PROGRESS IN LIQUID SEPARATION BY FILTRATION.

Mechanical liquid separation is still a relatively inexpensive process in spite of the rising costs of equipment. At low energy consumption even finely dispersed solids can be concentrated more than ten times, often in a single process stage. Among the wide variety of equipment available, the completely enclosed, gas-tight filter has achieved considerable importance in the chemical industry as a result of industrial hygiene and safety regulations. Several mathematical models have been proposed for the cake filtration operations of filtration, washing and dewatering. For practical purposes a simple, approximate description of the cake formation process by means of the Darcy equation is adequate in most cases. However, in the case of solids with high segregation tendencies and compressible filter cakes the assumption of a homogeneous filter cake structure is no longer permissible.