GB191128244A - Improvements in "Grinding Mills". - Google Patents

Abstract

28,244. Emerick, G. S. Dec. 15. Ball-and-ring mills.-In a mill provided with means for sifting the ground material, the carrier 20, Fig. 1, that drives the balls 22 round the grinding-ring 12 is provided on its upper surface with a feed-pan 24 having tangential channels 25 terminating a slight distance in advance of the centre of each ball, and on its lower surface with scrapers 27 to discharge the ground material through a central opening 28 in the floor 16 of the grinding- chamber 15. The material falls on to a disk 29 carried by the vertical driving-shaft 17, and is delivered into the space between two concentric vertical screens 30, 31. The fine material is blown through the outer screen 31 into a chamber 38 by fans 39 carried by the shaft 17, while the coarse material falls to the bottom and is discharged through the outlet 41<a> by scrapers 42. The coarse inner screen 30 prevents any lumps of material from being struck by the fans and projected against the outer screen. To prevent the screen 31 from becoming clogged, the inner end of a screwed rod 51 which passes through the outer wall 41 of the chamber 38 and a bracket 52 on the screen 31, is engaged by one arm 53, Fig. 3, of a spring- pressed tappet 54 pivoted to a bracket 56 on the inner screen, the other arm 58 being struck by an arm 59 on the shaft 17. The screw 51 can be adjusted by a handle 61 so as to move the arm 58 into or out of the path of the arm 59. Scrapers 48 carried by the shaft 17 deliver the fine material from the chamber 38 to the outlet 47. The upper and lower ends of the screen 31 are supported by rings 32, 33 formed on the casting 9 and base part 5, respectively, and the rings 34, 35 which support the inner screen 30 are carried by arms 36, 37 on the rings 32, 33.