to these parts will affect the agitator's operational stability and sealing performance.
  
4. Adjust the transmission system:
   
• Check whether the connection bolts, bearing seats and other parts of the transmission system are tight and reliable. If there is any looseness, tighten them in time to prevent vibration caused by unstable transmission. At the same time, check the working condition of the motor and reducer to ensure that they run smoothly without abnormal vibration and noise.
• 
  

Optimize the foundation support:

• If the foundation support of the reactor and its stirrer is not solid or defective, it should be optimized. This includes strengthening the foundation support structure, carrying out foundation reinforcement treatment and other measures to improve the stability and anti-vibration performance of the equipment.
  

Adjust the stirring speed:

• Adjust the speed of the stirrer according to the nature of the reactants and the stirring demand. Ensure that the stirring speed is suitable for the mixing requirements of the reactants, and avoid uneven mixing or vibration caused by too fast or too slow.
  

In summary, through the implementation of measures such as optimization at the design stage, control of the installation process, formulation of operational specifications, regular maintenance and inspection, and specific solutions for imbalance problems, the imbalance problem of the reactor agitator can be effectively prevented and solved.

I. Overview of mechanical seal
        Mechanical seal (face seal) is a device used to solve the sealing between the rotating shaft and the body. It is composed of at least one pair of fluid pressure and compensation mechanism perpendicular to the rotating axis of the end face of the role of elasticity (or magnetic force) and the auxiliary seal under the cooperation to maintain the fit under and relative sliding to prevent fluid leakage device, commonly used in pumps, compressors, reaction mixing kettle and other rotating fluid machinery, but also for gear boxes, ships tail shaft and other seals. Therefore, mechanical seal is a universal shaft sealing device.
        There are various mechanical seal structures, the most commonly used mechanical seal structure is the end seal. The static ring and the dynamic ring of the face seal form a pair of frictional sub, the role of the frictional sub is to prevent media leakage. It requires static ring, dynamic ring, with good wear resistance, dynamic ring can move flexibly in the axial direction, automatically compensate the seal surface wear, so that it is a good fit with the static ring; static ring has a floating, buffer role. For this reason, the seal surface requires good processing quality to ensure that the seal has a good fit performance. The basic components of the mechanical seal are static ring, dynamic ring, gland, push ring, spring, positioning ring, sleeve, dynamic ring seal, static ring seal sleeve seal, etc.

        Elastic element (spring, bellows) it mainly plays the role of pre-tightening, compensation and buffering, requiring always maintain sufficient elasticity to overcome the friction of the auxiliary seal and transmission parts and the inertia of the moving ring, etc., to ensure a good fit of the end seal and the moving ring follow, the material requires corrosion resistance, fatigue resistance.

        Auxiliary seal (O-ring, V-ring, U-ring, wedge ring and shaped ring, etc.) It mainly plays a static ring and dynamic ring sealing role, but also play a floating and buffering role. The sealing element of the static ring is required to ensure the sealing between the static ring and the gland, and the static ring has a certain floating, and the sealing element of the dynamic ring can ensure the sealing between the dynamic ring and the shaft or sleeve and the floating of the dynamic ring. Material requirements such as heat resistance.
 
1、Basic structure
        1）Frictional end seal
        2）Buffering reward and compression mechanism
        3）Auxiliary seal (secondary seal flexure element)
        4）Transmission mechanism

2、Basic sealing point
        1）The main sealing point of the end face
        2）Static ring and end cover auxiliary sealing point
        3）Dynamic ring and shaft (sleeve) auxiliary sealing point
        (4) end cover and pump body connection sealing point

Second, the advantages and disadvantages of mechanical seals
1、Advantages
        (1) reliable structure, the amount of leakage can be limited to very little, as long as the surface roughness and straightness of the main sealing surface can be guaranteed to meet the requirements, as long as the material wear resistance is good, mechanical seals can achieve little leakage, and even invisible to the naked eye leakage.
        (2) Long life. In the mechanical seal, the main wear part is the seal friction side face, because the amount of wear on the seal face under normal working conditions is not large, generally can be used continuously for 1 to 2 years, special occasions are also useful to 5 to 10 years.
        (3) No adjustment is needed in operation. Because the mechanical seal relies on spring force and fluid pressure to make the frictional sub-fitting, automatically maintain contact in operation, after assembly, there is no need to adjust the compression like ordinary soft packing.
        (4) It is vibration resistant. In the speed of 3000r/min maximum amplitude does not exceed 0.05mm using the PV value continues to improve
        (5) Small power loss. Packing seal is by the compression of the packing on the shaft or sleeve to play a role. Filler seal and shaft friction directly, the tighter the packing friction is greater, the greater the power consumption. The mechanical seal friction is in a semi-liquid friction state, the friction coefficient is very small, the mechanical seal power loss is 10 to 50% of the packing seal
        (6) The bellows seal shaft or sleeve is not subject to wear and tear, and is not sensitive to the swing of the rotating shaft and the deflection of the shaft to the shell.
        (7) Wide range of application. When the medium is flammable, explosive, toxic and harmful, the use of mechanical seals can ensure sealing. It is also suitable for high temperature, low temperature, high pressure, vacuum various speed and corrosive media equipment sealing.

2、Disadvantages
        (1) such as the structure is more complex than the packing seal, high processing accuracy requirements, and requires a certain installation technology, especially the installation of dry gas seal requirements are higher. And sealing technology is developing rapidly, new technologies continue to emerge to bring us new topics of maintenance.
        (2) Complex structure, disassembly and assembly inconvenience. Compared with other seals, mechanical end seals, the number of parts, precision requirements, complex structure. Especially in the assembly is more difficult, disassembly to extract the seal ring from the end of the shaft, you must disassemble the machine part (coupling) or all. This problem has been made some improvements, such as the use of easy disassembly and assembly quality can ensure that the split and set mechanical seals.

Third, the working principle of mechanical seal
        Mechanical seal, also known as end seal, is a pair or several pairs of perpendicular to the shaft for relative sliding end face in the fluid pressure and compensation mechanism under the action of elasticity (or magnetic force), relying on the auxiliary seal with the other end to maintain the fit, and relative sliding, so as to prevent fluid leakage.

Fourth, the choice of materials commonly used in mechanical seals
        Clear water, room temperature: (dynamic) 9Cr18, 1Cr13 welded cobalt-chromium-tungsten, cast iron; (static) dipped resin graphite, bronze, phenolic plastic.
        River water (containing sediment), room temperature: (dynamic) tungsten carbide, (static) tungsten carbide.
        Sea water, room temperature: (dynamic) tungsten carbide, 1Cr13 welded cobalt-chromium-tungsten, cast iron; (static) dipped resin graphite, tungsten carbide, cermet.
        Superheated water, 100 degrees: (dynamic) tungsten carbide, 1Cr13 overlay cobalt-chromium tungsten, cast iron; (static) dipped resin graphite, tungsten carbide, cermet.
        Gasoline, lubricating oil, liquid hydrocarbon, room temperature: (dynamic) tungsten carbide, 1Cr13 overlay cobalt-chromium-tungsten, cast iron; (static) dipping resin or tin-antimony alloy graphite, phenolic plastic.
        Gasoline, lubricating oil, liquid hydrocarbon, 100 degrees: (dynamic) tungsten carbide, 1Cr13 overlay cobalt-chromium-tungsten; (static) immersion bronze or resin graphite.
        Gasoline, lubricating oil, liquid hydrocarbon, containing particles: (dynamic) tungsten carbide; (static) tungsten carbide .


V. Types and uses of sealing materials
        Sealing materials should meet the requirements of sealing function. Due to the different media being sealed, as well as the different working conditions of the equipment, the requirements of sealing materials have different adaptability. The requirements for sealing materials are generally.
        1) Good denseness of the material, not easy to leak the medium.
        2) appropriate mechanical strength and hardness.
        3) Good compression and resilience, small permanent deformation.
        (4) high temperature does not soften, not decomposition, low temperature does not harden, not brittle crack.
        5) Good corrosion resistance, long-term work in acid, alkali, oil and other media, its volume and hardness change is small, and does not adhere to the metal surface.
        6) Friction coefficient is small, good wear resistance.
        7) With the sealing surface combined with the softness.
        8) Good aging resistance, durable.
        (9) processing and manufacturing is convenient, cheap, easy to take materials.

Six, mechanical seal installation, the use of technical essentials
        (1) the radial runout of the equipment shaft should be ≤ 0.04 mm, axial runout is not allowed greater than 0.1 mm.
        (2) the seal part of the equipment should be kept clean during installation, the seal parts should be cleaned, the seal end face intact, to prevent impurities and dust brought into the seal part.
        (3) during installation, banging and knocking are strictly prohibited, so as not to break the mechanical seal friction side and seal failure.
        (4) installation in contact with the seal surface should be coated with a layer of clean mechanical oil, so that it can be installed smoothly.
        (5) installation of the static ring gland, tighten the screws must be evenly stressed to ensure that the static ring end face and axis line vertical requirements.
        6）Push the moving ring by hand after installation, so that the moving ring can move flexibly on the shaft and have some flexibility.
        (7) after installation, hand-drive the rotating shaft, the rotating shaft should have no light or heavy feeling.
        (8) equipment must be filled with media before operation to prevent dry friction and seal failure.

Seven, mechanical seals in industrial development and applications
        Rubber is the most commonly used sealing material. In addition to rubber, suitable for sealing materials such as graphite, polytetrafluoroethylene and a variety of sealants.
        The current use of new materials and processes of a variety of mechanical seals of new technologies, progress faster, there are the following new mechanical seal technology. Sealing surface slotting sealing technology in recent years, in the mechanical seal sealing end face opened a variety of flow grooves to produce fluid static, dynamic pressure effect, and is still being updated.

        Zero-leakage sealing technology in the past always thought that contact and non-contact mechanical seals can not reach zero leakage (or no leakage). The new concept of zero-leakage non-contact mechanical face seal was introduced in Israel using slotted seal technology and has been used in lube oil pumps in nuclear power plants. Dry running gas seal technology This type of seal is the use of slotted seal technology for gas seals. Upstream pumping seal technology is to use the sealing surface to open the flow groove to pump a small amount of leakage fluid back upstream.
        The structural characteristics of the above-mentioned types of seals are: the use of shallow grooves, and the thickness of the film and the depth of the flow grooves are in the micron level, and the use of lubrication grooves, radial sealing dams and circumferential sealing weirs to form the sealing and load-bearing part. It can also be said that slotted seal is a combination of flat seal and slotted bearing. Its advantages are small leakage (even no leakage), large film thickness, elimination of contact friction, low power consumption and heat generation. Thermal fluid dynamic pressure sealing technology it is the use of a variety of shapes deeper sealing surface flow groove, resulting in local thermal deformation to produce hydrodynamic wedge effect. This kind of seal with hydrodynamic pressure carrying capacity is called thermal fluid dynamic wedge seal.

        Bellows sealing technology can be divided into formed metal bellows and welded metal bellows mechanical sealing technology.

        Multi-end seal technology is divided into double seal, intermediate ring seal, and multi-seal technology. In addition, there are parallel surface sealing technology, monitoring sealing technology, combined sealing technology, etc.

Eight, mechanical seal flushing program and characteristics
        The purpose of flushing is to prevent the accumulation of impurities, to prevent the formation of air pockets, to maintain and improve lubrication, etc. When the flushing fluid temperature is low, it also has a cooling effect. Flushing methods are mainly as follows.
(A) Internal flushing
1、Flushing
        (1) Features: The use of the working host of the sealed medium, from the outlet side of the pump through the pipeline into the sealing chamber.
        (2) Application: for clean fluid, p1 slightly greater than p into, when the temperature is high or impurities, can be set in the pipeline cooler, filter, etc.

2、Backflushing
        (1) characteristics: the use of the work of the main body of the sealed medium, from the pump's outlet end into the sealing chamber, after flushing through the pipeline flow back to the pump inlet.
        2) Application: Used for clean fluid, and p in < p1 < p out, when the temperature is high or there are impurities, coolers, filters, etc. can be set on the pipeline. < span

3、Full flush
        (1) Characteristics: Using the sealed medium of the working host, it is introduced into the sealing chamber from the outlet end of the pump through the pipeline, and then flows back to the pump inlet through the pipeline after flushing.

(2) External flushing
        Features: the introduction of the external system and the sealed media compatible with the clean fluid to the sealing chamber for flushing.
Application: The pressure of the external flushing fluid should be 0.05 - 0.1MPa greater than the sealed medium, and is suitable for applications where the medium is high temperature or solid particles. The flow rate of the flushing fluid should ensure that it takes away heat and also needs to meet the flushing needs without producing erosion of the seal. For this purpose, the pressure of the sealing chamber and the flow rate of the flushing need to be controlled, generally the flow rate of the clean flushing fluid should be less than 5m/s.

        Slurry liquid containing particles shall be less than 3m / s, in order to achieve the above flow rate value, flushing fluid and seal cavity pressure difference should be <0.5MPa, generally take 0.05 - 0.1MPa, double-ended mechanical seal can be 0.1 - 0.2MP, flushing fluid into and out of the seal cavity orifice location, should be set near the seal face, and should be close to the dynamic ring side, in order to prevent graphite ring is In order to prevent the graphite ring from being eroded or temperature difference deformation caused by uneven cooling, as well as impurity accumulation and coking, etc., tangential introduction or multi-point flushing can be used. If necessary, the flushing fluid can be hot water or steam.

Nine, mechanical seal typical failure causes analysis
(A) mechanical seal itself problems
        1, not in place or uneven mounting.
        2, the load factor is too large or end face pressure ratio design is not reasonable.
        3, improper material selection.
        4、The sealing surface is not flat.
        5、The sealing surface is too wide or too narrow.

(II) Auxiliary system problems
        1、Complex working conditions, but no flushing and other auxiliary facilities.
        2、Clogging of flushing pipe.
        3、Cooling pipe scaling.

(C) media and working conditions problems
        1、The medium is corrosive.
        2、Solid particles in the medium.
        3、Equipment evacuation.
        4、Sealing surface crystallization.
        5、Medium viscosity is too large.

(D) the pump problem
        1、Poor processing accuracy of the shaft, string shaft, jumping, installation clearance is too large.
        2、Vibration is too large after the pump is turned on.
        3、Gland gasket ring is not good.
        4、The seal box is not flat.
        5、The mechanical seal installation does not reach the proper compression amount.
Ten, the common leakage phenomenon
        The proportion of mechanical seal leakage accounts for more than 50 % of all maintenance pumps, mechanical seal operation directly affects the normal operation of the pump, is summarized and analyzed as follows.
1, periodic leakage
        (1) the pump rotor axial movement, the auxiliary seal and shaft interference, the dynamic ring can not move flexibly on the shaft. In the pump flip, dynamic and static ring wear, do not get compensation displacement.
Countermeasures: In the assembly of mechanical seals, the axial runout of the shaft should be less than 0.1mm, the interference between the auxiliary seal and the shaft should be moderate, while ensuring the radial seal, the dynamic ring assembly to ensure flexible movement on the shaft (the dynamic ring pressed to the spring can freely spring back).
        (2) Insufficient lubricating oil on the sealing surface causes dry friction or hair pulling on the sealing end face.
Countermeasures: The height of the lubricant surface in the oil chamber should be increased to a higher level than the moving and static ring sealing surface.

        (3) Rotor periodic vibration. The reason is that the stator and the upper and lower end caps are not aligned or the impeller and main shaft are not balanced, cavitation or bearing damage (wear), which will shorten the seal life and produce leakage.
Countermeasures: The above problems can be corrected according to the maintenance standards.

2、Leakage due to pressure
        (1) high pressure and pressure waves caused by mechanical seal leakage due to the spring pressure and total pressure ratio design is too large and the seal cavity pressure exceeds 3MPa, it will make the seal surface pressure is too large, liquid film is difficult to form, the seal surface wear serious, heat generation increased, resulting in thermal deformation of the seal surface.
Countermeasures: When assembling the machine seal, the spring compression must be carried out in accordance with the provisions, not allowing too large or too small phenomenon, the mechanical seal under high pressure conditions should take measures. In order to make the end surface force reasonable and minimize deformation, carbide, ceramic and other materials with high pressure strength can be used, and strengthen the cooling lubrication measures.

        (2) the mechanical seal leakage caused by the vacuum state operation pump in the start, shutdown process, due to pump inlet blockage, pumping medium containing gas and other reasons, it is possible to make the seal cavity negative pressure, the seal cavity if the negative pressure, will cause the seal face dry friction, internal mechanical seal will produce gas leakage (water) phenomenon, vacuum seal and positive pressure seal is the difference in the direction of the sealing object, and mechanical seal also has its adaptability in a certain direction.
Countermeasures: the use of double-ended mechanical seal, which helps to improve lubrication conditions and improve sealing performance.

3、Leakage caused by the medium
        (1) most of the submersible pump mechanical seal after disassembly, static ring and dynamic ring of the auxiliary seals are not flexible, some have rotted, resulting in a large number of machine seal leakage and even the phenomenon of grinding shaft. Due to high temperature, weak acids and alkalis in the sewage on the static ring and moving ring auxiliary rubber seal corrosion, resulting in excessive mechanical leakage, moving and static ring rubber seal material is nitrile-40, not high temperature, not acid and alkali resistance, when the sewage is acidic alkali easy corrosion.
Countermeasures: for corrosive media, rubber parts should be selected high-temperature resistance, resistance to weak acids, weak alkali fluorine rubber.
        (2) mechanical seal leakage caused by solid particles impurities if solid particles into the seal face, will scratch or accelerate the seal face wear, scale and oil in the shaft (sleeve) surface accumulation rate exceeds the speed of friction wear, resulting in the dynamic ring can not compensate for wear displacement, hard to hard friction vice operating life than hard to graphite friction vice long, because the solid particles will be embedded in the graphite seal ring sealing surface.
Countermeasures: In the location where solid particles can easily enter the tungsten carbide to tungsten carbide friction sub mechanical seal should be used.

4, mechanical seal leakage caused by other problems
        There are also mechanical seals in the design, selection, installation and other places not reasonable enough.
        (1) the spring compression must be carried out in accordance with the provisions, do not allow too large or too small phenomenon, error ± 2mm, too much compression to increase the end surface pressure, too much friction heat, resulting in thermal deformation of the sealing surface and accelerate end wear, too little compression static ring end surface pressure is insufficient, it can not be sealed.
        (2) Install the dynamic ring seal shaft (or sleeve) end face and install the static ring seal sealing gland (or shell) end face should be chamfered and repair light, so as not to touch the dynamic and static ring seal during assembly.

Eleven, the normal operation and maintenance of the machine seal
        1、Preparation work and precautions before starting    
        a Check whether the mechanical seal and the attached devices and pipeline installation are complete and meet the technical requirements.
        b Static pressure test before starting mechanical seal, check whether there is leakage of mechanical seal. If there is more leakage, the cause should be investigated to eliminate. If it is still not effective, it should be disassembled and reinstalled. General hydrostatic test pressure with 2-3 kg / cm2.

        c. Rotate the car according to the pump and check whether it is light and even. If the coiler is strained or not moving, check whether the assembly size is wrong and whether the installation is reasonable.

2、Installation and shutdown    
        a Before starting, keep the seal chamber full of liquid. For the transport of solidified media, the seal chamber should be heated with steam to melt the media. Before starting, it is necessary to pan the car in order to prevent the sudden start and cause the soft ring to break.
b For the mechanical seal using the oil sealing system outside the pump, the oil sealing system should be started first. Stop the oil sealing system last after stopping.

        c The cooling water of oil sealing cavity and end seal cannot be stopped immediately after stopping the hot oil pump, and the cooling water should be stopped only when the oil temperature at the end seal drops below 80 degrees to avoid damaging the seal parts.

3、Running    
        a If there is slight leakage after the pump starts, it should be observed for a period of time. If the leakage is not reduced after 4 hours of continuous operation, the pump should be stopped for inspection.
        b The operating pressure of the pump should be smooth and the pressure fluctuation should not be more than 1kg/cm2.

        c Pump in operation, should avoid evacuation phenomenon, so as not to cause seal surface dry friction and seal damage.

        The mechanical seal itself is a demanding precision part with high requirements for design, machining and assembly quality. In the use of mechanical seals, should analyze the use of mechanical seals of various factors, so that mechanical seals are suitable for a variety of pump technology and the use of media requirements and adequate lubrication conditions, so as to ensure the long-term reliable operation of the seal.

Calculation of stirring power
The stirring power calculation of a stirrer is mainly based on the type of stirrer, rotational speed, diameter, nature of the stirred material and other factors. The following are the power calculation methods for some common agitator types:

Power Calculation for General Purpose Agitators

The power formula for a general purpose agitator is usually as follows: [ P = N_p \cdot \rho \cdot n^3 \cdot D^5 ] where (P) is the required agitator power in watts or horsepower, (N_p) is the value of the power (depending on the type of agitator and the geometry of the equipment), (\rho) is the fluid density, (n) is the agitator RPM, (D) is the agitator diameter.

Power Calculation for Screw-Belt Agitators

The formula for calculating the power of a screw-type stirrer is as follows: [ P = k \cdot N \cdot D^3 \cdot L \cdot \rho / 1000 ] where (P) is the power required, (k) is a coefficient (usually 0.1-0.3), (N) is the speed of the stirrer, (D) is the diameter of the stirrer, (L) is the length of the stirrer, (\rho) is the density of the stirred material (in units), (n) is the stirrer speed, (D) is the diameter of the stirrer, (L) is the length of the stirrer, (\rho) is the density of the stirred material, (n) is the density of the stirred material, (D) is the diameter of the stirrer. ) is the density of the agitate (in kg/m³).



Power Calculation of Side Entry Agitator

The power calculation formula for a side-entry agitator is similar to that for a general-purpose agitator, but more specifically takes into account the effect of the agitation Reynolds number: [ P = Kd^5N^3\rho ] where (K) is the power quasi-count, which is a function of the agitation Reynolds number (Re_j) ((Re_j = d^2N\rho\\mu)), (d) and (N) are the agitator diameter and rotational speed, respectively, (\rho) and (\mu) are the density of the agitated material in kg/m³, respectively, and (L) is the agitator length. (d) and (N) are the diameter and speed of the stirrer, respectively; (\rho) and (\mu) are the density and viscosity of the mixture, respectively.

Considerations
Fluid Properties

The viscosity and density of the mixture have a significant effect on the mixing power. The higher the viscosity, the higher the power required.

The physical properties of the agitant need to be accurately understood during the calculation process.

Stirrer design

Factors such as the shape, structure, diameter and length of the stirrer will affect the stirring power.

The efficiency and power consumption of the stirrer should be considered during design to ensure that it meets the production requirements.

Experimental Measurements

For specific types of agitators and tanks, it is recommended to experimentally determine (K) as a function of (Re_j) to plot a power curve.

Experimental data can provide a more accurate basis for power calculations.



Practical adjustment

In practice, the stirring power is also affected by other factors such as the distance between the stirrer and the tank, and the shape of the blades.

Reasonable adjustment and optimization are needed according to the actual situation to achieve the best mixing effect.

Equipment selection

When selecting the agitator, it is necessary to consider the nature of the agitated material, the requirements of the agitation process and the investment in equipment and other factors.

Ensure that the selected agitator can meet the production requirements, and has high efficiency and stability.

Through the above calculation methods and considerations, you can accurately calculate the mixing power of the agitator, and make reasonable adjustments and optimization in the actual application, in order to improve the mixing efficiency and production benefits!

        As a common mixing equipment in the industrial field, the stable operation and long service life of the top-entry mixer are directly related to the production efficiency and product quality. Therefore, it is particularly important to carry out regular routine inspection, maintenance and repair. This article will be from the installation, use, inspection, maintenance and repair and other aspects, a detailed introduction to the daily management of top-entry mixer.

I. Preparation and precautions before installation
1. Foundation design and installation
        Foundation design: the foundation design and the location of embedded parts should be in strict accordance with the equipment size provided by the manufacturer, to ensure that the weight of the foundation does not exceed the load that the concrete structure can withstand, and the ground is flat, clean and free of foreign objects, and the level is controlled within 0~5mm.
        Pre-embedded parts fixed: pre-set ground screws should be fixed reliably with cement mortar to prevent displacement.
2. Equipment Inspection
        Integrity of parts: All parts of the mixer should be carefully checked before installation to ensure their integrity and accuracy, without damage or missing phenomenon.
        Horizontal position: During installation, keep the horizontal position of the mixer to ensure that it can maintain stable mixing effect during use.
3. Installation and commissioning
        Installation according to the instruction: according to the installation instruction provided by the manufacturer, carry out the correct installation to ensure that the parts are connected tightly and stably.
        Trial run: after the installation is completed, carry out trial run to check whether the operation of the mixer is normal, and whether there is any strange sound or vibration. If there is any problem, it should be investigated and solved in time.
II. Daily Inspection and Maintenance
1. Lubrication and sealing
       Regular lubrication: check the lubrication of the agitator, make sure the lubricant is enough and replace it regularly according to the usage. For the link pin between chain and sprocket, lubricant should be added to reduce friction and wear.
Sealing performance: Check the sealing performance of the equipment frequently to ensure that there is no leakage. If the sealing is found to be not tight, it should be dealt with in time to prevent fluid leakage leading to equipment damage or environmental pollution.
2. Cleaning and sanitation
        Regular cleaning: Clean the appearance and rotating part of the agitator regularly to avoid hygiene problems and dust accumulation. Especially the key parts such as rotating shaft and blades need to be thoroughly cleaned to remove oil and impurities.
Prevent foreign matter from entering: In the process of using, pay attention to prevent foreign matter from entering the agitator, so as not to affect its normal operation and damage the agitator.
3. Transmission and power unit inspection
        Transmission mechanism: Regularly check whether the transmission and power device of the agitator, including the reducer, motor and coupling parts are damaged or need to be replaced. Check whether the clearance of each running part is normal, as well as whether there is any friction phenomenon.
         Motor operation: regularly check whether the operation of the motor is normal or not. If abnormal sound, vibration or temperature rise is found, it should be stopped in time to check and deal with it.
4. Stirring paddle type and matching
        Stirring paddle type selection: According to different need conditions, select the appropriate stirring paddle type, such as propulsion, entrainment, jet type, etc.. At the same time, make sure the selected motor and reducer meet the requirements to match the selected mixing equipment.
5. Electrical and control system
        Electrical inspection: Regularly check the electrical wiring and control system to ensure that there are no short circuits, broken circuits or poor contacts. At the same time, pay attention to the heat dissipation of the electrical components to prevent overheating and causing malfunction.
Control system maintenance: For the mixer equipped with control system, software upgrade and parameter adjustment should be carried out regularly to ensure stable operation of the control system.
III. Maintenance and Extension of Service Life
1. Regular maintenance plan
        Formulate maintenance plan: according to the use of the agitator and the manufacturer's recommendations, formulate a detailed regular maintenance plan, including cleaning, lubrication, inspection, replacement of parts and components.
Execute the maintenance plan: Strictly follow the maintenance plan to execute the maintenance work to ensure that the agitator is always in a good operating condition.
2. Use of norms and safe operation
        Compliance with the use of norms: when using the agitator, should strictly comply with the use of norms, such as not overloading, not a long time of continuous use, etc., to avoid reducing the life of the machine or cause potential safety hazards.
Safe operation: When repairing or cleaning the agitator, be sure to pay attention to safety to avoid electric shock, cuts or injuries when moving the machine. Especially when used in harsh environments such as high temperature, high pressure, strong corrosion, etc., the relevant safety operating procedures should be followed.
3. Handling of abnormalities
        Abnormality detection: In the process of using, if you find that the mixer has abnormal sound, vibration or temperature rise, etc., you should stop the machine immediately for checking, and restart it after eliminating the faults.
Failure records and analysis: For the occurrence of failures and abnormalities, detailed records and analysis should be carried out in order to summarize the lessons learned and improve the level of equipment maintenance.
Fourth, summarize
        Routine inspection, maintenance and repair of the top-entry mixer is the key to ensure its stable operation and long service life. Through the development of a detailed maintenance plan, strict implementation of the inspection and maintenance work, compliance with the use of specifications and safety regulations and timely handling of abnormalities and other measures, can greatly extend the service life of the mixer, improve production efficiency and product quality. At the same time, attention should also be paid to strengthening the training and management of equipment operators, improve their maintenance awareness and skill level, to provide a strong guarantee for the stable operation of the equipment.

 As an indispensable key equipment in chemical, bioengineering, metallurgy and other industries, the professional knowledge of agitators covers a wide range of aspects such as design principle, classification, selection, application and maintenance. The following is a detailed discussion of the specialized knowledge of the agitator, aiming to provide readers with a comprehensive and in-depth understanding.

I. Basic Principle of Agitator
       The basic principle of the agitator is through the rotation of the stirring blades, so that the liquid, gas or solid particles in the container to produce forced convection and mixing. During the mixing process, the stirring blades will transfer mechanical energy to the fluid, forming shear force, squeezing force and diffusion force, etc., so as to promote intermolecular interactions within the fluid to achieve the purpose of uniform mixing. This process involves fluid dynamics, heat transfer, mass transfer and chemical reaction kinetics and other subject areas.

Second, the classification of agitator
       Stirrers can be divided into various types according to the structure, working principle and different applications. The following are some common ways to categorize agitators:

1. Classification according to working principle
Axial flow agitator: such as propeller-type agitator, its main role is to push the liquid along the axial direction to form an axial flow, suitable for mixing low-viscosity liquids.

Radial flow agitator: such as turbine agitator, its work produces liquid flow mainly along the radial direction, with high shear force and circulation rate, suitable for the mixing of medium and high viscosity liquid.

2. Classified according to structural features
Disc turbine agitator: including flat blade type, curved blade type and folded blade type, etc., through the rotation of the blades on the disc to produce a strong radial flow, suitable for all kinds of fluid material mixing and blending.

Propeller agitator: composed of propelling propeller blades, mainly causing axial liquid flow, suitable for mixing low-viscosity liquids.

Paddle agitator: including flat paddle and inclined paddle, simple structure, commonly used in the mixing of low-viscosity liquids as well as the dissolution and suspension of solid particles.

Anchor agitator: the shape of the outer edge of the paddle is consistent with the inner wall of the mixing tank, which is suitable for mixing high-viscosity liquids and removing the viscous reaction products on the tank wall.

Screw belt agitator: the rotation of the screw belt makes the liquid flow in axial direction, which is suitable for materials with high viscosity and poor fluidity.

3. Classified according to use and performance
Small diameter high speed stirrer: such as propeller and turbine stirrer, suitable for mixing low viscosity liquid.

Large diameter low speed agitator: such as paddle type, anchor type and spiral belt type agitator, suitable for mixing of high viscosity liquid.

Third, the selection of the agitator
      Selection of agitator is a key step to ensure the mixing effect and production efficiency. Selection needs to consider the following factors:

1. material characteristics
Viscosity: low-viscosity liquids should be selected with a small diameter, high speed agitator; high-viscosity liquids should be selected with a large diameter, low-speed agitator.

Density: For liquids with large differences in density, it is necessary to choose agitators that can generate strong shear and circulation rate.

Solid content: for the suspension containing a large number of solid particles, it is necessary to choose the stirrer that can effectively disperse and suspend the solids.

2. Stirring purpose
Homogeneous mixing: for materials that need to be highly homogeneous mixed, the stirrer that can produce strong shear force and high circulation rate should be used.

Dissolving and suspending: for materials that need to dissolve solids or suspend solids, agitators that can generate strong shear and vortex should be used.

Heat and mass transfer: for the reaction system which needs heat and mass transfer, the agitator which can promote the heat and mass exchange between materials should be used.

3. Vessel structure and size
Inner diameter and height: the inner diameter and height of the container affect the selection and arrangement of the agitator. Generally speaking, the larger the inner diameter of the container, the diameter of the required agitator should be increased accordingly.

With or without baffle or deflector: baffle or deflector can be set to eliminate the liquid surface depression vortex, enhance the turbulence of the liquid flow and mixing effect. Therefore, in the selection of the need to consider whether these auxiliary structures.

Fourth, the application of agitator
       Agitators are widely used in various chemical, biological engineering, metallurgy and other industries. The following are some specific application scenarios:

Chemical raw material mixing: such as titanium dioxide, rubber lining and other chemical raw materials in the mixing and preparation process, the agitator plays a vital role.

Crude oil resources mixing: in the processing and storage of crude oil resources such as gasoline and diesel fuel, the agitator can ensure the uniformity and stability of the oil.

Desulphurization and alcohol production: In desulphurization and alcohol production, agitators are used to promote chemical reactions and mixing homogeneity.

Bioengineering: In fermentation tanks, cell cultures and other bioengineering, agitators are used to promote cell growth and uniform distribution of metabolites.

Fifth, the agitator's maintenance and maintenance
       Maintenance and care of the stirrer is to ensure its long-term stable operation and extend the service life of the key. The following are some common maintenance and care measures:

Regular inspection: Regularly check whether the blades, bearings, seals and other parts of the agitator are worn or damaged, and replace them in time.

Cleaning and maintenance: Regularly clean and maintain the agitator to keep it clean and lubricated. Especially for the parts which are easy to be scaled or clogged, they need to be cleaned regularly.

Safe operation: Pay attention to safety during operation to avoid accidents. Especially when dealing with flammable, explosive or toxic materials, it is necessary to strictly abide by the safety operation regulations.

Lubrication management: For the parts that need lubrication (such as bearings), lubricant needs to be added or replaced regularly to ensure good lubrication performance.

Sixth, the future development of the agitator
       With the continuous progress of science and technology and the rapid development of the industrial field, the agitator is also constantly developing in the direction of more efficient, more intelligent and more environmentally friendly. The future development trend of agitator may include the following aspects:

Intelligent control: through the introduction of intelligent control system and sensor technology, real-time monitoring and automatic adjustment of the mixing process can be realized to improve the mixing efficiency and product quality.

Energy-saving and environmental protection: develop agitator products with low energy consumption, low noise and low emission to meet environmental requirements and reduce production costs.

Multifunctionalization: Design agitator products with various functions and uses to meet the needs of different industries and processes.

Application of new materials: the use of new materials (such as high-strength alloys, ceramics, etc.) to manufacture stirrer components to improve their wear resistance, corrosion resistance and high temperature resistance.

        In summary, as an important mixing equipment in the chemical industry and other industries, the professional knowledge of the agitator covers the design principle, classification, selection, application and maintenance and other aspects. Through in-depth understanding of these professional knowledge and reasonable application in actual production, can give full play to the performance advantages of the mixer and improve its efficiency.

