Patent ID: 7293657

Claim:
A hydrocyclone for separating and classifying solids, comprising a separation chamber which includes a cylindrical inlet section, a first conically tapered section having a cone angle of 15 to 45 degrees adjacent to the inlet section, and a second conically tapered section extending from the first conically tapered section and having a cone angle of 4 to 15 degrees, the separation chamber and the inlet section having an overall length to diameter ratio no greater than 7:1; an inlet passageway which extends along a volute path toward the inlet section for introducing a slurry of solid particles into the inlet section so that the slurry rotates about the axis of the cyclone and passes through the tapered sections; an overflow outlet for finer solids in the inlet section; and an underflow outlet for receiving coarser solids from the second tapered section.