Abstract: A centrifuge bowl for separating heavier particles from lighter particles and water comprises a first conical bowl wall leading to a pair of annular recesses at actually spaced positions. Each recess is generally re-shaped with an upper side wall, a lower side wall and a base. The base contains a plurality of angularly spaced discharge ducts each having a mouth projecting through the base into the interior of the bowl for collecting the heavier particles. A pinch valve is formed as an integral assembly with the mouth and duct and is mounted within a housing carried within the wall of the bowl. The housing, valve and duct can therefore be removed as a separate assembly by pulling from a chamber within the wall of the bowl. A compression fluid supply duct passes through the wall to communicate with the chamber.

Abstract: A centrifuge concentrator bowl of the type having a plurality of fluidized recesses at axially spaced positions along the peripheral wall of the bowl is modified by providing an increase in width of the area between each fluidized recess and the next. In the area between the fluidized recesses is provided a shallower recess which is non-fluidized which provides some collection of materials. The bowl is of a frusto-conical shape so that the open mouth is larger than the base and a restricting ring is attached at the open mouth to define and inner edge of a diameter less than that of the uppermost recess and approximating that of a recess lower in the bowl. The uppermost recess is a fluidized recess and at least one of the lowermost recesses are non-fluidized.

Abstract: A centrifuge bowl of the type having a base onto which the intermixed particulate materials in slurry form is fed for passing over the peripheral wall of the bowl includes a plurality of annular recesses at axially spaced positions on the peripheral wall with each recess having a plurality of openings at the base of the recess communicating with the jacket on the outside of the peripheral wall. Water is supplied through a channel in the support shaft of the bowl via a rotary union on the shaft which is arranged to cause a fluctuation in the flow rate of water passing to the jacket.

Abstract: A centrifugal separator for separating heavy metals from lighter ore includes a bowl rotatable about its axis and defining annular collection areas on the peripheral surface of the bowl at axially spaced positions along the bowl. At the peripheral wall in each area is provided a plurality of angularly spaced discharge openings which are controlled by pinch valves to periodically allow the radial escape of the collected material. The pinch valves of a first area are controlled at different timing to the pinch valves of a second area to vary the concentration of the materials collected in the different areas. The pinch valves are operated by a pressurized liquid system which is fed to the different areas through a swivel coupling mounted at a longitudinal shaft supporting the bowl.

Abstract: A centrifugal separator with substantially continuous discharge of the concentrate comprises a centrifuge drum with axially spaced rings projecting inwardly from the peripheral wall of the drum. The material between the rings is fluidized by injection of water. Each channel between the rings has a number of exit openings at the base of the channel for discharge of the concentrate. Each exit opening includes a pinch valve to restrict the discharge to predetermined time periods. Each exit includes injection openings around the exit for injecting water to replace the material discharged to maintain the fluidization between the channel.

Abstract: A centrifugal bowl is intermittently cleaned of concentrate by a scoop which projects into the bowl and is indexed in a direction axially of the bowl and moved radially of the bowl to enter each in turn of a plurality of annular grooves formed on the bowl surface. The fluidized material in the groove enters the scoop and is extracted from the scoop by suction.

Abstract: A centrifugal separator for extracting heavy metals from a slurry comprises a centrifuge bowl having an inwardly facing surface over which the slurry runs. A dam at a discharge end of the surface forms a shallow layer of particles which separate preferentially the heavy metals. The surface includes a portion formed by a plurality of annular membrane portions spaced axially and separated by radial rings extending from the surface to a supporting metal bowl. The membranes are deflated or retracted to gradually form annular cups for receiving the separated metals. The membranes are then inflated to discharge the collected materials while the feed is temporarily halted and the bowl continues to rotate.