       The axial flow agitator is a new type of axial flow agitator that can be used for liquid-liquid or liquid-solid suspension mixing. The arbitrary cross section of the agitator blade consists of an arc and two warped straight edge sections. The outer edges of the two straight edge sections form a wavy curve along the central axis of the blade from the end to the root, and the blade gradually widens from the end to the root. This mixer enhances the turbulence in the axial and radial directions, with good mixing effect and significant energy saving.
       The new JH axial flow agitator is a kind of space twisting propeller. From one end of the blade, it is made up of many similar arches, and when the fluid passes through the blade, there is no vortex area on the back of the blade to save work. The excellent axial flow characteristics of the new JH axial flow agitator allow the paddle to run away from the bottom of the kettle without affecting the operating effect.
       The axial flow agitator has the advantages of good axial flow characteristics, low energy consumption and simple manufacturing and installation. It can replace the existing axial three-blade folding stirrer and spiral stirrer, especially in the technical transformation of the stirred reactor, which can improve the stirring efficiency, save energy and reduce consumption, and has great economic benefits.
       Use of axial flow stirrer:It is suitable for solid suspension, liquid mixing and heat transfer, etc. It requires high pumping capacity, high flow rate and low shear.
       Technical level of axial flow agitator: Under the same operating process conditions, the diameter of axial flow agitator is slightly larger than that of traditional spiral agitator, but the power is only 70% ー80% of that of traditional paddle. Compared to conventional impellers, axial flow impellers have better axial flow characteristics, higher flow efficiency and lower torque requirements.

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        When using the side entry stirrer, plug in the power, put the vessel with the solution in the middle of the heating plate, and put the rotor into the solution of the vessel. Turn on the power, the indicator light will be on, then adjust the speed knob clockwise from slow to fast to the desired speed, and the rotor will rotate to drive the solution to stir. For heating, insert the temperature probe into the solution, insert the plug into the back seat of the side-entry stirrer instead of the standard side-entry stirrer, and adjust the temperature knob to the desired temperature. If accuracy of the solution temperature is required, measure the solution temperature with a thermometer at the same time and adjust the temperature knob to the desired temperature. If heating is not required, just adjust the temperature knob to below room temperature.
        There is a question about how to adjust the temperature of the side-entry stirrer. When using the side entry mixer, it is important to note that the right amount of water needs to be added before use. The water involved needs to exceed the standard line. If the water level below the standard line crosses the ground, the internal pipes of the side-entry mixer will overheat and burn, resulting in damage to the side-entry mixer.
        The next thing we need to do is turn on the power and then select the temperature you want and set it at the condition.
        The side-entry stirrer uses the property that magnetic substances are repulsive to the same polarity. By constantly changing the polarity of the two ends of the base, it drives the magnetic stirrer to rotate, and by the rotation of the magnetic stirrer, it drives the sample to rotate and make the sample mix evenly! Then set the temperature switch to the setting state, and then adjust the temperature control switch to the desired temperature.
        The number around the display is the temperature of the side entry stirrer tank (parts: high tank, reservoir and low tank). At this point, if the red light is on in the indicator, it means that it is heating up. When we end the heating, we should turn down the temperature control knob, and then cut off (cut off; cut off) the power. Be sure to pay attention to the sequence of issues, cut off the power.
        Side entry stirrer a few notes water bath pot if not used for a long time, to the water tank (parts: high water tank, storage tank, low water tank) in the water quickly swept clean, wipe clean with a rag, put in the sunlight exposure. If there is still water inside, it is likely to affect the data of the experiment after the side-entry mixer.
        And if there is no water in the tank, the side-entry side-entry mixer will not work at all. It is likely that the internal temperature of the side-entry stirrer is too high, and there is no water cooling, which causes the internal combustion of the side-entry stirrer.

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     The stirrer is one of the key components of the reactor. Choosing the appropriate stirrer according to the physical properties, capacity and stirring purpose of different media in the reactor can play a great role in promoting the speed of chemical reaction and improving the production efficiency. Knowing the classification and application of stirrer can help to choose the right stirrer and achieve better reaction effect. Let's learn more about the types of reactor stirrers and their application scope.

I.

Working Principle of Reactor Agitator

      The main component of the reactor stirrer is the impeller, which moves with the rotating shaft to apply mechanical energy to the liquid and induce the liquid to move. When the stirrer rotates, the mechanical energy is transferred to the fluid, and a high turbulence full mixing zone is formed near the stirrer, and a high speed jet is generated to push the liquid to circulate in the stirred vessel.

II.

Classification and application of reactor stirrer

1 Lunda Machinery/Axial flow stirrer

1.1. Propulsion type stirrer

● Features: strong ability of discharging liquid, large change of blade curvature and weak shear force.

● Scope of application: It is mainly used for mixing of liquid-liquid system, homogenizing temperature, preventing slurry settling in low concentration solid-liquid system, etc. It is not suitable for various dispersion and reaction operations that require high shear force.

1.2.3 Narrow-bladed Rotating Paddle

Features: The front end of the stirrer is curvilinear, with small shear force, strong axial flow, large circulation volume and low energy consumption;

● Scope of application: suitable for mixing, heat transfer, circulation, particle suspension, dissolution, etc. of low to medium viscosity fluids, and can be used in large mixing tanks with low to medium operating speed.

1.3. Four wide blade rotor / Three wide blade rotor

● Features: Its shear rate adapts to a wide range of viscosities, the spiral type of the paddle surface gives the stirrer a better axial flow, and the large area of the blades also prevents the gas from passing through the impeller as in a disc turbine, extending the gas-liquid contact time.

● Scope of application: It can be applied to the mixing of gas-liquid system, and it is also suitable for higher viscosity mixing, heat transfer, dissolution, reaction, solid particle suspension and other operations.

1.4. Two-blade arc paddle

● Features: Two-bladed arc paddle is strong axial flow type, its shear rate is adapted to a variety of viscosity range, the leaf end to the root of the paddle are curved surface, small shear force, strong axial circulation, small leaf end cross-section, large root cross-section, the entire stirrer area discharge balance, so that the stirrer has a very good axial flow.

● Scope of application: It is suitable for the operation of low and medium viscosity liquid-liquid mixing, heat transfer, dissolution, reaction, solid particle suspension, etc. It has relatively wide application in wet metallurgy.

1.5. Four-bladed arc paddle

● Features: Four-bladed arc paddle is strong axial flow type, its shear rate adapts to a variety of viscosity range, the leaf end to the root of the paddle are curved surface, small shear force, strong axial circulation, small leaf end cross-section, large root cross-section, balanced discharge throughout the stirrer area, so that the stirrer has very good axial flow.

● Scope of application: It is suitable for the operation of low and medium viscosity liquid-liquid mixing, heat transfer, dissolution, reaction, solid particle suspension, etc. It has relatively wide application in wet metallurgy.

2 Lunda Machinery/Mixed Flow Mixer

2.1. Four-bladed inclined paddle

● Features: Four-bladed inclined paddle is in the form of straight plate folded blade, with certain axial and radial action, certain shearing action, and better convection circulation ability.

● Scope of application: Ideal for mixing, microviscous crystallization, dispersion, reaction, dissolution, suspension, and heat transfer operations.

2.2. Six-bladed inclined paddle

● Characteristics: Six-bladed inclined paddle is in the form of straight plate folded blade, with certain axial and radial action, certain shearing action, and better convection circulation ability and larger circulation flow.

● Scope of application: It is very suitable for mixing, microviscous crystallization, dispersion, reaction, dissolution, suspension and heat transfer operation.

2.3. Three-bladed swept-back paddle

 ● Features: The three-blade swept-back paddle is a radial flow stirrer, with a baffle plate to obtain up and down circulation flow, with strong shear performance and large circulation volume.

Scope of application: It has wide use in PVC suspension polymerization reactor.

2.4. Six-slant lobe disc turbine

● Features: Six swash-blade disc turbine is a stirrer in both axial and radial directions. Due to the role of the disc, there is a reflux cycle under the disc and the linear velocity at the end of the inclined lobe is large, which has a strong shearing effect.

● Scope of application: It is suitable for the occasion of strong shear force and circulation flow, especially suitable for the occasion of gas dispersion and extraction of oil and water two-phase insoluble, also suitable for emulsification, solid crushing, solid-liquid suspension, dissolution, strong shear circulation reaction, etc. .

3 Lunda mechanical/radial flow stirrer

3.1. Four-bladed straight paddle

● Features: Four-bladed straight paddle WHCB140 is in the form of straight plate, with certain axial and radial action, certain shearing action and better convection circulation ability.

● Scope of application: Ideal for mixing, microviscosity crystallization, dispersion, reaction, dissolution, suspension, and heat transfer operations.

3.2. Six-bladed straight paddle

● Characteristics: Turbulent diffusion and high shear, large upward and downward circulation flow can be formed when there is a baffle, and a large range of speed and viscosity can be used.

● Scope of application: especially suitable for shear dispersion operation, also can be used for general reaction, dissolution, suspension, heat transfer, emulsification, crystallization operation, and higher strength than four straight-bladed open turbine stirrer under the same conditions.

3.3. Six straight-lobe disc turbine

 ● Features: used with baffle plate, radial flow to the baffle plate to form an up and down circulation flow, due to the role of the disc, there is a reflux cycle above and below the disc, the linear velocity of the straight leaf end is large, the blade vertical liquid, with a very strong shear effect.

● Scope of application: suitable for strong shear gas-liquid dispersion and oil-water extraction occasions, there is a wide range of use in the continuous series gas-liquid reactor.

3.4. Six-lobe parabolic disc turbine

● Features: Used with baffle plate, radial flow to the baffle plate to form up and down circulation flow, due to the role of the disc, there is reflux circulation above and below the disc, the open end of the parabolic facing the liquid, because the blades are parabolic shape, greatly reducing the back pressure at the back of the leaf end, shear force decreases, power consumption decreases a lot.

● Scope of application: mainly used for gas dispersion occasions.

3.5. Six-back curved blade disc turbine

● Features: Used with baffle plate, radial flow to the baffle plate to form an up and down circulation flow, due to the role of the disc, there is a return circulation above and below the disc, the linear speed of the leaf end is large, the backward curved blade back cut in the liquid, compared to the straight leaf has a larger discharge flow and some lower shear strength.

● Scope of application: suitable for strong shear gas-liquid dispersion and oil-water extraction occasions, also suitable for emulsification, solid crushing, solid-liquid suspension, dissolution, strong shear cycle reaction and other occasions . It is widely used in continuous series gas-liquid reactor.

3.6. Closed Disc Turbine Paddle

● Features: Stirrer for gas-liquid mixing, usually multi-layer stirrer used together, need to be used in conjunction with the air guide tube in the through liquid to make the gas fully achieve dispersion in the rising process.

● Scope of application: Suitable for use in large equipment.

4 Lunda Machinery/Radial Flow Agitator

4.1. Anchor Frame Type Agitator

● Characteristics: When there is no baffle, the flow shape is circular circumferential flow, and it is easy to form cone-shaped large vortex; when used with baffle, the radial flow can form up and down circulation flow at the baffle.

Scope of application: It is suitable for the mixing of medium and high viscosity materials, viscosity not more than 8 PaS is appropriate, also suitable for solid-liquid suspension occasions.

5 Lunda Machinery/Axial Flow Agitator

5.1. Spiral belt mixer

● Features: The outer side of the spiral belt lifts the material and the inner side of the material falls due to gravity, forming an axial circulation.

● Scope of application: Suitable for high viscosity and high solid content occasions, viscosity range is 10~100PaS.

5.2. Screw belt with screw agitator

● Features: The outer side of the screw belt lifts the material, and the inner side of the material falls due to gravity, forming an axial circulation.

● Scope of application: Suitable for high viscosity and high solid content occasions, viscosity range is 50~200PaS.

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Desulfurization baffle door is the bridge connecting boiler and FGD system device, which has great influence on the operation of boiler and the life of FGD system device. Flue gas desulfurization system baffle door contains inlet baffle door, outlet baffle door and bypass baffle door, involving such a wide range, which form of desulfurization baffle door? Then we have to look at the process requirements of the desulfurization baffle door.

In the normal operation of the desulfurization system, the flue gas from the tail of the boiler electric dust collector, after the flue gas desulfurization system inlet baffle door to the booster fan, and then cooled by the flue gas heat exchanger into the absorption tower, desulfurization of flue gas by the flue gas heat exchanger heated to about 80 ℃, through the flue gas desulfurization system export desulfurization baffle door into the chimney.

The flue gas desulfurization system is equipped with a bypass flue and a bypass baffle door, so that when the flue gas desulfurization system is overhauled, maintained or the flue gas condition is abnormal, the flue gas is directly discharged into the chimney by the bypass flue to ensure the safety of the desulfurization system. The isolation and connection between the power station and the FGD island is achieved through the opening and closing of the FGD baffle doors in the flue gas system. The baffle doors play a vital role in ensuring the normal and stable operation of the boiler and FGD system and the safety of the system equipment.

The importance of bypass baffle door setting.

1, if the bypass flue gas baffle is not set in the bypass flue, in actual operation, the flue gas pressure difference between the inlet and outlet side of the flue gas desulfurization system must be adjusted to "zero" in order to ensure the full flue gas desulfurization system, and in the operation of the flue gas desulfurization system always maintain this state without deviation, control is difficult, especially Flue gas conditions fluctuate (which is a relatively normal phenomenon) when the control is more difficult to achieve.

2, flue gas desulfurization system without bypass flue baffle, in actual operation there may be part of the net flue gas re-inhalation flue gas desulfurization system system or the original flue gas directly into the chimney. If the flue gas desulfurization system to desulfurization efficiency requirements are not very high (such as some domestic power stations) can not set bypass baffle, but the flue gas desulfurization system with high requirements for desulfurization efficiency, then the bypass baffle is very important to set.

3, if the flue gas desulfurization system is not set up bypass baffle, in the selection of the booster fan capacity to consider a certain margin, the cost of the booster fan and operating costs will increase a lot.

4, flue gas desulfurization system device start and stop, flue gas through the bypass, bypass baffle as required to open, flue gas desulfurization system into, export baffle closed at the same time, in this case, the bypass baffle can be made through the control of the opening degree and flue gas desulfurization system into, export baffle opening and closing coordination, and not due to the two flue resistance of different negative pressure on the boiler chamber has a significant impact, causing the boiler main fuel tripping situation .

Flue gas desulfurization system of desulfurization baffle door type and its application.

At present, in China's large and medium-sized power station boiler units in the flue gas desulfurization system used in the desulfurization baffle door mainly has a single shaft double louver baffle door, double shaft double louver baffle door, single shaft double seal baffle door and other types. Among them, single-shaft double louver baffle door and double-shaft double louver baffle door are used more.

1、Biaxial double louver flap door

This type of baffle door consists of two louvers, each louver is connected with a number of bearings, and two blades are fixed on the same shaft. The sealing piece of this type of baffle door uses special nickel-based alloy installed around the baffle door blade to set up a sealing air system to seal the air into between the two louvers. The sealed air system of the currently designed two-axis double louver baffle doors all guarantee a zero leakage rate in the flue and are equipped with accidental precautions in case of system load. This kind of baffle door investment is larger, weight and size is also much larger compared to the single shaft double louver baffle door, is the domestic power station unit flue gas desulfurization device in the use of the earlier type.

2、Single shaft double seal baffle door　　

This type of baffle door consists of a louver, each louver only a blade, in the upper and lower two blades and between the blade and the frame set two sealing piece, sealing air can be sealed by the sealing piece into the sealing frame, even in corrosive conditions using hot sealing air can maintain the seal. The weight and investment of single shaft double seal baffle door are less than double shaft double louver baffle door, along the flow direction of the medium is also slightly shorter than the latter.

3、Single shaft double louver baffle door

This type of baffle door consists of a louvered window, the louvered window consists of two blades, set up sealing air system, allowing sealed air to enter between the two blades. The advantage of this type of desulfurization baffle door is that its sealing piece has self-cleaning function, the weight of the baffle door is only about half of that of the double shaft double louver baffle door, and the investment cost also saves 50% compared with the double louver window baffle door. The strength of single shaft double louver baffle door is slightly lower than that of double shaft double louver baffle door, but at present the flue diameter and operating pressure of domestic power station flue gas desulfurization system can already meet the requirements.　　

In addition to the above three desulfurization baffle door, there is a single louver window baffle door, but the baffle door because of its sealing system performance inferior to the other three, so the use rate is not high. In a comprehensive comparison, the use of single shaft double louver baffle door is better, and the frequency of use is higher.

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        Flue gas baffle door is the bridge connecting boiler and FGD device, it has great influence on the operation of boiler and the life of FGD device. baffle door in FGD system includes FGD system inlet baffle door, FGD system outlet baffle door and bypass baffle door.
        Under the normal operation of FGD system, the flue gas coming from the tail of boiler electric precipitator will be cooled down by the flue gas heat exchanger into the absorption tower after the inlet baffle door of FGD system to the booster fan, and then the flue gas after desulfurization will be heated to about 80℃ by the flue gas heat exchanger and enter the chimney through the flue gas baffle door of FGD outlet.
        The FGD system is equipped with a bypass flue with a bypass flap door, so that when the FGD system is overhauled, maintained or the flue gas condition is abnormal, the flue gas is directly discharged into the stack by the bypass flue to ensure the safety of the FGD system. The isolation and connection between the power plant and the FGD island is realized by the opening and closing of the flue gas baffle doors in the flue gas system, which plays a vital role in ensuring the normal and stable operation of the boiler and FGD system and the safety of the system equipment.
The necessity of bypass baffle door setting
        1 bypass flue gas baffle is not set up in the bypass flue, in actual operation must be adjusted to the FGD inlet and outlet side of the flue gas pressure difference of "zero", in order to ensure the full FGD flue gas desulfurization, and in the FGD operation always maintain this state without deviation, control is difficult, especially when the flue gas working conditions fluctuate (which is a relatively normal phenomenon) control more This is especially difficult to control when the flue gas conditions fluctuate (which is a normal phenomenon).
        2 FGD system without bypass flue baffle, in actual operation, there is a possibility that some net flue gas will be re-absorbed into the FGD system or the original flue gas will be directly discharged into the stack. If the FGD requirements for desulfurization efficiency are not very high (such as some domestic power plants), the bypass baffle can not be set, but for FGD systems with high requirements for desulfurization efficiency, the setting of the bypass baffle becomes very necessary.
        3 If the bypass baffle is not set in the FGD system, a certain margin should be considered when selecting the capacity of the booster fan, and the cost and operation cost of the booster fan should be increased. 4 FGD device start and stop, the flue gas needs to take the bypass, bypass baffle as required to open, FGD inlet and outlet baffle closed at the same time, in this case, the bypass baffle can be controlled by the opening degree to make it and FGD inlet and outlet baffle opening and closing coordination, and not due to the two different flue resistance to the boiler chamber negative pressure has a significant impact on the boiler MFT situation.
        The seal gas pressure is at least 0.5KPa higher than the flue gas pressure. to prevent cold air from entering the flue gas system causing low temperature corrosion, a secondary electric heater is set at the outlet of the seal fan. The electric actuator of the baffle door is safe and safe, and its speed is required to meet the operating requirements of the power plant and the induced draft fan. All baffle doors require flexible, reliable operation and easy maintenance.

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        Desulfurization baffle door is an important equipment to enter and exit the operation of desulfurization device. Desulfurization baffle door is mainly used in the flue gas desulfurization system absorption tower inlet, outlet or bypass flue, or used in flue gas denitrification and flue gas dedusting system. To achieve the role of isolating and shutting off the flue gas.

About desulfurization baffle door performance advantages role is reflected in these aspects.  

        1, using a single shaft drive double shutter type baffle structure, double layer of blades in the middle of the design of the seal chamber to import the seal air, the seal air higher than the flue gas pressure 500Pa into the baffle, so that the double layer of baffle between the formation of sealed air isolation layer, blocking the passage of flue gas flow.

        2, desulfurization baffle door to take a single shaft with sealed air double baffle structure type. Each baffle blade surrounded by nickel alloy sealing piece, baffle door body sealed air inlet with sealed air valve, and the baffle door between the mechanical linkage.

        3, baffle type dampers dampers shaft for the horizontal arrangement, bearing seal tight, flexible operation, not easy to jam, using non-oil lubrication of high temperature resistant spherical bearings.

        4, double shutter type baffle door design structure is reasonable, good blade rigidity, stable and reliable operation, shutter type baffle blade sealing type: elastic seal and air seal.

        5、The double baffle is designed and installed with sealed air inlet valve, after passing into the sealed air, the baffle door sealing efficiency is.

        6、Baffle type dampers ensure a high closing tightness, the leakage rate is less than 2%.

        7、The sealing plate joint surface and each journal flange of the dampers, whether in the open state or in the closed state are no cold or hot air leakage and internal leakage, especially the locking device and the bearing of the driving device to ensure tight and no leakage.

        8、The electric device adopts electromechanical integration products, with torque protection and limit device and can be operated by remote control, the electric device also has manual and electric switching function for installation and commissioning, maintenance.

        9、The connection method between the dampers and the pipeline: flange seal welding connection or flange bolt connection.

        10、Two sealed fans of each set of FGD (one operation and one preparation) are equipped with a control cabinet, and the two fans are interlocked. The electric adder is equipped with a separate control cabinet and interlocked with the fan. When starting, the fan must be started before starting the electric heater, and when stopping, the electric heater must be stopped before stopping the fan, and there should be a delay of 5 to 10 minutes in between to ensure that the electric heating element is not burned.

        11, baffle type dampers blade for streamline design, is wing type, flow resistance is small. Rectangular baffle dampers sealing between the blades and blades and shell sealing stainless steel shrapnel seal, sealing effect is good; all dampers shaft end using the first seal after the support of the way, the force generated by the shaft rotation all act on the spherical bearing, the shaft in the rotation will not cause extrusion on the seal packing, effectively prevent the journal whether in the closed open state are no air leakage.

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        In the baffle door products, desulfurization type products are always more popular, because the sealing effect of these products is very outstanding, so in many with high safety requirements, or for the sealing needs of high occasions, it can play a very good role, if you want to apply this product, we should have an understanding of the structure of the product Features.

I. Air sealing isolation

        In this product is used in the single shaft drive type sealing role, in the product will cause the pressure higher than 500 Pa sealed air injection to the baffle between, so that the double layer of the middle of the blade can form a special sealing chamber, can effectively isolate the hot air layer, thus blocking the flow of smoke flow.

Second, the switch time adjustable

        In the use of desulfurization baffle door, the user can choose the corresponding opening, or closing time according to their own needs, usually, the product in the opening and closing time can only choose ≤ 60 seconds.

        In addition, the desulfurization baffle door has a lot of advantages, in the use of the time can actually bring people multiple aspects of help and benefits. If you have a high demand for sealing in this area, then it is recommended that you can choose this desulfurization type of product to use, I believe that you can get satisfactory results.

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        In the flue gas desulfurization system of large thermal power generating units, the flue gas desulfurization baffle door is an important equipment for entering and exiting the operation of the desulfurization device, which is divided into FGD main flue gas baffle (including the original flue gas baffle door and net flue gas baffle door) and bypass flue gas baffle.FGD main flue gas baffle meets the requirement of closing the FGD equipment for maintenance when the boiler is running, and the bypass flue gas baffle is used to isolate the flue gas from the chimney when the desulfurization device is running to ensure that the flue gas enters the absorption tower. Each FGD desulfurization baffle system consists of inlet and outlet baffle doors and bypass baffle doors, and a common sealed air system (including electric heaters). Each set of sealed air system includes two (one operation and one backup) sealed fans and one electric heater, as well as related dampers (valves), compensators, backstops, etc.

        1. The desulfurization baffle door takes the structure type of single shaft double baffle with sealed air. Each baffle blade surrounded by nickel alloy sealing piece, baffle door body sealed air inlet with sealed air valve, and baffle door for mechanical linkage between. When the flue gas baffle is open, the sealing air valve is closed; when the flue gas baffle is closed, the sealing air valve is open. When the baffle door is closed, sealed air is injected between the double layers of blades to effectively isolate the front and rear media. 

        2.The flue gas baffle drive device and the dampers are connected by direct connection, directly connected to the body of the dampers, and the protection level of the actuator and junction box is not less than IP65.The connecting rod mechanism is connected by ball twist to ensure that there is no empty stroke in rotation, and to ensure that the baffles on the same baffle door have good synchronization.

        3. The installation of the flue baffle is bolted flange connection, and the counter flange supplied by us is closely connected to the flue, and the load of the baffle door is transferred to the flue support through the steel flue. The baffle spindle is arranged horizontally. The spindle is made of suitable steel and is equipped with a clearly visible marking at the end of the spindle indicating the position of the baffle sheet and with an interlocking limit switch. The flue baffle drive is equipped with a hand wheel, which can be operated manually in case of power failure of the drive, and lifting lugs are provided at appropriate locations outside the frame to facilitate maintenance and installation.

        4. The flue gas baffle sealing wind pressure is at least 0.5kPa higher than the flue gas pressure, and the fan is designed with sufficient capacity and pressure head. Sealed wind turbine outlet is equipped with a backstop door, which is strictly closed to ensure that the standby fan does not reverse in the standby state. The capacity of the sealed wind power heater meets the requirements of the sealed wind volume working condition, to ensure that the sealed wind heating temperature is not less than 100℃, and the electric heater can automatically adjust the temperature according to the change of wind volume.

        5. Each set of FGD has one control cabinet for two sealed fans (one for operation and one for backup), and the two fans are interlocked. The electric adder is equipped with a separate control cabinet and interlocked with the fan. When starting, the fan must be started before starting the electric heater, and when stopping, the electric heater must be stopped before stopping the fan, and there should be a delay of 5~10 minutes in between to ensure that the electric heating element is not burned.

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     The high efficiency axial flow rotary mixer is widely used in servo, stepper and DC drive systems because of its small size, high efficiency, wide reduction range and high accuracy. Its role is to reduce the speed and increase the torque and reduce the load/motor inertia ratio, while ensuring a precise transmission. In the past few years, some users in the use of reducer, due to illegal installation and other human factors, and the output shaft of the reducer broke, so that the enterprise suffered unnecessary losses. Therefore, in order to better help the majority of users with a good reducer, Lunda editor today will briefly introduce how to correctly install the high-efficiency axial flow rotary mixer.

Correct installation, use and maintenance of the reducer is an important part of ensuring the normal operation of machinery and equipment. Therefore, when installing the high-efficiency axial flow rotary mixer, please be sure to strictly follow the following installation and use related matters, carefully assembled and used.
      1 Confirm that the motor and reducer are intact before installation, and strictly check whether the dimensions of the parts connected to the motor and reducer match, here are the dimensions and fitting tolerances of the motor's positioning boss, input shaft and reducer groove, etc.

      2 Unscrew the screw on the outer dust hole of the reducer flange, adjust the PCS system clamping ring so that its side hole is aligned with the dust hole, and insert the hexagonal screw. After that, take away the motor shaft key.

      3 Connect the motor to the reducer naturally. Connection must ensure that the output shaft of the reducer and motor input shaft concentricity is consistent, and the outer flange of the two parallel. If the concentricity is not consistent, it will cause the motor shaft to break or the gear of the reducer to wear.
In addition, during installation, it is strictly prohibited to hit with hammers to prevent excessive axial or radial forces from damaging the bearings or gears. Yiding should tighten the mounting bolts and then tighten the tightening bolts. Before installation, wipe the motor input shaft, positioning tabs and reducer connection parts of the anti-rust oil with gasoline or sodium zinc water. The purpose is to ensure the tightness of the connection and the flexibility of the operation, and to prevent unnecessary wear.

    4 Before connecting the motor to the reducer, the motor shaft keyway should be perpendicular to the tightening bolt. To ensure uniform force, screw the mounting bolts at any diagonal position first, but do not screw tightly, then screw the other two mounting bolts at diagonal positions and tighten the four mounting bolts one by one. After that, screw the tightening bolts. All tightening bolts need to be fixed and checked with torque plate hand according to the fixed torque data indicated.

    5 The correct installation between the reducer and mechanical equipment is similar to the correct installation between the reducer and the drive motor. The key is to ensure that the output shaft of the reducer and the driven part of the shaft concentricity of the same.

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        Although the side of the mixer is not complicated, to find the side of the mixer you must also find its key components. If a side-entry mixer has any problems in its application, the actual cause can be found and dealt with properly. The following material is for information purposes only:

        The side entry mixer is a common mechanical device in the field of machinery and equipment. The raw materials are mixed adequately according to the side entry mixer, which in turn provides a reasonable access to the high quality of manufacturing. The mixing wheel is the key piece of the side entry mixer. In today's side-entry mixer, the mixing wheel of the side-entry mixer has the following three key ways, let's inquire together.

        A, turbocharged structure impeller: turbocharged impeller design scheme generally has 4 ~ 6 blades, the installation of the blade probably has two different methods: one is to have a similar style with the paddle impeller development, the blade or decisive installation in a wheel circle, called the selection of open turbocharged raw material impeller; another is set on the wheel circle a garden disk, the blade installed in the garden disk, this type of hazard impeller can called the level disc type turbo impeller.

        Second, an aircraft propeller impeller: mixing impeller with three blades, blades with a certain spiral angle. Impeller skewed forward (or backward) to inhibit the radial movement of the liquid, in the tank circulation system.

        Third, the paddle impeller: paddle impeller is a comparison of the development of a simple according to the mixer, long and thin, continuous plate blades welded, riveted on the rim or on the pair of clamps together on the mixing shaft, so the period of low cost, about 35% to 40% of the side entry mixer key application research this type of type of mixer.

        The types of side-entry agitators and the way the mixing wheels are selected are also different, thus when selecting side-entry agitators, their specific application scenarios should be taken into account, and the design scheme and selection of the mixing equipment selected should be closely linked to the purpose of the actual mixing operation. Different mixing processes must be completed according to different mixing equipment. In the design scheme and model selection, the model specification of the mixer, the rated power of the motor and the mixing rate should be clarified according to the processing purpose and regulations, followed by the selection of the reducer, the sound card frame, the mixing shaft, the pump seal and other components.

        This part of the side of the mixer can be said to lack a line, we expect that we do not have to ignore this part of the side of the mixer.

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        The operator should be familiar with the structure and working principle of the top-entry mixer. Ensure that the top-in mixer motor power cord is connected correctly and the supply voltage is deformed. Before starting should check the duty record, the site control cabinet instigating switch. Pull the "manual" party committee.

        Operation to check the instigation lamp display; dial "active" gear, by the central control room to control the opening and closing. Press the "Run" button, the equipment is running, and the running instigator light is on. Press the "stop" button, the equipment ends to run, stop the instigator light on. When running continuously, do not let the air be sucked down by the impeller. It is strictly forbidden to make the air sucked down by the impeller when running frequently. It is strictly forbidden to frequently start the mechanical mixer, dry running time is not allowed to exceed 30 seconds. Fault report. When the alarm, the operator should immediately stop the system and respond to the relevant personnel. In the examination, maintenance work should be cut off before the start of the main switch power, but also to ensure that others can not start.

        The top entry stirring device that forces convection and uniform mixing of liquid and gas media. The type, size and speed of the mechanical stirrer have an effect on the mixing power deployed between the overall flow and turbulent pulsations. Individually, the power deployment of turbine mechanical stirrers is favorable to turbulent pulsation, while rotating paddle mechanical stirrers are favorable to the overall flow. For the same type of mechanical stirrer, under the premise of the same power consumption, large diameter, low speed mechanical stirrer, power consumption is important for the overall flow, which is conducive to macro confusion. Small diameter, high speed mechanical stirrer, power consumption is important in the turbulent pulsation, conducive to micro confusion.

        The amplification of the top-entry stirrer is a ponderous problem related to the process, which so far can only be amplified through a step-by-step lesson, and extrapolated to the industrial range based on the amplification criteria obtained.

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I. Overview
        Single shaft drive double vane type flue gas baffle is one of the louver type flue gas baffle series, which adopts the double sealing structure of mechanical seal and compressed air seal to ensure 100% sealing effect. The product is made on the basis of the introduction of foreign advanced technology and learning from the domestic experience of the same type of product design and operation.

II. Function
        Single shaft drive double vane type flue gas baffle is mainly used in the flue gas duct system for completely cutting off the medium, with full open and 100% full close function, flexible action, reliable operation, after closing, can ensure no medium leakage into the pipe after the flue gas baffle. For common media, carbon steel material can be used, for corrosive media, nickel-based alloy material can be used.

Three, structure and working principle
        Single shaft drive double vane type flue gas baffle is mainly composed of frame, vane, spindle, sealing piece, air sealing system, crank linkage mechanism, electric actuator and other parts (as shown in the attached figure). The frame is made of rolled and welded steel plate; the blade is welded into a cavity structure by the upper and lower panels and the middle reinforcement, and the main shaft is welded with the blade as a whole; the thin sealing piece is bolted to the edge of the upper and lower panels of the blade; the main shaft and the blade are supported by UCF bearings on the frame. 90-degree travel switch type electric actuator drives the drive shaft to rotate, and the drive shaft then drives all the blades to rotate around their respective main shaft centers through the connecting rod type crank linkage mechanism. When the blade is parallel to the medium flow direction, it is the flue gas baffle opening position, when the blade is perpendicular to the medium flow direction, it is the flue gas baffle closing position. Close position, the flue gas baffle blade up and down the two layers of the panel edge of the thin metal sealing piece and the corresponding two sealing edge plate on the inner wall of the flue gas baffle frame, forming a mechanical seal, at this time the blade, sealing piece and sealing edge plate has been the entire media flow channel cut off, and in the flow channel section to form a sealed cavity. Sealed air valve and electric actuator mechanical mechanical chain, when the flue gas baffle blade open sealed air valve closed, when the flue gas baffle blade closed sealed air valve open, then sealed air from the air inlet on the frame directly into and fill the entire sealed cavity, because the sealed air pressure is higher than the medium pressure, the medium can not pass the sealing barrier composed of the blade, sealing sheet, sealing side plate and sealed air to ensure 100% complete sealing.

