AIRPULL FILTER – air filter oil filter oil separator inline filter for all major compressor brands.
Oil separator is the key component to determine the quality of compressed air. The main function of oil separator is to reduce the oil content in compressed air and ensure that the oil content in compressed air is within 5ppm.
The oil content of compressed air is not only related to oil separator, but also to separator tank design, air compressor load, oil temperature and lubricating oil type.
The oil content in the outlet gas of the air compressor is related to the separator tank design, and the outlet gas flow of the air compressor should match the treatment capacity of the oil separator. In general, the air compressor must be selected to match the oil separator, which must be greater than or equal to the air flow of the air compressor. Different end users require different final differential pressure.
In practical use, the final pressure difference of oil separator used for air compressor is 0.6-1bar, and the dirt accumulated on oil separator will also increase at high oil flow rate, which can be measured by the amount of sewage. Therefore, the service life of oil separator cannot be measured by time, only the final pressure difference of oil separator is used to determine the service life. Air inlet filtration can extend the service life of downstream filter elements (i.e. lubricating oil filter element and oil separator). Impurities in dust and other particles are the main factors limiting the service life of lubricating oil filter element and oil separator.
Oil separator is limited by surface solid particles (oil oxides, worn particles, etc.), which eventually leads to the increase of differential pressure. Oil selection has an impact on the service life of oil separator. Only those tested, antioxidant and water insensitive lubricants can be used.
In the oil-gas mixture formed by compressed air and lubricating oil, lubricating oil exists in the form of gas phase and liquid phase. The oil in the vapor phase is produced by the evaporation of the oil in the liquid phase. The quantity of the oil depends on the temperature and pressure of the oil-gas mixture, and also on the saturated vapor pressure of the lubricating oil. The higher the temperature and pressure of oil-gas mixture, the more oil in gas phase. Obviously, the most effective way to reduce the compressed air oil content is to reduce the exhaust temperature. However, in the oil injection screw air compressor, the exhaust temperature is not allowed to be low to the extent that water vapor will be condensed. Another way to reduce the content of gaseous oil is to use lubricating oil with low saturated vapor pressure. Synthetic oil and semi synthetic oil often have relatively low saturated vapor pressure and high surface tension.
The low load of the air compressor sometimes leads to the oil temperature lower than 80 ℃, and the water content of the compressed air is relatively high. After passing through the oil separator, the excessive moisture on the filter material will cause the expansion of the filter material and the contraction of the micropore, which will reduce the effective separation area of the oil separator, resulting in the increase of the oil separator resistance and the blockage in advance.
The following is a real case:
At the end of March this year, the air compressor of a factory has always had oil leakage. When the maintenance staff arrived at the site, the machine was running. More oil was discharged from the air tank. The oil level of the machine also dropped significantly (below the mark under the oil level mirror). The control panel showed that the operating temperature of the machine was only 75 ℃. Ask the equipment management master of the air compressor user. He said that the exhaust temperature of the machine is often in the range of 60 degrees. The preliminary judgment is that the oil leakage of the machine is caused by the long-term low-temperature operation of the machine.
Maintenance staff immediately coordinated with the customer to shut down the machine. More water was discharged from the oil drain port of the oil separator. When the oil separator was disassembled, a large amount of rust was found under the cover of the oil separator and on the flange of the oil separator. This further verified that the root cause of the oil leakage of the machine was that too much water could not be evaporated out in time during the long-term low-temperature operation of the machine.
Problem analysis: the surface cause of the oil leakage of this machine is the oil content problem, but the deeper reason is that the water in the compressed air can not be evaporated out in the form of gas due to the long-term low-temperature operation of the machine, and the oil separation filter material structure has been damaged, resulting in the oil leakage of the machine.
Treatment suggestion: increase the operating temperature of the machine by increasing the fan opening temperature, and keep the machine operating temperature at 80-90 degrees reasonably.
Post time: Jul-10-2020