GB723270A - A pulverizing mill for wood knots or wood pulp - Google Patents

Abstract

723,270. Grinding and cutting mills. SAITO, T. July 17, 1952 [April 16,1952], No. 18138/52. Class 59. Apparatus for pulverizing wood knots or pulp comprises a device 6, 7 in a tank 2 for crushing and transmitting material and a second crushing device adapted to receive the material from the tank and reduce it to a more finely-divided form. Material to be pulverized is fed from a hopper into the tank 2 which is formed over part of its lower surface with teeth 3 and ribs 4 co-operating respectively with the teeth 5 on blades 6 and with a screw 7 to effect pulverization of the material. The latter then passes through a passage 11 to a disc-mill attached to the end of the tank 2, the passage being ventilated through a mesh 13 and an opening 12. Disc-mills.-The rotating annular disc 9 is provided with a plurality of teeth which are separated radially by circular notches arranged at different radii from those separating the teeth on the corresponding stationary annular disc 8. Blades 20 are provided on the periphery of the rotating disc and serve to discharge the fines, which are entrained with air sucked through the opening 12 by rotation of the disc, through a passage 14 tangential to the periphery of the mill casing 10. Liquid, such as water when pulverizing knots and a solution of caustic soda when pulverizing pulp, is fed through a pipe 18 to the disc pulverizer and, in the case of knots, the supply of liquid is controlled according to the moisture content of the knots. The mills and the screw 7 are driven by an electric motor 21 driving through pulleys 22, 23 and gears 24.