The plate and frame filter press consists of alternately arranged filter plates and filter frames to form a group of filter chambers. The surface of the filter plate has grooves, and its protruding parts are used to support the filter cloth. There are through holes on the corners of the filter frame and the filter plate, which form a complete channel after assembly, which can pass in the suspension, wash water and lead out the filtrate. There are handles on both sides of the plate and the frame, which are supported on the beam, and the plate and the frame are pressed by the pressing device. The filter cloth between the plate and the frame acts as a sealing gasket. The suspension is hydraulically pumped into the filter chamber by the feed pump to form a filter residue on the filter cloth until the filter chamber is filled. The filtrate passes through the filter cloth and flows along the groove of the filter plate to the corner channel of the plate frame, and is discharged centrally. After filtration, the filter residue can be washed with clean water. After washing, compressed air is sometimes introduced to remove the remaining washing liquid. Then open the filter press to remove the filter residue, clean the filter cloth, re-press the plate and frame, and start the next working cycle.

The plate and frame filter press can be applied to the suspension with large or almost incompressible filter residue. The solid particle concentration of the suitable suspension is generally below 10%, and the operating pressure is generally 0.3 to 0.6 MPa, and can be up to 3 MPa or higher in special cases. The filter area can be increased or decreased with the number of plates and frames used. The plate frame is usually square, the inner side length of the filter frame is 200-2000 mm, the frame thickness is 16-80 mm, and the filter area is 0.5-1200 square meters. The plate and frame are pressed by manual screw, electric screw and hydraulic pressure. Plates and frames are manufactured from materials such as wood, cast iron, cast steel, stainless steel, polypropylene and rubber.