With the development of science and technology, air compressors, as an important power equipment, are widely used in many industrial fields such as machinery, metallurgy, building materials, electronic power, chemical industry, food, textile and so on. However, in the long-term operation of the compressor, there will inevitably be many failure problems, and frequent loading and unloading is one of them. Frequent actions not only shorten the life of the unit's solenoid valve, compressor inlet door and unloading valve, but also seriously threaten the safe operation of the entire unit.   cause of issue What are the reasons for the frequent loading and unloading of the compressor? 1) Control reasons As we all know, the discharge pressure of the compressor is the main basis for controlling the loading and unloading of the compressor. If the difference between the two set values ​​becomes smaller, it may lead to frequent loading and unloading of the unit. When the loading pressure value of the unit increases, the unloading pressure value decreases at the same time; or simply the loading pressure value increases and the unloading pressure value decreases, which will shorten the loading and unloading cycle of the unit. The closer the value is, the more frequent the loading and unloading, and the greater the hidden danger of the safe operation of the equipment. 2) System reasons If the set value of the unit loading and unloading pressure is normal, it can be considered whether there is pipeline blockage between the compressor outlet and the gas storage tank. If the pipeline is blocked but not completely blocked, the flow of compressed air will be severely blocked, and the gas pressure between the blockage point and the compressor is difficult to be quickly relieved during the loading of the compressor, resulting in the unloading pressure value reaching the unloading pressure value in a very short time. . However, due to the limited air volume between the blockage point and the compressor outlet, coupled with system losses (such as filter drainage with air, air dryer regeneration) and a small amount of circulation to the air storage tank, the pressure quickly drops to the loading pressure value, the compressor Reloaded again, and so on. Specifically, there are the following factors: (1) The set value of the pressure difference between the loading and unloading of the pressure controller is too small, which may lead to frequent loading and unloading of the unit. (2) The pressure sampling tube is blocked or leaked, and the pressure decays too quickly. (3) The demand for compressed air during production is unstable, ranging from large to small or discontinuous. (4) When the compressor unit is unloaded, the minimum pressure valve is not closed in time or not strictly. (5) The loading control solenoid valve is faulty. The solenoid valve should be checked, it may be affected by oil, water and gas, which may cause the action to be insensitive or the coil is burned out. (6) The pressure sensor that controls the start and stop of the unit is faulty or damaged. When encountering the above problems, it should be solved in time, otherwise it will cause damage to related equipment and other failures. Solution 1. The treatment method for frequent loading and unloading caused by control reasons This kind of reason can be directly seen through the pressure display when the unit is loaded and unloaded. If there is any change, it can be solved by online calibration or by removing the pressure sensor, checking in detail and reinstalling the sensor. Of course, it is also common for the pressure sensor measurement pipeline to be blocked and cause measurement errors. The usual practice is to use compressed air to purge the sampling pipeline. 2. Handling methods for frequent loading and unloading caused by system reasons The treatment of the system reason is more complicated, which can be judged by the difference between the compressor outlet pressure and the refrigerating machine outlet pressure. If there is a difference or the difference is too large (generally the filter is less than or equal to 0.6bar, and the dryer is more than or equal to 0.2bar), it can be judged that the pipeline or equipment is blocked. Since there are many equipments in this pipeline, after long-term maintenance and observation, it is found that the equipments that are often blocked are: 1) Oil removal and water removal filter (the dust removal filter is located behind the refrigerating machine, and the probability of blockage is generally small): including the filter core; the filter drain solenoid valve; the filter screen in front of the drain solenoid valve. Among them, the filter screen in front of the sewage solenoid valve is most likely to be blocked, which can be solved by cleaning or replacement. The blowdown solenoid valve generally has the phenomenon of valve body jamming, coil burning, timer failure, etc., which can be solved by replacing it. In a f