The working principle of the box filter press consists of filter plates arranged to form filter chambers (where the filter plates are recessed on both sides, with two plates combined to create a box-shaped filter chamber).
The filter plate surface features pits and bosses for supporting the filter cloth. The center and corners of the filter plate have through-holes, which, upon assembly, form a complete passage for the slurry, wash water, and the extraction of filtrate. Handles on both sides of the filter plates are supported by beams and the plates are tightened by a clamping device. The filter cloth between the plates serves as a seal.
Under the pressure of the feed pump, the material liquid to be filtered is sent into each filter chamber, where it is separated from solids and liquids through the filter medium (selecting the appropriate filter cloth based on the industry). The solids accumulate on the filter cloth to form a filter cake until the filter chamber is full. The filtrate passes through the filter cloth and flows along the filter plate grooves to the lower outlet channel, where it is discharged collectively. After filtration, the filter cake can be washed with cleaning water. Sometimes, compressed air is introduced after washing to remove any remaining cleaning liquid. Upon completion of the filtration, the pressure filter is opened to remove the filter cake (stored between adjacent filter plates), clean the filter cloth, and re-tighten the plate filter to start the next work cycle.