Discussion on Operation of Injecting Screw Air Compressor in Alpine Environment Liu Linjiang, Gao Xiaoyong, Zhao Jianguo Baogang Group Barun Mining Co., Ltd. Baotou, Inner Mongolia 014080 q Steel Group Barrun Mining Co., Ltd. has 8 KY-310B roller rigs And 6 YZ-55B roller rigs, the slag air compressor system of the roller rig is an oil-injected screw air compressor. The external environment will have a major impact on the normal operation of the air compressor, especially the temperature effect. Winter is the high season of the failure of the air compressor of the roller rig. The mine belongs to the high and cold area. The average temperature in winter is -25*C, and the lowest temperature can reach -38*C. The design working environment temperature range of the air compressor is 1.746.0. *C. Practice has proved that in the high-cold environment, the injection screw air compressor cannot be started normally according to the method of use provided by the manufacturer. The company combined with the special Qr point of the oil-injected screw air compressor, after three high-cold environments in winter, explored the injector screw, .... A reasonable method for the rod compressor under the ring i. The working medium of the chamber filter press used by Jinchuan Company is a kind of electrolyte, which is very corrosive. One part of the chamber filter press is easily corroded, especially the beam and machine of the filter press. Foot, rot ML-250 oil-injected screw compressor is more serious due to the corrosion of the main engine and the motor. Under normal circumstances, the filter press only performs surface coating treatments such as simple, lubrication and cooling systems, pneumatic systems, oil and gas separation systems, and control sheet painting. In the case of strong corrosive conditions, the system cannot be manufactured and the protection system is composed. . A pair of compressor mainframe housings provide corrosion protection. In response to this problem, a new type of anti-interference rotor is adopted, and the motor directly drives the male rotor with the gear to prevent corrosion by flame coating. The technology uses a flame to rotate the rotor, and the injected oil and air are heated to a constant temperature between the rotor slots, and the special plastic powder is compressed. The lubricating oil forms an oil film between the rotor slots, which acts as a sealing gap and sprays to form a special anti-corrosion layer. In this way, the role of the rotor can be lubricated and mixed with air to remove most of the heat generated by the use of different thermoplastics for different working media due to air compression. Cover to meet different anti-corrosion requirements. On the van filter press, the unit selected for the screw compressor was controlled by INTELLISYS, and the EAA-"R45 plastic coated material was used as the anti-corrosion layer. The material has the ability to accurately control the discharge pressure of the compressor, the exhaust gas temperature, and the length of the separation before, and some of the filter plates are severely deformed. After testing, the maximum deformation reached 5mm, which seriously affected the sealing of the filter plate. The rubber sealing strip on the filter plate has also been seriously aged, and cannot be restored to its original shape after compression, and cannot compensate for the gap and deformation of the filter plate, so that a relatively serious leak occurs between the filter plates. In response to these problems, the rubber sealing strip was reworked and the cross-sectional dimension of the sealing strip was increased from 10 mm×12 mm to 10 mm×13 mm, so that the sealing strip can completely compensate the influence of the gap and deformation on the sealing surface of the filter plate, and completely solved the problem. Leakage of the filter plate. 3.5 Improvement of the fixed filter plate The fixed filter plate of the chamber filter press is usually also equipped with a filter cloth. Unlike the movable filter plate, the filter cloth on the fixed filter plate is fixed on one side, so it is difficult to fix the filter cloth, especially the fixed filter plate at the end of the thrust plate. Because there is a feed hole in the middle, it must be bolted through the pressure plate. It is very inconvenient to replace the filter cloth, so many units have cancelled the filter cloth on the fixed filter plate, so that the fixed filter plate loses the filtering effect. Since the fixed filter plate is designed with a concave flow path and the surface is not flat, it is very difficult to discharge the filter cake in the filter chamber at the fixed filter plate. The improved fixed filter plate structure, as shown, eliminates the concave flow path of the fixed filter plate, simplifies the structure of the fixed filter plate, and makes the filter plate easier to manufacture. Since the surface of the fixed fixed filter plate is flat, the unloading is very easy, thereby solving the problem of unloading. 