The working principle of the box filter press consists of filter plates arranged to form filter chambers (with each pair of filter plates forming a box-shaped filter chamber).
The filter plates have surface ridges and bosses to support the filter cloth. There are through-holes in the center and corners of the filter plates, which, upon assembly, form a complete passage for the suspension liquid, washing water, and the extraction of filtrate. Handles on both sides of the filter plates are supported by beams and are clamped to secure the filter plates. The filter cloth between the plates serves as a seal.
Under the pressure of the feeding pump, the material liquid to be filtered is sent into each filter chamber. It is separated from solids and liquids through the filter medium (suitable filter cloth selected according to different industries). Sludge forms on the filter cloth until it fills the chamber to create a filter cake. The filtrate passes through the filter cloth and flows along the groove of the filter plate 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 fluid. At the end of the filtration process, the pressure filter is opened to remove the filter cake (stored between adjacent filter plates), clean the filter cloth, and then re-tighten the plate filter to start the next work cycle.
