Abstract: A decanter centrifuge typically includes a bowl which is rotatable about its longitudinal axis and an independently rotatable screw conveyor mounted coaxially therein. A drive motor is provided to rotate the conveyor at a differential speed from that of the bowl, which has a separate drive motor. An engagement element, in the form of an indexing clutch, an over-running clutch or a selectively controllable clutching element, is provided between the conveyor drive motor and the bowl to simultaneously rotate the bowl and the conveyor during a cleaning in place operation of the centrifuge.

Abstract: A centrifuge apparatus having an adjustable weir surface for adjusting the depth of an annular pool of a light and heavy phase material mixture therein. A first annular plate is positioned over a discharge outlet and includes a plurality of notches, each defining a generally arcuate opening and in the periphery thereof. A second annular plate is positioned in coaxial parallel juxtaposition with said first annular plate and also includes an identical amount of notches, each defining a generally arcuate opening. The annular plates are angularly positioned with respect to each other such that the generally arcuate openings are placed in overlapping relationship. Therefore, depending upon the relative angular position of the annular plates with respect to each other, the weir length can be increased and decreased.