The Reclamation of USED OILS: PART THREE CENTRIFUGAL PURIFICATION

FILTRATION, ON ANY SCALE, would be a very slow affair if the only force available were the natural head of the liquid. It is the usual practice therefore to speed up the filtration rate by the application of an external force greater than that of gravity alone. In the laboratory, the chemist normally employs suction by means of a water activated filter pump and in full scale practice—as with a filter press for example—the force is provided directly by the feed pump or assisted by compressed air.