ABSTRACT
This chapter explains the solid-liquid filtration processes in which a liquid containing suspended solid is freed of some or all of the solid when the suspension is drawn through a porous medium. Filtration processes are divided into classes for convenience when considering the mathematical analysis of the factors involved. The chapter discusses the flow of liquids through packed beds and its application to cake filtration. In cake filtration the solid material accumulates on the surface of the medium, so that, after a short initial period, filtration is through the bed of deposited solid. The resistance to flow of the medium supporting the filter cake may be significant and must be taken into account. A truly incompressible cake will have constant permeability and porosity which are independent of the pressure difference or the liquid flow rate. Equipment that incorporates mechanical expression includes belt processes and tube presses which are fitted with deformable membranes used to effect compression of the filter cake.