V. Installation, use and maintenance precautions
       (A) installation and use of the flue gas baffle maintenance precautions.
        1, the body of the flue gas baffle in transport, storage and lifting process should lock the position locking device to ensure that the blade level to prevent deformation, and lifting point can only be the lifting lugs on the body of the flue gas baffle. For nickel-based alloy flue gas baffle plate, can not let it contact with carbon steel.
        2, lifting baffle, must be extra careful some sensitive parts, such as transmission device, limit switch, chain mechanism and bearings, etc.
        3, in order to prevent the deformation of parts, damage and sudden shift of the center of gravity, (for example: due to the unintentional rotation of the baffle blade), must check the locking and safety devices. If there is no relevant instructions on the installation drawings, the above devices can be removed only when the baffle is in a safe installation position.
        4, the flue gas baffle in the pipeline arrangement, should keep the blade spindle level.
        5, the flue gas baffle in the installation of the wind direction should be in accordance with the installation drawings or equipment marked on the wind direction markings.
        6, in general, from the flue gas baffle electric device, clockwise for off, counterclockwise for open;.
        7, the frame and flue interface flange surface contact to be added to the gasket, tighten the coupling bolts, and then welded in accordance with the drawings.
        8, the installation unit at the site site installation, if other support methods are used, must keep the flue gas baffle does not deform, while in the installation process, should ensure that the blade is not jammed.
        9, the flue gas baffle commissioning before, must be cleaned out of all the internal and external debris, all relevant solid parts on tight, electric actuators and limit switches must be in place accurately, the electrical wiring error-free;.
        10, commissioning to ensure that the blade action is flexible, the blade closed when the mechanical seal tight, sealing valve open, blade open when the sealing valve closed.
        11, flue gas baffle external insulation requirements with the system pipeline, but can not impede the action of the crank linkage mechanism, the journal sealing position in the structure made removable, in order to later adjust or replace the seal packing.
        12, flue gas baffle formal commissioning must ensure that the relevant supporting sealing system auxiliary parts and control equipment are all well commissioned and can be officially put into operation.
        13, flue gas baffle door in operation, such as found in the journal seal outside the leakage phenomenon, generally only need to adjust the sealing gland tightening nut can be. If the tightening is still leaking, it means that the packing in the seal box has been worn out, then you need to replace the new seal packing.
        14、The flue gas baffle needs to check regularly whether the sealing piece at the edge of the blade is intact during operation, if the sealing piece is damaged or worn, it will affect the sealing effect of the flue gas baffle and needs to be replaced immediately.
       (2) The installation, use and maintenance of electric actuator should be noted.
        1、Electric actuator and flue gas baffle drive shaft assembly, should be carefully assembled, can not use hard knocking type assembly.
        2、For details of commissioning, use and maintenance of electric actuator machinery, please refer to "Electric Actuator Installation and Maintenance Manual" and other related materials.
       (C) Installation, use and maintenance precautions for sealed see machine
See "Centrifugal Ventilator Instruction Manual" and other related materials for details of installation, use and maintenance of sealed fans.
       (D) Precautions before trial operation
        1、After the installation is completed, the baffle plate must be in the closed position before commissioning to prevent sensitive parts and blade sealing piece from being damaged due to the installation.
        2、After the installation is completed, it is recommended that the corresponding inspection be carried out by professionals, and the fine tuning of the components and the inspection of the operation condition can be completed during the commissioning.
        Before commissioning, must check the number of components provided, must be provided with the bulk parts in accordance with the drawings assembly and installation, and check whether the normal operation and meet the corresponding safety requirements.
        Note: Check the rotating areas such as baffle blades, connecting rods, etc.
        All rotating stops and related parts (for safety reasons) must be adjusted separately and ensured to be in proper condition.
        Precise work on the drive components and interlocking mechanisms, function tests and tightness checks are completed.
        Points that must be noted before the initial test run
        1. The installation of the baffle must be stable.
        2、No stuck parts due to wrong installation (e.g. deformation, interference).
        3、Stops for transport and installation must be removed.
        4, the blades and connecting rods must be able to move freely.

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        Side-entry mixers are widely used in petrochemical, paper, food, electric power, metallurgy, environmental and other industries. Due to the relatively small diameter of the mixing paddle, special installation position and small mixing power, they are used in some petrochemical industries in large quantities. In addition, due to the increasingly high requirements of environmental protection, sulfur dioxide emissions are strictly controlled, resulting in the rapid development of the construction of flue gas desulfurization devices in thermal power plants, side entry mixers are also widely used in thermal power plant desulfurization because of its many features. However, the flue gas desulfurization contains a large amount of chloride ions and gypsum slurry, and the requirements for mechanical seals are getting higher and higher.
        In view of the actual conditions and situation of the sealing system, Hilank has made targeted design and improvement in the overall and auxiliary system of the seal and reached a consensus, with good response from users.
Side agitator seal structure features.
        Single-end set balanced mechanical seal.
        The spring is not in contact with the medium externally, which can effectively prevent the medium from blocking, corrosion and wear of the spring.
        Bearing and machine seal are set separately, which can further reduce customer's cost.
        Assembled by professional factory technicians and qualified for gas tightness test before shipment.
        Simple installation on site and reliable performance.
Side stirrer seal operating parameters.
        Medium: solution, slurry and other clean or containing a small amount of particles, fibers, crystals and other media.
        Temperature: -20~150℃ 
        Speed: 25 m/s
        Pressure: 0~1.0MPa
Side stirrer machine seal recommended working conditions.
        Thermal power plant desulfurization / denitration slurry, paper mill pulp liquid and other side agitation.
Common specifications of agitator seal.
        Φ30~Φ180mm
Agitator seal engineering applications
        300MW, 600MW thermal power plant desulfurization, denitrification device side mixing, etc., service life of more than 8000 hours.
Detailed description.
        (1)The single-end multi-spring type mechanical seal is adopted, the media end seal is in direct contact with the material in the slurry tank, and the friction sub-material is non-pressure sintered silicon carbide to non-pressure sintered silicon carbide, which can not only prevent the mechanical seal from failing due to the particle material entering the friction surface, but also extend the service life of the mechanical seal,.
        (2)The mechanical seal of the slurry tank is located in the lower part of the agitator, there will be part of the material deposited in the bottom of the agitator, in order to prevent the slurry from entering the seal and causing mechanical seal failure, the front of the mechanical seal bearing is designed with a leakage hole, in favor of observing the mechanical seal leakage and protecting the slurry from entering the bearing.
        (3) In the lower part of the seal design tapered roller bearings, the purpose is to limit the axial runout and radial runout of the shaft, to ensure that the mechanical seal operation of the technical conditions.
        (4) In order to facilitate mechanical seal disassembly, installation, maintenance, and overhaul, the mechanical seal assembly is designed as a sleeve, and the bearing seat and mechanical seal are separated to facilitate maintenance and repair!

        Stirring equipment is widely used in industrial production, especially in the chemical industry, where many chemical production is more or less applied to stirring operations. The various chemical changes in chemical processes are predicated on the adequate mixing of the participating reaction substances. For physical changes such as heating, cooling and liquid extraction as well as gas absorption, stirring operations are also often used to get good results.

        Stirring equipment is used as a reactor in many applications. For example, in the production of the three major synthetic materials, stirring equipment as a reactor accounts for about 90% of the total number of reactors. Other industries such as dyestuffs, pharmaceuticals, pesticides, paints, etc. also use stirring equipment extensively.

        The non-ferrous metallurgy department has made a survey and power measurement of the stirring equipment in the national non-ferrous metallurgy industry, and the result is that more than 50% of the power consumption of many wet process plants is used for stirring operations. The reason for such a wide range of applications of stirring equipment is also due to the wide range of controllable operating conditions (such as concentration, temperature, residence time, etc.) of stirring equipment, which can also be adapted to diverse production.

        The role of stirring equipment is as follows: 1) to make the material mix uniformly; 2) to make the gas well dispersed in the liquid phase; 3) to make the solid particles (such as catalyst) uniformly suspended in the liquid phase; 4) to make the insoluble other liquid phase uniformly suspended or fully emulsified; 5) to strengthen the phase transfer (such as absorption, etc.); 6) to strengthen the heat transfer. For the homogeneous phase reaction, the main points are ① and ⑥. The fast or slow mixing, the degree of homogeneity and the good or bad heat transfer will affect the reaction results.

        As for the non-homogeneous phase system, it also affects the size of the phase interface and the mass transfer rate between phases, and the situation is more complicated. Therefore, changes in the stirring situation are often very sensitive to the quality and yield of the product, and examples of this are very common in production. In the solution polymerization and ontogenetic polymerization of the liquid phase polymerization reaction device, the main role of stirring is: to promote the flow of materials in the kettle, so that the uniform distribution of materials in the reactor, increase the mass and heat transfer coefficient.

        In the process of polymerization reaction, often with the increase of conversion rate, the viscosity of polymerization solution also increases. If the stirring situation is not good, it will cause a decrease in heat transfer coefficient or local overheating, material and catalyst dispersion is not uniform, affecting the quality of polymerization products, but also easy to lead to polymer sticky wall, so that the polymerization reaction operation can not be well carried out.

        Stirring plays a very important role in accelerating the reaction between immiscible liquids or liquid and solid interactions. This is because by increasing the rate of mixing of one phase into another, the contact surface increases and the substances interact at a greater rate.

        In some cases, stirring is an important factor in creating good conditions in the reaction process. For example, it enables enhanced heat transfer, reduces local superheating, as well as avoids coking of substances during the heating process. For example, in the production of high-pressure polyethylene, the stirrer makes the material have a certain residence time in the reactor, and more importantly, it makes the catalyst evenly distributed in the vessel to prevent the explosion caused by the local violent polymerization. Therefore, stirring equipment plays a very important role in industrial production.

        Stirring equipment is used in petrochemical production for material mixing, dissolution, heat transfer, preparation of suspensions, polymerization reactions, preparation of catalysts and so on. For example, in the petroleum industry, the mixing and refining of heterogeneous crude oil, the addition of additives such as tetraethyl lead to gasoline and mixing to homogenize raw materials or products. Chemical production, the manufacture of styrene, ethylene, high-pressure polyethylene, polypropylene, synthetic rubber, aniline dyes and paints and pigments and other processes, are equipped with various types of mixing equipment.

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Mechanical seal overhaul

        Mechanical seal should be assembled, clean and check not to forget. First look at the two rings and then look at the shaft, do not miss the wound cracks. Finally, in the rubber ring to see the diameter of the air hole to see. Various sizes need to be measured, the gap between the two rings should be adjusted. Tight force must be calibrated, a small spring is the key. The bolt should be evenly stressed, and it is a good habit to take it gently.

Mechanical seal disassembly precautions

        When disassembling the mechanical seal, it is strictly forbidden to use hand hammer and flat shovel to avoid damaging the sealing components. If there are mechanical seals at both ends of the pump, care must be taken in the disassembly process to prevent the loss of both. For the working mechanical seal, if the gland is loosened when the sealing surface moves, the static and dynamic ring parts should be replaced and should not be re-tightened for further use. Because after loosening, the friction vice original trajectory will change, the contact surface sealing is easily damaged.

        If the sealing components are bonded by dirt or cohesion, the condensate should be removed before the mechanical seal disassembly. 
(A) Mechanical seal disassembly
        Mechanical seal disassembly order and the opposite order of installation. In the process of dismantling the mechanical seal must be careful not to use hand hammer, flat shovel, not to knock the seal, not to damage the sealing surface of the seal dynamic and static ring, if too much dirt such as oil, can not be dismantled, shall be cleaned with kerosene and other cleaning before dismantling, so as to keep the parts of the seal intact.

(B) Mechanical seal maintenance
After removing the seal, first of all, check the pump body with the seal installed, then overhaul the mechanical seal: (1) check the mechanical seal components
     (1) check the mechanical seal components. (1) Check the mechanical seal components. The components must be complete and undamaged, and the moving and static ring sealing surfaces must be free of scratches, bruises and other defects.
    (2) Check whether the spring force is small, such as small spring shall be replaced.
    (3) Check whether there is any damage to the inner wall of the seal and the inner surface of the seal end cover, and if problems are found, repair them in time.

(C) the mechanical seal installation before the preparation and attention
After the above overhaul work is completed, the mechanical seal needs to be reinstalled, and the following preparatory work must be done before installation.
       1、If the new seal is replaced, the mechanical seal must be checked to see if the model and specification are correct and if the quality is up to standard.
       2, the static ring tail anti-rotation groove end and the top of the anti-rotation pin should maintain 1mm-2mm axial clearance to avoid buffer failure.
       3, moving and static ring end face cleaned with alcohol, the rest of the metal parts cleaned with gasoline and clean compressed air blowing dry, carefully check to ensure that the moving and static ring sealing surface without any damage. Before assembly, the two "0" shaped rubber seal should be coated with a layer of lubricating oil paste, moving, static ring end face is not allowed to apply oil.

(D) the installation of mechanical seals
Seals installation sequence and precautions are as follows.
        1、After the relative position of the rotor and the pump body is fixed, determine the installation position of the mechanical seal, according to the installation size of the seal and the position of the static ring in the gland, the positioning size of the seal on the shaft or sleeve is measured.
        2、Install the dynamic ring of the mechanical seal, after the installation of the dynamic ring shall ensure its flexible movement on the shaft.
        3、Assemble the assembled static ring part and dynamic ring part.
        4、Install the seal end cap in the seal body and tighten the screws.
Picture
(E) the mechanical seal overhaul misconceptions

1, the greater the spring compression sealing effect is better
        In fact, not, the spring compression is too large, can lead to sharp wear and tear of the friction sub, instant burnout; excessive compression makes the spring lose the ability to adjust the dynamic ring end face, resulting in seal failure.

2, the tighter the moving ring sealing figure the better
       In fact, the moving ring seal ring is too tight is harmful. First, intensify the wear between the seal and the sleeve, premature leakage; Second, increase the dynamic ring axial adjustment, moving resistance, in frequent changes in working conditions can not be adjusted in a timely manner; Third, excessive fatigue of the spring is easy to damage; Fourth, the dynamic ring seal deformation, affecting the sealing effect. 

3, the tighter the static ring seal the better
        Static ring seal is basically at rest, relatively tight seal effect will be better, but too tight is also harmful. First, the static ring seal caused by excessive deformation, affecting the sealing effect; Second, the static ring material to graphite mostly, generally brittle, excessive stress is very easy to cause shattering; Third, installation, disassembly difficulties, it is easy to damage the static ring.

4, multi-stage centrifugal pump impeller lock mother the tighter the better
        Mechanical seal leakage, the leakage between the sleeve and the shaft (inter-shaft leakage) is more common. In fact, there are many factors that lead to inter-shaft leakage, such as inter-shaft pad failure, offset, impurities in the shaft, shaft and sleeve with a large form error, contact surface damage, the gap between the parts on the shaft, the shaft thread is too long, etc. will lead to inter-shaft leakage. The locking mother over-lock will only lead to premature failure of the inter-shaft pad, on the contrary, moderate locking mother, so that the inter-shaft pad always maintains a certain compression elasticity, the locking mother will automatically lock in time during operation, so that the inter-shaft is always in a good sealing state.

5、The new one is better than the old one
        Relatively speaking, the pump using new mechanical seals better than the old, but the new mechanical seal quality or material selection is not appropriate, with a large size error will affect the sealing effect; in the polymeric and permeable media, static ring such as no excessive wear, or not to replace the good. Because the static ring in the static ring seat for a long time in a static state, so that the polymer and impurities deposited as one, played a better sealing role.

6, disassembly and repair is better than not dismantled
        Once the mechanical seal leakage will be eager to disassemble and repair, in fact, sometimes the seal is not damaged, just adjust the working conditions or properly adjust the seal can eliminate leakage. This will avoid waste and can verify their ability to determine the fault, and accumulate maintenance experience to improve the quality of maintenance.

       Cycloid reducer is a kind of novel transmission device which applies the principle of planetary transmission and uses cycloid needle tooth meshing. The whole transmission device of cycloid reducer can be divided into three parts: input part, reduction part and output part. The input shaft is equipped with a double eccentric sleeve misaligned 180°, and the eccentric sleeve is equipped with two roller bearings called swivel arms to form the H mechanism, and the center hole of the two cycloid wheels is the raceway of the swivel arm bearings on the eccentric sleeve, and the cycloid wheels are meshed with a set of circularly arranged needle teeth on the needle gear to form a tooth difference of the internal meshing reducer, (in order to reduce friction, in the reducer with small speed ratio, the needle teeth are (In order to reduce the friction, in the speed reducer with small ratio, the needle teeth have a needle tooth sleeve).
Application
        The cycloid reducer adopts the cycloid needle tooth meshing, planetary transmission principle, so it is usually called planetary cycloid reducer, planetary cycloid reducer can be widely used in petroleum, environmental protection, chemical, cement, conveying, textile, pharmaceutical, food, printing, lifting, mining, metallurgy, construction, power generation and other industries, as a driving or deceleration device, the machine is divided into horizontal, vertical, double shaft type and direct connection type assembly. The machine is divided into horizontal, vertical, double-shaft and direct-connection assembly. Its unique smooth structure can replace ordinary cylindrical gear reducer and worm gear reducer in many cases, therefore, the planetary cycloid reducer is widely used in various industries and fields, and is generally welcomed by the majority of users.
Conditions of use
         1、The cycloid reducer is allowed to be used in continuous working system, and it is allowed to run in both positive and negative directions. Some models of cycloid reducer are only allowed to rotate in one direction.
         2、The input shaft speed is rated at 1500 rpm, and it is recommended to use a 960 rpm motor when the input power is greater than 18.5 kW.
         3, horizontal installation of the cycloid reducer working position are horizontal position. In the installation of the horizontal tilt angle is generally less than 15 °. In more than 15 °, other measures should be used to ensure adequate lubrication and prevent oil leakage.
         4, the output shaft of the cycloid reducer can not be subject to large axial force and radial force, in the case of large axial force and radial force shall take other measures.

Lubrication

         1, horizontal cycloid reducer under normal circumstances using oil pool lubrication, the oil surface height is maintained in the middle of the oil window can be, in poor working conditions, the ambient temperature is at a high temperature can be used to circulate lubrication.
         2, the cycloid reducer at room temperature generally choose 40 # or 50 # mechanical oil lubrication, in order to improve the performance of the reducer, prolong the service life of the cycloid reducer, it is recommended to use 70 # or 90 # pressure gear oil, in the case of high and low temperature work can also be reconsidered lubricant.
         3, vertical installation planetary cycloid reducer to strictly prevent the oil pump oil break, in order to avoid damage to the components of the reducer. 
         4, when refueling can be screwed open the upper vent cap of the seat can be refueled. When releasing oil, unscrew the oil release plug on the lower part of the seat to release the dirty oil. The reducer is shipped without internal lubricant.
         5, when refueling 100 hours of operation should be replaced with new oil, (and the internal dirt oil flush clean) and then work continuously, every six months to replace (8-hour working system), if the working conditions are poor can be appropriate to shorten the oil change time, practice has proved that the reducer of frequent cleaning and oil change (such as 3-6 months) to extend the service life of the reducer has an important role. In the process of use should often replenish the lubricant.
         6, the factory reducer has been added lubricating grease, every six months to replace. The grease is aluminum disulfide-2# or 2L-2# lithium-based lubricating grease.

        Gear reducer is produced according to the national professional standard ZBJ19004 external mesh involute helical cylindrical gear reducer, gear reducer is widely used in East China, used in the tower crane machinery rotary mechanism, widely used in metallurgy, mining, lifting, transportation, cement, construction, chemical industry, textile, printing and dyeing, pharmaceutical and other fields.

        Gear reducer is generally used for low speed and high torque transmission equipment, the motor will also have several pairs of the same principle gears to achieve the desired deceleration effect, the ratio of the number of teeth of large and small gears, is the transmission ratio. With the continuous development of the reducer industry, more and more companies use the reducer.

         Gear reducer 1, R series coaxial helical gear reducer combined with the international technical requirements of manufacturing, with high technological content 2, space-saving, reliable and durable, high overload capacity, power up to 132KW; 3, low energy consumption, superior performance, reducer efficiency of up to 95% or more; 4, low vibration, low noise, high energy saving; 5, the use of excellent forged steel materials, steel cast iron box, gear surface After high-frequency heat treatment; 6, after processing to ensure shaft parallelism and positioning bearing requirements, the formation of helical gear transmission assembly of the reducer is configured with a variety of classes of motor, combined into electromechanical integration, fully guarantee the use of the product quality characteristics.

Speed reducer.

       1, high-speed shaft rotation is not greater than 1500 rpm.
       2, gear drive circumferential speed is not greater than 20 m / s.
       3、The working environment temperature is -40-45℃, if it is lower than 0℃, the lubricant should be preheated to above 0℃ before starting.

       4、Gear reducer can be used to run in both forward and reverse directions.

        Cycloid pinwheel reducer is a kind of application of planetary transmission principle, using a novel transmission device of cycloid pintooth meshing. The whole transmission device of cycloid pinwheel reducer can be divided into three parts: input part, reduction part and output part. The input shaft is equipped with a double eccentric sleeve misaligned 180°, and the eccentric sleeve is equipped with two roller bearings called swivel arms to form the H mechanism, the center hole of the two cycloid wheels is the raceway of the swivel arm bearings on the eccentric sleeve, and the cycloid wheels are meshed with a set of circularly arranged needle teeth on the needle gear to form the internal meshing reducer with a tooth difference, (in order to reduce friction, in the reducer with small speed ratio, the needle teeth are (In order to reduce the friction, in the speed reducer with small ratio, the needle teeth are equipped with a needle tooth sleeve).

        When the input shaft rotates with the eccentric sleeve for one week, the motion of the cycloid becomes a plane motion with both revolution and rotation due to the characteristics of the tooth profile on the cycloid and its limitation by the pin teeth on the pin gear, and when the input shaft is rotating for one week, the eccentric sleeve also rotates for one week, and the cycloid turns through one tooth in the opposite direction to get the deceleration, and then the low-speed rotation motion of the cycloid is transmitted to the output shaft through the pin with the help of the W output mechanism, so as to get a lower speed. The low speed self rotation motion of the cycloid wheel is transmitted to the output shaft through the pin by the W output mechanism, so as to obtain a lower output speed. Cycloid reducer lubrication is as follows.

        1, horizontal cycloid reducer under normal circumstances using oil pool lubrication, the oil surface height to maintain the middle of the sight window can be, in poor working conditions, the ambient temperature is at a high temperature can be used to circulate lubrication.

        2, the cycloid reducer at room temperature generally choose 40 # or 50 # mechanical oil lubrication, in order to improve the performance of the reducer, prolong the service life of the cycloid reducer, it is recommended to use 70 # or 90 # extreme pressure gear oil, in the case of high and low temperature work can also be reconsidered lubricant.

        3, vertical installation of planetary cycloid reducer to prevent oil pump oil break, in order to avoid damage to the components of the reducer.

        4, when refueling can be screwed open the upper vent cap of the seat can be refueled. When releasing oil, unscrew the oil release plug on the lower part of the seat to release the dirty oil. The reducer is shipped without internal lubricant.

        5, the first refueling operation 100 hours should be replaced with new oil, (and the internal dirt oil flush clean) and then work continuously, every six months to replace (8-hour working system), if the working conditions are poor can be appropriate to shorten the oil change time, practice has proved that the reducer frequent cleaning and oil change (such as 3-6 months) for extending the service life of the reducer has an important role. In the process of use should be frequently supplemented with lubricating oil.

        6, reducer has been added lubricating grease, replaced every six months. The grease is aluminum disulfide-2# or 2L-2# lithium-based lubricating grease.

       The main gas treatment equipment used in thermal power plants is flue desulfurization and denitrification equipment. The exhaust gas from boiler combustion is treated by the desulfurization and denitrification equipment, and the toxic and harmful substances in it have been properly treated. It will be discharged to the atmosphere only after it meets the emission standards required by the state.
        In the middle of the boiler flue and desulfurization and denitrification treatment equipment, there is this vital valve, which is --- flue baffle door, its role is when there is a boiler equipment needs to be serviced can be closed in time baffle door, to prevent other boiler equipment generated by the backflow of flue gas into, the body of the maintenance personnel caused injury.

        Baffle door is often used in power plants or other industries in the flue pipe, duct to do interception of media, the dampers open and close the angle of 90 ℃, it has a full open full close two functions, so that the system of a pipeline medium all circulation or closed.
        Flue gas electric baffle door in the use of the process of attention.

        According to the different driving methods of the flue flap door, divided into hydraulic cylinder drive and electric reducer drive, hydraulic cylinder drive flue flap door because of the design structure problems, in the use of the process is easy because of the high temperature corrosion of the flue gas and cause the cylinder seal to break off, oil leakage phenomenon of the cylinder, resulting in the flap can not be closed, the service life is greatly reduced. Hydraulic cylinder flue baffle door due to process problems, there will be a gap between the baffle and the two sides of the frame, both sides of the seal will appear after repeated use of the phenomenon of jamming and wear. So after a period of use also timely check the baffle sealing layer wear, the sealing layer adjustment screws for proper adjustment. Hydraulic oil in the case of relatively low temperature, condensation will occur, which will also cause the insert plate to open and close smoothly or can not be opened and closed normally. Therefore, according to the local temperature conditions, the hydraulic oil should be replaced regularly to ensure the smooth opening and closing of the flap.

        The electric baffle door adopts the driving method of motor reducer, compared with the hydraulic cylinder type flue baffle door, the new rack and pinion structure will not cause the cylinder seal inside the baffle to break and fall off due to the high temperature corrosion of the flue gas because the driving structure is above the baffle. The rack and pinion structure on both sides ensures the synchronization of the flap door in the process of opening and closing, so that the gap between the flap and the frame on both sides will not be inconsistent and lead to the jamming of the insert in the process of opening and closing, and the sealing layer will be broken, which prolongs the service life of the flap door.

       In the flue gas desulfurization (FGD) system of large thermal power generating units, the flue gas desulfurization baffle door is an important equipment for entering and exiting the operation of the desulfurization device. Each baffle blade is surrounded by a nickel alloy sealing piece, and the baffle door body is equipped with a sealing air valve at the entrance of the sealing air, which is mechanically linked to the baffle door. When the flue gas baffle is open, the sealing air valve is closed; when the flue gas baffle is closed, the sealing air valve is open. When the baffle door is closed, sealed air is injected between the double-layer blades to achieve effective isolation of the front and rear media. Desulfurization baffle door can operate safely for a long time, to ensure that under the working conditions, rotation, opening and closing flexible, no jamming phenomenon. Ensure tight and no leakage, sealing efficiency 100% (zero leakage rate).
        About the installation and use of electric actuator for desulfurization and denitrification flue gas baffle door, do you really understand? Today Lunda Xiaobian to give you a nagging it.
       1、Baffle door must be in the closed state before the actuator can be installed.
       2、Manipulate the actuator to the closed position.

       3、Installation procedure of actuator: 1) Remove the cover of position indicator, check whether the position of the keyway of the inner sleeve of the secondary reducer of the actuator is consistent with the position of the key of the drive shaft of the baffle door, if not, disassemble the inner sleeve of the secondary reducer and turn an angle to make the keyway consistent with the position of the key on the drive shaft. If there is a small deviation, the actuator can be manually operated to make the sleeve turn to the required position; 2) check whether the drive shaft head and key collision burrs, if available file, sandpaper to play polish and then install the actuator; 3) actuator installation, need to be vertical with the drive shaft, hand propulsion (the size of the actuator sleeve bore processing are generally 10-20um larger than the drive shaft); if it is difficult to advance, can be in If it is difficult to advance, use long bolts to pass through the bolt holes on the actuator mounting plate and the bolt holes on the reducer after the reducer sleeve enters the shaft head, and gradually tighten the bolts symmetrically and evenly to put the actuator in place. In this process, it should be noted that the depth of the bolt into the reducer does not exceed 20mm, so as not to top bad reducer sector gear.

       4, the actuator seat frame plate (installation fixed plate) is oval, three bolts fastened at each end. After the bolts are loosened, the seat plate has an adjustment amount of about 10mm up and down, if the actuator mounting holes and the seat plate mounting holes are misaligned, adjust the position of the seat plate so that its center coincides and then tighten all the connecting bolts.
       5、After the above work is finished, you must tighten the fixing bolts at both ends of the actuator plate.
       6、After the above steps, hand-operated actuator to the open position (marked as ' '), check whether the position of the baffle door meets the requirements, if the opening degree is not enough, the mechanical limit bolt on the actuator can be screwed outward, and then open the door to the required position, and then screw into the mechanical limit bolt, after touching the side of the sector gear, exit a circle with the back cap locking. Then screw in the mechanical limit bolt, touch the side of the sector gear, exit one turn and lock with the back cap.
       7, hand-operated actuator to the "off" position, check whether the baffle door is closed in place, if a little not in place, you can adjust the "off" direction mechanical limit bolts, the same method as above.
       8, the baffle door in the full off position, should also check whether the door sealing situation is good, bad when the seal should be adjusted to meet the requirements.
       9, after the above work to send on the actuator power, electrical commissioning.
       10, electrical commissioning, the first actuator in the local operation state, hand-operated actuator to the "off" position does not move so far.
       The above is our knowledge about desulfurization and denitrification flue gas baffle door, hope it will help you in your work.

1. Lifting and transportation

        1) The baffle door can only be lifted by lifting lugs, and the bending and deformation of the baffle door should be avoided.

        2) For the large outer frame of the baffle door lifting, should pay special attention to the force problem, to avoid permanent deformation of the external dimensions, affecting the operation of the equipment.

        3) When lifting the baffle door, adjusting the length of the sling, attention must always be paid to ensure uniform load distribution.

        4) Stainless steel seals need special protection from damage when installing and welding pre-assembled joints.

        5) The transport of the baffle door is the same as the assembly, and all accessories (actuators, limit switches, linkages, etc.) should be protected from damage when transporting in a single section.

2. Storage of flap door

        1) The baffle door must be stored on a dry horizontal surface, i.e. on a level ground with square wooden supports, with the support points on the frame around the baffle door. The distance between the supports must be appropriate to avoid skewing the baffle door. There must be enough distance between the baffle door and the floor to avoid the interference and pollution of the baffle door swing arm and other accessories.

        2) The flap door should be surrounded by necessary protective measures to prevent collision damage, etc.

        3) The baffle door with stainless steel parts (seal, metal plate lining, etc.) must be protected to avoid damage.

3. Installation of the baffle door

        Keep the baffle door in the closed state during installation. In order to ensure the sealing and service life of the bypass flap door, in the closed state, it is necessary to pass heated sealing air. Before installation, commissioning, maintenance or inspection of the baffle door, ensure the personal safety of the installation and maintenance personnel, the area where the flue is connected to the baffle door blades is a hazardous area. Blade operation can lead to particularly serious damage, even life-threatening. Before installation and commissioning maintenance flue gas flow in the flue is stopped, and ensure that the actuator power off to prevent actuator misoperation.

        Before installation, first check whether the flue baffle door bracket on the flue is safe and reliable, and whether the size meets the requirements. Also check whether the flue interface size and the baffle door match and require the flue interface section to be vertical.

1) Installation of baffle door body

        Adjust all the baffle door units flat and make them in the closed state.

        Lifting should ensure smooth and avoid collision.

        Note: When lifting from the ground, take special care not to pull up directly. Two lifting devices should be prepared for lifting in the middle lift mode. Gradually slow down the stretching speed of lifting equipment two, so that the baffle door is finally in a vertical state. Docking with the flue, must ensure that the baffle door support solid, vertical. After the size and position are adjusted in place, the welding construction will be carried out according to the drawing.

2) Installation of auxiliary parts

        The baffle door and the counter flange are firstly connected by bolts, and then sealed and welded. Assemble the auxiliary facilities of the baffle door, such as: sealing dampers, linkage mechanism, etc. Check whether the baffle door is damaged, especially the sealing piece, if it needs to be repaired or replaced. Check the damage of the paint and apply the patch as required. The anti-corrosion of the flue and baffle door connection is carried out according to the baffle door installation diagram

        The double louvered baffle door can ensure zero permeation rate of the FGD flue, and can realize the maintenance of the FGD equipment during normal operation of the boiler. It has two rows of blades, which are placed on a common frame behind one row in the other. When the baffle door is closed, a sealing space is formed between the blades, and the sealing air, which is larger than the flue air pressure, is heated and filtered into this space, so that the sealing effect can be guaranteed to reach 99.9%.

 　   Another feature of the louvered baffle door is that: after optimizing the design of the baffle blade after opening, the blade overlap becomes streamlined, so the pressure loss is reduced, and the general pressure loss should be less than 50Pa.

 　   All the design work of the flue gas baffle door adopts computer-aided design (CAD/CAPP/CAE) and other engineering design methods, using finite element method to calculate the flow field, sealing system, baffle door stiffness and deformation. The product has the advantages of high sealing, low flow resistance, streamline appearance, low maintenance, outstanding control performance, etc.

        Flue gas desulfurization stall plate door for boiler flue gas pipeline to regulate the flow of media used in the blade rotation 90 ° range of different bits, through different media flow, to control the pressure, temperature, quantity and other parameters of the media in the system. It has the characteristics of flexible rotation and excellent adjustment performance. Desulfurization stall door adopts steel plate press folded and welded structure, the blade is a streamline rhombus structure with sharp angle at both ends, which can change the airflow tail flow distribution condition. Its adjustment characteristics are in the blade opening degree 25 ° ~ 75 ° range, the resistance coefficient and opening degree into an approximately linear proportional relationship.

Flue gas desulfurization stall door
　　Flue gas desulfurization stall door has electric, manual, pneumatic and other driving methods; local, remote control, centralized control and other control methods. The dampers used for positive pressure hot air system are equipped with sealed air interface at the bearing end of the shaft, which can be connected with sealed air to block the external leakage of heat. Adjustment dampers have ordinary type and sealed type two kinds of structure. Ordinary type regulating door only plays a regulating role, must be used in conjunction with other types of isolation doors; sealed regulating door that has the regulating function, but also has the isolation function. For small capacity units can be dispensed with shut-off dampers or isolation doors. Sealed type regulating gear door of the blade on both sides and the frame inside the two through shaft side are pressed with stainless steel sealing piece, blade closed and steel pipe and frame inside close affixed, that is to ensure the sealing effect, but also can absorb the thermal expansion generated by the blade when heated.

　　In addition, remind users: in the selection of flue gas desulfurization stall plate door to pay attention to the following matters: stall plate door specifications in the width (W) or length (L) refers to the stall plate door cross-section of the inner side of the size, generally with the inner side of the pipe size, W for the vertical direction of the blade (i.e., out of the axis direction) size, L for the blade length direction size, and L size should be in the horizontal plane, the thickness of the stall plate door are 450mm. Wind door specifications according to the user Pipeline cross-sectional size requirements design and production. Order must provide dampers in the pipeline, the use, position, medium, pressure, temperature and other technical parameters.

      Boiler flue baffle doors play a very important role in the maintenance of large coal-fired boilers. When a thermal power plant is at the end of the heating period, the manufacturer will shut down some of these boilers for maintenance and repair so that they can produce normally with quality and quantity when the next heating season comes.

        The flue baffle door plays a role in which when the boiler equipment maintenance, can close the baffle blocking the flow of flue gas, to prevent the backflow of flue gas into the boiler equipment to cause harm to the equipment, as well as to protect the health of the maintenance personnel from the flue gas.

        For a high-quality flue baffle door to measure its standard is only one indicator, that is, zero leakage of flue gas. And if you want to achieve absolute zero leakage of flue gas, not only requires good materials used in the flap door. From the customer's actual use of site considerations, to make in line with the actual use of customer working conditions to ensure zero leakage of flue gas.

        The new electric rack and pinion flue baffle door adopts the latest patented drive structure, the motor speed can bring the torque to 20 tons after decelerating through the reducer, the torque redundancy design ensures that the baffle door can open and close normally under any working condition. The double side rack and pinion structure ensures the synchronization of the flap opening and closing, which solves the problems of jittering and jamming of the old hydraulic cylinder type flue flap door.

