Self-attritioning pulverizer

Claim 1

A self-attritioning pulverizer for reducing chunk material to a powder and comprising: a cylindrical shell including a peripheral wall and front and back end walls, said front wall being formed with a feed opening and said peripheral wall being formed with a outlet opening; cylindrical screen means received in telescopical relationship in said shell and open on at least the end facing said feed opening, said screen means cooperating with said shell to form an annular screened particle collection chamber in communication with said outlet; an axially disposed impeller received coaxially in said screen means and rotatably mounted from said back wall of said shell, said impeller including an axial shaft and a plurality of radially outwardly projecting blades terminating in radial outer ends; an array of axial baffles spaced in a cylindrical pattern about said screen means and projecting radially inwardly therefrom to terminate in blunt edges, spaced radially outwardly of said radial outer ends of said blades, said baffles cooperating together to define therebetween an annular holding zone, and said blunt edges cooperating together to form a substantially cylindrically shaped outline defining an attrition interface for projection radially inwardly therepast of such chunks to cause any chunks held in said holding zone with the respective radially innermost surfaces thereof projecting radially inwardly past said attrition interface to be rubbed by confronting surfaces of the chunks circulated about by said impeller to thus reduce the held chunks and circulated chunks; and drive means coupled with said impeller for rotation thereof whereby said chunks of material to be reduced may be fed progressively into said cylindrical screen means through said feed opening and said drive means actuated to rotate said impeller to cause said chunks to be orbited about by said impeller to be progressively thrown centrifugally outwardly into said holding zone to be retained by said baffles against orbiting and as said chunks build up in said holding zone the radially innermost surfaces of the chunks disposed radially inwardly in said zone will be held projecting radially inwardly past said interface and as further chunks are fed into said feed inlet, said further chunks will be orbited about a circular path defined by said radially innermost surfaces of the chunks retained by said baffles in said holding zone to thus wear the orbiting chunks against the retained chunks thus reducing said chunks against one another and causing the reduced particles to move radially outwardly between said retained chunks and through said screen means to be received in said collection chamber for removal through said outlet.