Image Number 4 for United States Patent #5800332.
A method and apparatus for separating solids from a liquid in a slurry using a centrifuge employing two simultaneous rates of rotation is disclosed. In the preferred form, the device includes an external bowl having at one end a hub with a central trough therein, plural passages from said trough through said hub extending radially outwardly to contact newly delivered slurry against the wall of the bowl, the wall comprising an elongate right cylinder construction terminating at a flange. A second portion of the bowl is tapered on the exterior and defines a rising beach portion on the interior. Inside, an elongate screw conveyor is deployed and is driven by the input velocity of an external motor rotating said bowl and said conveyor. The shaft connects to the conveyor through a differential motor which provides a scrolling speed of up to about 10 rpm. At the remote end, the conveyor tapers to cooperate with the beach portion of the bowl to scroll dry solids onto the beach and through an outlet. A skimmer chamber with a skimmer is incorporated to remove liquid.