GB1432907A - bodies - Google Patents

Abstract

1432907 Screw conveyers; discharging hoppers LA FAROE 22 Oct 1974 [24 Oct 1973] 45643/74 Headings B8A and B8S An elevator to feed grinding balls into a grinder column 55 comprises a conveyer screw 11 rotating inside a tube 10 at an angle of 30 to 60 degrees to the horizontal (and preferably at 45 degrees). The lower end of the tube 10 dips into a ball-reception hopper 13, while the upper end connects with a shoot 15 to discharge the balls into the grinder column 55 through its access door 56. The hopper 13 is in the shape of a triangular pyramid and has a bottom wall perpendicular to the tube axis, and two side walls at an angle of approximately 45 degrees on each side of the vertical plane containing the tube axis, one side wall 21 is tangential to the tube 10, while the other 22 is radial thereto. The first part of the screw 11, in the hopper 13, has an increasing pitch, feed of the balls to the screw 11 being controlled by a long roller 32, a short roller 33 and a bar 36, excess balls being recycled to the lower turns of the screw 11 down a spiral ramp 30, which ends the open section of the tube 10. Lubricant from spray apertures 53 is sprayed on to the balls in the hopper 13 to reduce friction.