Expressing filter plate - with diaphragm filter sheet having fluid passing opening protected against constriction or blockage

摘要

Expressing filter plate for a filter presS, comprises 2 base plate covered by a diaphragm sheet having a filter surface and formed with a fluid passing opening communicating with a filtrate or wash liquor passage in the base plate. A cover made of material of higher hardness than the diaphragm sheet has a tubular portion which fits in the fluid passing opening to provide a fluid inlet or outlet. Since the tubular portion is harder than the sheet it retains its shape without expanding inwardly towards the centre when the sheet is subjected to press. on its opposite surfaces. Thus the fluid passing opening will not be constricted or blocked due to plastic deformation.