Patent GB-260034-A (GB)
Title: Improvements in grinding, pulverizing, or disintegrating mills
IPC: B02C13/22
Filed: 1925-07-20
Abstract: 260,034. Cloud, W. A. July 20, 1925. impact pulverizers. - Relates to mills for grinding, pulverizing, or disintegrating shellac, gums, resin, sulphur, coal, and like materials that are detrimentally affected by heat. The invention refers to mills of the kind described in Specification 110,816, in which rotary discs or plates are provided with pins adapted to intermesh or co-operate with pins on stationary discs, the rotary discs revolving in vertical planes. The material after passing the pins on the rotary and stationary discs is expanded in a chamber surrounding the periphery and the back of a rotary disc the volume of which is not less than the total space occupied by all the pins on the rotary and stationary discs and the spaces left between the pins. A casing surrounding the discs is divided into compartments 21, 22, Fig. 1. The compartments are of different sizes and are provided with a pair of opposed rotary and stationary discs, the material being introduced from a shoot &c. 40 and through a central hole in the end-plate 38 of the casing, and discharged through an outlet into a balloon and other collector. The rotary discs 32. 33 are of such a size as to leave spaces 34 between their peripheries and the inside 37 of the outer casing for the passage of the material, the volume of the expansion chamber at the periphery and the back of a rotary disc being in no case less than the spaces occupied by the pins on the rotary and stationary discs and the spaces between the pins. The pins are preferably arranged in concentric circular rows on the rotary and stationary discs, and may be square or other shape in cross-section having a number of sides which may be flat or fluted. The spaces between the rotary and the stationary discs may be reduced as the diameters of the discs in their respective compartments increase.. and the lengths of the pins preferably decrease as the discs increase in diameter. The diameters of the pins and the distances between the pins on each rotary or stationary disc, or on both, may decrease from the centre to the periphery. Vanes or blades 46 may be secured to the back of the last rotary disc 33 to diminish the pressure at the outlet from the machine of the boss 47 of the disc, and an air-inlet 48 fitted with a slide 49 may be provided in the end plate of the casing. Instead of, or in addition to, the blades 46, a fan blade may be fitted on the main shaft 50 between each pair of compartments to throw the material outwardly from the centre of the machine. Fan blades 46a may be fitted at the periphery of the last rotary disc. The pins may have washers 52 seating in recesses 53 in the discs and be formed with screwed shanks 54 to engage tapped holes in the discs. On removing the end cap 56 and the nuts 57 on the end of the shaft 50 and detaching the securing bolts of the end plate, the driving-pulley 59, bearing 60, and end plate can be slid along the shaft 50. after which the whole of the working elements of the machine can be drawn out. One or more removable cleaning or clearing blocks may be placed in the first compartment of a machine to dislodge, any material that may be too large to pass through the first set of rotary and stationary pins. Square &c. pins 65. Fig. 5, may be provided on the edge of one or more of the rotary discs to co-operate with inwardly-extending stationary pins 66 on a compartment. A circular undulating lining or ring 67, Fig. 7. may be provided in a compartment and co-operate with outwardly extending teeth on the rotary disc. Blocks or segments 68 may be formed around the periphery of the rotary disc, or inwardlyextend - ing teeth may be provided at the side of the periphery of the rotary disc. The lining of the machine may be detachable and its surface may be smooth, angular, fluted, corrugated, &c. For heating or cooling purposes, the machine may be jacketed in one or more compartments; and the rotary or stationary discs may be made in sections with intervening spaces for heating or cooling. Fig. 11 shows a rotary hollow disc 32a with a divisional plate 77 and mounted on a shaft formed with passages 50a, 50b, 50<c> for the supply and discharge of steam, water, or air. The machines may be adapted for wet grinding with suitable discharge of water at one or all of the compartments. Fig. 12 shows a closed tank 79 at the top of the machine fitted with a baffle plate 82 and provided with an inlet 80 from the larger compartment of the machine and an outlet 81 to the smaller compartment. A preliminary crushing-apparatus which may consist of a number of pivoted hammers may be fitted in front of the first stationary disc. Two or more machines may be mounted on a single shaft, with the inlet shoot disposed between each pair of machines.