GB191024660A - Improvements in Rotary Dry Pan Mills for Grinding and Pulverizing Clay and similar Substances. - Google Patents

Abstract

24,660. P e n f i e l d , R. C. Oct. 24. Edge - runners and pans and like mills.-In an edge - runner mill, the screen is concentric with, in the same horizontal plane as, and is driven independently at a slower speed than the grinding-plates in the pan. The grinding-pan 17, Fig. 1, is secured to a vertical shaft 14, and is supported by a shoulder 15 on an enlarged portion 16 of the shaft. The rotary mullers consist of rings 20 secured by wooden wedges 24 or the like to a central portion 23, which is bored to receive one end of a sleeve 25 provided with a flange 27 let into and secured in a recess 28 in the part 23. Fitting over the other end of the shaft 25, by means of ball bearings, is an enlarged end 30 of a collar 37 supported on spring blocks 51 mounted on the framing of the machine. One or more horizontal screens 54 are supported by a skeleton frame 53, which has a central hub 55 mounted on ball bearings, and is revolved by bevel-gearing, enclosed in dust cases, on the shafts 71, 118 from the main driving- shaft 7. The screened material falls into a hopper 61, Fig. 2, with a cylindrical part 66 to prevent loose material from flying out of the pan. The lower end of the shaft 14 is mounted on a ball bearing, being supported in a casing 98 by arms 108, and provided with lubricating- means. Broken material may be screened by gratings 136 before being fed to the machine, the coarse material being delivered to the mullers and the fine material direct to the screens 54. The treated material passes through an opening 139 in the hopper 61, and is removed by an elevator. In a second form, the screen is formed in two parts, one made stronger than the other, and is secured to, and revolves with, the grinding - pen. A second screen is fixed below, and the fine materials passing through the two screens are separately removed by two concentric hoppers. In a third form, two or more pairs of mullers may be used, but the primary screen is actuated as shown in Fig. 1, and a secondary screen is fixed to the frame of, and revolves with, the primary screen, the materials being removed separately by two concentric hoppers. A circular rim 222, Fig. 8, surrounding the mullers is provided with an opening 222<a>, and a series of curved scrapers 225, 226, &c. are fixed on cross-pieces 223, 224, so that the material, during grinding, follows the direction of the arrows, finally leaving the grinding-area by the opening 222<a>. In a fourth form, the primary screen is mounted on the grinding-frame but placed on the inside, the grinding - plate being on the outside; the secondary screen is independently revolved in the manner shown in Fig. 1. The primary screen may also be revolved independently of the grinding-plates. In another form, shown in Fig. 11, a dust-pan 311 revolves with the screen 307, and the material is removed from the pan 311 by a plough 315 into a shoot 316. A secondary screen, which is fixed below, and rotates with, the screen 307, may be interposed between the screen and the dust-pan 311. A second plough may be provided to remove the tailings from the second screen.