3.6 Improvement of surface anti-corrosion The working medium of the chamber filter press used by Jinchuan Company is mainly various electrolytes, which are highly corrosive. The various components of the chamber filter press are easily corroded, especially the filter press. Corrosion problems are more serious with girders and machine feet. Under normal circumstances, the filter press only performs surface painting treatment such as simple painting, and it cannot prevent corrosion in the case of strong corrosiveness. In response to this problem, a new type of anti-corrosion measures was adopted for flame-coating and anti-corrosion. The technology uses a flame to heat a workpiece that needs to be preserved to a certain temperature, and at the same time sprays and melts a special plastic powder to form a special anti-corrosion layer. In this way, different thermoplastics can be used to coat different working media to meet different corrosion protection requirements. On the box filter press, EAA-jR45 plastic coated material was selected as the anti-corrosion layer. The material has the functions of anti-instrument editing An Xiuqing Li Wenmin pressure and the overheating and overcurrent protection of the fan and main unit of the electric control system. At startup, air is drawn into the compressor through the air filter. When the air compressor is running under unloading, the intake valve is almost closed to keep the airflow through the device to a minimum, and to minimize the starting torque of the motor. After the air is compressed by the compressor, it is discharged from the exhaust port through the check valve. At this time, it is a mixed gas of air and coolant, and the mixed gas flows quickly to the gas storage tank, and starts to separate the oil and gas in the separator. The separator tank pressure is 0.17 MPa, which drives the coolant from the separator to the air compressor mainframe. When the air compressor is loading and running, the deflation solenoid valve is closed, and the solenoid valve is loaded to make the pressure oil enter the control hydraulic cylinder through the pipeline. The suction valve is fully opened under the action of the hydraulic cylinder, and the air compressor enters the full load operation state. . The air is separated from the coolant in the gas storage tank, and the separated compressed air flows out through the minimum pressure valve. Its workflow is as shown. Venting solenoid valve exhaust pressure sensor secondary oil return small hole joint separation before pressure sensor cp check valve pressure valve f safety valve oil shutoff solenoid valve temperature switch oil filter thermostat: oil separation core oil separation barrel pressure difference switch ML -250 Oil Injection Screw Air Compressor Operation Principle The principle of the air compressor oil circulation system is as shown. The high-pressure air generated by the operation of the air compressor enters the oil and gas drum, and the lubricating oil is pressed into the radiator to be cooled. When the temperature of the coolant does not reach the set value of the temperature control valve, the coolant enters the host directly through the filter and the oil shutoff valve through the oil discharge port of the thermostatic control valve installed in the pipeline system. When the temperature of the coolant reaches the set value of the temperature control valve, the thermostatic control valve acts to allow the coolant to enter the main engine through the cooler, the thermostatic control valve, the filter, and the oil shutoff valve, and take away the heat generated by the compression of the main engine. 2 The impact of the cold environment on the oil circulation *C) Under the environment, the viscosity of the lubricating oil increases, the fluidity decreases, and the lubricating oil in the cooler freezes. Since the temperature control valve does not reach the opening temperature and cannot be turned on, the lubricating oil that needs to be cooled cannot enter the cooler. Even if it enters the cooler, it will freeze due to the operation of the cooling fan, which will cause the lubricating oil to circulate poorly, resulting in the air compressor. The main engine cannot operate normally due to lack of oil and high temperature alarm. In addition, poor lubrication of the lubricating oil leads to an increase in the pressure of the system piping, and even causes the cooler to rupture and cause leakage. 3 The key to the normal operation of the air-injected screw air compressor under high and cold environment is to ensure the smooth flow of the lubricating oil. Therefore, the air compressor cooling device and the starting method have been improved. 3.1 Improvement of the cooling device of the air compressor The ambient temperature in the cold environment is far lower than the normal operating temperature of the air compressor, so the cooling device of the air compressor must be improved. The cooling fan motor control switch is placed outside the control cabinet for operator control. An external heat shield is added to the outside of the cooler to minimize the leakage of the surrounding area. In the winter, the heater can be used to heat the outside of the cooler, and the lubricating oil in the cooler can be thawed to ensure the smooth flow of the air compressor. 3.2 Improved starting method Switch the unloading switch to the unloading position, disconnect the cooling fan control switch, and start the air compressor. Observe the operation of the air compressor through the display. When the temperature of the unloading air compressor reaches 7580 °C, use the temperature gun or touch the hand to test the temperature of the inlet and outlet of the cooler. If the outlet temperature does not rise, the air compressor can continue to run to about 90 °C in the unloaded state, and the inlet and outlet temperatures of the cooler are confirmed again. When the temperature difference between the inlet and outlet ports reaches 2030 °C, the air compressor is loaded and operated. When loading and running, the operator carefully observes the display data of the air compressor. If all the data shows normal, observe the air compressor exhaust temperature. When the temperature rises to 9095 °C, turn on the cooling fan control switch. The operator checks the operation of the unit under full load through the controller, and whether there is oil leakage around the unit and the cooler. Wait for the air compressor to run for 15~25min. If everything is normal, the operator can leave the starter cabinet. 