Patent GB-260952-A (GB)
IPC: B02C13/00
Abstract: 260,952. Riley Stoker Corporation, (Assignees of Riley, R. S., and Craig, 0.). Nov. 7, 1925, [Convention date]. Impact pulverizers, - A pulverizing-apparatus comprises a hollow casing having two peripherally communicating grinding-zones, the first zone, into which the coarse material together with air is fed, being provided with means for preliminarily crushing the material and with means for preventing hard foreign bodies from passing to the second zone, which is provided with impact bodies for finely grinding the material and with an outlet for the pulverized material. As shown, Fig. 1, the cylindrical casing 10 is divided into two chambers by a disc 15 carried by the central driving-shaft 13, the periphery of the disc being spaced from the inner periphery of the casing so as to form an annular passage 18 connecting the two grinding- zones 16, 17. The disc 15 is bolted to a flange 20 of a sleeve 19 keyed to the shaft 13, and hammer bars 25 are pivoted on pins 26 which pass through the flange 20 and flanges 27, 28 integral with the sleeve 19. Holes may be provided at each end of the bars 25 to allow the hammers to be reversed when they become worn. A grid 32. which may be in sections, surrounds the hammers 25. Any hard foreign body which enters the casing is thrown outwardly by the hammers through an opening provided in the grid into the annular space 34 and drops into a pocket 38 extending completely across the bottom of the casing 10. The pulverized material passes through the openings 40 in the grid and through the annular passage 18 into the second zone, where it is further reduced by means of pegs 50 on the disc 15 co-operating with stationary pegs 51 on the casing wall 52. The pegs 51 extend from the wall 52 to the disc 15, while the pegs 50 are short and are spaced some distance from the wall 52. The pegs consist of iron bodies 53, Fig. 6. cast in a flanged ferrule 54 of drawn metal. The peg is mounted loosely within a hole in its support, and the flange 55 of the ferrule is clamped between the support and a clamping-plate 56. The clamping- plate 56, Fig. 1. on the disc 15 is made in sections bolted to the disc. The pegs 51 are clamped between the wall 52 and a removable lining-plate 58 which, to enable access to be had to the pegs, can be turned round on a ring 66 secured to the tubular outlet passage 65. Pegs 70 project in. wardly from the casing to the periphery of the disc 15 and may have their flanges clamped between a liner 62 and the casing. A rejector device consisting of a series of blades 72 of U-shape in cross-section and bolted to a collar 74 on the shaft 13 revolves within the ring 66 and returns coarse particles to the grinding-zone 17. The ring 66 has a bevelled face 77 located close to the outer ends of the blades 72. Air, which may be heated, is drawn through a screened inlet into the first zone 16 by a fan 84 carried bv the shaft 13 and working within a casing 11 having a discharge pipe 85. When pulverizing fuel for combustion purposes, additional air may be admitted to the casing 11 through a rotary slidevalve 86. The casing 10 is divided on the axis of the shaft 13, and the upper part 61 is hinged to the lower part 60. The upper half of the fan casing 11 is removable for renewal of the blades of the fan and the liner 87, the outlet tube 65 and ring 66 being split on an horizontal diameter so that the fan cover may be lifted off after the casing cover 61 has been removed. A small opening 81 is provided adjacent the upper end of the feed-shoot 30, through which a strong blast of air is drawn to keep the shoot clean. In a modification, Fig. 8, pegs 91, 96 are provided on both sides of the disc 90 and engage between stationary pins 92, 97 on the casing walls, the disc 90 consisting of two plates between which the flanges of the pegs are clamped. The swing hammers 94 are all mounted with their inner ends in substantially a single plane. A collar 98 clamps the plates 90 to a flange 99 of a sleeve 100 on the shaft 101, and pins 102 passing through the flange and collar carry the swing hammers 94 on their outer ends. A collar 103 prevents the hammers from sliding off the pins. Specification 175,301 is referred to.