Patent ID: 8083071

Claim:
A classifier comprising: a central particle inlet; a coarse particle outlet; a fine particle outlet; a conical feed surface comprising an upper apex and a lower base; a plurality of particle feeding vanes disposed on the feed surface, wherein the plurality of particle feeding vanes rotate together with the feed surface about a central axis of rotation; a classification surface disposed below the feed surface such that the classification surface is disposed closer to the lower base of the feed surface than it is to the upper apex of the feed surface, wherein the classification surface is approximately perpendicular to the central axis of rotation; and a plurality of classification vanes disposed on the classification surface, wherein the plurality of classification vanes rotate together with the classification surface about the central axis of rotation; wherein the classifier is configured such that particles to be separated enter the classifier through the central particle inlet near the central axis of rotation and flow radially outward on the feed surface to the classification surface.