GB1460805A - Grinding mill - Google Patents

Abstract

1460805 Roller and ring mills, ball and ring mills MASCHINENFABRIK GUSTAV EIRICH 7 March 1974 [14 March 1973] 10286/74 Heading B2A A mill comprises a container 1 and a grinding member carrier A', 30 Fig. 1 supporting pivotally mounted trailing arms 32 with grinding members 3 rotatably mounted on the arms 32, Fig. 3. The carrier and the container are rotatable either in the same or in opposite directions at overcritical speeds. The container 1 is driven by a pulley S, and the carrier A', 30 is driven by a pulley S' and coaxial central shaft A. Streamlined weights 34 can be supported on the shafts 33 of the grinding members 3 to increase grinding pressure. The grinding members are preferably mounted in pairs with one above and one below the arm 30. Feed to the container is via a pipe 40 or 40' and fines are sucked out via a pipe 43. Air is impelled into the container by a bladed wheel 5 via a pipe 41, the amount of air being governed by adjustment of blades 51 Fig. 3 on the wheel. A cyclone or similar separator can be used with recycling of air via the pipe 41. Each grinding member may comprise a single large roller (3a) Fig. 4, not shown, or smaller rollers 3b on arms 30b, Fig. 5. This embodiment is particularly suitable for use with balls. An alternative embodiment employs out of weights, Fig. 6, not shown. The members are arranged in opposed pairs, or different sizes from pair to pair. A further embodiment emloys an eccentric carrier and the grinding rollers have a hub 3a Fig. 7 (not shown) with a resilient e.g. rubber layer 3b surrounded by a hard grinding ring 3c. The swing arms extend beyond the roller shafts and are governed by adjustable springs 54. A still further embodiment includes sealing by a compressed air filled tube 57 Fig. 8 to permit grinding under reduced pressure or in an atmosphere of low temperature gas. The drive motor 59 has two output shaft ends 60, 61 driving the container 1 and carrier A' respectively. The shaft end 61 and drive belt S' and carrier serves as a brake on the container. Discharge is via a hood 63 and stationary hopper 64. A screw conveyor may be used to facilitate discharge. Ventilation ribs may be fitted on the end faces of the grinding members 3.