Diaphragm pressure filter, also known as diaphragm press filter, is a pressure filter with an elastic membrane added between the filter plate and filter cloth. During operation, upon completion of the feed, a high-pressure fluid or gas medium can be injected into the diaphragm plate. At this point, the entire diaphragm will bulge and compress the filter cake, thereby achieving further dewatering of the filter cake, which is commonly referred to as squeezing filtration.

Membrane filter press is used in sludge and wastewater treatment. The moisture content of the filter cake has been reduced to below 60%. Compared to traditional box-type filter presses, the solid content of the filter cake can be increased by over twice, significantly lowering the transportation costs of the filter cake. The filter cake can be directly combusted in power plants, truly transforming sludge into a resource and wastewater into clean water, completely replacing the box-type filter press.