Abstract: In centrifuges for separating solids-liquid slurries and which discharge concentrated solids through nozzles at the periphery of the centrifugal bowl or rotor, it is necessary to maintain a feed or influent rate at least as great as the nozzle discharge rate. According to the present invention, this is accomplished by driving from the centrifuge drive train a pumping means for returning concentrated solids from the nozzles to the centrifuge for recycling through the bowl.

Abstract: In a centrifuge for the separation of solids from liquid in which concentrated solids are discharged from radial nozzles at the rotor periphery, there is a need for control of the solids concentration by controlling the recycle of solids to the centrifuge. The present invention provides a flow path divided into small cross-sectional areas, as with parallel plates, for the flow of recycled solids therethrough, at an appropriate pressure drop and flow rate to cause a strong dependence on fluid viscosity. A small receiving tank, with a fixed or adjustable weir, is attached to the inlet of the sectional flow path to provide a constant pressure drop through the device by maintaining a volume of concentrated solids at a pre-selected height above the inlet. The cross-sectional area available for flow is manually adjustable by means of a blocking plate at the inlet of the sectioned flow path.