Liang Zhenglu Yu Maoxia Guizhou Crystal Chemical Co., Ltd. Guiyang 5514020, Guizhou Introduction In the early 1990s, screw air compressors began to be used in China. Because of its reliable running performance, less wear and tear, less noise, lower automation and higher automation. In recent years, the medium-pressure medium-low pressure exhaust gas field in various industries is gradually replacing the piston compressor, and the scope of use is more and more extensive. Therefore, it is very important to master the correct maintenance and maintenance method of the screw air compressor. It is an important guarantee for the normal operation of the compressor unit, and also an important prerequisite for prolonging the service life of the compressor and reducing the wear of the parts. The first screw air compressor used by our factory is the 3 E-butyl 175-person screw air compressor produced by Shanghai Weiken Compressor Co., Ltd. After 2 years of maintenance and maintenance, the equipment is running normally and performing well. It is proposed to gradually upgrade the 3108 type 2268 compressor to a screw air compressor. Brief introduction of 131 175 type screw air compressor structure 81 175 type screw air compressor is a kind of double shaft volume type rotary type micro oil compressor. The air inlet is open on the casing, and the exhaust port is open to the lower part. The high-precision main-yang auxiliary rotor is horizontally and parallelly mounted inside the casing. The main rotor has 5 teeth, and the auxiliary rotor has 6 shapes. tooth. The diameter of the main rotor is larger, the diameter of the sub-rotor is smaller, the teeth are formed in a spiral shape, and surround the outer edge of the rotor, and the tooth shapes of the two mesh with each other. Both ends of the main and auxiliary rotors are respectively supported by bearings. There is a roller bearing at the intake end, and there are two symmetrically mounted tapered roller bearings at the exhaust end. The motor drives the main rotor through the belt, and the main rotor directly drives the auxiliary rotor to rotate. The cooling lubricating oil is directly injected into the inter-rotor meshing portion through the nozzle from the lower part of the compressor casing, and is mixed with the air to take away the heat generated by the compression to achieve the cooling effect. At the same time, an oil film is formed to prevent direct contact between the metal and the metal between the rotors and to close the gap between the rotors and between the rotor and the casing. The injected lubricant also reduces the noise caused by high speed compression. 2Maintenance and maintenance The maintenance and maintenance methods of the main components of the screw air compressor are as follows: 2.1 Air filter The air filter is an important protective barrier for the compressor. Its function is to filter out the dust in the air sucked by the compressor to ensure the intake of air. The cleanliness is to extend the service life of the oil filter separator core and oil, and is also an important barrier to ensure that the host is not damaged by foreign matter. The filter element is usually removed every 10001 in the shutdown state to remove dust. The method of removing dust is to use the dry compressed air of 0.23 or less to blow out the dust particles attached to the outside of the filter element from the inner cavity of the filter element, and then wipe the filter element back by cleaning the dirt on the inner wall of the filter cover. Under normal circumstances, the filter element needs to be replaced every 4,000 rpm, that is, the filter element must be replaced after cleaning for 4 or 5 times. However, in dusty areas, the time interval between cleaning and replacement of the filter element should be shortened. Otherwise, the overuse of the filter element is very harmful. For example, if the exhaust gas volume is reduced, the filter element resistance increases, the energy consumption of the unit increases, the filter element may be damaged, and the host enters the accident. 2.2 Oil filter The function of the oil filter is to remove impurities such as metal particulate oil deterioration in the oil, and the filtration precision is between 1015, which has perfect protection for the bearing and the rotor. The replacement of the oil filter can be judged according to the differential pressure finger. It must be replaced when the oil filter is blocked. After the first operation of the new unit 500, the oil filter needs to be replaced, and then replaced by the differential pressure finger. If the oil filter pressure difference is large and not replaced, it may cause the oil intake to be insufficient and the exhaust gas temperature to be high, which may affect the bearing life of the main engine. Change the motor acceleration and deceleration too fast to avoid current overshoot. The speed regulator uses the proportional integral 10 control principle to achieve no static speed regulation for the speed. The motor speed is varied following the given. The current regulator utilizes, 1 control adjustment to achieve automatic adjustment of the control amount, the principle is basically the same as the speed controller, but the control of the current amount is realized, which is a follow-up chat with the current changing with a given value. The actual value measurement forms a fixed proportional operation relationship by a constant resistance, and the input signal is converted into a ratio of the chamber and then output. In this system, it converts the speed signal detected by the tachogenerator into a voltage signal to realize feedback control... 5 command station module is also a logic control unit, which is used to control the working condition of each module to prevent false triggering and trigger failure. When the accident occurs, at the same time, there is no circulation, ensuring that only the group thyristors are turned on at any time. According to the working state of the system, the command system automatically switches. The trigger board module is composed of a basic circuit such as a synchronous voltage zero-crossing detection loop synchronous latching loop sawtooth generator comparator pulse gate circuit pulse suppression loop quadrant output unit, forms a trigger pulse, and realizes phase shifting of the trigger pulse according to requirements. The armature current balancing module subtracts the current actual value signals of the lifting mechanism and the opening and closing mechanism. The difference between the two is input as a negative feedback to the current control link to balance the current values ​​of the two mechanisms. The actual value reference value monitoring module compares the actual value with the reference value, and does not operate if the deviation between the two is within the allowable range. If the range is out of range, the built-in relay sends a signal to control. 