Fluidized impact mill

Abstract

A comminuting device for breaking-up charge bodies of frangible material to free their value content and to reduce it to a desired size employs an upright enclosure into which charge bodies are fed so as to minimize in-air flow and to provide a steady stream of the bodies into the upper end of a centrally positioned downflow feed duct from which a series of horizontally, radially outwardly extending and vertically spaced-apart discs of a rotating assembly are suspended to define a central chamber selection passageway that is open at its upper end to the lower end of the duct, and at its bottom end through a grating to a motor drive compartment into which a fluid is introduced under positive pressure. The bodies are selectively introduced into vertically spaced and radially extending side chambers defined by the discs on the basis of their respective weights, with the lighter weight and usually smaller bodies being first introduced and those of greater weight being the last, all in a progressive manner as the bodies are fed downwardly from the duct into the passageway. On being introduced into the side chambers the bodies are subjected to implosion and then flung radially outwardly from within the chambers against outwardly offset abutment portions within the central chamber selection passageway portion of the enclosure and moved upwardly as finally broken up particles or particulates along the inside of the enclosure into an upper chamber that is disposed between its outer walls and the feed duct.