Among the compressor faults, the exhaust oil fault is the most common, and the main factors causing the exhaust oil fault are: 1. The oil separation core is damaged. During the operation of the air compressor, the oil separation core is damaged, such as breakage and perforation, so it loses the function of oil-gas separation. That is to say, the mixed gas and the exhaust pipeline of the compressor are directly connected, so a large amount of cooling oil is not separated, and it will be discharged from the body together with the gas, which causes the oil-carrying fault in the exhaust process. 2. The oil return pipeline is out of order. In the working process of the screw air compressor, the oil return pipeline shoulders an important responsibility, and there will be a pressure difference between the inside of the oil separation core and the inlet of the compressor. Under the action of this pressure difference, the oil return pipeline is responsible for conveying the oil gathered at the bottom of the oil separation core back to the compressor and continuing to use it in the next cycle. If the oil return circuit is blocked, broken and improperly installed, the oil accumulated at the bottom of the oil separation core cannot be transported back to the compressor, resulting in too much oil accumulated at the bottom, so this part of the oil that has not been transported back to the compressor will be discharged with the gas, and there will be oil entrainment in the exhaust process. 3, the system pressure control is too low In the process of operation, if the system pressure is controlled too low, the centrifugal force in the separator will be less than the required centrifugal force, so the function of the separator will not be fully reflected, and the oil content of the gas entering the separator core in the next link will be too high, which will exceed its separation range, which will lead to incomplete oil-gas separation and oil-carrying failure in the compressor exhaust process. 4, the minimum pressure valve failure The function of the minimum pressure valve is to ensure that the system pressure is controlled above the minimum pressure during operation. If the minimum pressure valve fails, the minimum pressure of the system will not be guaranteed. Because the gas consumption of the luck equipment is very large, the system pressure will be too low, and the oil return pipeline cannot return oil. The oil gathered at the bottom of the oil separator core will not be sent back to the compressor, and will be discharged from the compressor with compressed gas, resulting in oil-carrying failure in the process of flat exhaust. 5. Too much cooling oil is added into the compressor. Before the operation of the compressor, too much cooling oil is added, which exceeds the range of the compressor, so in the operation of the compressor, because of the high oil level, although the oil and gas are separated by the separation system, in the gas discharge, the gas will also involve the cooling oil into the gas and discharge it, resulting in the high oil content in the discharged gas and oil-carrying failure. 6. The quality of cooling oil is unqualified Before the operation of the compressor, unqualified cooling oil was added, or the cooling oil exceeded the applicable time, and the cooling effect could not be achieved. Then, during the operation of the screw compressor, the cooling oil loses its function and cannot cool and separate the oil and gas. Then there is bound to be an oil fault in the exhaust process.
Troubleshooting steps When oil is found in the exhaust of the compressor, it is not necessary to disassemble the equipment blindly, but to analyze the above causes and follow the steps from easy to difficult to determine the location of the fault. This can reduce a lot of repair time and manpower. When the compressor starts normally and the system reaches the rated pressure, slowly open the exhaust gate valve, with the opening as small as possible, so that a small amount of gas can be discharged. At this time, point a dry paper towel at the discharged airflow. If the paper towel immediately changes color and has oil droplets, it can be judged that the oil in the exhaust of the compressor exceeds the standard. According to the amount of oil in the exhaust and different time periods, the fault location can be correctly judged. When the opening of the exhaust gate valve is increased, it is found that the exhaust airflow is in an uninterrupted dense fog shape, indicating that the oil content of the airflow is very high, and then check the oil return of the oil return pipe observation mirror. If the oil return of the oil return pipe observation mirror increases obviously, it is generally that the separator core is damaged or the cooling oil of the separator is added too much; If there is no oil return in the observation mirror of the oil return pipe, it is generally that the oil return pipe is broken or blocked. When the opening of the exhaust gate valve is increased, it is found that the front section of the exhaust airflow is dense fog, and it is normal after a period of time; Continue to increase the opening of the exhaust gate valve and open all the exhaust valves. At this time, observe the pressure gauge of the system. If the displayed pressure of the pressure gauge is lower than the set pressure of the minimum pressure valve, the exhaust valve continues to exhaust and the air flow is in an uninterrupted dense fog shape. When this happens, the fault is generally the failure of the minimum pressure valve. After normal shutdown, the automatic vent valve exhausts. If there is a lot of oil in the exhaust, it means that the automatic vent valve is damaged. Common fault removal measures There are various reasons for the oil fault in the exhaust of screw compressor during operation, and different solutions are needed for different reasons. 1, oil separation core damage problem The damage of oil separation core is a common phenomenon, so it is necessary to check the equipment before the operation of screw compressor, strictly follow the operating procedures during use, and regularly maintain the equipment after use. If the oil separation core is found to be damaged and perforated, it should be replaced in time to ensure the normal operation of the equipment. 2. There is a problem with the oil return circuit. During the operation of the equipment, if the oil return circuit is blocked, it is necessary to check the pressure drop of the separator first. If there is no problem with the pressure drop, it is necessary to clean the oil separator core. If the oil separator core breaks, it must be replaced in time. 3, the system pressure control is too low. For operators, they should be familiar with the control pressure of the equipment, and reduce the load of the system when problems are found, so that the system pressure can reach the rated working pressure. 4, the minimum pressure valve failure problem In actual operation, if the minimum pressure valve is found to be invalid, it must be replaced, and the work will be carried out after the replacement is completed. 5. Excessive cooling oil is added to the compressor. When adding cooling oil to the compressor, we should first know the theoretical value of how much cooling oil should be added to the equipment, and there should be a special person responsible for the addition of cooling oil, which should generally be controlled below the middle of the mirror. 6, cooling oil quality problems The addition of cooling oil should be strictly in accordance with the requirements of equipment for cooling oil, because different equipment has different requirements for cooling oil. After adding, the adding time should be recorded, and the cooling oil should be replaced on time after it reaches its service life. The quality of added cooling oil should be strictly controlled to prevent unqualified cooling oil from being added. Troubleshooting and solving matters needing attention
There are several points that must be paid attention to in the process of fault resolution, otherwise the fault can not be ruled out, but may lead to greater consequences. If it is judged that there is a problem with the oil return pipe, the oil return pipe can be cleaned and blocked or welded again. In this process, attention should be paid to: firstly, the oil return pipe must be unobstructed, and the inner diameter of the pipeline should not be reduced because of welding; Secondly, the installation position of the oil return pipe must be correct. Generally, the gap between the bottom center recess of the separator core and the end of the oil return pipe is 3 ~ 4 mm.. If it is judged that there is a problem with the separator core, only a new separator core can be replaced. Attention should be paid in this process: firstly, carefully check whether the new separator core is deformed or damaged; Secondly, it is necessary to clean the joint surface between the separator cylinder and the top cover; Finally, when installing, check whether there is any conductor such as metal on the sealing paper pad at the top of the separator core, because the cooling oil rotates at high speed inside the separator, which will produce a lot of static electricity on the separator core. If it is judged that there is too much oil level in the separator, it should be discharged properly. To check the oil level of the separator correctly, firstly, the unit must be parked horizontally. If the inclination angle of the unit is too large, the display on the oil level meter of the separator is inaccurate. Secondly, the inspection time should be chosen before driving or after stopping for half an hour. Although the screw compressor is a highly reliable model, it is not without maintenance. It should be noted that any equipment is “three points in use and seven points in maintenance”. Therefore, whether there is oil in the exhaust or other faults, the maintenance work in operation should be strengthened to nip the faults in the bud.