        The inner baffle is filled with aluminum silicate heat insulation material, which effectively prevents the baffle from thermal deformation due to the big temperature difference between the two sides of the baffle. The baffle reduces frictional resistance in the process of opening and closing, and makes the opening and closing more smooth.

        The design of bottom ash cleaning slot with baffle plate solves the problem of flue gas leakage caused by the accumulation of flue gas dust at the bottom of the flue flap door after a long time of use. When the flue flap door is opened, the baffle above the ash removal tank will block the dust from entering the ash removal tank, and when the flue flap is closed, the baffle above the ash removal tank will automatically open the baffle due to the fall of the flue flap so that the flue gas dust will fall into the ash removal tank at the bottom. It not only solves the problem of flue gas leakage, but also saves the maintenance time of the maintenance personnel.

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        It is a kind of equipment that can be used for liquid-liquid or liquid-solid two-phase suspension mixing, its paddle arbitrary cross-section consists of an arc and two ends warped straight edge section, two straight edge section outer edge by a number of semi-circular arcs to form a wave-type curve, paddle from the end to the root along the axis of the paddle is twisted, and the paddle from the end to the root gradually widened. The mixer enhances the degree of turbulent turbulence in the axial and radial directions, with good mixing effect and significant energy saving.

   　  The new JH axial flow paddle is a spatial twist paddle type, from one end of the blade, which is composed of many similar arches, with the increase of the half warp blade angle gradually reduced, reasonable blade angle and arch degree composed of the paddle, so that when the fluid passes through the blade, in the back of the blade does not produce vortex area, to achieve the purpose of saving work, JH paddle excellent axial flow characteristics can make the paddle away from the bottom of the kettle for operation without affecting the operation in any way The excellent axial flow characteristics of the JH paddle allows the paddle to operate away from the bottom of the kettle without affecting the operation.

         1、The axial flow stirring paddle has the advantages of good axial flow characteristics, low energy consumption, easy manufacturing and installation, etc. It can replace the existing axial flow three-blade folding pulp and propeller, especially in the technical transformation of the stirring reactor, to improve the mixing efficiency, energy saving and consumption reduction, has significant economic benefits. 
         2、Application scope Suitable for solid suspension, liquid mixing and heat transfer, etc., requiring high pumping capacity, large flow rate and low shear occasions. 
         3、Technical level: In the same operating process results, the axial flow type paddle is slightly larger than the traditional diameter, but its power is only 70% to 80% of the traditional paddle. Axial flow type stirring paddle has better axial flow characteristics, higher flow efficiency and lower torque requirements than the traditional type.

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        As the name suggests, the blade shape of anchor frame agitator is similar to the anchor of a ship. The blade size of the anchor agitator is similar to the size of the mixing tank, and only a small gap is left between the two when they are combined, so that the blades of the anchor agitator can remove the reactants on the inner wall of the mixing tank when they rotate and maintain the mixing effect of the agitator. The anchor stirrer can be used to stir materials with high viscosity.
        The anchor stirrer has a simple structure and is suitable for mixing fluids with viscosity below 100 Pa-s. When the fluid viscosity is 10~100 Pa-s, a horizontal paddle can be added in the middle of the anchor paddle, which is a frame stirrer, to increase the mixing in the container.
        Anchor frame stirrer is simple in structure and suitable for fluid stirring with viscosity below 100Pa-s. When the fluid viscosity is 10~100Pa-s, a horizontal paddle can be added in the middle of the anchor paddle, which is the frame stirrer, to increase the mixing in the container.
Special Frame Anchor Frame Agitator:
        These stirrers are slow-speed stirrers, which are often used in processes such as mixing of medium and high viscosity liquids and heat transfer reactions.
        1. Anchor Frame Type (MKS) can get large shear force along the wall when rotating at low speed, which can prevent settling and wall adhesion, and the bottom shape fits the oval tank with the bottom bearing in the middle.
        2. Anchor belt type (MDS) is a combination of screw belt and frame type, combining the functions of screw belt type and frame type agitator.
        3. Square frame type (FKS), square grid type (FSS), the shape is simple and easy to produce, the performance is the same as the frame type, medium viscosity mixing, dissolution is more suitable.
        4. plate and frame type (BKS) is a viscosity range of application of a wide range of mixing impeller, impeller structure is simple, the impeller in the longitudinal section of the mixing tank projection area accounted for a large proportion of the longitudinal section of the tank area. With high mixing efficiency and large shear force, it is suitable for solid-liquid suspension, liquid-liquid dispersion, as well as gas-liquid mass and heat transfer operations where the gas is drawn from the liquid surface.
Applications:
        The shape of the outer edge of the paddle is consistent with the inner wall of the mixing tank, and there is only a small gap between them, which can remove the viscous reaction products attached to the tank wall or the solids accumulated at the bottom of the tank, and maintain a good heat transfer effect. The circumferential speed of the outer edge of the paddle is 0.5~1.5m/s, which can be used for stirring Newtonian and plastic fluids with viscosity up to 200Pa-s (see Viscous Fluid Flow). Only when stirring high viscosity liquid, there is a large stagnation zone in the liquid layer.

         Open vortex mixer is more than the blade directly welded to the hub, folding leaf open turbine mixer blade in welding, usually in the hub slot, blade embedded after welding. Small open turbine mixer also has the whole casting, especially the folding blade, such as mass production, with the casting is more convenient than the welding. For large diameter open turbine, also all blades or radially symmetrical pair can be made into a detachable connection with the hub for easy installation.
        Turbine mixers are usually designed with two to four blades, which can be flat or curved, mounted on a horizontal disc. The turbine mixer creates a highly turbulent radial flow of material as it rotates. Turbine mixers are suitable for mixing between gases or liquids with low viscosity and poor inter-solubility.
Classification
        According to the paddle type, it can be divided into flat open turbine mixer, inclined open turbine mixer and curved open turbine mixer; according to the connection method of blade and hub, it can be divided into integral open turbine mixer and detachable open turbine mixer; according to the number of blades, it can be divided into three-blade open turbine mixer, four-blade open turbine mixer and six-blade open turbine mixer.
Common operating conditions
        Rotational speed N=10~300r/min; linear speed V=4~10m/s for folded blade paddle type; linear speed V=2~6m/s
Commonly used medium viscosity range.
         Less than 5X10 4mPa-s folded-blade paddle type and back-bending blade paddle type less than 10 4mPa-s
Flow state.
        Flat straight blade and backward curved blade for radial flow type. When there is a baffle impeller as a boundary to form the upper and lower two circulation flow, folding leaf and axial diversion, nearly axial flow type.
Working principle.
        The radial flow turbine rotates to draw in the liquid from the direction of the shaft and discharges it in the direction perpendicular to the shaft (radial). When there is a baffle inside the tank, the discharge stream meets the tank wall and separates up and down, so that the tank forms the up and down circulation flow pattern. This impeller power consumption, strong shear force, but also has the ability to discharge. Therefore, it is suitable for both strong shear, but also to have a certain circulation flow occasions, such as in the liquid-liquid system for emulsification, emulsion polymerization, suspension polymerization, extraction, etc.; in the solid-liquid system is used to dry and wet filter cake and then mash into a slurry and make the solid side of the broken side of the dissolution; for gas-liquid system is used in the oxidation reaction as the gas dispersion and with the chemical reaction of absorption, etc.. For the disc turbine, it is used in many gas-liquid operations because it can hold the gas under the impeller for a time and thus disperse it, reducing gas waste.
Axial flow turbines allow the liquid to be discharged in a direction parallel to the shaft, allowing for effective axial circulation. To produce the same displacement, this impeller requires only half the power of a radial flow turbine, so it is an effective impeller for applications where circulation flow in the tank is important. This impeller is mainly used in liquid-liquid and solid-liquid systems where strong circulation is required, such as homogeneous mixing, reactions, heat transfer, etc.
        Bending leaf radial flow turbine blade is made of steel plate bending, some occasions with flattened round tube to make a bending type blade, and in order to make the impeller can be close to the bottom of the tank head installation, the blade slightly upward (upward angle of about 15 ° or so), the blade has two leaves, three leaves and four leaves, of which three leaves with more, and often the blade inclination is not 90 but 75 ° ~ 80 °, the custom is often called These impellers are often called swept-back impellers, because it is Fawoodula company developed, it is often used with finger-shaped baffle for mixing, heat transfer, suspension, gas absorption and emulsification. Three-bladed swept-back impellers are also commonly used in glass-lined mixing kettles.
        The swept-back impeller, which is made of flattened circle, has about 20% lower mixing power than the bent-blade turbine with the same number of blades, blade diameter and blade width, and the same speed for mixing the same low-viscosity liquid, and the liquid discharge performance of the swept-back impeller is lower than that of the corresponding bent-blade turbine, i.e., the proportion of its power consumption used to produce the discharge is greater than that of the bent-blade turbine. Almost all of the new suspension polymerization reactors use swept-back impellers.
Brumagin impellers are also bent-blade radial flow turbines, but their discharge performance is less than that of bent-blade turbines and three-blade swept-back impellers, and their circulation performance is better.

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&nbsp; &nbsp; &nbsp; &nbsp; It is a relatively simple structure of the equipment, its mixing parts are two blades, it can be divided into flat paddle mixer and inclined paddle mixer according to the different characteristics of the blade shape. The flat paddle mixer generates radial force and the inclined paddle mixer generates axial force. Paddle agitators are suitable for mixing low viscosity liquids, suspensions and dissolved liquids.<br /> The design and selection of the stirring device is closely related to the purpose of the stirring operation. Different stirring processes need to be realized by different stirring devices. In the design and selection, firstly, the stirrer type, motor power and stirring speed should be determined according to the purpose and requirements of the stirring operation, and then the reducer, frame, stirring shaft, shaft seal and other components should be selected. Total specific steps and methods are as follows.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 1. In accordance with the process conditions, mixing purposes and requirements, select the agitator type. When selecting the agitator type, fully grasp the power characteristics of the agitator and the causal relationship between the flow state generated by the agitator in the mixing process and various mixing purposes.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2. In accordance with the determined agitator type and the flow state generated by the agitator in the mixing process, the process control requirements on mixing and blending time, settling speed and dispersion, determine the motor power, mixing speed and agitator diameter through experimental means and computer simulation design.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3. In accordance with the motor power, stirring speed and process conditions, select and determine the reducer model from the reducer selection table. If the reducer is selected according to the actual working torque, the actual working torque should be less than the allowable torque of the reducer.<br /> <p> &nbsp; &nbsp; &nbsp; &nbsp; 4. Select the frame and coupling of the same type and specification as d according to the output shaft head d of the reducer and the support method of the mixing shaft system. </p> <p> <img src="/Uploads/Editor/2022-10-15/634a0cf676de7.jpg" width="921" height="366" title="三叶桨式搅拌器-江苏隆达机械设备有限公司-https://www.longdaml.com/" alt="三叶桨式搅拌器-江苏隆达机械设备有限公司-https://www.longdaml.com/" /> </p> &nbsp; &nbsp; &nbsp; &nbsp; 5. Select the shaft seal type according to the size of the agitating head do of the frame, installation space, working pressure and working temperature.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 6. According to the installation form and structural requirements, design and select the structure type of mixing shaft, and check its strength and rigidity.<br /> If the design is based on rigid shaft, n/nk≤0.7 under the condition of meeting strength.<br /> If the design is based on flexible shaft, n/nk>=1.3 under the condition of meeting the strength.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 7. According to the nominal heart DN of the frame, the type of shaft and pressure level of the mixing shaft, choose the installation base cover, flange base or flange flange<br /> &nbsp; &nbsp; &nbsp; &nbsp; 8. According to the support and vibration resistance conditions, determine whether to configure auxiliary support.<br /> &nbsp; &nbsp; &nbsp; &nbsp; In the above selection process, the key size of the connection between the components in the combination and configuration of the mixing device is the size of the shaft head, and the components with the same size of the shaft head can be interchanged and combined in principle. <hr /> <strong><img src="/Uploads/Editor/2022-04-29/626b4d52d3839.jpg" width="960" height="111" title="搅拌器画册下载|减速机|挡板门|机械密封-江苏隆达机械设备有限公司https://www.longdaml.com" alt="搅拌器画册下载|减速机|挡板门|机械密封-江苏隆达机械设备有限公司https://www.longdaml.com" /></strong><br />

         A rigid coupling is a torsionally rigid coupling that does not have any slewing clearance even when subjected to a load, and rigid couplings rigidly transmit torque even when there is a deviation to produce a load.
Definition.
        If there is any misalignment in the system, it can lead to premature damage to the shaft, bearing or coupling, meaning that it cannot be used in high speed environments because it cannot compensate for the relative displacement between shafts due to the high temperatures generated by high speed operation. Of course, rigid couplings can perform in servo applications if the relative displacement can be successfully controlled. In particular, small-size rigid couplings have the advantage of light weight, low inertia and high sensitivity, and in practice, they are maintenance-free, highly oil-resistant and corrosion-resistant.
        Although the use of rigid couplings in servo drives was not favored in the past, small-size aluminum alloy rigid couplings are increasingly used in motion control applications due to their high torque tolerance, rigidity and zero backlash performance.
Classification.
       Rigid couplings are divided into flange couplings, radial key flange couplings, sleeve couplings, jacket couplings and parallel shaft couplings Flange couplings: couplings that use bolts to connect the flange of two halves of the coupling to realize the coupling of two shafts Radial key flange couplings: couplings that use radial keys and common bolts to connect two halves of the coupling Sleeve couplings: couplings that use common sleeves to connect two shafts in some way Jacket Coupling: A coupling that uses two axially-sectioned clamping housings clamped in a certain way to realize the coupling of two shafts Parallel shaft coupling: A coupling that uses an intermediate disk to realize the coupling of two parallel shafts by means of a pin.

        Elastomeric couplings are one-piece metal elastomers, usually wire-cut from metal round bars, commonly made of aluminum alloy, stainless steel, and engineering plastics, suitable for a wide range of deviations and torque transmission.
        Elastomeric couplings contain an elastic compound of pre-pressed rubber that provides additional strength and extended service life. The coupling can accommodate all types of deviations. The hub material is a high-strength aluminum alloy, which is both lightweight and corrosion resistant. The rubber component in it is mainly used for vibration damping, allowing smooth and quiet power transmission, thus protecting the drive as well as the driving machine.
        Installation is simple, as the rubber part is a split insert, it can be inserted after the shaft is aligned.
        Flexible couplings use parallel or helical grooving systems to accommodate various misalignments and transmit torque. Flexible couplings often offer good performance and price advantages, making them a good choice for many practical applications in stepper and servo systems. The one-piece design allows the flexible coupling to transmit torque with zero backlash and without maintenance. There are two main basic series of flexible couplings as follows: spiral groove type and parallel groove type.
Features.
        (1) One-piece molded metal elastomer.
        (2) Zero slewing clearance and synchronous operation.
        (3) Elastic action to compensate for radial, angular and axial deviations.
        (4) High torque rigidity and high sensitivity.
        (5) Identical clockwise and counterclockwise slewing characteristics.
        (6) Maintenance-free, oil and corrosion resistant.
        (7) Available in aluminum and stainless steel.
        (8) The main two types of fixing methods are top wire and clamping.

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Oil Leakage

No matter what kind of reducer it is, this is a problem it has to face. The causes of oil leakage are various, involving the oil seal brand, oil seal assembly, shaft processing technology, usage method, etc. Moreover, there are real oil leakage and false oil leakage.

The so-called false oil leakage refers to the oil leakage soon after the operation, the oil leakage is not large and will not appear after a short time. This is usually the internal pressure release, the pressure is released and there is no problem. The time point of real oil leakage is variable, it may be the beginning of oil leakage, which is likely to be the problem of product quality or assembly quality; it may also appear after a long time of operation, which is mainly the problem of oil seal life.

Accuracy

There are two kinds of accuracy, one is the angular drive accuracy, which is indicated in the manual of the reducer, and it affects the absolute positioning accuracy of the robot; the other is the repeat positioning accuracy, which is not indicated in the manual of the reducer, and it affects the repeat positioning accuracy of the robot. The angular drive accuracy is generally provided by the reducer manufacturer, but the customer can also design some simple methods to measure it by themselves. The same applies to the repeatability accuracy.

For new gearboxes, to reach the nominal 1 arc minute or less, many manufacturers' are fine, but the biggest problem is consistency and stability.

Repeat positioning accuracy is the same. It is not a problem to achieve high repeat positioning accuracy in a short time, but it is difficult to keep it for a long time.





Heat generation

This is a very intuitive but lesser noticed point. Heat generation is related to the accuracy mentioned above. The accuracy of the reducer depends on the degree of gear meshing, the meshing gap is too large, the accuracy of the reducer is poor, and the use of micro-overload, the accuracy will be improved, but it will lead to excessive heat problems. rv reducer, the difference between the heat of the Teijin structure is not so obvious, and harmonic reducer, the degree of heat of different brands is much different. Of course, the heat generation is not only related to the gears, but also related to the grease and the assembly, and the good or bad grease and the ability of the assembly will have a significant impact. There are many details of the process here, which depends mainly on the manufacturer's process.

Life span

Life is also the biggest injury of the domestic reducer. In fact, the life of the reducer depends mainly on the life of the bearing, generally speaking, the bearing is the first to go bad, especially the harmonic, RV words, the planetary structure part is also very easy to damage. Wear and tear will generally occur in a few months to about a year, depending on the operating conditions, so manufacturers who want to take advantage of the robot boom to store a large number of industrial robots or gearboxes should think about it.


Transmission efficiency

Transmission efficiency is related to accuracy, heat, grease, etc. Transmission efficiency is also one of the important evaluation indicators for gearboxes. To test the transmission efficiency also needs the support of professional equipment, it is difficult for customers to measure the specific data by themselves. But it can be measured by the opposite side. Heat generation is one of the most intuitive way to compare. Heat generation is large, representing more power of the motor is used to eliminate friction, that the output power is less. Output power is less, the load capacity is naturally weak, the acceleration is naturally small.

01 Dry Run<br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Hear that popping sound? That's the sound a mechanical seal makes when it's running dry.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Mechanical seals are designed to use a small amount of process fluid between the sealing faces, and this fluid keeps the sealing faces lubricated and cool. However, when the fluid vaporizes between the sealing faces, an audible popping sound is produced.<br /> <br /> The following are common causes of lubricant/coolant vaporization.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 1) Improper axial adjustment<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2) Entrained air<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3）Vapor trapped in the stuffing box<br /> &nbsp; &nbsp; &nbsp; &nbsp; 4）Solids trapped in the stuffing box<br /> &nbsp; &nbsp; &nbsp; &nbsp; 5) Dry pump operation<br /> &nbsp; &nbsp; &nbsp; &nbsp; 6）Insufficient cooling<br /> &nbsp; &nbsp; &nbsp; &nbsp; 7）No or wrong flushing scheme installed<br /> &nbsp; &nbsp; &nbsp; &nbsp; 8) High fluid vapor pressure<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; To prevent dry running, keep heat away from the mechanical seal face by increasing the flushing flow rate or reevaluating the stuffing box construction design, seal flushing system or flushing scheme.<br /> <br /> Release trapped vapor by evacuating gas from the stuffing box gland or by using a conical bore stuffing box gland.<br /> <br /> 02 High Temperature<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; If radiating cracks (thermal cracking) or buildup (coking) are seen on the seal face, then it may be due to high temperatures. In this case, the high temperature to which the seal is exposed is caused by the heat generated during pump or seal operation.<br /> <br /> Thermal cracking<br /> &nbsp; &nbsp; &nbsp; &nbsp; Thermal cracks can be identified by radial cracks that appear in the center of the seal face (see Figure 3). These cracks act as cutting edges and cause premature wear of the seal faces when they rub against each other.<br /> <br /> Coking<br /> &nbsp; &nbsp; &nbsp; &nbsp;Coking can leave a buildup or abrasive debris on the atmospheric side of the mechanical seal. This buildup occurs when the seal is operated at too high a temperature, but it can also occur due to unclean flushing fluids or contamination from the external environment, etc.<br /> Excessive heat is generated when the pump (on the performance curve) is operated away from the BEP; the seal generates excessive heat due to high speed operation or excessive pressure applied to the seal face.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Certain seal materials are not designed for high temperature applications. Premature mechanical seal failure can occur when the wrong materials of construction are used when pumping high temperature fluids.<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; Keeping seals cool is critical to their long-term reliable operation. If signs of thermal cracking or coking can be seen, it's time to take a closer look at the seal flushing program (or if additional seal flushing programs are necessary).<br /> <br /> Consider increasing the flush flow rate, or changing the flushing scheme.<br /> &nbsp; &nbsp; &nbsp; &nbsp; Are the seals properly selected for the application? The correct materials of construction and seal design ensure that the seal can withstand high temperatures.<br /> <br /> 03 Impacts<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; There are several different types of shocks that can cause mechanical seal failure, including mechanical and thermal shocks.<br /> Mechanical shocks are caused by deteriorating equipment operating conditions, such as bearing damage, cavitation, excessive torque, uneven loading and shaft misalignment. More commonly, however, mechanical shocks are caused by improper seal operation and improper assembly.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Thermal shock occurs when a seal is exposed to large temperature fluctuations over a short period of time. Different areas of the seal face can expand and contract to varying degrees, which can cause excessive stress or strain on the seal face.<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; How to solve this particular situation? The first step requires a full understanding of why it occurs. The following points should be kept in mind when dealing with shocks.<br /> &nbsp; &nbsp; &nbsp; &nbsp;1) When installing mechanical seals, avoid uneven fastener tightening or over-tightening<br /> &nbsp; &nbsp; &nbsp; &nbsp;2) Take care to ensure that a flushing solution is installed to match the seal<br /> &nbsp; &nbsp; &nbsp; &nbsp;3) Check to ensure that flushing fluids and emergency cooling systems are designed to minimize possible momentary interruptions<br /> &nbsp; &nbsp; &nbsp; &nbsp;4) Add vibration checks to the daily program checks<br /> &nbsp; &nbsp; &nbsp; &nbsp;5) If operating parameters specify a large temperature difference, as a general rule of thumb, limit the variation to 1°F per minute.<br /> <br /> 04 Poor lubrication<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;If a mechanical seal squeaks during operation, the cause may be a lack of lubrication between the sealing surfaces.<br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Lubrication plays a key role in the operation of a mechanical seal. Its function is not only to lubricate but also to cool, seal, clean the sealing surfaces and protect.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Poor lubrication on hard surfaces, such as silicon carbide or ceramic, may lead to thermal cracking. Thermal cracking shows the presence of radiating cracks on the sealing surface. The height and distance between the cracks may vary from very small to very large (see Figure 6).<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;When two rotating surfaces are in contact under heavy loads, localized high temperatures may occur due to excessive frictional heating near the surfaces. The superposition of heat generation, poor lubrication between the sealing surfaces and mechanical loads leads to cracking of the material near the contact area.<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; Verify that operating conditions such as seal chamber pressure are within the limits of the seal design; verify that the seal chamber is or can be adequately vented of air; provide sufficient continuous (lubrication) flushing of the seal.<br /> <br /> 05 Rotational Speed/Torque<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; As is the case with almost any rotating equipment, RPM is often fatal. High starting or operating torque, frequent starting/stopping of equipment can cause damage to mechanical seals.<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; Check the condition of the equipment and repair it to the proper limits. Select the appropriate drive mechanism based on torque or other equipment operating conditions. Use balanced seals to reduce seal face torque and pressure torque.<br /> <br /> 06 Chemical Erosion<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Some of the most serious damage to mechanical seals can come from chemical attack. Incompatible materials can have a dramatic effect. When seals are subjected to chemical attack, any of the following conditions may occur.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; 1) Severe leakage<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2) Signs of excessive wear<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3) Fragile or broken parts<br /> &nbsp; &nbsp; &nbsp; &nbsp; 4) Pitting of sealing surfaces<br /> &nbsp; &nbsp; &nbsp; &nbsp; 5) Corroded metal parts<br /> &nbsp; &nbsp; &nbsp; &nbsp; 6) Swollen O-rings<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Chemical erosion is caused by improper selection of seals and their materials of construction. It is vital that the selection of mechanical seals is made by someone who has extensive experience with the different materials used in mechanical seals and also understands how certain chemicals react.<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; In order to properly select the right material for a process fluid, a complete chemical analysis should be completed. When selecting a seal material, learn in detail all operating conditions under which the seal may be present, including the characteristics of the clean chemical and its operating temperature. Select a flushing solution that will use clean, compatible fluids.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;In some cases, dual mechanical seals may be required to neutralize or control corrosive environments.<br /> <br /> 07 Pressure<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Mechanical seal overpressure can result in gravitational contact at the outside diameter of the dynamic and static ring sealing surfaces and gradually decrease inward until there is virtually no visible contact. High pressure can result in shattering (chipping) at the edge of the outer diameter of the main seal ring.<br /> How to prevent or repair<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Reduce seal cavity pressure as much as possible. A change in seal design or material may be required to reduce deformation caused by high seal cavity pressure.<br /> <br /> 08 Solid particles<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Solid particles (abrasives) + wrong seal material = seal wears much faster than expected.<br /> <br /> Signs of damage to the seal face caused by solid particles are as follows.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 1) Severe wear of the seal surface<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2) Worn grooves have the appearance of a "phonograph record"<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3) The seal face may have broken edges or be rounded<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; Before applying to solids containing conditions, the fluid properties must be determined, including solids content, solids size and solids type.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Select the appropriate material of construction, or a seal specifically designed for solids-containing applications.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Next, look at the flushing solution. Modify the flushing arrangement so that the flushing fluid flushes over the seal face, increase the flushing rate, and increase the seal chamber pressure by installing a throat bushing.<br /> <br /> 09 Misalignment<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Misalignment is one of the most common causes of damage to mechanical seals. Misalignment can be caused by pipe strain, deflection during hard start, shaft runout, and countless other conditions. Misalignment can put excessive stress on mechanical seal components, causing them to fail to function properly, wear prematurely, and eventually fail.<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Always follow proper installation guidelines and use tools such as laser alignment to ensure accurate alignment of the pump rotor. However, the pump may become misaligned during operation, even if it was perfectly aligned during installation. Equipment displacement due to thermal expansion and dynamic load changes can throw the pump off course.<br /> <br /> 10 Vibration<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Vibration can cause problems in almost any type of equipment, from pumps to fans. How can I tell if vibration is the culprit for mechanical seal failure?<br /> <br /> Just like misalignment, vibration can have many sources.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 1) Unbalance<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2) Misalignment<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3) Running away from the BEP<br /> &nbsp; &nbsp; &nbsp; &nbsp; 4) Pump cavitation<br /> &nbsp; &nbsp; &nbsp; &nbsp; 5) Entrained air<br /> &nbsp; &nbsp; &nbsp; &nbsp; 6）Improper piping design<br /> <br /> How to prevent or fix<br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Proper equipment installation is critical to solving vibration problems. Pump bases should be properly installed and grouted to prevent soft bases. The pump shaft should also be laser and other accurately aligned with the motor shaft.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;OEM spare parts should be used. Vibration problems may occur when parts are out of dimension and tolerance as specified in the design.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Finally, proper piping techniques (according to ANSI/HI standards) can have a significant impact on minimizing vibration.<br /> <br /> 11 Installation errors<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Mechanical seals can easily be damaged during installation. The following are some common installation errors that occur with mechanical seals.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 1) Installed stuffing box end face is not perpendicular to the shaft<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2) Mounting the coupling to the shaft by hammering<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3) Inadequate or improper lubrication for mounting (sliding) the mechanical seal on the shaft<br /> &nbsp; &nbsp; &nbsp; &nbsp; (4) Not following the installation procedures described in the mechanical seal manual<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; Mechanical seals need to be handled and installed with care. The following are some tips for the installation process.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 1) Do not remove the packaging of the mechanical seal until it has been formally installed<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2) Wash your hands well before installation! Even tiny particles or oil on the skin may cause wear and leakage to the seal mating surface during operation<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3) Do not touch the seal mating surface with your hands<br /> &nbsp; &nbsp; &nbsp; &nbsp; 4) Place a clean layer of wrapping paper on the workbench to prevent contamination of the mechanical seal<br /> &nbsp; &nbsp; &nbsp; &nbsp; 5) Clean the seal face with a clean soft cloth and approved solvent before installing the mechanical seal on the pump<br /> &nbsp; &nbsp; &nbsp; &nbsp; 6) Use the manufacturer's recommended lubricant according to installation instructions<br /> <br /> 12 Installing a new seal on a worn pump<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; Before installing and/or replacing a mechanical seal, inspect and ensure that the pump (the parts that work with the seal) are in good condition.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;A scored shaft or sleeve can damage the mechanical seal before it is operational; scored shafts and sleeve can damage the O-ring when the mechanical seal is installed (slid in).<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Bent pump shafts, old and out-of-spec bearings, and unbalanced impellers can cause vibration, contact friction between moving/static parts inside the pump, and bearing damage, all of which can shorten the life of the mechanical seal.<br /> How to prevent or repair<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;All used parts should be thoroughly inspected before reuse to ensure they meet the design dimensions and tolerances. If the size of used parts is out of design requirements, they should be replaced with new parts.<br /> <br /> 13 Operation error<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;There is no doubt that accidents happen from time to time. Whether it's improperly starting a pump or running it with the valve closed, these accidents can have costly consequences.<br /> <br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Improperly starting a pump can cause the motor to trip, twist the shaft, or even cause abnormal mechanical seal movement. Starting the pump dry means encountering all the problems that occur in method #1, which can eventually damage the mechanical seal. Operating the system with the suction valve closed (dry run) or the outlet valve closed (shutdown head) can lead to premature seal failure.<br /> <br /> How to prevent or repair<br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Ensure that all operators are trained in the proper start-up of the pumping unit and system operating procedures.<br /> <br /> Summary<br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;To reduce seal failures, look at all phases of equipment application - how to select seals, installation practices, all the way to operation. Seal failures are usually repeatable. If the seal operates in the same manner, the same failure rate is expected.<br />

        As we all know, machinery and equipment running for a long time, there will be wear and tear and different degrees of failure, mechanical seals are no exception, mechanical seals will also be due to a long period of high-torque mechanical movement, resulting in gear box meshing gap gradually become larger, noise and equipment vibration has become more and more obvious. At the same time, the seal part due to long-term high-speed, high-temperature operation, the seal part of the oil leakage occurs from time to time.
        The main reasons for the leakage of the seal are as follows.
        First, the quality of the oil seal problems and lead to leakage.
        Second, improper lubrication management, such as excessive (over level) refueling or lack of quantity (or direct lack of oil dry grinding).
        Third, improper maintenance, in the process of maintenance damage to the seals caused by seal failure.
        Fourth, the oil level exhaust hole blockage resulting in excessive pressure, etc..
        The above problems appear not only affect the safe and continuous operation of enterprise production equipment, while causing substantial consumption of enterprise costs.
        Based on the concept of reducing energy consumption and protecting the environment, and more importantly, reducing the cost of production and operation of enterprises, we should try to avoid the above-mentioned situations, while also using superior quality mechanical seals (such as our company's production of Lunda mechanical seals) and new materials of lubricants, superior quality lubricants can form a film of inert materials on the equipment components, thereby reducing friction, gear noise and leaks. This reduces the direct contact between metals. It also significantly reduces torque stresses and meets the need for power decompression. It can be used on gasket faces or as a packing supplement to prevent fluid leakage by sealing. It is also very effective in repairing mechanical seal failures as well as those with minor leaks.

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        Mechanical seals are one of the precise and more complex mechanical basic components, which are key parts of various pumps, reaction synthesis kettles, turbocompressors, submersible motors and other equipment. Its sealing performance and service life depends on many factors, such as selection, precision of the machine, the correct installation and use.
        First, the selection method mechanical seal according to the working conditions and the nature of the medium, there are high temperature, low temperature mechanical seal, high pressure, corrosion-resistant mechanical seal, mechanical seal and particle media mechanical seal to adapt to the easy vaporization of light hydrocarbon media mechanical seal, etc., should be selected according to the different uses of different structural types and materials of mechanical seals. The main parameters of the selection are: sealing cavity pressure (MPa), fluid temperature (℃), working speed (m / s), the characteristics of the fluid and the effective space for installation of the seal. The basic principles of selection are
        1. According to the sealing cavity pressure, determine the seal structure using balanced or unbalanced, single-ended or double-ended, etc.
        2. According to the working speed, determine the use of rotary or stationary, fluid dynamic pressure type or non-contact type.
        3. According to the temperature and fluid properties, determine the friction and auxiliary sealing materials, as well as the correct choice of lubrication, flushing, insulation, cooling and other mechanical seal cycle protection system.
        4. According to the installation of the effective space of the seal, determine the use of multi-spring or single spring or waveform spring, internal or external installation type.
         Second, the installation and use of mechanical seals requirements
        1. Mechanical seal requirements for machine precision (mechanical seal for pump, for example)
         (1) the installation of mechanical seal parts of the shaft (or sleeve) of the maximum tolerance of radial runout does not exceed 0.04 ~ 0.06mm.
         (2) rotor axial runout of not more than 0.3mm.
         (3) The maximum tolerance of runout on the surface of the shaft (or sleeve) between the sealing cavity and the sealing end cover combined with the positioning end does not exceed 0.04~0.06mm.
        2. Confirmation of seals
        (1) Confirm whether the installed seal is consistent with the required model.
        (2) Before installation, carefully check with the general assembly drawing to see if the number of parts is complete.
        (3) The mechanical seal with spring drive, the spring has a left, right rotation, according to the rotation of the shaft to choose.
         3. Installation installation method varies with the type of mechanical seal, the type of machine, but the installation essentials are almost the same, installation steps and precautions are as follows.
        (1) The installation size of the installation, according to the product manual or sample, to ensure that the mechanical seal installation size.
        (2) Before installation, the shaft (sleeve) and gland should be free of burrs and the bearings should be in good condition; the seal, shaft, sealing chamber and gland should be cleaned. To reduce frictional resistance, the part of the mechanical seal installed on the shaft should be thinly coated with a layer of oil for lubrication, taking into account the compatibility of the rubber O-ring, if oil is not suitable, soapy water can be applied. Floating static ring without anti-rotation pin structure, should not be coated with oil, should be installed dry into the gland.
        (3) first static ring and gland together on the shaft, pay attention not to touch with the shaft, and then the dynamic ring components into. The tightening screws of the spring seat or drive seat should be tightened evenly in several times. Before fixing the gland, use the hand to push the compensation ring for axial compression, loosen the compensation ring can automatically spring back without jamming, and then lock the gland screw evenly.
          4. Use
        (1) When the conveying medium temperature is high, too low, or contains impurity particles, flammable, explosive, toxic, must take the corresponding blocking, flushing, cooling, filtering and other measures.
        (2) Before operation, use the hand pan, pay attention to whether the torque is too large, there is no rubbing and abnormal sound.
        (3) Pay attention to the rotation direction, whether the coupling is centered, whether the lubricating oil of the bearing parts is properly added, and whether the piping is correct.
        (4) Before running, first open the medium and cooling water valve, check whether the gas in the sealing chamber is fully discharged to prevent leakage caused by static pressure, and then start the machine to run.
        (5) Whether the work is normal and stable after driving, whether there is abnormal torque caused by shaft rotation, and abnormal sound and overheating phenomenon.

