Pocket centrifuge and method of operating same

Abstract

A pocket centrifuge has a plurality of sieve pockets having sieve surfaces and orbitable about an axis with the sieve surfaces forming sieve angles with perpendiculars to planes including this axis. A filtrant is fed radially to these pockets so that solids collect on the surfaces thereof and a filtrate passes through the surfaces. These solids have a friction angle measured to a perpendicular to the centrifugal force acting on them which is dependent on the magnitude of this force and their coefficient of friction. The angular orbiting speed of the pocket is periodically varied between one speed at which the respective friction angle of the solids is smaller than the sieve angle and the solids slide on the sieve surface and another angle at which the respective friction angle of the solids is greater than the sieve angle and the solids sit on the sieve surface. This variation in angular orbiting speed can be obtained by periodically braking or accelerating the rotor carrying the pocket, or by mounting this rotor for rotation about two axes for continuous acceleration and deceleration of the pockets. Alternately the sieve angles can be changed by pivoting the pockets on the rotor to achieve the same effect.

Dependencies are inferred from the claim text.