1. The working principle of screw air compressor:
The main components of screw air compressor are: air filter, low pressure rotor, intermediate cooler, electronic motor, high pressure rotor, rear cooler, transmission parts, gear box, regulator control system, safety valve and muffler housing, etc.
2. Common failures and treatment
2.1 Excessive temperature of air output
(1) Reduce the air input temperature. Increase the ventilation of the air compressor room, add an exhaust hood on the roof of the air compressor room to remove hot air, and control the indoor temperature not too high, especially in hot summer, the temperature of the air compressor room should not exceed 40 C.
(2) Reducing the input temperature of cooling water, keeping the water temperature at 18 C in winter and 24 C in summer.
(3) Increase the flow rate of cooling water. According to the calculation, the difference between the input temperature and output temperature of cooling water is L5 C, and the flow rate of cooling water is 3.7 liters per second.
(4) Clean up scales or dirty sediments in cooling water. The cooling water system is dredged by adding detergent in the cooling water.
2.2 Excessive Oil Temperature
The air compressor has oil temperature protection settings. When the oil temperature exceeds 70 C, the air compressor shuts down frequently. The reason of high oil temperature is the failure of oil cooler. Because the cooling water pipeline in the oil cooler is thin, it is not easy to clean up after scaling, resulting in the oil temperature can not fall down. It costs $2,800 to replace an oil cooler. After research, we remove the oil cooler, soak in the detergent for one day, and then use a small pump to pour pressure water into the oil cooler to wash repeatedly, which can remove the scale. With this method, the air compressor in our unit has not replaced the oil cooler, and the oil temperature in summer can also be controlled below 60 C.
2.3 Frequent failure of air filter
When the compressor is in use, the air filter can only be used for one month. The analysis shows that the ambient air environment is dirty. In order to prolong the service time of the filter, a net cover (pre-filter) is added above the air filter of the air compressor.
2.4 Other requirements for air compressors
(1) In summer, the ambient temperature of air compressor room can not start up normally until it is below 40 C. When the air compressor is installed, the distance between the machines should be more than 2.5 meters, so as to facilitate the heat dissipation and ventilation of the air compressor room.
(2) Compressor has two reference data: maximum working pressure and general working pressure. When choosing air compressor, the general working pressure should be used as reference data to select air compressor. If the air compressor is selected with the maximum working pressure, it is easy to make the compressor run overloaded for a long time and burn down the motor.
(3) Water-cooled air compressors require high water quality. Common failures are related to scaling of cooling system caused by poor water quality. Therefore, when installing air compressor, a set of water softening treatment device must be installed, which can greatly reduce the failure of air compressor.
3. Hopping and Stopping Treatment of Twin Screw Air Compressor
In the work of twin screw air compressor, there is a breakdown of tripping and stopping. That is, normal air supply during work, but sometimes suddenly stop. First of all, we check the motor part and find no obvious problems; then check the compressor temperature automatic protection and pressure automatic regulation system, the temperature control part is normal. After disassembling and inspecting the pressure regulating valve and the relief valve, it was found that the rubber film inside the relief valve was damaged and there was a small hole in the film. Due to the damage of rubber film, the size of air inlet of air compressor can not be adjusted in time when the air supply pressure is changed, and the load of unit does not match the power of diesel engine, which causes the overload protection of diesel engine to stop, and after replacing the rubber film in the load relief valve, troubleshooting will occur.
Start immediately after the jump-stop, occasionally normal start, work for a period of time still jump-stop. After checking, the temperature of lubricating oil and exhaust pressure are not high. Temperature protection switch is temporarily short-circuited and stop phenomenon disappears. This indicates that it is the jump and stop caused by high temperature, but the heat emitted by the lubricating oil radiator is not felt. The lubricating oil circuit was checked, the temperature protection switch and temperature control valve were normal, the filter element of oil filter was replaced, the radiator was cleaned, and the fault remained. The check valve was examined by disassembly. It was found that the rubber film was damaged by the pressure difference between the front and back of the lubricating oil, and the troubleshooting was carried out after replacement. It can be seen that the jumping and stopping of air compressor is often caused by the failure of a valve in the pressure regulating system. Rubber seals, plastic diaphragms, springs and other parts of the valve are liable to fail, which is often hidden and easy to cause illusions.