4 Conclusion In the cold environment, the ambient temperature is much lower than the design requirements of the injection screw air compressor. According to the operation method provided by the manufacturer, the air compressor fails frequently or even fails to start normally. Through the improvement of the air-injection screw air compressor, it can also operate well in the cold environment, and improve the operation efficiency of the installation of this column of the equipment, An Xiuqing Li Wenmin, so as to better serve the mine production and construction. Improvement of the boring machine's walking machine 枸 guiding device Liang Xiuyun Anhui Huainan Kaisheng Heavy Industry Co., Ltd. R & D Center Anhui Huainan 232058 experience cantilever type roadheader has become the main equipment for most coal mine roadway excavation in China. The cantilever roadheader mostly uses the crawler traveling mechanism to support the weight of the machine and the traction and transfer machine. When the excavation work is performed, the traveling mechanism is subjected to the reaction force, the overturning moment, and the dynamic load of the cutting mechanism. The reliability of the walking mechanism plays a vital role in the whole machine. 1 Problems exist The traveling mechanism works on the sediment-mixed floor. The roller and the guiding device are often immersed in the moist sediment, so high requirements are placed on the structure and service life of the roller. During operation, the track chain and the guides perform periodic shifting movements, so that the parts that are connected to the steering sprocket also produce periodic speed changes that cause dynamic loads. The greater the mass and acceleration of the track chain, the greater the dynamic load. Dynamic loads, impacts caused by the moment of meshing of the track chain and the sprocket, and axial displacement of the sprocket during cornering of the running portion can cause damage to the internal seal of the guide. The driving guide of the roadheader produced by Kaisheng Heavy Industry Co., Ltd. adopts a floating seal, and the gap between the bushing and the shaft is matched, and the sprocket and the bushing have an interference fit. The original guide structure is as shown. The original guiding device structure is effective for prolonging the service life of the floating seal and reducing wear. The floating sealing gap is designed to be 3 mm. The gap of the floating seal needs to be ensured by the axial dimension of the sprocket, the bushing, the shoulder and the end cap, and the dimensional chain is mixed. U Since this gap can only be guaranteed by the axial dimension chain, the assembler cannot adjust it and the quality inspector cannot measure it. During use, the A and B sides have relative friction, and the floating seal gap will become smaller and smaller with wear, thereby crushing the floating seal ring and causing damage. 2 Structural Improvements The improved guide structure is as shown. The sprocket, bushing and end cap I form an independent dimensional chain that is positioned by the shoulder. The position of the end cap can be appropriately adjusted by the round nut according to the experience of the assembler. During assembly, the worker can adjust the gap of the floating seal according to experience to compensate for the shortcomings of the floating seal gap that cannot be directly measured, machining error and assembly error. 1. Set screw 2. Sprocket 3. Bushing 4. End cap: 6. Floating seal 7. Round nut improved structure. After the end cover n is improved, the gap of the floating seal can be adjusted by adjusting the round nut, which can appropriately reduce the processing precision of the shoulder size chain, reduce the rework rate and reduce the labor intensity of the worker. 3 Conclusion After more than 2 years of practice verification, the service life of the improved guide device is significantly improved. When the roadheader was overhauled, it was found that the floating seal wear was small, basically no damage, no need to replace the entire structure, only need to repair the worn parts, saving a lot of cost. Editor-in-Chief Editor An Xiuqing Li Wenmin Gas and low viscosity liquid mixer features simple structure, no rotating components, small maintenance and low energy consumption.This kind of mixing machinery can be divided into four types: air mixing, pipe mixing, jet mixing and forced circulation mixing.
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The accessories of the mixer are mainly made of wear-resistant alloy, including high-speed spatula, fin, wear-resistant lining, mixing arm, spatula, planetary spatula, spatula, stirrer, and harrow
Mixing machines with medium and high viscosity liquids and pastes generally have strong shearing action.
Thermoplastic material mixing machinery is mainly used to mix thermoplastic materials (such as rubber and plastics) with additives.Mixing machinery for powder and granular solid materials is usually operated intermittently, including mixing and grinding machinery such as roller mill.
The moving parts of the mechanical stirrer also shear the liquid while rotating. The liquid is also sheared when it flows through the wall of the machine and various fixed members installed in the container. These shearing action will cause a lot of local eddy current diffusion.
For liquids with different densities, different components, and each other, the shear action and strong turbulent motion produced by agitation shred the denser liquid into small droplets and dispersed them evenly into the main liquid.
Common types of mixer:
Common mixers are: plough blade mixer, screw mixer, gravity-free mixer, V type mixer, double spiral cone mixer, high and low speed liquid mixer, planetary power mixer, etc.