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        Double louver electric baffle door is used in the flue and wind duct system for cutting off the medium, generally consisting of baffle door body, electric actuator, sealed air inlet valve, fan, electric heater, control system and related pipeline accessories.

        Double louver electric baffle door is used in the flue of power plant flue gas desulfurization system, is one of the important equipment in the flue and duct system of boiler unit of thermal power plant, it is used in the flue and duct system to circulate and shut off the medium, applicable to the boiler unit of power plant, there are more than 400 kinds of specifications for users to choose.

       Double louver electric baffle door of the baffle plate rotation 90 ° stroke, in the boiler smoke, air system for opening or closing (also can be adjusted as a whole). Generally can be arranged in the air preheater inlet, dust collector outlet, induced draft fan inlet, outlet and other air ducts, flue ducts.

Order instructions for double louver electric baffle door.

       a. Provide the cross-sectional size of the pipe and the installation position of the pipe (horizontal pipe or vertical pipe).

       b, opening and closing time: ≤ 60s (can be selected by the user).

       c. Circulation medium, working pressure, working temperature.

       d, connection mode: flange bolt connection or flange plane butt welding connection.

       e, operation requirements: electric or manual.

      f、The use and location of the baffle door in the pipeline.

      g. The supplier provides the general installation diagram to the demander for confirmation before ordering.

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    In daily industrial production often have to use the seal, there are many kinds of seal classification, common packing seals and mechanical seals, and mechanical seals with its unique advantages are quite widely used, today Lunda Xiaobian to talk to you about the advantages of mechanical seals.
     (1) reliable structure, leakage can be limited to very little, as long as the surface roughness and straightness of the main sealing surface to ensure that the requirements can be met, mechanical seals can achieve little leakage, and even invisible to the naked eye leakage.
     (2) Long life. In the mechanical seal, the main wear part is the seal friction side face, because the seal face wear in normal working conditions is not large, generally can be used continuously 1 to 2 years, special occasions are also useful to 5 to 10 years.
     (3) No adjustment is needed in operation. Because the mechanical seal relies on spring force and fluid pressure to make the frictional sub-fitting, automatically maintain contact in operation, after assembly, there is no need to adjust the compression like ordinary soft packing.
     (4) It is vibration resistant. In the speed of 3000r/min maximum amplitude does not exceed 0.05mm using the PV value continues to improve
     (5) Small power loss. Packing seal is by the compression of the packing on the shaft or sleeve to play a role. Filler seal and shaft friction directly, the tighter the packing friction is greater, the greater the power consumption. The mechanical seal friction is in a semi-liquid friction state, the friction coefficient is very small, the mechanical seal power loss is 10 ~ 50% of the packing seal
     (6) wide range of applications. When the medium is flammable, explosive, toxic and harmful, the use of mechanical seals can ensure sealing. It is also suitable for high temperature, low temperature, high pressure, vacuum various speed and corrosive media equipment sealing.

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　　We know that the mechanical seal is now more frequently used in industrial production of an accessory, but in the process of product application, it is easy to some application misconceptions to influence people's calibration, resulting in the application of efficiency landing, damage to the environment, so Lunda Xiaobian to chatter with you about the use of mechanical seals three major misconceptions:
　　1, the greater the spring compression sealing effect is better
　　In fact, it is not, the spring compression is too large, can lead to conflict vice sharp wear, instant burnout; excessive compression makes the spring fall short of the ability to adjust the dynamic ring end face, resulting in seal failure.
　　2, the tighter the moving ring seal the better

　　In fact, the moving ring seal ring is too tight is harmful. First, intensify the wear between the seal and the sleeve, premature leakage; Second, increase the dynamic ring axial adjustment, moving resistance, in frequent changes in working conditions can not be adjusted when the order; Third, excessive fatigue of the spring is easy to damage; Fourth, the dynamic ring seal deformation, affecting the sealing effect.

　　3, the tighter the static ring seal the better
　　Static ring seal ring is basically in a static state, compared with the tight seal effect will be better, but too tight is also harmful. First, the static ring seal due to excessive deformation, affecting the mechanical sealing effect; Second, the static ring material to graphite mostly, generally more brittle, excessive stress is easy to cause shattering; Third, installation, disassembly difficulties, easy to damage the static ring.
       Everything is a degree, many times the opposite, the use of mechanical seals is also the case.

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First. What is a flue gas baffle door?
        Flue gas baffle doors are commonly used in power plants or other industries as intercepting media in flue gas ducts and air ducts. Flue gas baffle door is an important equipment to enter and exit the operation of desulfurization device, divided into flue gas desulfurization main flue gas baffle door (including original flue gas baffle door and net flue gas baffle door) and bypass flue gas baffle door.

        Under the normal operation of FGD system, the flue gas coming out from the tail of boiler electric dust collector will be cooled down by flue gas heat exchanger to enter the absorption tower after the inlet baffle door of FGD system to the booster fan, and then the flue gas will be heated to about 80℃ by the flue gas heat exchanger and enter the chimney through the flue gas baffle door of FGD outlet.
The flue gas baffle door adopts special sealing device with good sealing performance. The actuator of the flue gas baffle door can be electric or pneumatic, and it can be operated from near or far range, and the opening and closing time can be set as needed.

Second, what is the role of the flue gas baffle?
        The flue gas baffle door has three functions: isolating the equipment, controlling the flue gas flow and discharging the flue gas. Most FGD bypass flue gases are equipped with isolation baffle doors to prevent raw flue gases from entering the stack. Flue gas flow control baffles are mainly used for bypass flue gas in bypass flue gas heating systems, and evacuation baffle doors are installed on top of the GGH or absorption tower to facilitate timely evacuation of flue gas from the vessel when the system is shut down.
Desulfurization flue gas baffle door usually adopts louvered double-layer baffle structure, when shutting off the double-layer baffle plate between the passage of sealed air for gas sealing, to achieve the role of isolation shutdown flue gas.

Third, the flue gas baffle door in which areas?
        Flue gas baffle door is mainly used in the flue gas desulfurization system absorption tower inlet, outlet or bypass flue, or in the flue gas denitrification and flue gas dedusting system.
FGD flue gas baffle door is mainly used in the flue gas desulfurization system of thermal power plants to isolate the flow of flue gas, and can also be used in other flue gas ducts with high operational isolation requirements.

Fourth, what are the characteristics of the flue gas baffle door?
        The electric heater can automatically adjust the temperature steplessly, saving energy consumption and making the life longer.
        Flue gas baffle door adjustable linkage mechanism, to ensure that the door leaf positioning quasi-complete, flexible rotation; linkage adopts joint bearing connection, no clearance brought about by the empty travel and impact.
        Easy to install - the middle support is added to the extra wide door, and both sides of the door leaf adopt staggered design to avoid the middle bearing bite, and at the same time, it is easy to overhaul and maintain.
        High reliability--Use finite element method for strength and deformation calculation to fully guarantee the reasonable structure of the parts.
        Perfect anti-corrosion design - The anti-corrosion surface design avoids the penetration of carbon steel when welding alloy steel, and the strict welding process ensures the welding quality and the anti-corrosion performance of the weld.
        Bypass door quick-opening booster design--The quick-opening booster structure adopts patented technology to reduce the starting torque of the actuator and increase safety and reliability.
        Safety measures safety device - equipped with switch positioning interlocking device and external travel switch to ensure reliable operation, safe operation of equipment and prevent misoperation.
        Smaller resistance - block door is divided into blocks without intermediate frame, reducing resistance and leakage points.
        Adjustable linkage mechanism to ensure accurate positioning and flexible rotation of the shutter door.

&nbsp; &nbsp; &nbsp; &nbsp; Turbine agitator, also called turbine impeller, is a device that makes liquid and gas medium forced convection and uniform mixing. It has various styles, and the main part is turbine. This wheel generates a large centrifugal force when rotating. It can throw the liquid in all directions. The common turbine can produce both radial and tangential liquid flow, and the radial liquid flow is dominant when the speed is accelerated. The turbine mixer can be used to mix liquids well regardless of their viscosity.<br /> Introduction<br /> &nbsp; &nbsp; &nbsp; &nbsp; There are various types of turbine stirrers, which can be divided into disc turbine stirrers and open turbine stirrers according to the presence or absence of a disc, and into flat, folded and backward curved impeller turbine stirrers according to the impeller. The ratio of turbine stirrer diameter d to kettle inner diameter d is 0.2-0.5, with 0.33 being the majority. The speed is generally 10~300 r/min, which is suitable for mixing low or medium viscosity liquids (viscosity less than 50 Pa-s).<br /> &nbsp; &nbsp; &nbsp; &nbsp; The turbine stirrer has high circulation rate and high shearing effect. It generates both strong radial flow and strong axial flow. The disc turbine stirrer is compared with the open turbine stirrer, because the presence of the disc makes the circulation rate of the disc turbine stirrer lower than that of the open turbine stirrer. Folded blade turbine mixer is compared with flat turbine mixer, because the axial flow of folded blade turbine mixer is strong and the shearing effect is relatively small. Compared with the flat turbine mixer, the curved blade turbine mainly lies in the curved blade turbine mixer impeller is not easy to wear, and low power consumption.<br /> &nbsp; &nbsp; &nbsp; &nbsp; The type, size and speed of the stirrer have an effect on the distribution of stirring power between the overall flow and turbulent pulsations. Generally speaking, the power distribution of turbine agitators is favorable for turbulent pulsations, while rotating paddle agitators are favorable for the overall flow.<br /> Principle.<img src="/Uploads/Editor/2022-10-09/63421d88d0687.jpg" width="934" height="471" title="轮式搅拌器-江苏隆达机械设备有限公司-https://www.longdaml.com/" alt="轮式搅拌器-江苏隆达机械设备有限公司-https://www.longdaml.com/" /><br /> &nbsp; &nbsp; &nbsp; &nbsp; Turbine agitators are divided into disc turbine agitators and open turbine agitators; according to the impeller, they can be further divided into flat blades and inclined blades. The speed of turbine agitator is larger, generally 300~600r/min. The main advantage of turbine agitator is high mixing efficiency when energy consumption is not much, and the mixing produces very strong radial flow. Therefore it is suitable for emulsions, suspensions, etc.<br /> &nbsp; &nbsp; &nbsp; &nbsp; The turbine stirrer has a large shear force, which can make the fluid micro-clusters dispersed very fine, and is suitable for mixing, liquid-liquid dispersion, liquid-solid suspension of low to medium viscosity fluids, as well as promoting good heat transfer, mass transfer and chemical reaction.<br /> Selection.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 1. Select the stirrer type according to the process conditions, stirring purpose and requirements. When selecting the stirrer type, you should fully grasp the dynamic characteristics of the stirrer and the causal relationship between the flow state generated by the stirrer during the stirring process and various stirring purposes.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 2. In accordance with the determined agitator type and the flow state generated by the agitator in the mixing process, the process control requirements on mixing and blending time, settling speed and dispersion, determine the motor power, mixing speed and agitator diameter through experimental means and computer simulation design.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 3. In accordance with the motor power, stirring speed and process conditions, select and determine the reducer model from the reducer selection table. If the reducer is selected according to the actual working torque, the actual working torque should be less than the allowable torque of the reducer.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 4. Select the frame and coupling of the same type and specification as d according to the output shaft head d of the reducer and the support method of the mixing shaft system.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 5. Select the shaft seal type according to the size of the mixing shaft head d of the frame, installation space and working pressure and working temperature.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 6. Select the installation bottom cover, flange base or flange according to the nominal heart size DN of the frame, the type of shaft and pressure level of the mixing shaft.<br /> &nbsp; &nbsp; &nbsp; &nbsp; 7. According to the support and vibration resistance conditions, determine whether to configure auxiliary support. <hr /> <strong><img src="/Uploads/Editor/2022-04-29/626b4d52d3839.jpg" width="960" height="111" title="搅拌器画册下载|减速机|挡板门|机械密封-江苏隆达机械设备有限公司https://www.longdaml.com" alt="搅拌器画册下载|减速机|挡板门|机械密封-江苏隆达机械设备有限公司https://www.longdaml.com" /></strong><br />

        Mastering the necessary general knowledge of the use of reducer can ensure normal industrial production, reduce the daily operation and maintenance costs of enterprise equipment, and can ensure the normal production and operation of the company. Today, Jiangsu Longda Machinery Equipment Co., Ltd.'s editor to tell you about the use of common sense reducer.

         The first point, the reasonable construction of the reducer installation site.
        The installation of the reducer, the first requirement of the ground level, ventilation conditions as good as possible, to know that good installation and use of the site will have a great impact on the normal use of the reducer in the future.

        The second point, do a good job reducer routine maintenance
        The use of any machinery and equipment are less routine maintenance, reducer is no exception, only use not to raise, which is also the use of reducer taboo, then good equipment, not maintenance, its service life will be greatly reduced, according to statistics, at least one-third reduction.
        So the daily maintenance of the reducer is particularly important, the daily maintenance of the reducer mainly includes: the use of lubricant replacement, check the installation base, seals, drive shaft, etc. is normal, shell in addition to debris and other important parts of the maintenance.
        Among them, gearbox cleaning and maintenance machine can use the gearbox to drain the oil system and by filtering the old oil can be achieved on the gearbox cleaning, waste oil fast filtration, filling new oil and other functions, the advantage of doing so is that the operating process does not change the hardware facilities, do not add cleaning agent, to ensure the safe operation of the gearbox and extend the service life.

        The third point is to pay attention to the maintenance of the gearbox during decommissioning, which is often neglected.
        Many people think that the reducer are out of use during the period do not care, always think that the period of disuse does not need maintenance, in fact, like a car, every day to drive no problem, but if a year, regardless of the wind and sun, and then use the problem constantly. In fact, for a long time, the equipment in the lubricant will also be aging failure, oil impurities will also be precipitated, the oil circuit also has the possibility of blockage, and some unexpected potential problems. So the reducer idle period, must pay attention to the requirements of the manual, regular inspection and maintenance, in order to ensure that the reuse of the machine on the use, and will not have out of the accidental failure to produce.

        When we go to school, we need to better grasp the classroom knowledge, we need to prep knowledge, understand the main points of the course and focus on the difficulties, so that the class will be comfortable; reducer operation is the same, to be able to a better operation and safe production, we need to master the main points of equipment knowledge in advance, while doing a good job of equipment maintenance to ensure the normal operation of the equipment. Today, I will talk to you here, please correct any deficiencies.

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         Today Lunda Xiaobian will explain to you the basic problems of couplings.
First, let's understand what is a coupling
        Coupling is commonly known as shaft joint, it is a mechanical part that connects the drive shaft and driven shaft of motor, etc. and transmits power. In many cases, the coupling has the flexibility to allow the eccentricity between the two shafts (error adjustment), thus greatly reducing the failure caused by uneven wear of the bearings and error adjustment of the device vibration, etc.
Second, let's understand the role of the coupling
      (1), connecting the drive shaft and the driven shaft - used to transfer power The biggest role of the coupling is to connect the motor and other drive shafts and ball screws and other driven shafts, the motor power to the driven shaft.
There are various ways to connect to the shaft, such as "set screw fixed type" which connects directly to the shaft by pressing the screw, "clamping type" which connects by friction, "expansion sleeve type" which uses the wedge effect, etc. "etc.
       (2), allow the installation error of the drive shaft and driven shaft axis.
In actual production, the axis of the drive shaft and driven shaft in many cases there will be a certain deviation, we call it error. And this error by the eccentric, eccentric angle, axial deviation (shaft direction deviation) three cases, and these will deviate from the error often may lead to vibration, noise, uneven bearing wear and other causes of device failure, the flexure coupling can minimize such deviations brought about by the failure, that is, the coupling has a tolerance assembly can not fully adjust the role of error adjustment.
      (3) Absorb shock and vibration of the device.
The plummer type coupling is embedded with elastomer etc. as intermediate parts, so it is a coupling that can absorb shocks and vibrations.
      (4) Improve the performance of the device.
Depending on the type of coupling, some can also improve the performance of the device. For example, high damping capacity rubber "high damping capacity rubber type" can improve the limit gain and shorten the adjustment time by suppressing the resonance of the servo motor, thus improving productivity.
        Through Lunda brief explanation of the coupling, I believe that you have a preliminary understanding of the coupling, of course, please correct the deficiencies.

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        The coupling is widely used in industrial machinery, in many production applications, especially in large transmission equipment is an important part of the application, the actual production requirements of the coupling is also getting higher and higher, today Jiangsu Longda mechanical small to give you a detailed account of the coupling assembly of those things.
First, the coupling assembly requirements

        For rigid couplings, the connection requirements are relatively high, the coaxiality and rotation accuracy of both sides of the shaft to be connected requires a high degree of consistency, while axially there can be no offset interference, before assembly, we must first check whether the fit size is appropriate, and try to use pressure in the assembly (see the second part of the coupling assembly method) and avoid knocking the assembly of unilateral parts to prevent deformation of the connected parts under the action of external forces; for flexible couplings Allow a large error (including shaft eccentricity, angle, axial position), but must ensure that the error can not be greater than the selected coupling compensation capacity range.

        After the coupling is installed in position, it should be corrected, mainly by measuring its coaxiality and parallelism within the allowable error range (i.e. radial displacement or radial clearance, angular displacement or axial clearance within the allowable error range), and the following methods are available for specific measurement.

        1、The more widely used measurement is the use of right angle ruler to measure the coaxiality of the coupling (radial displacement), the use of plane gauge and wedge-shaped gap gauge to measure the parallelism of the coupling (angular displacement), although this method is simple, but the accuracy is not high, mainly used for low speed or medium speed and other less demanding operating equipment.

        2、Measure the coaxiality and parallelism of the coupling directly with the percentage table, plug gauge and center card. Adjustment method: Usually the method is to add or subtract the shim under the foot of the main machine (motor) in the vertical direction or move the position of the main machine in the horizontal direction to achieve.

Second, the method of coupling assembly

        The assembly of the coupling on the shaft is quite critical to the installation of the coupling. Most of the coupling and shaft fit is interference fit (i.e., relying on the interference value of the shaft and hole, the assembly of the parts surface between the elastic pressure, so as to obtain a tight coupling, interference fit structure is simple, good coaxiality, can withstand large axial force, torque and dynamic load), the coupling is divided into keyed coupling and keyless coupling, the shaft hole of the coupling is divided into two forms of cylindrical shaft hole and tapered shaft hole. Assembly methods are static press-in method, power press-in method, temperature difference assembly method and hydraulic assembly method, etc.

        (1) Static press-in method

         This method is based on the size of the press-in force required for assembly, the use of clamps, jacks, manual or motorized presses, static press-in method is generally used for tapered bore. Due to the limitations of the static press-in method by the pressure machinery, it is difficult to apply a large force when the interference is large. At the same time, the process of pressing in will cut away the uneven tiny convex peak on the mating surface between the coupling and the shaft, so that the mating surface is damaged. Therefore, this method is generally not much used.

        (2) Power press-in method

        This method refers to the use of impact tools or machinery to complete the assembly process, generally used in the coupling and the shaft fit is a transition fit or interference is not large occasions. The assembly site is usually hand hammered method, the method is to put a wooden block or other soft material on the end face of the hub as a buffer, relying on the impact of the hand hammer, the coupling knocked into. This method is not suitable for couplings made of brittle materials such as cast iron, hardened steel and casting alloys because of the risk of local damage. This method will also damage the mating surface, so it is often used for low speed and small coupling assembly.

        (3) Temperature difference assembly method

        The coupling is heated so that the coupling is heated and expanded or cooled so that the shaft end is cooled and contracted so that the wheel coupling can be easily installed on the shaft. This method has many advantages compared with the static press-in method and the power press-in method. For hubs made of brittle materials, the temperature difference assembly method is very suitable.

        The temperature difference assembly method mostly uses the heating method, and the cooling method is used less often. There are various methods of heating, some put the hub into high flash point oil for oil bath heating or torch baking, and some use the oven to heat, and the assembly site mostly uses oil bath heating and torch baking. The maximum temperature that can be reached by oil bath heating depends on the nature of the oil and is generally below 200°C.

        When the hub is heated by other methods, the temperature of the coupling can be made higher than 200℃, but from the perspective of metallographic and heat treatment, the heating temperature of the coupling cannot be arbitrarily increased, and the recrystallization temperature of steel is 430℃. If the heating temperature exceeds 430℃, it will cause changes in the internal organization of the steel, so the upper limit of the heating temperature must be less than 430℃. In order to be safe, the upper limit of the heating temperature should be set at 400℃ or less. As for the actual required heating temperature of the coupling, it can be calculated according to the interference value of the coupling and shaft fit and the requirements of the coupling after heating to the shaft set.

        The above is the assembly requirements of the coupling and the assembly method, please correct any deficiencies. For more information, please pay attention to the website update.

        Mechanical seal is the most widely used and indispensable transmission device in pump and kettle equipment, is one of the most important transmission devices. Today, Lunda Xiaobian to chatter with you about this magic weapon "mechanical seal".
         A, can improve machine efficiency, reduce leakage, reduce energy consumption.
        1, to reduce the machine's internal leakage, external leakage and wear leakage, improve the efficiency of the machine volume.
        2、Reduce the friction loss, improve the mechanical efficiency of the machine. For example, changing the double end seal to single end seal, unbalanced type to balanced type, double-supported reduced bottom pump closed end (so-called chopper pump) to reduce the seal can reduce friction loss and improve mechanical efficiency.
        3, change the sealing method to improve the efficiency of the machine or unit. For example, change the shield pump to mechanical seal pump, so that the motor efficiency; the use of magnetic drive pump to improve the efficiency of the machine.
        4, change the auxiliary system to reduce energy consumption and improve the efficiency of the unit. For example, change the self-flushing of hot oil pump to small impeller circulation flushing; change the double-end seal to single-end seal to save the energy consumption of oil sealing auxiliary system.
        Second, save raw materials. For example, process fluid recovery, reduce or eliminate the loss of power steam and process fluid, reduce the loss of sealing oil, etc.
        Third, improve machine reliability. For example, the leakage loss and life of shaft seal determine the reliability of shaft seal and machine.

        IV. Safety and environmental protection. According to a plant survey report, 32 out of 86 accidents occurred were caused by leakage (42%). In addition, process fluid leakage will also cause environmental pollution, including pollution of the atmosphere, water pollution and environmental pollution of the workshop.

Mechanical seal installation, the use of technical essentials
       1. the radial runout of the equipment shaft should be s0.04 mm, axial runout is not allowed to be greater than 0.1 mm.
       2. The sealing part of the equipment should be kept clean during installation, the sealing parts should be cleaned, the sealing end face is intact, to prevent impurities and dust from being brought into the sealing parts.
       3. during installation, banging and knocking are strictly forbidden to prevent the mechanical seal from breaking and sealing failure.
       4. Installation in contact with the seal surface should be coated with a layer of clean mechanical oil, so that the installation can be smooth.
       5. When installing the static ring gland, tighten the screws with uniform force to ensure the vertical requirements of the static ring end face and shaft centerline.
       6. After installation, push the moving ring by hand to make it move flexibly on the shaft and have some flexibility.
       7. After installation, hand-drive the rotating shaft, the rotating shaft should be free of light and heavy feeling.
       8. The equipment must be filled with medium before operation to prevent the seal from failing due to dry friction.

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I. Bearings
         In general, the stirring shaft should be designed as cantilevered as far as possible, so as to facilitate the installation and maintenance, and reduce the impact of media corrosion. If the cantilever of the stirring shaft is too long and thin, the shaft will often be twisted and bent, and the centrifugal force will increase, which can damage the stirring shaft in serious cases. Some stirring reactors have long stirring shafts, and intermediate bearings or bottom bearings need to be installed to prevent the lower part of the stirring shaft from swinging too much.
        Although the installation of intermediate bearings and bottom bearings can change the support conditions of the stirring shaft and reduce the deflection of the stirring shaft. But at the same time, it will increase the structure of the summer, which will bring difficulties to the installation and maintenance; moreover, it is difficult to align the multi-pivot bearing, and the bad installation will produce eccentricity, intensify the wear and vibration of the bearing; the lubrication of the bearing in the equipment is carried out by using the liquid in the container, therefore, when there are abrasive particles, they will enter the bearing and cause wear and blocking. Therefore, intermediate bearings and bottom bearings should be avoided as much as possible.
Second, the intermediate bearing
         The intermediate bearing is usually installed under the shaft seal, or the middle of the mixing shaft, and its position mainly depends on the stability of the shaft and the convenience of installation and maintenance. However, if the intermediate bearing is submerged in the medium, the bearing is fixed with the wall of the tie rod acts as a horizontal baffle, which increases the consumption of stirring power and makes the shearing effect between the liquid molecules increase, and also must consider the corrosion and wear of the medium, and therefore should not be used as far as possible.
Commonly used between the bearing structure type are three tie bar type, three groove steel three shaft tile type, well groove steel type and three tie bar hanging type.
Bottom bearing
        The bottom bearing is installed at the bottom of the stirring shaft. The commonly used bottom bearing structure types are three-foot type, bottom flange type and labyrinth three-foot type, etc.

Four, coupling

         The role of the coupling is to firmly link the shafts of two independent equipment together for the transmission of motion and power. According to the different coupling structure, the upper coupling can be divided into rigid coupling, flexible coupling and hydraulic coupling. Rigid couplings connect two shafts with good axis alignment, allowing rotation in any direction, simple structure and easy manufacturing. The elastic coupling has better compensation of relative displacement, cushioning and shock absorption due to the elastic element which can produce large elastic deformation and damping effect. The hydraulic coupling device has the ability to protect the motor from overload and improve the motor starting performance, and can isolate vibration and moderate shock.
        According to the different installation position, the coupling can be divided into lower coupling and upper coupling.
V. Lower coupling
        The lower coupling is mainly for coupling the stirring shaft in the stirring tank, and rigid coupling must be used; there are two types of installation methods: welded and detachable.
Sixth, upper coupling
        The upper coupling refers to the coupling between the stirring shaft and the transmission or motor output shaft.
        ① When no pivot point frame is used and there is no other pivot point except the motor or transmission pivot point, rigid coupling must be used.
        ② in the case of transferring less power and smaller bearing load, rigid couplings can be used for no intermediate bearings, bottom bearings and shaft seals on the single pivot point rack without bearings;.
        ③ with one of the following conditions, the flexible coupling should be used.
        a, the use of double pivot point frame.
        b. Single pivot frame with bottom bearing or intermediate guide bearing or shaft seal body with bearing that can be used as support.
In addition, it must be noted that
        When the mixing shaft system is a cantilever structure, the reducer output shaft support and the frame support form the two support points of the mixing shaft system, and the connection between the reducer output shaft and the mixing shaft must use rigid coupling. When the stirring shaft system is single span structure, the frame support and the bottom bearing in the kettle form the two supporting points of the stirring shaft system, and the connection between the output shaft of the reducer and the stirring shaft must use the flexible coupling.
        When the shaft seal of the mixing shaft system is equipped with auxiliary bearing or intermediate bearing in the kettle, because these two bearings are auxiliary bearings to improve the rotation accuracy of the shaft seal and the anti-vibration ability of the shaft system, the mixing shaft system should still be handled according to the structure form before the configuration of these two auxiliary bearings. For cantilever structure, rigid coupling must be used to connect the output shaft of the reducer with the mixing shaft. For the single-span structure, the connection between the output shaft of the reducer and the mixing shaft must adopt the flexible coupling.
VII. Frame
        The frame of the mixing equipment should make the mixing shaft have enough support distance to ensure that the deflection of the lower end of the mixing shaft is not large during operation. The frame should ensure that the output shaft of the transmission and the N mixing shaft are centered, and it should also be centered with the shaft seal device. The frame bearing should bear the axial force generated by the mixer in addition to the radial load. In most cases, the middle of the frame should also install intermediate bearing device to improve the support conditions of the mixing shaft. The type of frame can be divided into three types: no pivot point frame, single pivot point frame and double pivot point frame.

        According to the "General Office of the State Council on the arrangement of some holidays in 2022 notice" (State Office Fa Mingdian [2021] No. 11) spirit, by the company research, now our 2022 Mid-Autumn Festival holiday arrangements and related matters are notified as follows.
        First, the schedule: administrative departments from September 10 (Saturday) to 12 (Monday) holiday, a total of 3 days. September 13 to resume normal work, the workshop on September 10, one day off, the details of the workshop departments in charge of the study and reported to the company comprehensive office.
        II. Notes.
        1. All departments shall make arrangements for the work in advance according to the holiday time, do a good job of security measures before the holiday, properly arrange the work of duty and safety and security, and effectively maintain the security and stability of the company.
        2. All departments shall organize a safety inspection before the holiday and take strong measures to investigate and eliminate safety hazards. During the holiday, pay attention to fire prevention and theft prevention, especially to strengthen the management of key departments.
        3. Please report in advance if you have the need for overtime work, and coordinate the arrangement.
        Wish all employees a happy Mid-Autumn Festival!
                                                                    Lunda Machinery General Office 2022.9.9

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        Jiangsu Lunda Machinery Equipment Co., Ltd. has a professional research and development, production technology of mixing transmission device company. After more than twenty years of development, the company's products have been widely recognized and applied by users. Today, Lunda Xiaobian and everyone to learn a piece of agitator in the use of what precautions?
        First, when the stirrer is used for the first time, we first check the instrument and equipment against the instruction manual, focusing on whether the instrument comes with complete accessories and whether the accessories are compound standards.
        Second, the speed of the equipment should be adjusted gradually from low speed to high speed, no special needs, do not high-speed gear directly start, so as to avoid the initial rate of the stirrer is not synchronized and caused by violent jumping.
        Third, try to avoid no-load operation of the stirrer, not stirring can not be heated, do not work when the power should be cut off, pay attention to the use of safety.
        Fourth, the overall equipment should be kept clean and dry, mixing equipment / mixer / mixing equipment / mixing equipment / mixing machine / especially do not make the solution into the machine.
        Fifth, in the mixing process, if the stirrer is found to jump or not stirring at all, should be immediately shut down to check, to avoid damage to the equipment or damage to further expand;.
        Sixth, if the speed requirement is not high, try to keep the equipment running at medium speed, which can extend the service life of the agitator and reduce the maintenance cost of enterprises.
        Seven, the use of electrical equipment will generate static electricity, equipment used for a long time will also generate leakage, static electricity, leakage will be harmful to equipment, personnel, so the equipment must do the work of ground conductor leakage.
 Stirrer is suitable for biological, physical and chemical, cosmetics, health care products, food, reagents and other experimental fields. It is the experimental equipment for liquid mixing and stirring.

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    Reducer is the most commonly used transmission equipment in the field of machinery, its normal and smooth operation is essential for production. Once there is a failure, especially the reducer oil leakage problem, not only will lead to safety production accidents, increase the operating costs of enterprises, but also waste reducer has the use of.

A reducer oil leakage cause analysis
 Before bad is always good, when the reducer after a long period of operation, will be subject to the design process and manufacturing, pressure and vibration and a variety of factors such as the comprehensive impact, and there will be different degrees of oil leakage phenomenon, can be said to reduce the inevitable. However, after years of work experience and long-term exploration, the following factors leading to oil leakage are summarized.

   (A), the casting box and in the welding box leakage factors

     The welded box is mainly made of steel plates spliced together. In the welding process, sometimes there is not completely melt through the welding or the existence of virtual welding, in the later long-term use process, the box will inevitably cracking situation, and the welding seam will occur ceramic leakage.


    Casting boxes in many cases will have different degrees and different types of casting defects. Inevitably, there are slag, shrinkage holes or porosity, which may cause the box to break under stress during long-term use, and slight cracks may occur, leading to oil leakage.

   (ii) The combination of the dividing surface of the box is not tight

   If the box's dividing surface is not tightly combined, then the long-term use process will produce gaps in the box's welds, making ceramic seepage out of the joint. There is also the case that the combination of the dividing surface width and thickness design results do not meet the standard, can not give full play to the box casting and welding stress.

    Sealant if not used as required, while the fastener tightening torque is not enough, the reducer will produce alternating load and vibration during operation, and the joint action of alternating load and vibration will lead to fastener deformation and loosening. The final formation of the split surface gap.

   (C) the reducer high-speed shaft and low-speed shaft oil leakage factors

 First, seal wear leads to seal failure. After the long-term coaxial surface of the oil seal lip is rubbed, it is easy to trigger the lip burning and carbonization problem, and the rubber will lose certain flexibility and elasticity, gradually harden and wear, thus forming a gap in the coaxial contact part.

 In addition, whether the shaft connector is a high-speed shaft or a low-speed shaft, it needs coaxial interference connection and the oil seal is subject to heat transfer and radiation problems during the heating installation, which may lead to deterioration and deformation at an early stage.

 Secondly, oil leakage is triggered by shaft surface wear. Shaft and oil seal are in contact with each other in the process of use, and due to the long-term high pressure and high temperature, the surface roughness of the shaft will be elevated, which will lead to shaft damage and the oil seal will not be well matched.

 Finally, the mechanical seal leaks oil. Long-term use, the impurities in the oil body will gradually rise, the stationary state will produce precipitation, precipitation will be adsorbed in the oil return orifice, a long time accumulation will lead to blockage of the oil return hole or become smaller, and the oil return channel is not smooth when the accumulated oil will leak with the oil collection cover on the separation surface of the oil splash ring.

(D) Observe the leakage hole and air filter blockage factor

Usually, the observation hole is equipped with Plexiglas for easy observation, and it is easy to form cracking damage during the assembly and application process, resulting in oil leakage. In addition, in the production operation of the reducer, the gears encounter the effects of rolling and sliding friction, which generate a lot of heat, thus increasing the pressure of the gas and forming a difference with the external pressure, resulting in oil leakage along the gap of the tank.


         (v) Other leakage factors

           Other factors include leaks from drain holes, leaks from thin oil lubrication lines, leaks from fastener preload torque during gearbox maintenance, and leaks from oil bath splash lubrication. Filled oil can create leakage problems.


Second, the effective prevention and control measures of the reducer oil leakage
Through the analysis of the above five factors, we will identify the corresponding targets in the production process and the use of the process,, the technical targets in the good improvement, the use of targets to prevent, you can well prevent and control oil leakage.

(1) when welding the box steel plate, must be strictly in accordance with the requirements of the operating instructions, improve the casting process of the casting, so that the design is more scientific and reasonable.

