TM 5-814-3/AFM 88-11, Volume III
e. Filter presses. The plate-and-frame press is a batch device that has been used to process difficult to
dewater sludges. Recent improvements in the degree of automation, filter media and unit capacities have led
to renewed interest in pressure filtration for application to municipal-type sludges. The ability to produce a
very dry cake and clear filtrate are major points in favor of pressure filtration, but they have higher capital
and operating costs than vacuum filters. Their use in preference to vacuum filters will be acceptable providing
they can be economically justified. Figure 16-7 illustrates a cross-section of a filter press.