Sludge centrifuge

Claim 1

IN A SLUDGE CENTRIFUGE OF THE TYPE ADAPTED FOR INTERMITTENT DISCHARGE OF SEPARATED SLUDGE, THE COMBINATION OF A HOLLOW ROTOR HAVING A SEPARATING SPACE FOR A FEED MATERIAL TO BE SEPARATED, AND ALSO HAVING A SLUDGE DISCHARGE OPENING LEADING THROUGH THE ROTOR WALL FROM SAID SPACE, A SLIDE VALVE IN THE ROTOR MOVABLE LENGTHWISE OF THE ROTOR AXIS TO POSITIONS FOR OPENING AND CLOSING SAID DISCHARGE OPENING, THE SLIDE VALVE HAVING AN INNER SURFACE PARTLY DEFINING SAID SEPARATING SPACE AND HAVING AN OUTER SURFACE PARTLY DEFINING A CONTROL CHAMBER LOCATED BETWEEN SAID OUTER SURFACE AND THE ROTOR WALL, SAID CONTROL CHAMBER INCLUDING AN INNER PORTION HAVING AN INLET AND ALSO INCLUDING AN OUTER PORTION EXTENDING RADIALLY INWARD FROM THE ROTOR WALL TO A RADIUS SUBSTANTIALLY SHORTER THAN THE MAXIMUM RADIUS OF SAID SEPARATING SPACE, A DEVICE FOR SUPPLYING AN OPERATING LIQUID TO SAID INLET TO ACCUMULATE IN SAID CHAMBER A BODY OF LIQUID OPERABLE UNDER CENTRIFUGAL FORCE TO HOLD THE SLIDE VALVE IN ITS CLOSING POSITION AGAINST THE PRESSURE IN THE SEPARATING CHAMBER, THE ROTOR HAVING MEANS FORMING AN OUTLET LEADING FROM SAID CHAMBER BETWEEN ITS INNER AND OUTER PORTIONS, WHEREBY DISCHARGE OF LIQUID THROUGH SAID OUTLET IS OPERABLE TO REDUCE SAID LIQUID BODY AND EFFECT MOVEMENT OF THE SLIDE VALVE TO ITS OPENING POSITION WHILE RETAINING LIQUID IN SAID OUTER PORTION OF THE CHAMBER, AND A CONTROL VALVE CARRIED BY THE ROTOR FOR OPENING AND CLOSING SAID OUTLET TO CONTROL SAID LIQUID DISCHARGE, SAID OUTER PORTION OF THE CHAMBER HAVING SUFFICIENT VOLUMETRIC CAPACITY AND RADIAL EXTENT THAT, IN SAID OPENING POSITION OF THE SLIDE VALVE, SAID RETAINED LIQUID IS OPEABLE TO RETURN THE SLIDE VALVE TO ITS CLOSING POSITION AUTOMATICALLY WHEN THE SEPARATION MATERIAL IN SAID SPACE HAS RECESSED TO A PREDETERMINED LEVEL.