23 JULY 2003
material tends to plug the passages from the corner port to the chamber area. The
surfaces of the perimeter of the plate and stay bosses are flat to provide a proper seal.
The surfaces of the recessed plate area are constructed with rows of grooves to provide
support for the filter cloth and allow paths of filtrate drainage. The construction of the
variable-volume plate filter press is similar to that of the fixed-volume press, with the
addition of a polypropylene or elastomeric diaphragm attached to the face of the plate.
Figure 2-7. Schematic side views of recessed plate and filter frame
filter presses (EPA 1988).
2-220.127.116.11 Filter media can be installed on fixed-volume filter press plates with or without
gaskets. In non-gasketed plates, the filter media are draped over the entire plate and
held in place by hooking grommets located at the top of media over clothdogs on the
top of the plates. For this design, the filter media provide the seal between adjacent
plates when they are closed. A reinforcing strip of heavier media is typically sewn on the