Centrifugal separator having hydraulically operated outlet valves

Claim 1

In a centrifugal separator suitable for the concentration of suspended solids having a rotatable drum, hydraulically operated outlet valves uniformly distributed about the periphery of the drum mantle in the plane of greatest drum diameter and including housings containing nozzles having apertures and movable valve bodies shielded from the pressure of the drum charge, the valve bodies being movable by the centrifugal force of the drum at full rotating speed to close the nozzle aperture, the improvement which comprises a ring valve movable between a closed and an open position, for the hydraulic operation of the outlet valves, a passageway network having an inlet adjacent the drum axis, extending through the ring valve and on to the outlet valves for supplying operating liquid to the outlet valves for holding the valve bodies so that the nozzles are open, said passageway network being closed with the ring valve in the closed position so that the passageway network holds the operating liquid therein, and means for moving the ring valve to the open position wherein the passageway network is opened permitting draining of operating liquid from the outlet valves and movement of the valve bodies under the centrifugal force to close the nozzle apertures.