Patent ID: 6796934
Filing Date: 2004-09-28
Classification: B04B

Abstract:
A centrifugal concentrator for separating particulate material of higher specific gravity from particulate material of lower specific gravity, comprising a) a rotating member adapted for rotation about an axis, (b) material supply means to deliver said particulate material into said rotating member, c) a plurality of cavities for receiving said particulate material of higher specific gravity, extending radially outwardly with respect to the axis of rotation of said rotating member, said cavities each having an outwardly-extending outlet, and d) a flow control valve for controlling the flow of material from said outwardly-extending outlets of said cavities; wherein said flow control valve comprises a fluid inlet communicating with said outwardly-extending outlet, a fluid outlet and a passage communicating therebetween and having a cross-sectional radius in the plane perpendicular to the longitudinal axis of said passage, wherein said passage is radially constrictible from a fully open to a closed condition while maintaining a cross-sectional shape which is substantially circular over a major range of such radial constriction wherein said flow control valve comprises a cylindrical elastomeric valve member disposed within said passage, and an annular elastomeric constrictor element mounted coaxially around said cylindrical elastomeric valve member and having a central thickened region for contacting and constricting said cylindrical elastomeric valve member and wherein said flow control valve further comprises a valve body, said valve body comprising a passageway communicating with a compressed gas supply for supplying gas under pressure to the exterior of said annular elastomeric constrictor element to thereby constrict said passage, and wherein said flow control valve comprises a pressure relief passage extending from the outer surface of said cylindrical elastomeric valve member, at a location axially inwardly from said annular elastomeric constrictor element, and communicating to the exterior of the valve body.