Abstract: A centrifuge rotor includes a dynamically balanced casing assembly having upper and lower parts that define a hollow bowl with a continuous peripheral gap between such casing parts. The casing parts are held in position by a series of bolt assemblies which maintain the axial spacing. Each bolt assembly has a pair of portions respectively, rigidly secured to the casing parts, such bolt assembly portions having concentric interfitting surfaces, with a screw extending through one of said bolt assembly portions into the other. The concentric interfitting surfaces preferably include a step whereby precise location of the casing parts with respect to each other is achieved, even upon reassembly, thereby facilitating disassembly and reassembly as well as assuring maintenance of dynamic balance.

Abstract: A solid bowl centrifuge for separating substances of varying densities particularly for separating solid liquid mixtures having a self-emptying feature where the heavier material is discharged through an annular gap, the size of which is controlled by an annular slide valve separated by a pressure chamber and spring biasing means with the pressure chamber operative to close the valve and capable or rapid movements of the valve and moving the valve to a predetermined position by virtue of control valves and a measuring or dosing valve for the hydraulic fluid delivered to the pressure chamber.