Patent ID: 6962560
Filing Date: 2005-11-08
Classification: B04B

Abstract:
1. A method of separating a slurry containing intermixed particulate materials of different specific gravity comprising: providing a centrifuge bowl having a peripheral wall and an open mouth; rotating the bowl about a longitudinal axis so as to rotate the peripheral wall around the axis; feeding the materials to the bowl so as to pass over the peripheral wall and causing the materials to separate such that a heavier portion of the materials collects on the peripheral wall while a lighter portion of the materials in the slurry escapes over the open mouth; defining on the peripheral wall at least one axially localized annular recess for collecting the heavier portion of the materials; defining in the recess an upper side wall and a lower side wall converging to a base interconnecting the side walls; providing at the recess a plurality of angularly spaced discharge ports each for allowing materials collecting in the recess to discharge outwardly from the peripheral wall, each discharge port being located with a mouth at the base; providing for each discharge port a valve operable for closing the port for preventing discharge of collecting materials and for opening the port, and periodically operating the valve during the separation of the materials to allow said discharge; collecting the outwardly discharge materials; injecting fluidizing liquid into the recess through a plurality of fluid injection ports arranged at angularly spaced positions around the recess for fluidizing the material in the recess; providing in the recess a bed of movable bodies free to move within the recess and located inwardly of the fluid injection ports and inwardly of the discharge ports; the movable bodies being larger than the particles and shaped to as to define interstices between the bodies so as to allow the particles to pass therebetween; and confining the movable bodies within the recess.