2) Surface hardening bushings should be added to the input and output shafts to improve the surface roughness, ensure the hardness and roughness of the oil seal lip, increase the special lubrication of the oil seal, and prevent the oil seal from wearing early.

3) Strict assembly quality requirements, correct installation, use and maintenance of the reducer, and to ensure that the ball valve and seal quality meet the standard requirements.

(4) the use of thin oil lubrication and mechanical seal reducer need to increase the upper part of the bearing seat oil return hole. According to the flow calculation requirements, set the throttle sleeve and accurately distribute the flow distribution of each lubrication point to prevent excess or short supply of oil due to uneven oil distribution.

       Gaskets are used between the cover plate of the reducer and the box to increase the thickness of the observation hole cover plate and to reduce the roughness of the joint part. The threads of the oil drain hole were machined after welding to ensure that the threads have a high fit and meet the tolerance requirements. In addition, the area where the screw plug contacts the end face of the drain hole is raised to ensure that the end face of the gasket has a tight contact effect. For various causes of oil leakage, measures are taken to reduce the leakage of ceramics, maintain good efficiency of the reducer and ensure the safe operation of the main machine. It not only can reduce the maintenance cost, but also can avoid the danger of oil leakage.

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        Mechanical seal belongs to one of the precision and more complex structure of mechanical foundation components, is the key component of each pump with mechanical seal species pumps, reaction synthesis kettle, turbocompressor, submersible motor and other equipment. Its sealing performance and service life depends on many factors, such as selection, precision of the machine, the correct installation and use.

I. Selection method

        Mechanical seal according to the different working conditions and the nature of the medium, there are high temperature, low temperature mechanical seal, high pressure, corrosion-resistant mechanical seal, particle resistant mechanical seal and adapt to vaporization of light hydrocarbon media mechanical seal, etc., should be selected according to the different uses of different structural types and materials of mechanical seal.

        The main parameters of the selection are: sealing cavity pressure (MPA), fluid temperature (℃), working speed (M / S), the characteristics of the mechanical seal for fluid kettle and the effective space for installation of the seal.

        The basic principles of selection are.

        1. according to the sealing cavity pressure, determine the seal structure using balanced or unbalanced type, single end face or double end face, etc.

         2, according to the working speed, determine the use of rotary or stationary, fluid dynamic pressure type or non-contact type. 3.

         3, according to the temperature and fluid properties, to determine the friction and auxiliary sealing materials, as well as the correct choice of lubrication, flushing, insulation, cooling and other mechanical seal cycle protection system.

       4, according to the installation of the effective space of the seal, to determine the use of multi-spring or single spring or waveform spring, internal or external installation type.

Second, the installation and use of mechanical seals requirements

        1, mechanical seal requirements for machine precision (mechanical seal for pump, for example)

         (1) Installation of mechanical seal parts of the shaft (or sleeve) of the maximum tolerance of radial runout of 0.04 ~ 0.06MM.

         (2) Rotor axial runout of not more than 0.3MM.

         (3) The maximum tolerance of runout on the surface of the shaft (or sleeve) between the sealing cavity and the sealing end cover combined with the positioning end is not more than 0.04~0.06MM.

         2、Confirmation of seals

         (1) Confirm that the installed seal is consistent with the required model.

         (2) Before installation, carefully check with the general assembly diagram to see if the number of parts is complete.

         (3)The mechanical seal with spring transmission, the spring has left and right rotation, and must be selected according to the rotation of the shaft.

3、Installation

         Installation method varies with the type of mechanical seal, the type of machine, but the installation essentials are almost the same, installation steps and precautions are as follows.

         (1)Determination of installation size

         Installation, according to the product's instruction manual or samples, to ensure that the mechanical seal installation size.

        (2) Before installation, the shaft (sleeve) and gland should be * pricked and the bearing in good condition; the seal, shaft, sealing chamber and gland should be cleaned. To reduce frictional resistance, the part of the mechanical seal installed on the shaft should be thinly coated with a layer of oil for lubrication, taking into account the compatibility of the rubber O-ring, if it is not appropriate to use oil, can be coated with soapy water. Floating mounted static ring without anti-rotation pin structure, should not be coated with oil, should be dry mounted into the gland.

        (3) first static ring and gland together on the shaft, take care not to touch with the shaft, and then the dynamic ring components into. The spring seat or drive seat tightening screw should be tightened evenly in several times.

         Before fixing the gland, push the compensation ring by hand for axial compression, and the compensation ring can automatically spring back without stalling after releasing, then lock the gland screw evenly.

         4、Use

        (1)When conveying medium temperature is high, too low, or contains impurity particles, flammable, explosive, toxic, must take corresponding blocking, flushing, cooling, filtering and other measures.

         (2) Before running, hand pan the car, pay attention to whether the torque is too large, there is no rubbing and abnormal sound.

         (3) Pay attention to the rotation direction, whether the coupling is centered, whether the lubricating oil in the bearing part is properly added, and whether the piping is correct.

         (4) Before running, first open the medium and cooling water valve, check whether the gas in the sealing chamber is fully discharged to prevent leakage caused by static pressure, and then start the machine to run.

         (5) Whether the work is normal and stable after driving, whether there is abnormal torque caused by shaft rotation, and abnormal sound and overheating phenomenon.

         Reasonable and scientific selection and use of mechanical seals will achieve twice the result with half the effort, more reduce the production costs of enterprises, creating greater value.

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        Daily check the oil level, oil temperature and pressure is normal, check the output of the reducer, the input end and the pipe system at each joint for oil leakage, check the temperature of the bearings is normal, listen to the sound of normal operation, etc., found abnormalities should be immediately excluded.

         1. Daily inspection content.

         The oil temperature (temperature rise) of the reducer is normal.

         Observe whether the oil pump and cooler are open, whether the lubricating oil road is smooth, and whether the current and pressure of the roller press are normal.

         Check whether the sound of the reducer is normal and whether there is any strange sound.

         2、Weekly inspection content.

         Use kerosene or gasoline to clean the filter and magnetic rod and the inner cavity of the filter shell and wipe clean, the foreign matter from the filter cleaning needs to be precipitated, preserved and analyzed, when there are copper chips need to be cleaned regularly every two days, observe the change of copper chips, if there is no reduction then it should be stopped immediately to open the box to check, which is the precursor of the bearing cage non-normal wear.

         After cleaning the reducer filter should add the loss of lubricating oil, pay attention to the added lubricant grade, quality and use of the same.

        Check whether the bolts are loose, and tighten them immediately if they are loose.

        Check the input and output shafts of the reducer for oil seepage, noise and temperature abnormalities.

        Check whether the coupling bolts between the motor and reducer are tightened every month, and check whether the coupling bolts between the reducer and the installation base are tightened every week.

        3. Monthly inspection content.

        Tighten the bolts connecting the reducer to the torque disk and the bolts of the locking disk, pay attention to the tightening method according to the specification requirements.

        Check whether the heat exchange of the cooler is normal, whether the water pressure and flow rate have changed, and whether cleaning measures need to be taken.

       Check the last oil change time, ensure that the oil is changed every 6 months (if found deterioration, emulsification, etc. should be replaced immediately).

        4. Annual inspection content.

        Stop the machine for maintenance, remove the dust from the input and output of the reducer, clean the breathable cap, and repaint the appearance of paint loss.

        Replace damaged components, according to the equipment in the usual use of the process of the replacement of wear and tear parts.

        Check whether the locking plate bolts are tightened, and tighten them again with the rated torque.

        Clean the cooler and circulating system pipeline scale. Note that when disassembling the pipeline, you need to wrap the joints with a clean cloth to avoid dust entering the reducer.

       Every three years need to return to the factory to open the machine for overhaul, replace bearings, oil seals and other damaged parts, and repair or replace individual wear parts.

       The above is the basic points of daily inspection and maintenance of the reducer brought to you by Lunda, the use of qualified equipment is also an important guarantee of our own personal safety.

        In our ordinary life, probably in doing something, it is necessary to go to the mixing, so that the mixing of such a process, or can really attract the attention of people. But also, in many enterprises production, is also in order to be able to go to production, so that will be used to the mixer, so you can go to complete the current mixing.

        Because of this, such a mixer, has begun to be used in many places, especially in many industries and fields will be used to the machinery and equipment, in the use of this equipment, the mixing efficiency of the problem, is to become a lot of business concerns to the problem.

        This time, in the use of such equipment, or need to take into account how the performance of the equipment itself, which is very important, this time, will directly affect the efficiency of the use. Not only that, because such equipment will be in the classification is more, so is able to not through the nature of the material to mix, that the enterprise in the choice of equipment, or to consider their own to mix the material.

        So now many enterprises, if the time to choose the mixer, it is necessary to consider a lot of aspects, including the type of equipment, there is such equipment is for what kind of material to mix, so that only in the choice of good performance equipment, can go to complete the mixing of materials, to really ensure the efficiency of the mixing, become the The enterprise can choose to the equipment.

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I. Liquid-liquid dispersion operation is usually employed for the following purposes.
      (1) To increase the phase interface through liquid-liquid dispersion. 
      (2) To reduce the diffusion resistance outside the dispersed phase droplets.
      (3) to generate turbulence to promote concentration and temperature homogenization
      (4) To make the droplets of the dispersed phase repeatedly break up and condense, thus promoting the mass transfer between the droplets of the dispersed phase.
        In liquid-liquid dispersion, stirring plays a key role in controlling the aggregation, breakage and floating of droplets. Stirring affects the strength and direction of liquid flow and then affects the distribution and uniformity of droplets.
Second, the stirring and mixing of mutually soluble liquids
       (1), mixing and stirring of low-viscosity liquids
         Stirring of interdigitated liquids is two or more interdigitated liquids under the action of stirring, any point of concentration, density, temperature and other physical state to achieve uniformity of the process, usually also known as the mixing process, it is the basic process of stirring a process. Sometimes in order to emphasize the characteristics of homogeneous stirring. Also known as blending or blending.
The main feature of the mixing process of low-viscosity interdigitated liquids is that there is no phase interface for the transfer process. For a purely physical mixing process, the mixing of low-viscosity inter-soluble liquids are easy to complete the process. However, if the mixing process is accompanied by chemical reactions, it tends to complicate the process, mainly in two aspects: first, there are more stringent requirements for the mixing time to avoid some undesired side reactions; second, most of the heat of reaction is exported or imported heat, thus increasing the difficulty of controlling the mixing process. The mixing operation of low-viscosity inter-soluble liquids is generally carried out in a turbulent state. Therefore, this process has a strong body diffusion, turbulent diffusion and molecular diffusion, in the process of macroscopic mixing accompanied by a strong microscopic mixing process.
        In order to achieve a homogeneous state of mixing liquid, the mixing of low-viscosity interdigitated liquids first requires the provision of sufficient circulation to avoid dead zones in the equipment, so that all stirred liquids can produce rapid convective circulation movement. Secondly, it is also required that the stirrer caused by the intensity of liquid turbulence or shear rate to be large, especially when the viscosity difference between the two liquids is relatively large, the presence of shear will facilitate the dispersion of high-viscosity liquids in the equipment, which is conducive to the strengthening of turbulent diffusion. In addition, when the number of two liquids that need to be mixed differs greatly, the location of a small amount of liquid filling is important, and the appropriate location is the impeller area, or near the impeller inlet, to ensure that the feed can be fast through the impeller, prompting the mixing liquid to quickly reach concentration homogenization.
        The main performance indicators to evaluate the mixing effect of the mixer are mixing time, energy consumption and shear performance. Among them, the mixing time is an important performance indicator to determine the mixing effect.
       (2), mixing and blending of highly viscous fluids
Industrial production of high-viscosity fluids are increasingly used, many polymers are high-viscosity fluids, they are mostly non-Newtonian fluid. In the mixing process, the viscosity will also change, thus the requirements of the stirrer is high, requiring the stirrer to adapt to changes in viscosity to complete the mixing operation. Mixing of highly viscous fluids often refers to the mixing of mutually soluble high-viscosity fluids. However, the mixing of highly viscous fluids in industry also includes dispersion, solid dissolution, chemical reaction and other non-homogeneous operations.
        Stirring operation, the use of stirrers for low-viscosity mutual solution to cause turbulence is not difficult but viscosity reaches a higher level, due to the influence of viscous forces, there is only a laminar flow state. Particularly difficult is that this laminar flow can only appear in the vicinity of the stirrer, a little further away from the paddle where the high viscosity liquid is still stationary. This will be difficult to cause the circulation of liquid flow in the stirring equipment, that is, there will be a dead zone in the equipment, mixing, dispersion, heat transfer, reaction, and other mixing processes are not conducive. Therefore, the problem of high viscosity liquid stirring is to solve the problem of fluid flow and circulation. In this case, you can not rely on increasing the stirring speed to increase the circulation flow of the stirrer, because the fluid viscosity is high, the stirrer discharge less flow, too high a speed will also form a trench flow in the high-viscosity solution, while the surrounding liquid is still a dead zone. A more effective solution is to try to make the stirrer to push a wide range of fluids. Therefore, the ratio of the diameter of the stirrer to the inner diameter of the equipment and the ratio of the width of the paddle to the inner diameter of the equipment for high-viscosity liquids are required to be relatively large, and sometimes the number of layers of the stirrer is required to increase the stirring range.
        From the point of view of the mixing mechanism, in the laminar flow area mixed with high viscosity liquid, the liquid unit subjected to shear subdivision is elongated, elongated or divided, with the increase in shear time, gradually achieve mixing. At the same time, because the shear field within the mixing equipment is not uniform, such as anchor stirrer in the gap between the anchor and the wall of the kettle is a strong shear zone, the liquid mixing rate is faster, while the middle region of the kettle is a low shear zone, the mixing rate is slower, so the high shear zone and low shear zone between the liquid exchange rate or liquid circulation capacity in the kettle is also an important factor affecting mixing. In addition, the speed fluctuations of the fluid in the equipment can also promote mixing. In other words, the mixing rate of high-viscosity liquids depends mainly on the relative movement rate between the stirrer and the surface of the kettle wall and the distance between each other. In the actual production process, the commonly used viscous fluid stirrers are anchor stirrers, ribbon stirrers, frame stirrers, etc.
        The main performance indicators to evaluate the mixing effect of the mixer are mixing time, mixing energy per unit volume, etc.. Among them, mixing time is an important performance index to judge the mixing effect.

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         Stirring device mainly consists of stirring paddle or impeller and attached components. The transmission device is mainly composed of motor, reducer, bracket, etc. The stirring shaft system is mainly composed of stirring shaft, bearing, coupling, etc.

        The reason for setting the baffle or deflector: the agitator is prone to swirling flow when the speed is high, which affects the stirring effect.

        Propulsion stirring device is not high degree of turbulence when stirring, mainly volume circulation, high circulation rate, small shear effect, good up and down tumbling effect, simple structure, easy to manufacture, etc. Suitable for low viscosity, high flow rate, with a smaller stirring power can get a better mixing effect, mainly used for liquid-liquid mixing, is the temperature uniformity, in solid-liquid to prevent solids from settling.

        Paddle stirrer is a kind of stirrer with simple structure, its stirring part is two blades. Paddle agitator can be divided into flat paddle agitator and inclined paddle agitator according to the shape characteristics of the blades. The flat paddle agitator generates radial force and the inclined paddle agitator generates axial force. Paddle agitator is suitable for low viscosity liquids, suspensions and dissolved liquids.

         The rotating paddle agitator is a type of agitator with two or three propeller-type rotating paddles as the mixing parts. The rotating paddle stirrer has a high rotating speed when stirring, which can make the material move in the axial direction, so that the material can be fully circulated and mixed. The rotating paddle mixer is mostly used for mixing low viscosity liquids, suspensions, corrosive liquids and other materials.

        The turbine mixer usually has two to four blades, which can be flat or curved, and is mounted on a horizontal disc, which creates a highly turbulent radial flow of material when rotating. The turbine mixer is suitable for mixing between gases or liquids with low viscosity and poor mutual solubility.

        Anchor mixers have blades similar in shape to the anchor of a ship. The blade size of the anchor agitator is similar to the size of the mixing tank, and only a small gap is left between the two after the combination, so that the blade of the anchor agitator can clearly mix the reactants on the inner wall of the tank when rotating and maintain the mixing effect of the agitator. The anchor type stirrer can be used to stir materials with high viscosity.

        The spiral belt agitator has two or three spiral belts mounted on a screw in the middle of the agitator. The pitch of the spiral belt agitator determines the outer diameter of the belt. The spiral belt agitator is usually operated in laminar flow condition. It is suitable for mixing liquid fluids with high viscosity.

        The selection of agitator is mainly based on the nature of the material, the purpose of mixing and the performance characteristics of various agitators.

        According to the purpose of mixing selection: low viscosity homogeneous liquid mixing generally choose the propulsion type, turbine type, paddle type. For non-homogeneous liquid-liquid dispersion, choose turbine, propeller, paddle type; for gas-liquid dispersion, choose flat disc agitator; for solids suspension, choose propeller, open turbine agitator; for solids dissolution, choose open turbine agitator; for easy caking, choose paddle or frame agitator; for crystallization, choose turbine, paddle type. For heat transfer-based mixing operation, choose turbine type.

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　　In the agitator manufacturers to its design, a reasonable choice of sealing device is quite critical, which uses the shaft sealing device can be divided into two kinds, mainly stuffing box seal and mechanical seal, by comparing its two sealing methods, we will choose the mechanical seal as the shaft sealing device, can pass the following understanding of the mechanical seal.
　　1、Mechanical seal refers to two ring-shaped sealing elements, in the mixer smooth surface flat end face, relying on the role of media pressure or spring force, in the case of mutual fit for relative rotation, thus constituting a sealing structure.
　　2、When the shaft rotates, it drives the spring seat, spring, spring pressure plate, dynamic ring and other parts to rotate together, due to the action of spring force, the dynamic ring is pressed tightly on the static ring, when the shaft rotates, the dynamic ring rotates together with the shaft, while the static ring is fixed on the seat frame, and the ring seal end surface in contact with the static ring of the mixer prevents the leakage of medium. Therefore, from the structural point of view, the mechanical seal is mainly the axial seal which is easy to leak, and change to the end seal which is not easy to leak.
　　From this, we know that the reason why the agitator chooses mechanical seal as its shaft sealing device is mainly because the mechanical seal has a better sealing structure and is not easy to leak, while it can promote the use and give full play to its performance.

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        To solve this problem, we first need to understand certain parameters of the reducer, which parameters need to know in the end? Let Lunda Xiaobian give you a rant. What determines the calibration of the thermal power in the reducer? It is the temperature of the surrounding environment. This is a data we need to analyze, as a reducer, it should have a motor inside, the number of stages of this motor is exactly how much, appropriate or inappropriate, and what is its power, we also need to do an in-depth analysis, in addition, how the safety factor of the reducer, the safety of everyone can not be reliably guaranteed, is the most important, must not be ignored. There is also the reducer in what equipment to use, as well as the use of some of its possible results, but also absolutely can not be sloppy matters. The reducer output shaft radial force and axial force calibration, is also a point that needs to be noted.

        The power of the motor. The power of the motor should be selected according to the power required by the production machinery, while the reducer is selected according to the power or torque to be transmitted, as well as the speed required for the work.

        The power of the motor. The power of the motor should be selected according to the power required by the production machinery, and the motor should be operated under the rated load as much as possible. The following two points should be noted when choosing.

        (1) If the motor power is too small. (1) If the motor power is too small, it will be "small horse-drawn car" and cause the motor to be overloaded for a long time. Make its insulation damaged by heat. Even the motor will be burned up.

         (2) If the motor power is too large. It will appear "big horse-drawn car" phenomenon. Its output mechanical power can not be fully utilized, power factor and efficiency are not high, not only to the user and the grid is not good. And it will also cause waste of electricity.

         To choose the correct power of motor, the following calculation or comparison must be made. 

         (1)For constant load continuous working mode, if we know the power of the load (i.e. the power on the production machinery shaft) Pl(kw). The required motor power P(kw) can be calculated according to the following formula: P=P1/n1n2 where n1 is the efficiency of the production machinery; n2 is the efficiency of the motor. That is, the transmission efficiency. According to the above formula to find out the power, not necessarily the same as the product power. Therefore. The rated power of the selected motor should be equal to or slightly greater than the calculated power. Example: The power of a production machine is 3.95kw, the mechanical efficiency is 70%, if the efficiency of the motor is 0.8, how much kw should the power of the motor be? Solution: P1/n1n2=3.95/0.7*0.8=7.1kw Because there is no 7.1kw this specification. So use 7.5kw motor.

         (2)The motor of short-time working quota. Compared with the motor with the same power and continuous working quota, the maximum torque is large, the weight is small, and the weight is small. The maximum torque is large, the weight is small and the price is low. Therefore, when the condition permits, the motor with short working quota should be used as much as possible.

        (3) For the motor with intermittent working quota, the power should be selected according to the size of the load duration rate, and the motor specially used for intermittent running mode should be chosen. The formula for calculating load duration Fs% is FS%=tg/(tg+to)×100% where tg is working time, t. is stopping time min; tg10to is working cycle, and the role of reducer is to improve the torque, to choose a good motor, we must know the maximum starting torque torque*speed=power and to ensure that the motor is self-locking at standstill, not to let the motor rotate

       1. P = W / t This is a formula applicable to any power, of course, also applies to mechanical power

       2.P=F*V This formula is only applicable to mechanical power.

       F means the power of the machinery, V is the speed of uniform motion of the machinery

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        Cycloid pinwheel reducer is a kind of application of planetary transmission principle, using a novel transmission device of cycloid pintooth meshing. The whole transmission device of cycloid pinwheel reducer can be divided into three parts: input part, reduction part and output part. The input shaft is equipped with a double eccentric sleeve misaligned 180°, and the eccentric sleeve is equipped with two roller bearings called swivel arms to form the H mechanism, the center hole of the two cycloid wheels is the raceway of the swivel arm bearings on the eccentric sleeve, and the cycloid wheels are meshed with a set of circularly arranged needle teeth on the needle gear to form the internal meshing reducer with a tooth difference. (In order to reduce the friction, in the speed reducer with small ratio, the needle teeth are equipped with a needle tooth sleeve).

        When the input shaft rotates with the eccentric sleeve for one week, the motion of the cycloid becomes a plane motion with both revolution and rotation because of the characteristics of the tooth profile on the cycloid and its limitation by the pin teeth on the pin gear. The low speed self rotation motion of the cycloid is transmitted to the output shaft through the pin by the W output mechanism, thus obtaining a lower output speed. Cycloid reducer lubrication is as follows.

        1, horizontal cycloid reducer under normal circumstances using oil pool lubrication, the oil surface height to maintain the middle of the sight window can be, in poor working conditions, the ambient temperature is at a high temperature can be used to circulate lubrication.

        2, the cycloid reducer at room temperature generally choose 40 # or 50 # mechanical oil lubrication, in order to improve the performance of the reducer, prolong the service life of the cycloid reducer, it is recommended to use 70 # or 90 # extreme pressure gear oil, in the case of high and low temperature work can also be reconsidered lubricant.

        3, vertical installation of planetary cycloid reducer to prevent oil pump oil break, in order to avoid damage to the components of the reducer.

        4, when refueling can be screwed open the upper vent cap of the seat can be refueled. When releasing oil, unscrew the oil release plug on the lower part of the seat to release the dirty oil. The reducer is shipped without internal lubricant.

         5, the first refueling operation 100 hours should be replaced with new oil, (and the internal dirt oil flush clean) and then work continuously, every six months to replace (8-hour working system), if the working conditions are poor can be appropriate to shorten the oil change time, practice has proved that reducer frequent cleaning and oil change (such as 3-6 months) for extending the service life of the reducer has an important role. In the process of use should be frequently supplemented with lubricating oil.

        6, reducer has been added lubricating grease, every six months to replace. The grease is aluminum disulfide-2# or 2L-2# lithium-based lubricating grease.

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       For more than 100 years, a variety of seal materials such as packing have been used to reduce the outward leakage of liquid from the liquid pump casing along the main shaft. Although the modern process used in the liquid pump, still widely used the oldest seal design - stuffing box, because of its low start-up costs, and familiar to the plant staff. However, due to environmental concerns, the use of packing seals has gradually become unacceptable, especially for the more prevalent and corrosive liquids in modern processes. Therefore, in practical applications, mechanical seals are increasingly used instead of packing seals.

        The basic elements of the seal mechanical seal is the use of two planes running on the principle of mutual friction to achieve the purpose of sealing. The rotating sealing surface is mounted on the main shaft of the liquid pump, while the fixed sealing surface is mounted inside the sealing gland. Since one sealing surface is in motion and the other is stationary, this type of seal is called a dynamic seal. The sealing between the rotating surface and the stationary surface is the most critical factor to determine the sealing performance of the basic mechanical seal, in which there are four leakage paths to be sealed: 1. the path between the sealing surface; 2. the path between the rotating surface and the spindle; 3. the path between the stationary surface and the gland; 4. the path between the gland and the stuffing box. The latter two leakage paths are generally sealed statically because there is no relative motion between the two parts. This part of the seal is usually referred to as a tertiary seal with a gasket or an O-ring that is compatible with the process fluid.

        In older seal designs, the secondary seal, which is located under the rotating surface, is left with some clearance to move back and forth on the spindle and is therefore susceptible to wear and premature failure. In the newer seal design, however, the secondary seal is stationary and therefore avoids the problem of wear and corrosion on the main shaft. In normal operation of a liquid pump, the pressure between the rotating and stationary surfaces is maintained in a sealed state by the pressure generated by the fluid in the stuffing box, which is maintained by the pressure generated by the spring during start-up and shutdown (or even by the pressure of the spring instead). Most mechanical seal designs use softer materials for the rotating surfaces, allowing them to rotate and rub against the harder stationary surfaces. For many years, the most common combination was to use carbon material as the rotating surface to run on a ceramic stationary surface.

        This type of material is still commonly used, but the stationary surface is made of stainless steel or harder materials such as tungsten carbide or silicon carbide. Regardless of the material used, a liquid film must always be maintained between the contact surfaces to provide lubrication. However, in the stuffing box, a combination of spring load and liquid pressure is used to provide a good seal between the sealing surfaces. However, if the sealing pressure is too high, the formation of a liquid film between the contact surfaces is affected, leading to increased heat and premature wear. If the sealing pressure is too low, the gap between the contact surfaces increases, which can easily cause liquid leakage. Seal manufacturers are constantly working to improve the straightness of the contact surfaces, and they use special polishing plates for grinding. Then, they are inspected using a grating plate with a monochromatic light source.

        From this point of view, it is very important that these seal contact surfaces must be handled with care and that installation instructions are strictly followed to ensure that the seal surfaces are properly protected and properly seated. Flexibility in sealing The axial and radial movement of the selected spindle requires a certain amount of flexibility with the spring to ensure a seal between the contact surfaces. However, only a certain degree of flexibility can be provided. The mechanical condition of the liquid pump and its length to diameter ratio (a measure of the ratio of the diameter of the spindle to its extended length, the lower the ratio the better) play an important role in the reliability of the seal. The flexibility of the seal is generally provided by a large main spring and a series of small springs or corrugated seal devices to ensure. Traditional seal designs used in the chemical industry have sealing pressure applied to the rotating surface, which is called a rotary seal because the spring or bellows seal rotates with the spindle. The newer designs have the elastomeric or corrugated seal mounted on a stationary surface. Both of these seal types are very commonly used on today's mechanical seals so that there is some flexibility for installation. Many mechanical seals of early design used a single large spring arranged around the main shaft to provide a strong sealing force on the sealing surface during the start-up of the liquid pump. The seal relies on the rotation of the spindle to tense the spring coil. Later designs of the seal use a series of smaller springs arranged around the spindle to provide a more uniform load pressure on the sealing surface. Since the smaller springs can be installed in advance, most of these seals are completely isolated from the fluid being pumped.

        The use of multiple smaller springs creates a more even load pressure on the sealing surface and therefore greater sensitivity to clogging. For many of the more corrosive applications, the most common design is a metal bellows seal. This bellows consists of a series of metal discs welded together to form a corrugated seal that prevents leakage. The use of this device allows for more uniform sealing pressure between the sealing surfaces, and there is no need for additional secondary seals on the sealing surfaces, so that naturally there is no corrosion and wear. Figure 3 metal bellows sealing device is generally applied to the more corrosive liquids in general, although its main sealing pressure depends on the pressure of the stuffing box itself, but the spring and bellows can compensate the liquid pump in the process of starting and stopping due to the lack of pressure of the spindle movement, so that the sealing surface always maintain a certain sealing pressure. Corrosion and wear problems can cause radial and axial movement of the spindle of a liquid pump for a variety of reasons, including, for example, bearing tolerances, shaft end play, vibration and spindle misalignment.

         In addition, because it is very difficult to maintain absolute parallelism between the contact surfaces, it is normal for the mechanical seal itself to move internally. Such movement is often caused by equipment and installation tolerances, thermal expansion, piping stresses or improper spindle commissioning. In order to keep the sealing surfaces always cooperating with each other, the spring plays a constant regulating role between the mechanical seal and the moving spindle. When a synthetic rubber seal is used between the rotating surface and the spindle, the elastomer moves back and forth across the spindle. This repeated frictional action will abrade the anti-corrosion material on the spindle and lose the protective layer of the spindle's oxide film, which will eventually form wear grooves on the spindle's friction surface, causing fluid to leak from the grooves and increasing the necessary maintenance work or even replacing the spindle. To solve this problem, a replaceable sleeve is usually installed in the stuffing box. However, the only permanent solution to the corrosion and wear problem is to remove the dynamic seal inside it. Today, most major seal manufacturers produce non-corrosive wear type seals to prevent corrosive wear of liquid pump parts. Balanced and unbalanced seals The balance of a mechanical seal has a significant effect on the sealing pressure at the contact surface. This sealing pressure depends on the effective cross section of the seal itself as well as the pressure inside the stuffing box. The opposite cross section of the rotating face of a non-equilibrium seal is completely exposed to the pressure range of the stuffing box, a situation that creates a high sealing pressure between the sealing faces, which can lead to higher operating temperatures and faster wear. Under high temperature operating conditions or where the liquid is corrosive and abrasive, the service life of the mechanical seal can be greatly reduced. Balancing the mechanical seal can reduce the sealing pressure and extend the service life of the seal.

        Generally use the spindle and sleeve with steps to reduce the effective section of the rotating surface, it can achieve the above purpose. However, never adjust the net seal pressure to a level close to zero, as this may result in unstable working conditions between the sealing surfaces and may blow the seal open due to sudden changes. The answer to these sealing problems may be the use of unbalanced seals, and for some services, perhaps better results can be achieved with unbalanced seals. For example, in some applications, there may be more emphasis on safety issues caused by fluid leakage than on the life of the seal. In this case, the choice of seal may be interpreted as a preference for a higher sealing pressure. Similarly, the increase in operating temperature may be insignificant when selecting a seal for a colder fluid. Regardless of the considerations, balanced seals are generally recommended when the pressure in the stuffing box exceeds 50 psi. The most common practice for internal and external seals is to mount the seal inside the stuffing box. However, this practice requires that the wet end of the liquid pump be disassembled during seal maintenance. The main benefit is that the sanitation of the seal is easily controlled. External seals are installed by reversing the orientation of the static sealing surface, with the rotating unit on the main shaft located outside of the stuffing box gland.

       The external seal has the following five main benefits: 1. easy to install; 2. relatively low cost; 3. can be continuously monitored and cleaned; 4. suitable for very small stuffing boxes where the seal cannot be installed internally; 5. less difficult effect on spindle deviation due to its location close to the bearing. Its main disadvantage is that centrifugal force will throw solid particles from under the seal to the contact surface of the seal. Therefore, this type of seal is mainly suitable for clean and non-abrasive fluids. In recent years, breakaway seals have become another important additional feature in external seals. The split seal is a complete assembly that is mounted between the stuffing box and the bearing sleeve. With this design, it is not necessary to disassemble the pump each time the seal needs to be replaced. This type of seal combined with the exploration of other design standards are gradually being developed. As this design is easy to replace the seal, it is important to resist the temptation to just replace the seal, without further investigation of the root cause of the failure. Cartridge seal A cartridge seal is an all-in-one seal that includes all sealing elements, gland and sleeve inside. Since this type of seal does not require They are also well protected against accidental damage, as the sealing surface and sealing elastomer are well protected. These advantages also mean that seal repair and replacement times can be reduced.

         Self-contained, fully functional cartridge seals simplify installation and protect internal components from accidental damage, are available on the market in almost all types of cartridge seals, thus reducing the risk factor in use and saving the maintenance time inherent in using ordinary seals. Double seals and liquid barrier devices use a double sealing surface instead of a single seal to provide a higher degree of leak resistance. Most of these double seals are used for highly volatile, toxic, carcinogenic, hazardous and poorly lubricated fluids.

        There are three general designs of double seals, each of which requires a liquid barrier system between the double sealing surfaces to prevent leakage of liquid or gas. The more commonly used low-cost double seal is a seal mounted back-to-back, with the rotating sealing faces arranged in opposite directions. It often requires a barrier fluid with a pressure higher than the stuffing box pressure, about 20 psl, which ensures that the internal seal is always lubricated by the barrier fluid and also ensures that the sealing surfaces reach a certain sealing pressure. In the more complex structure of the face-to-face type seal, the rotary sealing surface is arranged in a face-to-face manner between them, and they often act in the opposite direction of the same static sealing surface. This type of seal can be used both high-pressure barrier liquid system, and low-pressure barrier liquid system. The rotary face of such seals is installed in a face-to-face manner, and the third design type of seal uses a serial arrangement, that is, both rotary sealing faces leave the impeller and are arranged in the same direction. This type of seal is generally lower than the liquid pump barrier liquid pressure pressure of the pump. In fact, the equivalent of two seals, two stages of pressure reduction of the combined work of the device.

        All types of double sealing devices require a barrier fluid system. They are generally external closed-loop systems where the fluid used internally is generally different, but must match the fluid in the process. The system includes a reservoir with a bit-pick that should be as close to the seal as possible. There is a wide range of design variations for these systems. Some systems use a type of pump ring in the seal, while others use the thermosiphon effect principle. The liquid in the reservoir is often heated or cooled by an auxiliary method. In addition, an alarm device can be added to remind the staff to change the liquid in time. Depending on the nature of the liquid being sealed, the liquid barrier system can work with a pressure lower or higher than the stuffing box pressure. In order to achieve the goal of zero leakage throughout the drive operation, the sealing industry has also developed gas-barrier seals, which use a class of inert gas such as nitrogen instead of a liquid-barrier system. In a double seal with a gas barrier, if there is a failure inside the sealing surface, only the inert gas will leak, while the liquid inside will not leak, thus not causing environmental pollution.

