GB464007A - Discharge for grinding mills - Google Patents

Abstract

464,007. Ball mills. AMERICAN BALL-MILL CO. May 8, 1936, No. 13078. Convention date, Sept. 9, 1935. [Class 59] In a ball mill having a classifier provided with conduits alternately communicating with the interior of the drum and the discharge side, the separating walls between the conduits are curved to provide a substantially radial portion and a portion extending at an angle to the radius, the two portions being united with each other by a curve, and the portion extending at an angle to the radius having a grating for permitting the material to pass from one conduit into the adjacent conduit for discharge from the drum after having passed through the grating in the wall. As shown the rotatable drum 6 is provided with a discharge trunnion 8 in which is secured a trunnion liner 13 having an extension with alternate reversely directed ports 17, 19. Each port 17 is connected to a curved conduit 23 formed by curved walls 24, 25 closed by an inner and outer wall 27, 26 respectively, and the wall 24 is provided with a grating 29. End wall liners 33 on plates 31 abut the walls 27 of the conduits 23 so that the space between two conduits forms a return conduit 30 which is in communication with the interior of the mill through ports 19, 20. A space 34 between the end wall liner 33 and the cylinder liners 32 permit crushed material to enter the chambers 30 where the fines are sifted through the gratings 29 into the conduits 23 for discharge through a port 17 into trunnion 13 whilst the coarse material is raised in the chambers 30 and discharged back into the mill through ports 19, 20. The space 34 is less than the diameter of the crushing balls and the trunnion extension is provided with a flange 22 which serves as a barrier to deflect the balls. The apparatus may be used, without the extension 13, as a classifying means between two crushing chambers of a compound mill.