Abstract: A multiple hydrocyclone device wherein cyclone units are integrally formed in radial relationship in premolded discs which are mounted in stacked concentric and internested relationship one upon the other within a common housing. The hub portions of the discs provide a central chamber to receive the underflow fraction from the cyclones with the overflow discharged from openings in the periphery of the discs to an outer chamber. Sealing rings are arranged between the internested discs to maintain leak proof integrity of the stacked discs with spring urgent thrust plate means disposed at the top of the stack to permit movement or expansion of the discs in operation of the device without disturbing the sealed relationship.

Abstract: A nozzle type centrifugal machine designed for two-fraction separation of feed slurry, wherein the rotor has a light fraction overflow at the top, while feed slurry as well as underflow return slurry from the nozzles are introduced into the rotor from below into respective feed accelerating pumping chambers, and wherein improvements in the pumping chambers results in reduced power requirement and in improved overall performance of the machine.

Abstract: A nozzle type centrifugal machine with provision for light and heavy phase overflow delivery from top and bottom respectively of the rotor bowl, and equipped with control devices operable for correctively shifting the location of the interface within the limits of the centrifugal separating zone located within the area surrounded by a stack of separating discs.