Patent ID: 6648253
Filing Date: 2003-11-18
Classification: B02C

Abstract:
A method for operating air circulation and conveying stock flow in a housing (1) of a hammer mill during comminution of scrap material, comprising the steps of:(a) continually feeding the scrap material to be comminuted through a stock inlet (3) provided in the housing (1) having an upper and a lower portion, (b) comminuting the scrap material with a rotor (2) including tools, the rotor is rotatably supported in the housing (1) and produces a blower effect with an air flow, (c) conveying the stock flow of the comminuted scrap material through a stock outlet in an upper classifying grate (4) provided in the upper portion of the housing (1), and conveying the stock flow of the comminuted scrap material through a stock outlet in a lower classifying grate provided in the lower portion of the housing, within an internal air circulation loop, a plane of the upper classifying grate is inclined relative to a rear wall of the housing (1), and wherein the stock flow is guided between grate bars of the upper classifying grate that are oriented substantially perpendicular to the inclined grate plane, wherein the air flow produced by the blower effect of the rotor (2) together with the classified stock flow that passes through the upper classifying grate (4) of the comminuted scrap material is diverted by a deflector hood (8) and guided downwardly in a duct (6) that is separate from the housing (1), and wherein the stock flow is combined in a region of the lower classifying grate (5) with the stock flow of the comminuted scrap material classified at the lower classifying grate (5), and wherein the air flow is repeatedly guided in a loop by underpressure in the loop between the lower classifying grate (5), the comminution chamber (7), the upper classifying. grate (4) and the duct (6), and wherein the combined stock flow of the comminuted scrap material is conveyed to a device (11) for further processing.