3 Conclusion 87400 is an editable logic controller that can be used to achieve almost all automation tasks by selecting the right components. The system was upgraded from Siemens 35 series to 57400 series, and the main mechanisms such as grab lifting and closing were upgraded from the original analog speed control to digital DC drive control, which made the control more precise and easy to find faults, which was helpful for mastering the equipment operation. Reduce the time for repair and elimination, improve equipment output, and reduce the labor intensity of employees. Therefore, this transformation and upgrade effectively improved the overall performance of the equipment. It is best to change the oil filter at the same time. 2.3 Oil fine separator The oil fine separator is a component that separates compressed air from lubricating oil. It can control the oil particle size in compressed air below 0.1μl. The oil content is less than 3xl0. Under normal operation, the oil fine separator The use of about 40001, but the quality of the lubricating oil and the degree of pollution of the surrounding environment have a great impact on its service life. Therefore, in the harsh environment, the maintenance and replacement cycle of the air filter must be shortened, and even the front air filter should be considered. When the oil separator is expired or the pressure difference is greater than 0.1213, it must be replaced. Otherwise, the motor overload oil separator will be damaged and run. Replacement of the oil separator. Follow the steps below to confirm that the system has no pressure after the shutdown. 3 Disassemble the pipe joints and fixing screws above the oil and gas tank cover, and remove the oil and gas tank top cover and the oil separator. Replace the new oil fine separator with 3 in the reverse order of the disassembly to install the oil and gas barrel; 4 When replacing the oil fine separator, take care to prevent the unclean items from falling into the oil and gas barrel, so as not to affect the operation of the air compressor. 2.4 Lubricating oils have a decisive influence on the performance of screw air compressors. If used improperly or incorrectly, it will cause serious damage to the compressor body. Good oil has the characteristics of good oxidation resistance, good separation, fast foaming and good corrosion resistance. The selection of lubricating oil is generally based on the oil grade recommended by the screw air compressor manufacturer. 2.4.1 Characteristics of Lubricating Oil When the viscosity level is 401, the viscosity point of the flash point must be higher than the ambient temperature. 5. or more. When the exhaust pressure is higher than the normal pressure range of 0.8, 1.0MPa, the lubricating oil may suddenly fire. When the exhaust pressure is as high as 1.5, 2.2MPa, oil with a particularly high ignition point should be used. 2.4.2 Factors affecting oil change time Mixing of different grades of lubricants. 2.4.3 Oil change step Start the screw air compressor to run for 5 minutes, so that the oil temperature rises above 50.C to facilitate discharge and then stop; slowly open the drain valve to release the lubricating oil, and then close the pressure due to the drop. The oil draining speed is very fast, the oil is easy to be sprayed, and special attention should be paid when draining oil. Therefore, the drain valve should be slowly opened to prevent the lubricating oil from opening the fuel cap or screw plug to inject new oil, so that the oil level is in the range of the oil mark Inside, install the oil cap or tighten the screw plug to check for oil leakage. 2.4.4 Precautions for the use of lubricating oil. 1 If the screw compressor is used for the first time, the oil change time is difficult to determine. After the oil is used for 100 hours, the oil sample can be taken for testing to determine the quality of the lubricant, and then repeated every 100 hours, after several times. The oil change interval of the compressor can be determined without wasting oil. 2 Lubricating oil should be replaced on time, avoid overdue use, otherwise the quality of oil products will drop, the lubricity will be poor, the ignition point will drop, and it will easily cause accidents... After 2 years of use of the compressor, the lubricating oil can be used as the secondary system cleaning work. The specific method is to change the lubricating oil, let the compressor run for 6, 8h, and then replace the new oil, so that the remaining organic components in the original system can be cleaned to ensure a better service life of the new oil. Different grades of lubricating oil should not be mixed, otherwise it will cause serious damage to the compressor. 2.5 The cooling effect of the cooler cooler directly affects the operating temperature of the compressor. The oil cooler is cooled by air and water. The compressor uses a cooling effect of air-cooling, so every 1500 or so, the dust on the fin surface of the cooler is blown off with dry compressed air of 40 or more. When it cannot be blown off, it is cleaned with a solvent. To ensure that the cooling surface of the cooler is clean. 2.6 Belt adjustment The new unit will check the belt after 30 hours of the first operation. If it is too loose, it should be adjusted immediately and then adjusted every 150 times. The tightness of the belt is based on the deformation of the middle section of the belt, which is 8 standard. For U5kW and below, use 2kgf to press b37kW and below to press 4kgf, 75, and the following to press down dlkW and below with 12kgf. 1 Using a tension meter and a spring balancer, the load is applied to the belt to measure the deformation amount. If it is within the standard value, it is not necessary to adjust. If the deformation exceeds the standard value, the belt tension needs to be adjusted; when adjusting the belt tension, the motor is first adjusted. The fixing screws of the base are slightly relaxed. Then adjust the belt tension with the adjusting screw, and then tighten the motor fixing screw after measuring with the tension meter. If the belt is replaced, all the belts should be replaced, and only the strips or several belts must be replaced. Otherwise the tension will be unbalanced; when adjusting or replacing the belt, be careful not to spill the oil on the belt or pulley. 3 Conclusion The normal and reliable operation of the screw air compressor is inseparable from the correct maintenance and maintenance. For different types of screw air compressors of different brands, it is necessary to formulate detailed maintenance plans according to their maintenance requirements, and carry out regular inspections and records to improve the maintenance of the units to ensure the normal operation of the compressors and extend the service life of the units. 7 Reference 1 Shanghai Weiken Compressor Co., Ltd. Screw air compressor installation and maintenance manual for technical management. Vulcanizing Press For Conveyor Belt Vulcanizing Press For Conveyor Belt,Belt Conveyor,Flameproof Vulcanizing Machine,Conveyor Belt Vulcanizer Press SUZHOU ARPHU INDUSTRIAL CO., LTD , https://www.arphuind.com