When oil purifier works, the polluted oil goes into the heater from the inlet under the combined function of outside atmospheric pressure and vacuum suction.  The heated oil goes into the primary filter where the large particles are removed. Then, the oil goes into the vacuum oil separator and flows past special divergent device. This device makes the oil in unit volume generate huge surface area to atomize polluted oil. The dropped oil is exposed to the atmosphere in very low relative humidity and thus the water in the oil evaporates instantly and also the gas together with light ends in the oil is removed.

    The mixed gas formed by the water vapor, gas and light ends, all of which are evaporated by oil purifier, condenses into liquid through water tank and cooler and goes into the water receiver. The remaining gas is pumped out by vacuum pump. The oil after removal of water passes the oil pump and is pumped to the fine filter to remove micro impurities. That is purifying oil to finish one purifying procedure. According to the water quantity in the oil, several purifying circles are needed to remove the water completely.