GB235955A - Improvements in or relating to grinding, milling and pulverizing apparatus - Google Patents

Abstract

235,955. Mayhew, M. J., and Ramsay, R. K. March 26, 1924. Impact pulverizers.-In a grinding, milling, or pulverizing machine in which the material is shattered by means of hammers or maces pivoted to a rotary shaft, the material undergoes a progressive pulverizing action in a single chamber. a portion of the chamber for the preliminary or initial stage of the pulverizing having an imperforate wall, excepting for a feed-opening, thereby preventing the egress of any sparks which may fly off the mateirial, and a portion for the final pulverizing having a perforated wall or screen through which the pulverized material is drawn by means of a fan communicating therewith by means of an air duct. As shown, Figs. 1 and 2, the hammers 6 are carried by an horizontal shaft 1 within a cylindrical casing forming a. single chamber, the curved wall of which is perforated as to one half 9 and imperforate as to the other half 10, excepting for the feedopening 11 at the lower end of the shoot or hopper 12. The upper half of the screen-like portion 9 is enclosed by a semi-cylindrical cover 13. The pulverized material escapes through the wall 9 into an air duct 16 which is fitted with a perforated plate 17 or sheet of wire gauze and communicates with a centrifugal &c. fan on the shaft 1. The hammer links or bars 6 are carried separated by distance-pieces 3 on the shaft 1, and the terminal pieces or mace heads 7 may have a limited movement on their attachment pins 8. The wall 10 may be formed with a boxlike recess 18, provided or not with a flap 19, to receive any heavy foreign bodies present in the material.