Patent ID: 7712158

Claim:
A shredder for shredding solid matter in an incoming liquid-solid feed, the shredder comprising: a housing; an inlet defined by said housing for receiving the incoming feed; an end-cap contained within said housing, said end-cap having a downstream surface, said end-cap defining an axial opening communicating through said end-cap, said axial opening in fluid communication with said inlet, said axial opening defining a conduit for transfer of the feed through said end-cap; an impeller assembly located within said housing, said impeller assembly comprising: a rotatable shaft having an axis of rotation, said axis of rotation being coaxial with said axial opening in said end-cap; a circular impeller plate mounted axially on said shaft, said impeller plate having an upstream face; a plurality of impellers attached to said upstream face of said impeller plate, said plurality of impellers extending radially about said axis of rotation of said rotatable shaft, said plurality of impellers, said rotatable shaft and said end-cap in combination defining a centrifugal pump, each of said plurality of impellers having an impeller cutting surface opposite to said upstream face of said impeller plate, each said impeller cutting surface being generally normal to said axis of rotation, said end-cap defining a plurality of recesses along a periphery of said axial opening of said end-cap, each said impeller cutting surface located adjacent to and abutting said end-cap downstream surface proximal to said plurality of recesses, wherein rotation of said impeller cutting surface proximal to said downstream surface of said end-cap defines a shredding engagement; a cutting blade integrally affixed to said impellers and extending axially in an upstream direction from said impeller cutting surfaces, said cutting blade defining a blade cutting surface, said blade cutting surface oriented generally parallel to said axis of rotation and normal to said impeller cutting surfaces, said cutting blade projecting through said axial opening, said plurality of recesses and said axial opening in combination defining a plurality of stationary cutting teeth, wherein said plurality of recesses and said plurality of cutting teeth are located alternately along said periphery of said axial opening, said blade cutting surface defining a rotating motion proximal to said stationary cutting teeth, wherein said rotating motion of said blade cutting surface proximal to said stationary cutting teeth defining a shredding engagement within said axial opening; and a motor connected to said shaft and configured to rotate said shaft.