Abstract: This invention is concerned with axial conveying of sludge through a stationary tube from inside to outside a rotating centrifuge. It incorporates a high speed auger screw to move the material. High speed implies spinning of the auger too fast for sludge adhesion, and operating the auger only partially full. The feed to the auger is by an unrestrained jet of material from which any material not driven axially by the auger is permitted to fall freely away from the auger feed section. The combination of high rotational forces, open ballistic feed, and partially full screw, combine to assure transport of thixotropic materials.

Abstract: A process for screening materials as a function of particle size differences by feeding the materials onto one side of a substantially planar screen and vibrating the screen by producing a translational screen oscillation in directions normal to the screen plane and a torsional screen oscillation about an axis normal to the screen plane so that each point of the screen moves in a helical path. Screened material is collected at the other side of the screen and screened retentate is transported by the torsional screen oscillation to an exit port at a location spaced from the axis of torsional oscillation.The process is particularly applicable to shipboard or other mobile use, since the spring stiffness provides good structural support under tilt or side acceleration conditions.