        Regardless of whether liquid or gas is used, the barrier system must be suitable for the specific sealing application and should be able to immediately identify an alarm in the event of any failure inside the sealing surface so that appropriate action can be taken in a timely manner. Environmental control In many applications, where seals are installed, reliable operation of the seal and control of the environment needs to be taken into account and therefore the following points must be noted: 1. The seal should be installed on a high strength spindle with minimum deviation. Although the industry standard specifies a maximum deviation of 0.002in for the seal surface, the requirements for the spindle can be even higher. 2. The seal should be installed in a large diameter seal chamber, which will improve the reliability of the seal. These products are available from almost all liquid pump manufacturers.3. Control the internal pressure of the stuffing box to avoid rabbits reaching the flash point.4. Keep the temperature inside the stuffing box within the operating parameters of the seal material.5. Keep the liquid inside the stuffing box clean.

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　　With the rapid development of the mixing industry, various types of agitators gradually into people's lives, desulfurization agitator as one of them, its as an environmentally friendly equipment, can effectively reduce the pollution of our environment by sulfur, in order to facilitate a better understanding of this equipment, the next to its detailed introduction.
　　Which stirring requirements for dissolved oxygen is low, and now the domestic project more perforated tube aeration stirring. Also to ensure uniform air mixing, perforated tube more than arranged into a loop, aeration pipeline material can be selected according to the actual water quality, if the conditions allow the use of plastic pipe as far as possible, the reason is that the steel perforated pipe orifice is easy to oxidation rust. The shedding of oxidation and sediment deposition in the pipe is likely to cause blockage of the perforated pipe orifice. There are also environmental protection companies on the market to develop down-bending ring perforated pipe, the choice of ABS plastic pipe to make the entire pipeline, different pipe diameter perforated pipe and dry pipe using a special pipe reducer coupling connection; Japan developed porous aeration tube, the entire surface are distributed with microscopic pores, can be uniformly produced only micron size of the diameter of the bubble, so the oxygenation and mixing effect is very good. In addition, the stirring dispersion aeration is also a new technology in air mixing.
　　In the actual engineering application experience, generally in the desulfurization mixer design perforated tube aeration stirring, the required aeration is about 0.01 ~ 0.015 m3 / (min - m2), the opening aperture ≥ 5 mm, because the aperture is too small easy to block. The aperture form generally uses the bottom both sides of 45 ° open hole. In addition, the perforated pipe length should not exceed 10 m; to ensure the effect of aeration and mixing, the perforated pipeline may not be evenly distributed; the perforated pipe diameter is as large as possible, and the friction of the pipe wall is as small as possible.
　　Air mixing is generally set in the bottom of the pool perforated pipe, perforated pipe and blower air pipeline connected to the use of compressed air for aeration and mixing. Its main working principle is to use the air and the pool water contact, stirring the water body to prevent the suspended matter in the water body to sink, accelerate the transfer of oxygen in the air to the water body to complete the purpose of oxygenation.
　　From this, we know that the specific application of desulfurization agitator, its equipment can be effectively adapted to the mixing work of a variety of different industries, so that it is fully mixed evenly to promote the efficiency of the use of substances.

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         Helical gear reducer adopts the most optimized, modular combination system advanced design concept, with small volume, light weight, large transmission torque, smooth starting, transmission ratio grading fine and other properties, according to user requirements for any connection and a variety of installation position selection. The following Xiaobian take you together to understand what are the common problems of helical gear reducer?
         Common problems.
         Heat and oil leakage
         In order to improve efficiency, worm gear reducers generally use non-ferrous metals for worm gears, and worm gears are made of harder steel. Because of the sliding friction transmission, the operation will generate more heat, so that the reducer parts and the difference in thermal expansion between the seal, thus forming a gap in the mating surface, lubricating oil liquid due to the rise in temperature becomes thin, easy to cause leakage. There are four main reasons for this situation, one is the unreasonable collocation of materials; two is the poor quality of the meshing friction surface; three is the incorrect choice of lubricant addition; four is the poor assembly quality and use environment.
        Worm wheel wear
        The worm wheel is generally made of tin bronze, and the paired worm material is hardened with 45 steel to HRC4555 or 40Cr hardened to HRC5055 and then ground to a roughness of Ra0.8μm by the worm grinder. the reducer wears slowly in normal operation, and some reducers can be used for more than 10 years. If the wear rate is faster, we should consider whether the selection is correct, whether overload operation, and the material of worm gear, assembly quality or use environment and other reasons.
        Gear wear
        Generally occurs on the vertical installation of the reducer, mainly related to the amount of lubricant added and oil variety. When installed vertically, it is easy to cause insufficient amount of lubricating oil, and when the reducer stops running, the transmission gear oil is lost between the motor and the reducer, and the gears are not protected by proper lubrication. When the speed reducer starts, the gears are not effectively lubricated, resulting in mechanical wear and even damage.
        Worm gear bearing damage
        When a failure occurs, even if the gearbox is well sealed, it is still often found that the gear oil in the reducer is emulsified, and the bearing is rusted, corroded and damaged. This is because after running the reducer for a period of time, the gear oil temperature rises and the condensate generated after cooling mixed with water. Of course, also closely related to the bearing quality and assembly process.
        Helical gear reducer, is a novel reducer transmission device. Using the most optimal, modular combination system advanced design concept, with small size, light weight, large transmission torque, smooth starting, transmission ratio grading fine and other properties. So what to do when the helical gear reducer fails? The following is a summary of a few troubleshooting methods for you.
        Troubleshooting.
        Ensure the quality of assembly
        Can buy or homemade some special tools, disassembly and installation of reducer components, try to avoid knocking with other tools such as hammers; replacement gears, worm gear, try to use the original parts and pairs of replacement; assembly output shaft, pay attention to the tolerance fit; to use anti-adhesive or red Dan oil to protect the hollow shaft, to prevent wear and rust or fit area scale, difficult to disassemble when repair.
        Lubricant selection
        Helical gear - worm gear reducer generally use 220 # gear oil, for heavy load, start frequently, the use of poor environment reducer, can choose some lubricant additives, so that the reducer in stop running gear oil is still attached to the gear surface, the formation of protective film, to prevent heavy load, low speed, high torque and start direct contact between the metal. The additive contains seal adjuster and anti-leakage agent, so that the seal remains soft and elastic, effectively reducing lubricant leakage.
        Installation position selection
        The location allows, as far as possible, not to use vertical installation. When installed vertically, the amount of lubricant added is much more than that of horizontal installation, which is likely to cause heat and oil leakage of the reducer.
        Lubrication maintenance
        According to the lubrication work "five" principle for the maintenance of reducer, so that each reducer are responsible for regular inspection, found that the temperature rise is obvious, more than 40 ℃ or oil temperature more than 80 ℃, the quality of oil decline or oil found in more copper powder and produce abnormal noise and other phenomena, to immediately stop using, timely maintenance, to Troubleshoot and replace the lubricant. When refueling, pay attention to the amount of oil to ensure that the reducer gets the correct lubrication.

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        Cycloid reducer can be widely used in petroleum, environmental protection, chemical, cement, conveying, textile, pharmaceutical, food, printing, lifting, mining, metallurgy, construction, power generation and other industries, the following to introduce you to the five advantages of the cycloid reducer!
        1、Large transmission ratio　　
        Cycloid reducer has a higher speed ratio, the transmission ratio is 1:7 to 1:87 at the first deceleration; two-stage deceleration rotation ratio of 1:121 to 7569, there is a higher three-stage deceleration, customers can also choose this type according to their own circumstances.　　
         2、High transmission efficiency　　
         Cycloid reducer because of the machine tooth meshing part of the rolling mesh, gnawing the surface is also no relative sliding, the general efficiency can be in more than 90%.　　　

         3、Small volume, light weight　　

         The cycloid reducer adopts the planetary transmission principle, the input shaft and output shaft are on the same axis, and has the unique feature of being directly connected with the motor, so that its model gets the smallest possible size. Therefore, the cycloid reducer has the characteristics of small size, compact structure and light weight. Compared with the ordinary two-stage cylindrical gear reducer, the volume can be reduced by more than 2/3; the weight is reduced by about 1/3 or more.
         4、Easy to disassemble and install, easy to maintain　　
         Due to the reasonable design of the structure of the cycloid reducer, simple disassembly and installation is easy to maintain, the number of parts used is small, lubrication is also very simple.
         5、Long life, low noise　　
         Due to the principle of planetary transmission, the number of cycloid teeth gnawing together during operation, the overlap coefficient is large, the overall body balance operation, the main parts are made of bearing steel quenched and finely ground, the wear is reduced to as low as possible, low so the noise emitted during operation is low and long life.

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       Last we told the 5 advantages of the cycloid reducer, today we are more specific to tell a white now on the specific characteristics of the reducer, the next Lunda small make up and you chatter about its its characteristics!

　　★High speed ratio and high efficiency single-stage transmission, it can reach 1:87 reduction ratio, the efficiency is above 90%, if multi-stage transmission, the reduction ratio is greater. Cycloid reducer one-stage drive reduction ratio of 9 ~ 87, two-stage drive reduction ratio of 121 ~ 5133, multi-stage combination can reach tens of thousands, and the needle tooth meshing system sleeve rolling friction, no relative sliding of the meshing surface, so a reduction efficiency of 94%.
　　★Compact structure and small volume because of the planetary transmission principle, the input shaft output shaft in the same axis line, so that its models to obtain the smallest possible size.

　　★Smooth operation and low noise The cycloid needle tooth meshing has a large number of teeth, a large overlap coefficient and a mechanism of machine balance, so that vibration and sound are limited to the smallest possible extent.

      ★The number of pairs of teeth in contact at the same time during operation is large and the overlap is large, resulting in smooth operation, high overload capacity, low vibration and noise, and low noise for models of various specifications.

      ★The main parts are made of bearing steel and quenched (HRC58～62) to obtain high strength, and part of the transmission contact is made by rolling friction, so it is durable and long-lived.

　　★Because the main parts are made of bearing steel quenching treatment (HRC58-62), and then finely ground, and the cycloid teeth and needle gear set meshing transfer to the needle teeth to form a rolling friction payment, the friction coefficient is small, so that the meshing area without relative sliding, very small wear, so durable.

　　★ Reasonable design, easy maintenance, easy decomposition and installation, the number of parts needed less and simple lubrication, so that the cycloid reducer deep user trust.

　　★Compared with other reducers of the same power, the weight and volume are more than 1/3 smaller, and because of the planetary drive, the input and output shafts are on the same axis to obtain the smallest possible size.

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        After the reducer leaves the factory, it is generally stipulated that there is a break-in period of about 200 hours (over the time must be changed), which is stipulated by the technical characteristics of the initial use of reducer machinery. The break-in period is an important link to ensure the normal operation of the reducer, reduce the failure rate and extend its service life. However, some users, due to the lack of common sense reducer use or because the allowable torque is not enough, or want to gain revenue as soon as possible, small machine, and ignore the special technical requirements of the new machine break-in period.
        Some users even think that the manufacturer has a warranty period, the manufacturer is responsible for repairing the machine, so the reducer in the break-in period for a long time overload use, resulting in frequent reducer failure, which not only affects the normal use of the reducer, shorten the service life of the reducer. Therefore, the use and maintenance of the reducer break-in period should be given full attention.
First, the characteristics of the break-in period.
        1. Fast wear rate
         As a result of new reducer parts processing, assembly and commissioning and other factors, the mating surface contact area is small, and the allowable torque is large. Reducer in the process of operation, the concave and convex parts of the parts surface embedded friction, grinding down the metal debris, and as abrasive, continue to participate in the friction, more accelerated parts with the surface wear. Therefore, the wear period is easy to cause parts (especially with the surface) of the wear, wear speed is too fast. At this time, if overload operation, it may lead to damage to the parts, resulting in early failure.
        2. Poor lubrication
         As the newly assembled parts with a small clearance, and due to assembly and other reasons, the lubricant (grease) is not easy to form a uniform oil film on the friction surface to prevent wear. Thus reducing the lubrication efficiency, resulting in early abnormal wear of the machine parts. Seriously will cause precision with the friction surface scratching or galling phenomenon, resulting in failure.
        3. Loosening occurs
         New processing and assembly of parts, there is a geometric shape and fit size deviation, in the early stage of use, due to impact, vibration and other alternating loads, as well as the impact of heat, deformation and other factors, coupled with rapid wear and other reasons, easy to make the original fastened parts loose.
        4. Leakage phenomenon occurs
        Due to the loosening of parts, vibration and reducer heat, the sealing surface of the reducer and pipe joints, etc., leakage will occur; part of the casting and other defects, difficult to find during assembly and commissioning, but due to vibration and impact during operation, this defect is exposed, manifested as leakage (seepage) of oil. Therefore, leakage may occasionally occur during the break-in period.
        5. Many operating errors
        Due to the lack of understanding of the structure and performance of the reducer (especially new operators), it is easy to cause malfunctions due to operational errors, and even cause mechanical accidents and safety accidents.
        Second, the use and maintenance of the break-in period
        1. Special reducer, the operator should receive the manufacturer's training, guidance, the structure of the reducer, performance to fully understand, and to gain some experience in operation and maintenance before operating the reducer. The manufacturer provides the product use and maintenance manual, is the necessary information for the operator to operate the equipment, before operating the reducer, be sure to read the use and maintenance manual, according to the requirements of the manual for operation and maintenance. And keep the information for a long time to facilitate maintenance.
        2. Pay attention to the work load during the break-in period, the work load during the break-in period should not exceed 85% of the rated work load in general, and arrange a suitable workload to prevent the occurrence of overheating caused by the continuous operation of the reducer for a long time.
        3. Pay attention to frequent observation, abnormalities, should be promptly stopped to eliminate, in the cause is not found, before the fault is not removed, should stop the operation.
        4. Reasonable choice of lubricants, especially the input power of more than 11KW reducer shall be injected in the load gear oil. Pay attention to the frequent inspection of lubricating oil, hydraulic oil, coolant, oil level and quality, and pay attention to check the sealing of the whole machine. The reason should be analyzed if too much oil is missing during the inspection. At the same time, the lubrication of each lubrication point should be strengthened, and it is recommended that the lubrication point should be filled with grease every week during the break-in period (except for special requirements). Vertical reducer with oil pump when connected to the power supply pay attention to the direction of rotation of the oil pump, clockwise rotation is correct.
        5. In keeping the reducer clean, timely adjustment, tighten the loose parts to prevent loose and aggravate the wear of parts or lead to the loss of parts.
        6. At the end of the break-in period, the machine should be mandatory maintenance, good inspection and adjustment work, while paying attention to the replacement of oil.
         In short, the requirements for the use of reducer maintenance during the break-in period can be summarized as follows: strengthen training, reduce the load, pay attention to inspection, and strengthen lubrication. As long as we pay attention to and implement the maintenance and repair of the reducer during the break-in period as required, we will reduce the occurrence of early failures, prolong the service life, improve the production efficiency and make the reducer bring you more revenue.

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1. reducer heat and oil leakage

　　In order to improve efficiency, worm gear reducers generally use non-ferrous metal for worm wheel and harder steel for worm shaft. Because of the sliding friction transmission, the operation will generate more heat, so that the reducer parts and seals between the thermal expansion differences, thus forming a gap in the mating surface, lubricating oil liquid due to the rise in temperature becomes thin, easy to cause leakage. There are four main reasons for this situation, one is the unreasonable collocation of materials; two is the poor quality of the meshing friction surface; three is the incorrect selection of the amount of lubricant added; four is the poor assembly quality and use environment.

2. Worm wheel wear

　　The worm wheel is generally made of tin bronze, and the paired worm material is hardened to HRC4555 with 45 steel, or 40Cr hardened to HRC5055 and ground to a roughness of Ra0.8μm by the worm grinder. the reducer wears slowly in normal operation, and some reducers can be used for more than 10 years. If the wear rate is faster, we should consider whether the selection is correct, whether the overload operation, and the worm gear material, assembly quality or use environment and other reasons.

3. Drive small helical gear wear

　　Generally occurs in the vertical installation of the reducer, mainly related to the amount of lubricant added and oil varieties. Vertical installation, it is easy to cause the amount of lubricating oil is not enough, when the reducer stops running, the transmission gear oil loss between the motor and reducer, gears do not get the proper lubrication protection. When the reducer starts, the gears are not effectively lubricated, resulting in mechanical wear and even damage.

4. Worm gear bearing damage

　　Failure occurs, even if the gearbox is well sealed, or often found in the gear oil in the reducer is emulsified, bearing rust, corrosion, damage. This is because after running the reducer for a period of time, the gear oil temperature rises and the condensate generated after cooling mixed with water. Of course, also closely related to the quality of the bearing and assembly process.

        In the daily use of helical gear reducer we should focus on these four aspects of the problem, and do a good job of its maintenance and maintenance, in order to reasonably extend the service life of the reducer, decelerate the cost of production and operation of enterprises to obtain maximum profit.

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         A new reducer (gear reducer) the first refueling production after half a month of operation, the oil in the box will be released, refill the new oil to the middle line of the oil window. No oil window horizontally placed gear reducer refueling, the upper end of the reducer observation cover removed with the probe dipstick inserted vertically into the bottom of the box (probe dipstick vertical box bottom), the oil level height of 55mm-65mm; strictly prohibit the use of new and old oil mixture.

        Second, weekly inspection, monthly inspection of tilted gear reducer, the reducer will be removed from the upper end of the observation cover with the probe dipstick inserted vertically into the bottom of the box (probe dipstick vertical box bottom), No. 1 disk reducer oil level height of 285mm-300mm, No. 2 disk reducer oil level height of 215mm-225mm, No. 3 disk reducer oil level height of 195mm-205mm (that is, the oil level over the lowermost ball).

        Third, the weekly inspection, monthly inspection reducer, observe the oil window so that the oil level is located in the middle line of the oil window position.

        Fourth, gear reducer, cycloidal reducer, worm gear reducer every six months with a new oil, summer with the summer oil, winter with the winter oil, oil change will be cleaned when the old oil, strictly prohibit the old and new oil mixed use.

        Before oil injection clean the reducer upper end cover impurities, refueling process is strictly prohibited foreign objects into the reducer box wear reducer gears, worm gear, reduce the life of the reducer, oil injection is completed clean the reducer upper end cover impurities and timely cover, the upper end cover and reducer combination with sealant filled to prevent oil leakage, the upper end cover under the gasket and tightly combined with the reducer.

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         Lunda Xiaobian today to nag you about several reasons for oil leakage in reducer equipment.
        1. Too much oil: During the operation of the reducer, the oil sump will be stirred violently and the lubricant will be scattered on the whole machine.
        2. The structure design of the reducer is not reasonable.

        3. There is no oil return groove in the case, and the lubricating oil accumulates in the shaft seal, end cover, joint surface, etc. and leaks from the gap under the action of pressure difference; the inspection hole cover is too thin and easily deformed after tightening the bolt, resulting in uneven bonding surface and oil leakage from the contact gap.

        4. During the manufacturing process of the reducer, the casting is not annealed or aged, and the internal parts are not removed. Inevitably, stresses and deformations lead to gaps and leaks.
        5. The shaft seal structure design is impractical. Early reducers mainly used oil groove and felt ring type shaft seal structure, and the felt was deformed by compression during assembly, and the gap between the sealing joint surfaces. If the contact between the journal and the seal is not ideal, the seal will fail quickly due to very low felt compensation. The oil tank has an oil return hole, but it is easily blocked and difficult to obtain oil return.
        6. Pressure difference between the inside and outside of the reducer: During the operation of the reducer, the temperature of the reducer rises due to the frictional heat of the motion pair and the ambient temperature. If there is no ventilation hole or the ventilation hole is blocked, the pressure inside the machine will gradually increase. The higher the temperature inside the machine, the higher the pressure difference with the outside world and the pressure difference will lead to lubrication through the gap. The oil may then leak.

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        The reducer is generally used for transmission equipment with low speed and high torque. High-speed electric motors, internal combustion engines or other power through the input shaft on the few gears and the output shaft on the large gear mesh reducer to achieve the purpose of deceleration. Ordinary human reducer also has several pairs of gears to achieve the desired deceleration effect by the same principle.
        Gear reducer is characterized by the fact that it can perform power shunt when transmitting power; meanwhile, its input shaft and output shaft have coaxiality, that is, output shaft and input shaft are set on the same main axis. Therefore, gear reducer transmission is now used to replace ordinary gear transmission, but as a speed increaser and variable speed device in various mechanical transmission systems.

The reducer is relatively large and can realize the synthesis and decomposition of motion. With the correct choice of gear transmission type and gear matching scheme, several gears can be used to obtain a large transmission ratio. The gear reducer transmission is only used to transmit motion, and its transmission ratio can reach several thousand It should be noted that when the transmission ratio is very large, the gear transmission can still maintain the advantages of compact structure, small mass and small size. In addition, it can realize the synthesis and decomposition of motion and realize complex motion with various speed changes.

        The gear reducer is small in size, small in mass, compact in structure, and large in load capacity. Because the gear drive has power shunt, the center wheel forms coaxial drive, and the internal meshing gear pair is reasonably applied, the gear drive structure can be very compact. In addition, because multiple wheels are evenly distributed around the center wheel to share the load together, each gear is subjected to a smaller load and these gears allow for a smaller module size.
         In addition, the structure makes full use of the large load carrying capacity of the internal mesh and the allowable volume of the inner gear ring itself, which facilitates the reduction of the outer dimensions, resulting in a small size, low mass, very compact structure and large load carrying capacity. Generally speaking, the external size and mass of gear transmission is about 1/2 ~ 1/5 of that of ordinary gear transmission (i.e. under the same load conditions)

        Gear reducer transmission efficiency due to the symmetry of the gear transmission structure, i.e. it has several evenly distributed wheels, the reaction forces acting on the center wheel and the rotating arm bearing can balance each other, thus helping to improve the transmission efficiency. Under proper transmission mode selection and reasonable structural arrangement conditions, the efficiency can reach 0.97~0.99.

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         Reducer lubrication is an important part of reducer maintenance, and there are certain points to note when we use lubricants on gear reducers. The following I will give you a rant, I hope to give you some help.
        1. For dilute oil centralized lubrication gearbox system, because the lubricant or oil tank temperature has more strict requirements, usually use the cooler (steam cooling) or cooling coil (water cooling) to make it cool. Although gear oil is required to have better anti-emulsification performance, it is very easy to emulsify the oil after a considerable amount of water is infiltrated into the oil. After emulsification of gear oil with extreme pressure anti-wear agent, the additive is separated by hydrolysis or precipitation and loses its original performance, and harmful substances are produced, so that gear oil deteriorates rapidly and loses its performance. Tieba lubricating oil engineers remind everyone that emulsified oil cannot be used continuously. For water (or steam) cooling lubrication system must pay attention to prevent water (steam) leakage, so as not to cause unnecessary damage to the reducer.

        2. For the reducer system using pump for circulation lubrication, pay attention to the differential pressure of the pump and timely cleaning of the screen. If the pressure difference of the pump is larger in a short time, or the frequency of cleaning the screen increases significantly, and the sludge and metal abrasive chips on the screen increase significantly, it means in a certain sense that the lubricating oil is not in good condition. In addition to the material and design problems, it can be said that the lubricant is not chosen reasonably enough: one is that the viscosity is not suitable enough, and the other is that heavy load can be used instead of medium load, that is, the gear oil of a higher grade is chosen, and the effect will be obviously better.

        3. It is necessary to avoid the mixing of new oil poured into old oil (instead of making up oil according to regulations), or the practice of adding high-viscosity oil because the viscosity drops but in order to reach a certain viscosity. Doing so, there may be some short-term effect, but the use of oil performance will be significantly reduced, while making the equipment lubrication conditions worse, leading to increased wear, in a sense will shorten the service life of the equipment. In addition, may be different because of the main agent, when mixed with additives "fighting" thing, so that the additives should play a role in offsetting each other, the consequences for the equipment is unthinkable.
        4. On the issue of oil replacement cycle, theoretically speaking, the oil change period is short, can better reduce friction wear and extend the service life of the equipment, while providing a necessary condition to ensure its normal operation. However, from the perspective of economic efficiency, the oil should be used more accurately and effectively. Whether to change the oil, when to change the oil, in addition to follow the oil change period regulations, should also be based on the equipment start time, start rate and other factors to consider, so that the oil as much as possible to maximize the use.

        5. To regularly monitor the oil temperature, vibration, noise and other issues of oil-using equipment. Because of poor lubrication conditions caused by tooth surface damage, can directly lead to vibration and noise significantly strengthened.

        Reasonable and scientific maintenance and repair of the reducer can better extend the service life of the reducer and stable production operations.

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        1. Good anti-wear properties Anti-wear properties refer to the ability of reducer lubricants to form and maintain an oil film on the friction surface between moving parts to prevent mutual contact between metals and reduce wear. The anti-wear property of gearbox lubricant mainly depends on oiliness and extreme pressure (shear resistance). Oiliness refers to the ability of gear oils to adsorb to the friction surfaces of parts to form an oil film to reduce friction and wear. Usually we say that the oiliness of gear oil is good means that it has strong adsorption ability, which can improve the ability of anti-wear. Extreme pressure refers to the friction surface contact pressure is very high, the oil film is prone to rupture of the very high pressure lubrication conditions, to prevent sintering, gluing and other damage to the friction surface performance, also known as bearing capacity.
        2. Viscosity and viscosity-temperature reducer lubricant must have suitable viscosity and good viscosity-temperature. Generally speaking, the use of high viscosity lubricating oil is beneficial to prevent damage to machine parts and reduce noise, while transmission efficiency, cooling effect and oil transmission, etc., but low viscosity lubricating oil is better. For the viscous temperature performance, although the reducer lubricating oil is not as big as the engine oil temperature change, but because of its tooth surface pressure is very big, also requires good viscous temperature performance, especially in cold areas when using. Otherwise, it will cause increased wear and increased oil consumption.
        3. oxidation stability The lubricant of speed reducer is agitated by the movement of gears, and the constant contact with oxygen, and various oxides are formed under the catalytic effect of metal, so that the viscosity of lubricant increases, the color becomes darker, the acid value rises, the precipitate increases, the color becomes darker, and causes the corrosion of machine parts, resulting in the anti-foaming and anti-oxidation of lubricant becomes worse, so that the lubricant has to be replaced. The lubricant with good oxidation stability will have a long service life. Therefore, antioxidants are usually added to the lubricant to improve the oxidation stability.
         4. Rust and corrosion resistance Rust resistance refers to the performance of the gear oil to prevent rusting of metals. Corrosion resistance refers to the performance of gear oil to prevent metal corrosion. The rust of metal parts is mainly caused by the presence of oxygen and water in the lubricant. Corrosion, on the other hand, is caused by acids and sulfides in the oil. Usually, anti-rust additives and anti-corrosion additives are added to the lubricant of gearbox to improve it.
        5. Anti-foaming speed reducer lubricant will produce many small bubbles under the fierce agitation when the gear is in motion. If the small bubbles disappear quickly, it will not affect the use. If the stable bubbles no longer disappear and emulsification and deterioration occur, overflow will occur on the tooth surface, destroying the lubricant film and aggravating wear.

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        Helical gear reducer, is a novel reduction transmission device. Using the most optimal, modular combination system advanced design concept, with a small size, light weight, large transmission torque, smooth starting, transmission ratio grading fine and other properties. So what to do when the helical gear reducer fails? The following is a summary of a few troubleshooting methods for you.
Troubleshooting.
       Ensure the quality of assembly
       Can buy or homemade some special tools, disassembly and installation of reducer components, try to avoid knocking with other tools such as hammers; replacement gears, worm gear, try to use the original parts and pairs of replacement; assembly output shaft, pay attention to the tolerance fit; to use anti-adhesive or red Dan oil to protect the hollow shaft, to prevent wear and rust or fit area scale, difficult to disassemble when repair.
        Lubricant selection
        Helical gear - worm gear reducer generally use 220 # gear oil, for heavy load, start frequently, the use of poor environment reducer, can choose some lubricant additives, so that the reducer in stop running gear oil is still attached to the gear surface, the formation of protective film, to prevent heavy load, low speed, high torque and start direct contact between the metal. The additive contains seal adjuster and anti-leakage agent to keep the seal soft and flexible and effectively reduce the lubricant leakage.
        Installation position selection
        The location allows, as far as possible, not to use vertical installation. When installed vertically, the amount of lubricant added is much more than that of horizontal installation, which is likely to cause heat and oil leakage of the reducer.
        Lubrication maintenance
        According to the lubrication work "five" principle for the maintenance of reducer, so that each reducer are responsible for regular inspection, found that the temperature rise significantly, more than 40 ℃ or oil temperature more than 80 ℃, the quality of oil or oil found in the more copper powder and produce abnormal noise and other phenomena, to immediately stop using, timely maintenance, to Troubleshoot and replace the lubricant. When refueling, pay attention to the amount of oil to ensure that the reducer gets the correct lubrication.

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        A speed reducer is a power transmission mechanism that uses a gear speed converter to reduce the number of revolutions of an electric motor (motor) to a desired number of revolutions to obtain a greater torque. Reduction gears have a very wide range of applications through the mechanisms currently used to transmit power and motion.
        Operating tips for speed reducers.
        1. Users should use the protection regulations reasonably, record carefully the operation of the reducer and the problems found in the inspection, and strictly implement the above regulations.
        2. When changing oil, wait for the reducer to cool down and then stop the machine to avoid the danger of incinerator, but still need to keep warm. When completely cooled, the viscosity of oil increases and it becomes difficult to increase the oil viscosity. Note: Turn off the transmission to prevent accidental energization.
        3. If the oil temperature exceeds 80°C or the oil pool temperature exceeds 100°C and abnormal noise occurs during operation, discontinue use. The reason is that the fault must be solved and the lubricant replaced before continuing operation.
        4. After 200-300 hours of operation, the first oil change should be performed. For future use, the oil should be checked regularly. The mixed impurities or deteriorated oil should be replaced in time. In general, the reducer running continuously for a long time should be replaced with new oil in 5000 hours or once a year, and the reducer not used for a long time should also be replaced with new oil first. The speed reducer must use the same oil as the original trademark and must not be mixed with oil of different trademarks. Oil with the same trademark but different viscosity can be mixed.
        Various types of machinery, from ships, automobiles, locomotives, heavy machinery for construction, processing machinery used in the machinery industry and automatic manufacturing equipment, can see the reducer. Its application extends to transmission. From high power to light load, reducer applications exhibit precise angular transmission, while in industrial applications, the reducer has the ability to slow down and increase torque. As a result, it is widely used as a speed and torque converter.

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        Due to the long-term use of the reducer, there are often wear, leakage and other failures: 
        1. The main wear parts of the reducer gear shaft shaft diameter wear are the shaft head and keyway.
        2. Wear of drive bearing position.
        3. Bearing chamber wear.

        The traditional solution for the wear of cycloid reducer is to repair the weld or brush plating after machining, but both have disadvantages. The thermal stresses generated by the high temperature of the repair weld cannot be completely removed, and the easily damaged material causes the part to bend or fracture. Brush plating has a limited coating thickness and is prone to flaking. In addition, the two methods above are methods of using metal to repair metal. In the "hard-to-hard" adjustment-related action, it will cause secondary wear.

        Some large bearing companies cannot even achieve on-site solutions and have to resort to outsourced repairs. Modern Western countries began to use polymer composite materials to solve the wear problem, the advantage of the product has a unique compressive strength, super plastic deformation and super processing performance, in the processing of wear problems have been equipped and embodied. Due to its durability, free from dismantling and processing, it is not affected by non-repair welding thermal stress, and has no limitation on the thickness of the patch, as well as the flexibility to absorb shock and impact. Potential wear significantly extends the service life of equipment components and significantly saves valuable downtime. The company can solve the problem itself in the first instance.
        For leakage problems, oil leakage failures in cycloid gearboxes are usually more likely to occur in gearboxes, bearing boxes, threaded seals, mechanical seals, etc. Long-term, high-torque mechanical movements tend to increase the gearbox meshing gap. It may cause noise or vibration of the equipment. In addition, oil leakage often occurs due to the seal part operating at high speed and temperature for a long time. The traditional method of disassembling the gearbox, replacing the gasket and applying the sealing material takes time, and the sealing effect is difficult to guarantee, and leakage may occur again during operation.
        The modern general is to add new lubricant to the operation of the equipment to solve this problem. Super lubricant is an oil additive that does not contaminate or degrade the oil and can reach a shutdown to solve potential safety problems, and the company saves high maintenance and replacement costs. The lubricant has excellent self-lubricating properties, effectively reducing gaps in the engagement zone and reducing equipment noise and oil leaks in the sealing zone. Polymer materials can also be used in the field to deal with leaks, and their very good adhesion, oil resistance and 350 elongation allow them to overcome the effects of reducer vibration and solve reducer leakage problems.

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         Cycloid pinwheel reducer principle: a novel transmission device that adopts the principle of planetary gearing and uses cycloid pintooth meshing.
        All drives can be divided into three parts: input part, reduction part and output part. A double eccentric sleeve with 180° displacement is mounted on the input shaft, and two roller bearings called cycloidal arms are mounted on the eccentric sleeve to form the H mechanism. The center holes of the two cycloid needles are the upper cycloid bearings of the eccentric bushing. To reduce friction, in the low speed ratio reducer, the cycloid pin wheel engages a set of pin teeth arranged in rows on the pin gear, thus forming an internal meshing reduction mechanism with one tooth difference.)
        When the input shaft rotates one revolution with the eccentric sleeve, the motion of the cycloid gear becomes planar in both rotation and rotation due to the characteristics of the upper tooth shape of the cycloid gear and the restriction of the pin gear of the pin gear. When the input shaft rotates forward, the eccentric sleeve also rotates one revolution and the cycloid gear rotates one tooth in the opposite direction to decelerate, and the W output mechanism transmits the low-speed rotational motion of the cycloid gear to the output via a pin. shaft to reduce the output speed.

        How to install the cycloid reducer correctly?

        Cycloid reducer structure diagram
        The general cycloid reducer is divided into flange type and special motor direct connection type. The general motor with flange is more convenient to separate and disassemble the motor and flange connection part directly, generally for the motor direct connection is no problem. Usually, the motor side from the output shaft side of the vertical ground, remove the oil seal, remove the end cover from the base, remove the swing parts, eccentric bearings and needle housing in turn. Usually, disassembly is not a problem, but special care must be taken when installing the cycloid reducer.

