Homogeneous substitution method and apparatus for cake using filter press

Abstract

In homogeneous substitution washing method and apparatus for a cake using a filter press which comprises pairs of opposed squeezed and squeezing filtering plate units, pairs of opposed squeezed and squeezing filtering cloths, each pair of filtering cloths being arranged between the pair of filtering plate units, and diaphragms. Each diaphragm is arranged on one side of one of the pair of filtering plate units. Stock solution is supplied into a space between the pair of filtering cloths, and is pressurized and dehydrated by the diaphragm to form the cake. The cake is processed in washing to obtain a clean raw material. In parallel with the pressurizing and dehydrating step of the stock solution, a washing liquid is poured into a space between the diaphragm and the squeezing filtering cloth abutted against the diaphragm, at a pressure at least a pressurizing and dehydrating pressure applied to the stock solution through the diaphragm, to wash the cake between the pair of filtering cloths.