The oil-air separator is a crucial component in screw air compressors for separating compressed air and lubricating oil. If the oil-air separator is damaged, clogged, or has poor separation performance, a large amount of lubricating oil will be discharged along with the compressed air, resulting in excessive oil consumption. For example, if the filter element of the oil-air separator has not been replaced in time after long-term use, its filtration accuracy will decline and it will be unable to effectively block the lubricating oil, thus allowing the oil to enter the compressed air pipeline.
Whether the oil return pipeline is unobstructed directly affects the oil return situation of screw air compressors. If the oil return pipeline is blocked, bent, or improperly installed, it will hinder the smooth return of the lubricating oil to the oil tank, causing part of the lubricating oil to remain in the system and be carried away by the compressed air. For instance, during the installation or maintenance of the equipment, if the angle of the oil return pipeline is unreasonable and forms an "oil accumulation dead zone", it is likely to lead to the problem of increased oil consumption.
The oil level of screw air compressors should be maintained within an appropriate range. If the oil level is too high, when the compressor is in operation, the high-speed rotating components will splash too much lubricating oil into the compression chamber, and then it will be discharged together with the compressed air. If the operators do not add oil according to the oil level standard specified by the equipment when refueling, or if the oil level sensor of the equipment malfunctions and misjudges the oil level, it may result in an excessive oil level.
Using lubricating oil that does not meet the requirements or has deteriorated will also lead to excessive oil consumption of screw air compressors. The performance indicators such as viscosity, oxidation resistance, and anti-foaming property of inferior lubricating oil may not meet the standards. During the operation of the compressor, it is easy to generate foam, and these foams will be discharged along with the compressed air. Moreover, deteriorated lubricating oil will lose its proper lubricating and sealing performance, resulting in poorer sealing effect inside the compressor and more oil leaking into the compressed air.
The minimum pressure valve is used to ensure that a certain pressure is maintained in the system when the compressor is running under load, so that the lubricating oil can circulate and be separated normally. When the minimum pressure valve malfunctions, such as poor sealing or spring failure, it will cause the compressed air to flow backward and carry out the oil in the oil-air separator, resulting in an increase in oil consumption.
After long-term operation of screw air compressors, the internal screw rotors, bearings, and other components will experience wear. The increased clearance between the worn components makes it easier for the lubricating oil to leak into the compressed air, thus leading to increased oil consumption. For example, the wear of screw rotors will damage the seal between them and the casing, allowing the lubricating oil to enter the compression chamber and be discharged.
After understanding these reasons for the excessive oil consumption of screw air compressors, enterprises can conduct targeted inspections, maintenance, and upkeep to ensure the normal operation of screw air compressors, reduce operating costs, and improve production efficiency.