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Folded-lobe stirrer
    According to the physical properties of different media, capacity and mixing purpose, choose the corresponding mixer, which can play a great role in promoting chemical reaction speed and improving production efficiency. Folding leaf mixer is suitable for mixing pools in water supply and drainage projects, mixing of raw water and various chemicals in reaction pools and stirring of reflection process, stirring speed is generally 30-1400r/min. When stirring, it can make the material circulate in the reactor, the effect is mainly volume circulation, the shearing effect is small, and the up and down tumbling effect is good. When a larger flow rate is needed, the reactor is equipped with a flow guide cylinder.
Operation of Folding Leaf Stirrer
　　According to the physical properties of different media, capacity and stirring purpose, choosing the corresponding stirrer can play a great role in promoting the speed of chemical reaction and improving production efficiency. The folding leaf turbine stirrer is generally adapted to the reaction of gas and liquid phase mixing, and the stirrer revolution should generally be selected above 300r/min.
Folding leaf stirrer material selection

　　Agitator material selection according to the different use of different environment selection of different materials. The general use of weak acid, no corrosion of normal materials can choose stainless steel stirring. If there is a strong acidic material stirring to choose carbon steel epoxy, if the agitator has higher requirements for service life that is recommended to use carbon steel lined with rubber

The principle of folding leaf agitator
Centrifugal principle
　　When the suspension containing fine particles is stationary, the suspended particles gradually sink due to the gravitational field. The heavier the particles, the faster they sink, and conversely, particles with a density smaller than that of the liquid will float. Particles in the gravitational field of the speed of movement and particle size, form and density, and with the strength of the gravitational field and the viscosity of the liquid. Particles the size of red blood cells, a few microns in diameter, can be observed in the usual gravitational effect of their sedimentation process.
　　In addition, the material settling in the medium is accompanied by the phenomenon of diffusion. Diffusion is unconditional. Diffusion is inversely proportional to the mass of the substance, and the smaller the particle the more severe the diffusion. Settling is relative, conditional, to be subject to external forces in order to move. Settlement is proportional to the weight of the object, the larger the particle, the faster it settles. For particles smaller than a few microns, such as viruses or proteins, they become colloidal or semi-colloidal state in solution, it is impossible to observe the settling process using gravity alone. Because the smaller the particle the slower it settles, and the more severe the diffusion phenomenon. Therefore, it is necessary to use a centrifuge to generate a strong centrifugal force in order to force these particles to overcome diffusion and produce a settling motion.
　　Centrifugation is the use of the powerful centrifugal force generated by the high speed rotation of the rotor of the centrifuge to accelerate the settling speed of the particles in the liquid and to separate the substances with different settling coefficients and buoyancy densities in the sample.

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       When it comes to turbine mixers, many of you are not very familiar with them. Do you also want to know more about the turbine mixer? Then don't go away, we immediately for all friends, for the introduction, we all together with the editor together to understand it.
1、Turbine mixer
       Turbine stirrer (also known as turbine impeller), is a widely used stirrer, can effectively complete almost all the stirring operations, and can handle a wide range of viscosity fluid. It consists of two to four flat or curved blades mounted on a horizontal disc. The ratio of outer diameter, width and height of the blades is generally 20:5:4, and the circumferential speed is generally 3~8m/s. The turbine causes highly turbulent radial flow when rotating, and is suitable for the dispersion of gases and insoluble liquids and liquid-liquid phase reaction processes.

2、Working principle

       When working, the turbine stirrer is like a centrifugal pump without a casing. The impeller rotating at high speed causes tangential and radial movement of the liquid in the kettle. The liquid flowing out at high speed along the impeller radius direction pushes the liquid in the kettle to the kettle wall, and then flows back to the entrance of the stirrer after encountering obstacles, forming two circuits respectively, thus forming a general circulation. The tangential velocity of the outflowing liquid will cause circular motion of the liquid in the kettle, which should be suppressed by measures. Compared with the propulsion stirrer, the circuit of the overall circular flow generated by this type of stirrer is more tortuous, and because of the higher exit velocity, the liquid near the blade end is more turbulent, resulting in a larger shear force.
      The turbine stirrer not only produces a large amount of liquid circulation, but also produces a strong shearing effect on the liquid near the outer edge of the paddle, and is commonly used in the reaction, mixing, heat transfer and dissolution of solids in liquid, suspension and gas dispersion of liquids with viscosity less than 50 Pa-s. However, for easy stratification of materials, such as suspensions containing heavy particles, such stirrers are not applicable.
3、Classification
     Turbine agitator is divided into disc turbine agitator and open turbine agitator; according to the impeller can also be divided into flat and straight leaves and inclined blade leaves.
     The content of the turbine stirrer is introduced here for your friends, is not a new understanding of the turbine stirrer, the above content from the network, please correct the deficiencies.

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What is a speed reducer

       The reducer plays the role of matching the speed and transmitting torque between the prime mover and the working machine or actuator, and it is a relatively precise machine, the purpose of using it is to reduce the speed and increase the torque. According to the number of transmission stages can be divided into single-stage and multi-stage reducer; according to the shape of the tooth plant wheel can be divided into cylindrical gear reducer, bevel gear reducer and bevel-cylindrical tooth guide wheel reducer; according to the form of transmission arrangement can be divided into unfolded, shunt and the same into the shaft reducer. The reducer is an independent part consisting of gear drive, worm drive and gear-worm drive enclosed in a rigid shell, and is often used as a reducer between the prime mover and the working machine. It plays the role of matching speed and transmitting torque between the prime mover and the working machine or actuator, and is widely used in modern machinery.

        The reducer is generally used for low speed and high torque transmission equipment, the motor, internal combustion engine or other high-speed power through the input shaft of the reducer gears with fewer teeth meshed with the output shaft of the large gear to achieve the purpose of deceleration, ordinary reducer will also have several pairs of the same principle gears to achieve the desired deceleration effect, the ratio of the number of teeth of large and small gears, is the transmission ratio.

       Reducer is a relatively precise machinery, the purpose of using it is to reduce the speed and increase the torque. It has a wide variety of types and models, and different types have different uses. According to the transmission type, it can be divided into gear reducer, worm gear reducer and planetary gear reducer; according to the number of transmission stages can be divided into single-stage and multi-stage reducer; according to the shape of the gear can be divided into cylindrical gear reducer, bevel gear reducer and bevel-cylindrical gear reducer; according to the arrangement form of transmission can be divided into unfolded, shunt and coaxial type reducer.

Reducer composition structure

        The reducer is an independent transmission component used to reduce speed, transmit power and increase torque. Reducer is an independent closed transmission device between the prime mover and the working machine, used to reduce the speed and increase the torque to meet the work needs, in some occasions also used to increase the speed, known as speed increaser. The selection of reducer should be based on the working machine selection conditions, technical parameters, the performance of the power machine, economy and other factors, compare different types, varieties of reducer outline size, transmission efficiency, bearing capacity, quality, price, etc., choose the most suitable reducer. Reducer is a relatively precise machinery, the purpose of using it is to reduce the speed and increase the torque.

The basic structure of reducer is mainly composed of transmission parts (gear or worm), shaft, bearing, case and its accessories. Its basic structure has three major parts.

1、Gear, shaft and bearing combination
       Pinion and shaft made of one, called gear shaft, this structure is used for the diameter of the gear and shaft diameter is not related to the case, if the diameter of the shaft is d, the diameter of the gear tooth root circle is df, then when df-d ≤ 6 ~ 7mn, this structure should be used. And when df-d＞6～7mn, the structure that gear and shaft are separated into two parts, such as low-speed shaft and large gear, is used. At this time, the gear and shaft circumferential fixed flat key connection, shaft parts using the shoulder, sleeve and bearing cover for axial fixation. Deep groove ball bearings are used for both shafts. This combination, used to bear radial load and not large axial load situation. When the axial load is large, angular contact ball bearings, tapered roller bearings or a combination structure of deep groove ball bearings and thrust bearings should be used. The bearings are lubricated by using the thin oil splashed up when the gears rotate. The lubricating oil in the oil pool in the box seat is splashed up to the inner wall of the box cover by the rotating gear, and flows along the inner wall to the bevel of the sub-box surface and then flows into the bearing through the oil guide groove. When the circumferential speed of oil-immersed gear υ≤2m/s, grease should be used to lubricate the bearing, and in order to avoid the possible splashing of thin oil to wash off the grease, the oil retaining ring can be used to separate it. In order to prevent the loss of lubricating oil and external dust from entering the box, sealing elements are equipped between the bearing end cover and the outstretched shaft.

2、Box body
       The box is an important component of the reducer. It is the base of the transmission parts, should have sufficient strength and rigidity.

The box is usually made of gray cast iron, for heavy load or impact load reducer can also use cast steel box. Single production of the reducer, in order to simplify the process and reduce costs, can be used to weld the box of steel plate.

        Gray cast iron has very good casting performance and vibration damping performance. In order to facilitate the installation and disassembly of the shaft system components, the box is made along the axis of the horizontal split type. The upper box cover and the lower box body are bolted together as one. Bearing seat coupling bolt should be as close as possible to the bearing seat hole, and bearing seat next to the tab, should have enough support surface, in order to place the coupling bolt, and to ensure that the wrench space required when tightening the bolt. In order to ensure that the box has sufficient rigidity, support ribs are added near the bearing holes. In order to ensure the stability of the reducer placed on the foundation and minimize the machined area of the box base plane, the box base generally does not use the complete plane.

3、Reducer accessories
        In order to ensure the normal operation of the reducer, in addition to the gear, shaft, bearing combination and the structural design of the box to give sufficient attention, should also take into account the reducer lubricating oil pool injection, oil drainage, check the height of the oil surface, processing and disassembly and maintenance of the box cover and box seat precise positioning, lifting and other auxiliary parts and components of reasonable selection and design.

       1) inspection holes for checking the engagement of transmission parts and injecting lubricant into the box, should be set in the appropriate location of the box inspection holes. The inspection hole is located at the top of the box cover where the gear meshing part can be directly observed. Normally, the inspection hole cover plate is fixed on the box cover with screws.

        2) ventilator reducer work, the temperature inside the box, gas expansion, pressure increases, in order to make the box of thermal expansion of air can be freely discharged, in order to maintain the pressure balance inside and outside the box, does not cause the lubricating oil along the sub-box surface or shaft extension seals and other gaps leakage, usually installed in the top of the box ventilator.

        3) bearing cover to fix the axial position of the shaft system components and bear the axial load, bearing seat hole ends with bearing cover closed. Bearing cover has flange type and embedded two kinds. Using hexagonal bolts fixed in the box, outreach shaft bearing cover is through-hole, which is equipped with sealing devices. The advantage of the flange type bearing cover is easy to disassemble and adjust the bearing, but compared with the embedded bearing cover, the number of parts is larger, the size is larger, and the appearance is not flat.

         4) positioning pin to ensure that each time the box cover is disassembled, still maintain the accuracy of the bearing housing hole manufacturing and processing, should be in the finishing bearing hole before the box cover and box seat coupling flange with the positioning pin. Placed in the box longitudinal both sides of the joint flange, symmetrical box should be symmetrical arrangement, so as to avoid misassembly.

        5) oil surface indicator to check the height of the oil pool in the reducer, often keep the oil pool has the right amount of oil, generally in the box body for easy observation, the oil surface of the more stable parts, installed oil surface indicator.

        6) oil release screw plug for oil change, discharge of dirty oil and cleaning agent, should be in the bottom of the box seat, the lowest position of the oil pool to open the oil release hole, usually plug the oil release hole, oil release screw plug and the box body should be added between the joint surface of the gasket for leak prevention.

        7) open box screws to strengthen the sealing effect, usually in the assembly of the box body split surface coated with water glass or sealant, and therefore often difficult to open the cover when disassembled because of the tightly glued. For this reason, often in the appropriate location in the box cover coupling flange, processing ~ 2 screw holes, screwed into the cylindrical end of the box or flat end of the opening screw. Rotate the opening screw can be top box cover up. Small reducer can also not set the opening screw, open the cover with a screwdriver to pry open the cover, the size of the opening screw can be the same as the flange coupling bolt.

       Basic classification
       1, according to the use of reducer can be divided into two categories of general-purpose reducer and special reducer, the design, manufacture and use of the two different characteristics. 1970s-80s, the world reducer technology has developed a lot, and the development of new technology revolution closely integrated. Its main types: gear reducer; worm gear reducer; gear - worm reducer; planetary gear reducer.

       2, general reducers are helical gear reducer (including parallel shaft helical gear reducer, worm gear reducer, bevel gear reducer, etc.), planetary gear reducer, cycloid reducer, worm gear reducer, planetary friction type mechanical stepless speed changer, etc.

        1) Cylindrical Gear Reducer
        Single-stage, two-stage, two-stage above two-stage. Layout form: unfolding type, split type, coaxial type.
        2)Bevel gear reducer
        Used in the case where the input shaft and output shaft positions become intersecting.
        3)Worm gear reducer
        It is mainly used for the occasion of transmission ratio i>10, and the structure is compact when the transmission ratio is large. Its disadvantage is low efficiency. At present, Archimedes worm gear reducer is widely used.
        4)Gear-worm reducer
        Compact structure if the gear drive is in the high speed stage.
        If the worm drive is in the high speed stage, it has high efficiency.
        5)Planetary gear reducer
        High transmission efficiency, wide range of transmission ratio, transmission power 12w~50000kw, small volume and weight.
        
        3、The types of common reducers
        1)The main feature of worm gear reducer is that it has reverse self-locking function and can have a large reduction ratio, and the input shaft and output shaft are not on the same axis or in the same plane. However, it is generally larger in size, less efficient in transmission and less accurate.
        2) Harmonic transmission of harmonic reducer is the use of flexible components controlled elastic deformation to transmit motion and power, the volume is not large, high precision, but the disadvantage is that the life of the flexible wheel is limited, not impact resistant, rigidity is poor compared with metal parts. The input speed cannot be too high.
        3) Planetary reducer has the advantages of more compact structure, small return clearance, high precision, long service life, and rated output torque can be made very large. But the price is slightly expensive. Reducer:In short, the general power of the machine is designed and manufactured, its rated power is not changing, at this time, the greater the speed, the smaller the torque (or torque); the smaller the speed, the greater the torque.

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        Proper understanding, installation, use and maintenance of the reducer is an important part of ensuring proper machine operation. The reducer is mainly composed of transmission parts (gears or worm gears), shaft, bearings, case and accessories. Its basic structure has three major parts.

        1. Gear, shaft and bearing combination pinion and shaft made into one, called gear shaft, when the diameter of the gear has nothing to do with the diameter of the shaft, this structure can be used. The diameter is d, and the diameter of the gear tooth root circle is df. If df-d ≤ 6-7mn, this structure can be used. Similarly, in the case of df-d→ 6-7mn, a structure that divides the gear and shaft into two parts, such as a low-speed shaft and a large gear, should be used. In this case, the gear and shaft are connected by a fixed flat key, and the shaft part is fixed axially by the shoulder, sleeve and bearing cap. Deep groove ball bearings are used for both shafts.

        This gearbox combination is used to carry radial and, to a lesser extent, axial loads. If the axial load is large, a combination of angular contact ball bearings, tapered roller bearings, deep groove ball bearings and thrust bearings must be used. The bearings are lubricated by thin oil that is dispersed as the gear rotates. The lubricating oil in the oil sump of the box seat is dispersed by the rotating gear on the inner wall of the box cover, flows along the inner wall into the grooves on the surface of the box, and flows into the bearings through the oil guide grooves. If the circumference of the oil-immersed gear is less than 2 m/s, the bearings should be lubricated with grease. They can be separated using a retaining ring to prevent spilling of thin oil and to wash away the grease. A sealing element is installed between the bearing end cap and the extension shaft to prevent lubricant and external dust from entering the case.

         2. The case is an important part of the reducer. It is the foundation of the transmission parts and must be strong enough.
Boxes are usually made of gray cast iron, cast steel boxes can also be used for reducers subjected to heavy or shock loads. Steel plate welded boxes can be used to simplify the process and reduce the cost of one-piece formed reducers.

         Gray cast iron has excellent casting and vibration damping properties. The box is divided horizontally along the shaft to facilitate installation and removal of the shaft system components. The upper case cover and lower case are bolted together. The attachment bolts on the bearing housing should be as close as possible to the holes in the housing, and the tabs next to the housing should have sufficient support surface to hold the attachment bolts and provide the necessary wrench space when tightening the bolts. Support ribs are added near the bearing holes to provide sufficient rigidity to the housing. To ensure stability of the reducer when placed on the foundation and to minimize the machined area of the box base plane, the box base is usually not used as a complete plane.

        When mounting the reducer, make sure that the motor and reducer are not damaged and that the dimensions of the motor and reducer parts match. There are motor positioning bosses, input shafts, gearbox recesses, etc. Dimensional and fit tolerances. Unscrew the screw on the dust hole on the outside of the reducer flange, adjust the snap ring on the PCS system so that the side holes align with the dust hole, then insert and tighten the hex. Then remove the motor shaft key.

        Reducer products are all very high efficiency, up to 96%, small vibration, I noise, excellent performance and good sealing. Can adapt to corrosion and moisture and other harsh environments.

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      Reasonable adjustment of the use of the stirrer temperature can better ensure the operation of the equipment and the use of efficiency, in this regard, it is very critical to master the method of reasonable adjustment, the next on its method of introduction.
　　When the equipment is used, it should be plugged into the power supply, place the vessel with the solution in the middle of the heating plate, and put the rotor into the solution of the vessel. Turn on the power, the light is on, then adjust the speed knob clockwise, the speed from slow to fast, adjust to the desired speed, the rotor rotates to drive the solution for stirring operation. When constant temperature heating is needed, insert the temperature measuring probe into the solution, and insert the plug into the back of the equipment and adjust the temperature knob to the desired temperature. If the accuracy of the solution temperature is required, a thermometer should be used to measure the solution temperature at the same time, and then adjust the temperature knob to reach the required temperature. If heating is not required, simply adjust the temperature knob to below room temperature.

　　First of all, the stirrer that needs to adjust the temperature is divided into ordinary equipment and constant temperature equipment. For how to adjust the temperature, there are doubts generally for the constant temperature stirring equipment, in the use of constant temperature equipment must be noted in the use of the appropriate amount of water must be added before. Add the water must exceed the standard line, if the water level below the standard line of the phenomenon will lead to the internal piping of the equipment overheating temperature is too high and burned, resulting in damage to the equipment

　　The next step we need to do is to turn on the power, and then select the temperature you want, and set at a constant temperature. Using the property of magnetic material is repulsive to each other, the magnetic stirrer is pushed to rotate by changing the ends of the base continuously, and the sample is driven to rotate by the rotation of the magnetic stirrer to make the sample evenly mixed! Then turn the switch of temperature to the setting state, and then mobilize the temperature control switch to adjust to the temperature you want. The number on the display next to the equipment is the temperature of the water tank (components: high water tank, storage tank, low water tank). At this time, if the red light is on inside the indicator, it shows that it is in the heating work, when we are finished heating the temperature control knob to a small value, and then cut off (cut off; cut off) power. Must pay attention to the sequence of issues, must cut off the power.
　　Constant temperature equipment needs to pay attention to a few things is that if the water bath is not used for a longer period of time, the water tank (components: high water tank, storage tank, low water tank) in the water quickly excluded, scrubbed with a rag and dried clean. If there is remaining water inside is likely to have an impact on the data of the experiment after the equipment. And if there is no water in the case of the tank mixer is resolutely not to use, it is likely that the internal temperature is too high and no water to cool down the mixer internal burn.

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        When using a mixer, how do you lubricate it to optimize performance? If you have not carried out lubrication treatment before, you can see the method common to the mixer in the following article, and then know how to operate.
        1, a hydraulic Wen leg sigh 収起. Serves long time only use, should charm tires off placed well, with things will tire flange wrapped well, the body with sleepers or masonry pillar stable support. Traction should be removed and placed well.
        2, with 1 control valve to start the arm, raise the arm. Before opening the arm, check whether the wire rope is worn, broken and whether the rope card screw is tightened, whether the wire rope is in the sliding wheel groove.
        3、Raise the boom gently, do not operate too fast.
        4、If the hydraulic cylinder is not in place, check the hydraulic tank oil, if the amount is small, please inject hydraulic oil again.
        5、The clutch has been adjusted before leaving the factory, adjust again in use depending on the situation.
        6, often check the lubrication of various parts, according to the requirements of the lubrication table oil injection.
        7、Check the electrical wiring installation and connection, whether the grounding is solid, safe and reliable, and whether the power supply voltage meets the requirements.
        8, do a good job of cleaning, remove the body dust and oil. Each part of the bolt must not have loose and defective.
        9. Check the diagonal belt tightness, wire rope looseness, find the problem Nai time to adjust
        10. Before starting the pump, water must be made to fill the inlet pipe and pump cavity, and the motor is not allowed to proceed without water. Otherwise, the mechanical seal will be damaged.

        11, hydraulic pump is strictly prohibited to reverse, must be rotated in the direction of the arrow.

        12、The feeding hopper must be put down only after the big arm is raised.
        13、In the operation of the machine, attention should be paid to check whether there are abnormalities in each ministry, such as high temperature, abnormal impact sound, etc. The temperature rise of the oil pool of the gearbox should not exceed 35 degrees Celsius.
        14、After each work, must clean up the ash inside and outside the mixing cylinder. You can pour the right amount of stones and water into the mixing cylinder for mixing and cleaning, and finish the stones and water row in ~ ッv.
        15、After the shift, you must land the tipping bucket to the ground.
        16、Put the speaking hopper lever in the disengaged position after shift.
        17、The power must be cut off after the shift to prevent accidents.
        18、In case of freezing weather, the water supply system must be drained after shift.
Lubrication of the mixer
         The mixer is working in the environment with a lot of gray sand, in order to ensure the reliability of the machine work, reduce the wear and tear of machine parts and the loss of power. Lubrication work should be done in time.
         1, gears and bearings of the gearbox is the use of gear rotation to splash oil to the inner wall of the box, into the bearings to lubricate. The oil level of the gearbox should be kept between the two lines of the oil scale is appropriate. The oil level is too high or too low will cause the temperature of each ministry to rise or poor lubrication, increasing power loss and causing the machine to work poorly. The new machine began to use the first 150 hours and 300 hours to replace the oil once, in order to exclude the test run not completely clean dirt. When working, the oil level should be checked frequently, the shortage should be timely replenishment.
        2, where the exposed parts need to be adjusted and rotating with the position should always maintain the lubricant. But the brake belt part should not be stained with oil and water, so as not to affect the braking effect.
        3、The lubrication of the motor should be carried out according to the motor manual.
        4、Other lubrication position and lubrication period according to the lubrication system table.
These are the important parts of the lubrication process of the mixer. I want to know if there are any unclear questions after reading?

      The agitator is composed of two major parts, namely the transmission device and the mixing device. The mixing device also consists of mixing blades, mixing shaft, shaft seal, frame, drive shaft and other major components. Here we focus on the common failures, causes and treatment methods of various gear reducers, cycloidal reducers, worm gear reducers and mechanical seals in the transmission device and its cycle protection system.
1. Reducer.
a. Strange sound when running
      Causes: rolling bearing damage, tapered roller bearing clearance is too large, gear or worm vice wear serious, pin tooth pin, sleeve, wheel wear.
b. Gear box or bearing temperature rises
      Reasons: Too much lubricating oil or too little lubricating oil, no oil or bad lubrication, bearing damage, tapered roller bearing clearance adjustment is too tight, the two coupling junction is not the same center, bearing bias grinding, lubricant deterioration, overload operation.
C. Shaft head or combination surface oil leakage

      Reason: Oil level is too high, sealing failure of the joint surface, loose joint surface compression bolts, oil seal damage.

d. Reducer amplitude is large
      Reason: The relative displacement of the two coupling joints is too large, there is looseness in the parts of the coupling, the bearing or other parts are damaged, overload use.
2. Mixing vessel
Large amplitude of stirring vessel
      Causes: Excessive relative displacement of the two shaft joints in the kettle or loose coupling bolts, offset of the bottom bearing and guide bearing center or bearing damage, imbalance of the stirrer body, liquid level in the kettle lower than the stirrer (especially the flexible shaft), bending of the stirring shaft.
3. Mechanical seal and its circulating protection system
Mechanical seal leakage is too large and humidity is too high
      Reasons: Axial stringing of the shaft exceeds the allowable value, radial displacement of the shaft at the shaft seal exceeds the allowable value, pressure in the seal cavity is lower than the pressure in the kettle, solid impurities in the seal liquid, serious wear of the seal surface, high temperature of the seal liquid exceeds the allowable value, damage of the O-ring at the dynamic and static ring, etc., liquid surface in the lubrication box of the single-end external seal is lower than the seal surface, verticality of the end face of the single-end external static ring and the stirring shaft is too poor.

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The main types of agitators are as follows.
         ①Spinning paddle stirrer consists of 2~3 propeller blades with high working speed and the circumferential speed of the outer edge of the blades is generally 5~15m/s. The spinning paddle stirrer mainly causes axial liquid flow and generates large circulation volume, which is suitable for stirring low viscosity (<2Pa-s) liquids, emulsions and suspensions with less than 10% solid particles. The shaft of the stirrer can also be inserted horizontally or obliquely into the tank, where the circulation circuit of liquid flow is asymmetrical, which can increase turbulence and prevent liquid surface depression.
        ②Turbine type stirrer consists of 2~4 flat or curved blades installed on a horizontal disc. The ratio of outer diameter, width and height of the blades is generally 20:5:4, and the circumferential speed is generally 3~8m/s. The turbine causes highly turbulent radial flow when rotating, and is suitable for the dispersion of gas and insoluble liquid and liquid-liquid phase reaction process. The viscosity of the stirred liquid generally does not exceed 25 Pa-s.
        There are two types of paddle stirrers: flat paddle type and inclined paddle type. The flat paddle stirrer is composed of two flat and straight blades. The ratio of blade diameter to height is 4~10, the circumferential speed is 1.5~3m/s, and the radial liquid flow speed is small. The two blades of the inclined paddle mixer are turned 45° or 60° in opposite directions, thus producing axial liquid flow. The paddle stirrer has a simple structure and is often used for mixing low-viscosity liquids as well as dissolving and suspending solid particles.
        There is only a small gap between the outer edge of the paddle and the inner wall of the mixing tank, so that the viscous reaction products attached to the tank wall or the solids accumulated at the bottom of the tank can be removed and the heat transfer effect can be maintained. The circumferential speed of the outer edge of the paddle is 0.5~1.5m/s, which can be used for stirring Newtonian and plastic fluids with viscosity up to 200Pa-s (see viscous fluid flow). Only when stirring high viscosity liquid, there is a large stagnation zone in the liquid layer.
        ⑤ Spiral stirrer with the outer diameter of the spiral belt and the pitch equal, specifically for stirring high viscosity fluids (200~500Pa-s) and plasticized fluids, usually operating in the laminar flow state.
        ⑥Magnetic stirrer Corning digital heater with a closed circuit knob to monitor and adjust the stirring speed. The microprocessor automatically adjusts the motor power to suit water quality, viscous solutions and semi-solid solutions.
        The Corning digital heater stirrers have an optional external temperature controller (Cat. No. 6795PR), and they can also monitor and control the temperature in the vessel.
         The power P output of the stirrer to the liquid is calculated according to the following formula: P=Kd⁵N³pwhere K is the power quotient, which is a function of the stirring Reynolds number Rej (Rej = d2Nρ/μ); d and N are the stirrer's diameter
diameter and speed; ρ and μ are the density and viscosity of the mixture, respectively. For a certain geometry of the stirrer and stirring tank, the function of K and Rej can be determined experimentally, and the function is plotted as a curve, called the power curve. The type, size and speed of the stirrer have an effect on the distribution of the stirring power between the overall flow and turbulent pulsations. Generally speaking, the power distribution of turbine agitators is favorable for turbulent pulsations, while rotating paddle agitators are favorable for the overall flow. For the same type of agitator, under the same conditions of power consumption, large diameter, low speed agitator, the power is mainly consumed in the overall flow, which is beneficial to macro mixing. Small diameter, high speed stirrer, the power is mainly consumed in turbulent pulsation, which is beneficial to micro mixing. The scale-up of the stirrer is a complex issue related to the process, and so far can only be extrapolated to industrial scale through a step-by-step empirical scale-up, based on the obtained scale-up criteria.

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　　With the widespread use of mixers, in order to prevent equipment failure and danger, the correct method of operation is very important, in order to reduce human failure, which requires us to conduct a series of relevant training for operators, so that operators understand the operating standards of the equipment, then the specific standard requirements are as follows.
　　Staff not only need to be licensed to work, and should have no less than one month of refresher training time each year, after the annual training and refresher training still need to accept the assessment, after passing the examination to continue to have a license qualification, this is to minimize personnel misuse, and mixing work more safely and reliably. A negligence in the mixer can directly cause an increase in production costs.
　　Staff should be present during the operation of the mixer, on-site supervision and observation to ensure the normal operation of the machine, if the machine has abnormalities, should be the first to detect and deal with the corresponding, so as to have a more healthy and safe production effect.
　　If the mixer needs to run for a long time, different operators need to hand over according to work hours, then a special operating manual should be prepared, filled out by the staff to effectively let the succession of personnel to understand the situation of the machine, so as to better deal with some sudden problems.
　　In short, in the use of the mixer, we are still more stringent requirements for the operator, to avoid negligence because of personnel, thus causing a series of equipment failure, that is, affecting the use of equipment, but also threaten the safety of the operator's life. At the same time, we should always keep in mind that safety comes first.

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　　Desulfurization agitator is a kind of equipment that mainly strengthens the slurry disturbance to prevent the slurry from settling, in which the turning of the desulfurization agitator, almost the same as the Shun pointer turning, but occasionally there will be uncertainty, mainly depends on the blade installation, in the blade rotation process, the agitator will be paddle to the oblique down to push the slurry, according to this judgment agitator rotation direction.

　　Desulfurization agitator is used in many industries today, and it has more models and types. In view of the characteristics of domestic flue gas desulfurization, it absorbs the advanced technology of similar products at home and abroad, and through a lot of experiments and long-term practice, it has developed a new generation of top-in stirrer for desulfurization. The motor power range is 1.5-55kw.

　　At the time of debugging if the agitator rotating in the wrong direction, so that the general current is significantly lower, the mixing effect is very poor; agitator blade is generally not installed against, some manufacturers equipment blade against the installation can not be installed, there are also agitator against can also be installed, the specific or according to the blade to distinguish. Agitator is strictly prohibited to idle, so the motor should be first test run, confirm the steering, and then agitator test run. When the absorption tower liquid level is higher than the stirrer to start the fixed value, you can test run. In the commissioning process, the stirrer test run, the liquid level is lower than the fixed value, when higher than (blade high position + blade length) can also be test run. Agitator test run is strictly prohibited idling (machine seal will be bad), forbidden liquid level is less than the fixed value, blade striking water vibration is very large. Agitator current and slurry concentration has a direct relationship, but the agitator and slurry pump is different, its current fluctuates greatly, general fluctuations 10A is normal.
　　Desulfurization agitator is now often used as mixing equipment in the flue gas desulfurization device, because its reliability and life expectancy are very high, with high efficiency, long life, uniform mixing and easy maintenance characteristics, so that the desulfurization device can be safe and effective operation, but the use of different desulfurization agitator in different applications are not quite the same role, according to the specific situation specific analysis.

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      Reactor with stainless steel stirrer a good selection method is best to have two conditions, one is the selection of reasonable results, one is the selection method is easy, but these two points are often difficult to have at the same time.
　　As the viscosity of the liquid has a great impact on the state of stirring, so according to the size of the viscosity of the stirring medium to select is a basic method. Several typical stirrers have different ranges of use with high and low viscosity. The order of using various stirrers with increasing viscosity is propulsion type, turbine type, slurry type, anchor type and spiral type, etc. Here the propulsion type is divided into finer points, and low speed is proposed for large-capacity liquid and high speed for small-capacity liquid. This selection chart does not absolutely specify the limits of the use of pulp type, in fact, the use of a variety of pulp type is overlapping, for example, the pulp type because of its simple structure, with a baffle can improve the flow pattern, so it is also more commonly used in low viscosity. The turbine type is almost the most widely used slurry type due to its convective circulation ability, turbulent diffusion and shear force.
　　The slurry type applicable to the process is judged according to the purpose of the mixing process and the flow state caused by the agitator, which is a more suitable method. Since the Soviet Union has its own customs in the selection of slurry type, it is not the same as our common slurry type.

　　The recommended slurry type is divided into two categories: fast and slow, the former operating in the turbulent state and the latter in the laminar state. The selection is based on the purpose of mixing and the flow state to determine the slurry type and baffle conditions, the decision of the flow state to be influenced by the viscosity of the mixing medium.

　　The conditions of use are more specific and include not only the slurry type and the purpose of mixing, but also the recommended range of medium viscosity, the range of mixing speed and the range of tank capacity.
　　The proposed selection table is also based on the purpose of stirring and the flow state during stirring. It also has the advantage of dividing the use range of the slurry type according to the characteristics of different stirring processes, making the selection more specific. Comparing the above table, we can see that the selection basis and results are still relatively consistent. Here are some more descriptions of some of the main processes.
　　The mixing of low-viscosity homogeneous liquids is one of the least difficult mixing processes, and is only difficult when the volume is large and the mixing time required is very short. The propulsion type is the most suitable because of its high circulation capacity and low power consumption. Turbine type because of its high power consumption, although there is a high shear capacity, but for this mixing process is not very necessary, so if used in the mixing of large-capacity liquids, its circulation capacity is not enough.
　　Dispersion operation process, turbine type because of the high shear force and greater circulation capacity, so the most suitable, especially the shear force of the straight leaf turbine than the folded and curved leaves of the shear force effect, it is more appropriate. Propulsion type, pulp type because of its shear force than the flat turbine type is small, so only in the case of small amount of liquid dispersion available, and the pulp type is rarely used for dispersion operation. The dispersion operation has baffles to enhance the shearing effect.
　　Solids suspension operation has the largest use of turbine type, of which the open turbine type is the best. It does not have the middle part of the disc, not to obstruct the liquid phase mixing above and below the paddle, and the advantages of the curved blade open turbine is more prominent, it is good discharge, the paddle is not easy to wear, so it is used for solids suspension operation more I suitable. The use of the propulsion type is narrower, the solid-liquid specific gravity difference is large or the solid-liquid ratio of 50% or more is not applicable. When using the baffle, attention should be paid to prevent the accumulation of solid particles on the corner of the baffle. Generally when the solid-liquid ratio is relatively low, the baffle plate is used, while the folding leaf opening turbine and propulsion type have axial flow, so they can also be used without baffle plate.
　　The gas absorption process is most suitable for the disc type turbine, which has strong shearing force, and the bottom of the disc can store some gas, so that the gas is spread more smoothly, while the open turbine does not have this advantage. Pulp type and propulsion type are basically not suitable for gas absorption process, only in a small amount to absorb the gas required dispersion is not high when it can also be applied.
　　Crystallization processes with agitation are difficult, especially when strict control of the crystallization size is required. Generally, fast stirring with small diameters, such as turbine type, is suitable for particle crystallization, while slow stirring with large diameters, such as slurry type, can be used for crystallization of large crystals.

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