ABSTRACT

Filtration involves separation of solids from liquid using a porous medium or screen. Filtration is a mechanical separation and requires less amounts of energy than drying. There are two broad categories of filtration: conventional or dead-end filtration and crossflow or tangential flow filtration. The direction of the fluid feed in relation to the filter medium differentiates between these two categories. When the fluid feed is flowing perpendicular to the medium it is the conventional filtration and when it is parallel to the medium, it is crossflow filtration. In figure 12.1 a schematic of these two categories are shown. In case of conventional filtration, the cake thickness builds up fast as compared to the crossflow filtration (Figure 12.1). The medium used for conventional filtration are filter clothes, meshes, or screens. Crossflow filtration uses membranes for separation.