GB948819A - Improvements in granulators - Google Patents

Abstract

948,819. Ball &c. mills. UNITED GAS INDUSTRIES Ltd. May 2, 1961 [May 2, 1960], No. 15340/60. Heading B2A. Apparatus for granulating or reducing substances such as bone, chalk or furnace ash comprises a rotatable or oscillatable drum to receive the substance to be treated and having an operative zone formed with discharge perforations, a number of balls or other bodies contained in the drum and adapted to pound the charge, during the movement of the drum, a receiving chamber adapted to co-operate with the operative zone of the drum to receive therefrom the treated substance and discharge it directly into a container, and means for rotating or oscillating the drum about an axis to ensure the retention of the charge substantially on the lowest part of the operative zone during- the treatment of the substance. The operative zone may be formed in exchangeable sections. Where the drum is to be oscillated, the operative zone may extend only partly about the drum. In the apparatus shown, the drum 1 comprises truncated conical portions 2, 3 connected by a cylindrical portion 4, and the operative zone of the drum is formed by the portions 2 and 4 and by an inner end wall 5, the portion 2 and part of the wall 5 being provided with discharge perforations 9. The drum has a charging opening closed by a plug 15 and is driven from an electric motor 12 through reduction gearing which may include variable or change gearing, the drum, gear casing 11 and motor being together supported by a pedestal 13. The outer surface of the drum is lagged with sound-insulating material. The receiving chamber, which is stationary, is formed by an annular back plate 18 and by a cylindrical wall 19 which carries a flexible sealing ring 20. The receiving chamber has a discharge funnel 21 that is adapted to fit closely within the neck of an urn 22, the urn being supported by a platform 37 which can be raised or lowered. The plate 18 is swept by rubber wipers, brushes or scrapers, each of which is carried by an arm 23 fixed to the boss 6 of the drum, the outer ends of the arms being secured to a cylindrical skirt 24 the lower rim of which is fitted with a flexible sealing ring 25 that bears upon the plate 18 as the skirt rotates. The wall 19 and skirt 24 may be coned outwardly and downwardly. The pedestal 13 is supported by a base plate 26 fitted above a framework 27 provided with supporting rollers 28. Mounted upon the framework is a cabinet 29 which is lined with sound-insulating material and is provided with a charging opening closed by a plate 30. The cabinet may have a time clock and a signal lamp. The drum may be charged directly from the furnace or through the intermediary of a transfer container 45. The axis of rotation of the drum may be horizontal. The walls of the receiving chamber may be provided on the outer surface thereof with automaticallyoperable tappers or beaters for dislodging dust that may tend to cling to the inner surfaces of the walls. The drum may be oscillated by means of a slotted arm and a rotary cam or eccentric, or by means of a pinion and quadrant drive, the quadrant being oscillated by a reversing pinion.