Centrifugal separator with presedimentation means

Claim 1

A centrifugal separator comprising a rotor forming a separating space and also a peripheral space for receiving separated sludge from the separating space, the rotor having peripheral outlets for discharging the separated sludge, a valve bowl movable axially in the rotor to open and close said sludge outlets, a stack of conical separation disks in said separating space, the rotor having a central inlet chamber for receiving a sludge-containing mixture to be centrifuged, a distributor forming a conical wall having openings through which said inlet chamber is connected to said separating space, the rotor also having opposed annualar surfaces fixed relative to the rotor and forming between the surfaces an annular slot through which said inlet chamber is connected to said peripheral sludge space independently of said wall openings, there being a presedimentation space located radially outward from said openings and leading from said inlet chamber to said annular slot, and annular flexible valve means for said slot, said valve means being fixed to the rotor and having one side directed toward the presedimentation space and an opposite side directed toward the peripheral sludge space, said valve means being operable to close said slot when subjected to substantially equal liquid pressures on said sides thereof and to open said slot upon creation of a substantial pressure difference on said sides in response to opening of said sludge outlets.