GB1015287A - Apparatus for and method of segregating garbage - Google Patents

Abstract

1,015,287. Rotary sieves; magnetic separators. GENERAL SOCIETY OF REFUSE RECOVERY Ltd. Oct. 23, 1962, No. 39997/62. Headings B2H and B2J. Raw garbage to be segregated is fed at 22 to the interior of a rotary sieve screening drum 2, Fig. 1, where it is disintegrated by revolving breaker arms 21, and the fine and comminuted material passes through the screen 3 and is discharged by a conveyer 24 as a first separate stream, while the coarse material is agitated by blades 4 whereby the pieces of paper contained in the garbage are rubbed against one another with the interposition of dust produced by the disintegrating action and are thereby cleaned, the unscreened ferromagnetic material being then separated magnetically and discharged as a second separate stream by means of a conveyer 38, Fig. 3, and the remainder of the unscreened material containing the cleaned paper being discharged by means of a conveyer 37 as a third separate stream. The drum 2 is mounted on an inclined frame 1 and consists of the screen 3 surrounding the blades 4 which are rigidly secured to T-shaped ring members 5, Fig. 2, extending outside the screen 3 for engagement by supporting metal wheels 7 and pneumatic tyre driving wheels 8, the drive being by electric motor through reduction gearing. A thrust wheel 50 rotatably supported on an upright 40<SP>1</SP> is provided at the outlet end of the drum. The breaker arms 21 are secured to a shaft 16 supported in bearings 15, 17 and belt-driven by an electric motor 19. The drum 2 is enclosed by an outer stationary shell 26 having inclined lower portions 27 for directing the screened material on to the conveyer 24 and provided with a duct 54 through. which dust is exhausted and returned to the conveyer 24. The ends of the shell are closed by flexible curtains 53. The inside of the shell is lined with longitudinally extending steam coils 28 for warming the garbage so as to dry the paper and initiate biochemical reactions. A curved plate 51 protects the coils and the shell in the region of the breaker arms. Magnetic separation is effected near the outlet end of the drum 2 by means of an arcuate permanent magnet 32 secured by non-magnetic bolts to a bracket 31, Fig. 3, and disposed close to the drum 2 which in this region comprises a cylindrical plate 34 of non-magnetic material, the blades 4 being replaced by non-magnetic members 35 in the same region. The conveyers 37, 38 are mounted on each side of a bar 39 cantilevered on uprights 40 and are driven, together with conveyers 24, 25, by a motor through chain and sprocket arrangement 49. Conveyer 37 extends from 42 outside the drum to 41 just short of the magnet 32 and is disposed in the sector zone embraced by the magnet, whereas conveyer 38 is disposed outside that zone and terminates at 44 past the upstream side of the magnet and at 45 outside the drum. Deflectors 43, 46 extend along the inner portions of the conveyers 37, 38. Inverted V- shaped deflector plates 47, 48 extend upwardly respectively from the bar 39 in the magnetizing zone and over the conveyer 38 in the magnetizing zone. As the coarse material enters the magnetizing zone the ferromagnetic components adhere to, and rotate with, the plate 34 of the drum until a point opposite the upper end 36 of the magnet where they become demagnetized and drop on to conveyer 38 from which they fall on to a transverse conveyer leading to a treating station. Non-ferromagnetic material lifted by the portions 35 of the blades 4 falls back to the bottom of the screen assembly and is lifted again outside the magnetizing zone by the blades 4 and eventually falls on to conveyer 37. Any material not falling on conveyer 37 will fall on the plate 48 and back on to the bottom of the drum 2. Material other than paper is removed manually from the conveyer 37 which carries the paper to a baling press. The screened material, the dust and the unscreened coarse material, other than paper, are directed by conveyer 25 to digesters.