Plate and frame oil filter consists of a primary filter, an oil pump, and a filter device. The primary filter of the plate and frame oil filter is a cylindrical metal mesh that prevents large solid particles in the impure oil from entering the oil pump. The oil pump of the plate and frame oil filter is usually a gear pump that delivers the impure oil to the filter device. The filter device of the plate and frame oil filter is a small manually tightened plate and frame filter press, using special filter paper as the filter medium. The impure oil enters the plate and frame filter press under the pressure of the oil pump, passing through the filter paper to become filtered oil. Solid impurities in the oil are trapped on the surface of the filter paper, and a small amount of moisture is absorbed by the capillary pores of the filter paper. The filtration pressure is usually not greater than 0.3 MPa. When too much impurity accumulates on the surface of the filter paper and the filtration pressure rises to 0.35 MPa, or when the moisture absorbed by the filter paper is nearly saturated and the residual moisture in the filtered oil no longer decreases, the filter paper should be replaced after stopping the machine. If the oil viscosity is high, it can be preheated to reduce viscosity before filtration. This type of plate and frame oil filter can only remove solid impurities and a small amount of moisture, and is suitable for purifying general electrical oil and lubricating oil. When the oil contains excessive moisture and impurities, it must be pretreated before being sent to the oil filter. The processing capacity of the plate and frame oil filter is 25~200 L/min. The square filter frames of the filter device have two inner side lengths: 200 mm and 250 mm. The filter plates and frames are made of cast iron or polypropylene.
