GB621051A - Improvements in or relating to milling or grinding machines - Google Patents

Abstract

621,051. Impact pulverizers. BALLS, D. W. May 21, 1946, No. 15357. [Class 59] In impact pulverizers of the type comprising an outer casing enclosing a milling chamber having a perforated circumferential wall spaced from the inner surface of the casing, the material to be milled is delivered to the chamber through an inlet disposed in alignment or substantially in alignment with the axis of rotation of the hammers or beaters, and the milled material is expelled through the perforated wall in a substantially radial direction and thereafter delivered to a discharge outlet by the action of an air stream which is caused to flow over the whole of the perforated wall in a direction parallel to the outer surface thereof. The mill shown comprises an outer casing 10 having a detachable cover plate 12, a fan casing 21 formed with a tangential discharge outlet 23, and a milling chamber 16 in which revolve beaters 26 mounted on a shaft 24 which also carries an exhauster fan 22. The chamber 16 is defined by a disc 15 with a central feed aperture 18 which is carried by the cover plate, a disc 29 secured to stream-lined projections 30 on the casing, and a circumferential perforated screen 31. The plate 12 is formed with air inlets 14, the size of which is adjustable by rotating an apertured disc 19 mounted on a boss 17 of the disc 15. Ingress of dust, &c. to the shaft bearings 27, 28 is prevented by seals 32, 33. The casing 21 is adjustable on the casing 10 so that the outlet 23 may be positioned horizontally, vertically or at an angle. The plate 12 and disc 15 are removable as a unit to enable the screen 31 to be exchanged for one of coarser or finer mesh.