Working principle of screw air compressor and several common problems

Working principle of screw air compressor: the compressed air system adopts twin-screw air compressor. The operation of the machine is divided into three processes: air inlet, compression and exhaust: 
　　

(1) inhalation process: 
　　

The motor drives the rotor. When the air inlet end of the rotor and the air inlet space become larger, it points to the outer space from the main wall. When the rotor end face on the intake side moves away from the inlet of the housing, the teeth become teeth. The air between the grooves is trapped between the main rotor and the driven rotor and the shell to complete the suction process. When the gas fills the entire groove, the end of the rotor inlet side moves away from the housing inlet, and the gas in the groove is sealed
　　

(2) compression process: 
　　

At the end of suction, the peak value of the main rotor and the peak value of the driven rotor are closed to the housing. At this time, the gas will not flow out of the slot and the tooth surface will gradually move towards the exhaust end. The space between the tooth surface and the exhaust port decreases gradually, and the gas in the groove increases with the compression pressure
　　

(3) exhaust process: 
　　

When the toothed end face of the rotor is connected with the exhaust port of the shell, the compressed gas begins to be discharged until the tooth surface and groove of the tooth tip move to the exhaust end face. At this time, the tooth surfaces of the main rotor and auxiliary rotor are discharged from the shell. The space of the port cover plate is zero, which means that the exhaust process is completed, and the length of the backlash between the rotor tooth surface and the air inlet of the housing is the longest, and the air inlet process is carried out again
　　

Because the temperature of screw air compressor is too high, the typical shutdown reasons are as follows: 
　　

　　1. Insufficient environmental ventilation and heat dissipation. There are three main situations. The environment around the screw air compressor affects the heat dissipation: one is too close to the wall barrier, and the other is another heat source near the screw air compressor. The third is that the front door and side door of the screw air compressor are opened during operation to produce strong air flow
　　

　　2. The blade of screw pneumatic electromechanical fan is cracked or sagging. If the blade breaks, the air compressor will run for 5 minutes, the temperature will rise and stop automatically. When abnormal sound is heard, the cooling blade will reduce the amount of cooling air and affect the heat dissipation. At this time, the fan blade needs to be replaced or adjusted 
　　

　　3. Screw air compressor oil filter is too dirty. When the dirt is serious, the resistance oil can not enter the air compressor at the normal flow rate, and the air pressure is rapid due to the lack of cooling oil. If the hydraulic pressure difference between the inlet and outlet exceeds 0.18 MPa, the filter element must be replaced
　　

　　4. The cooling oil level is too low. When observing the refrigerator, once the oil level is lower than the lower end of the test tube, the oil level should be corrected immediately. You must correct the position below the mimeograph center you are working on
　　

　　5. The quantity of cooling oil is small or the quality of oil is poor. Screw air compressor is selected from the manufacturer's special air compressor oil, but using other low-grade or residual oil, the viscosity and specific heat will not meet the specification, and the temperature will be too high
　　

　　6. The radiator is blocked. If there is a lot of dust around the screw air compressor, the long layer of work will form a layer of dust and sludge adhered to the surface of the radiator. The internal copper pipe is also simply blocked by the accumulation of grease, which will affect the heat dissipation. The air cooler shall be cleaned with a dust blower, but if it is not cleaned, it shall be removed, cleaned with a high-pressure water gun and cleaned with special liquid medicine. For the water cooler, use the water pump to recover the liquid medicine
　　

　　7. The oil cut-off valve of screw air compressor will be damaged. There is a fuel shut-off valve between the oil filter and the air compressor. If the oil cut-off valve cannot be opened, the temperature of the screw air compressor will rise rapidly after starting and stop within a few seconds due to no oil lubrication and cooling
　　

     8. The filter element of oil-gas separator is too dirty. When it is too dirty and the oil circulation is affected due to excessive resistance, resulting in overheating shutdown, it should be sorted or replaced.