Precoat Filter consists of a layer of fine but permeable material laid down on a mesh or media and then act as a depth medium for fine particle. The coarser particle may form a cake on the precoat.
The precoat can also be added to the feed slurry . This is known as body feed. The body feed increase the volume of the cake to be filtered. Precoat are finer than granular media so that fine particles can be trapped without coagulation or flocculation.
It is usually impossible to regenerate or recover the precoat medium for reuse, because it is trapped in the filter cake.