Patent ID: 6439394
Filing Date: 2002-08-27
Classification: B07B,Y10S

Abstract:
A system for dry separation of powders into at least two fractions comprising:a) a hollow body rotatable about a vertical axis of rotation, the hollow body having a cavity defined by a surface having an axis of rotation having a central axis coinciding with the axis of rotation of the hollow body, the surface defining the cavity having an upper edge having a greater diameter than a lower edge of the surface defining the cavity; b) a system controlling the rotation of the hollow body; c) at least one feeder constructed and arranged to substantially continuously feed dry powder into a feeding zone adjacent to the cavity surface near its lower edge, the length of the feeding zone being at least an order of magnitude less than the circumference of the cavity surface in its lower portion; d) at least one of the at least one feeder constructed and arranged to feed the dry powder into the hollow body at a location offset from the hollow body vertical axis of rotation; e) at least one discharge device constructed and arranged to substantially continuously remove powder from the cavity surface as a result of the cavity surface moving relative to the at least one discharge device; f) at least two hoppers, one of which is constructed and arranged to receive a powder fraction comprising powder particles passing over the upper edge of the cavity surface in the course of separation, and the second of which is constructed and arranged to receive a powder fraction remaining on the cavity surface essentially until the discharging device removes it from the rotating surface into the second hopper.