Patent GB-1322192-A (GB)
Title: Trash separating apparatus
IPC: B03B7/00
Filed: 1970-07-20
Abstract: 1322192 Reclaiming paper from waste DICKSON PAPER FIBRE Inc 20 July 1970 [31 July 1969] 35023/70 Headings B2H and B2J Paper materials are reclaimed from mixed shredded trash by classifying the trash by size into large and small particles, classifying the small particles by weight to remove lighter paper and plastics particles therefrom, classifying the large particles by weight to remove the lighter paper and plastics particles therefrom, directing both groups of lighter particles through an extraction device and extracting plastics particles from these lighter particles to yield lighter paper materials. As shown in Figs. 1 and 2, the trash is deposited on a sloped vibrating screen 43 which permits the passage therethrough of small sized trash particles. These particles then pass onto another sloped vibrating screen 44 whereby minutely sized particles pass therethrough into a hopper 46 to be delivered to a chute 48 which deposits these particles on a discard belt 52. The smaller sized particles which do not pass through the screen 44 enter a chute 57 which has a cross-current of air created therein by a blower 63, Fig. 3, whereby lighter particles such as paper and thin sheet plastics are forced from the smaller sized mixture into a side chute 74 to be delivered on to a conveyor 77 which deposits them on to a conveyor 144. The heavier particles fall vertically down the chute 57 and are delivered on to the discard conveyor 52. The larger sized particles that do not pass through the first screen 43 are delivered on to a rotating trash wheel 103 which throws these larger particles across a screened enclosure 93 beneath which is located a series of bins 88, 90, 91 and across which an air screen is provided by a nozzle 114. The larger particles thrown by the wheel 103 travel a given distance depending upon their weight or upon their ability to be thrown. Light paper particles with a certain amount of sheet plastics have the shortest trajectory and are collected in the bin 88 to be deposited on to the conveyor 144. Metal and hard heavy plastics particles have the greatest trajectory and are collected in the bin 91 to be delivered on to another discard conveyor 152. Larger paper, carboard, and some metal particles are collected in the intermediate bin 90. The air screen produced by the nozzle 114 ensures that light weight particles are not deposited in the bin 91 but are directed to the bin 90. The particles leaving the bin 90 are deposited on to another, vertically adjustable, sloped vibrating screen 167 whereby larger paper materials slide over the screen on to the conveyor 144 and the remaining particles pass through the screen on to the discard conveyor 152. The conveyor 144 then passes beneath an extractor 23, Figs. 9 and 10, in which sheet plastics are removed from the paper materials by means of two sets of electrostatically charged brushes 194, leaving the reclaimed paper on the conveyor 144. The extractor 23, Figs. 9 and 10, comprises two extraction devices 184, 185 and an intermediate paper pick-up device 208. The devices 184, 185, 208 are vertically adjustable relative to the upper run of the conveyor 144. Each extraction device comprises a U-shaped yoke 186 supporting a motor-driven set of spaced wire brushes 194 between which extend the teeth 197 of a fixed comb 196. Electrostatic charge is induced on the brushes due to their contact with the particles on the conveyor and with the teeth 197. A hood 198 is provided above the comb 196 and the brushes 194, and its interior communicates via a duct 201 to a vacuum withdrawal line 202 for removing the sheet plastics components scraped off the brushes 194 by the comb teeth 197. The pickup device 208 includes a U-shaped yoke 210 supporting a straight or helically bladed rotary impeller 211 surrounded by a housing 218 having an inlet 220 which acts as a scoop to skim up from the conveyor 144 paper particles from which plastics components have been separated by the first extraction device 184. The paper particles are delivered by the impeller 211 through a duct 221 back on to the conveyor 144 downstream of the second extraction device 185 which serves to extract the remaining plastics components from the conveyor. The screens 43, 44 are disposed in a trough 40 mounted on vibratory supports 28-32. Each support, e.g. 28, includes a base 33 in which is disposed a threaded member 34 which is recieved in an upper member 35 secured by a pin 36 to a side wall of the trough. A cam device may be provided within each support for oscillatory motion of the upper end 35 of each support upon rotation of the cam. Alternatively, electric or pneumatic vibratory means may be remotely provided for actuating the supports. The hopper 46 is secured to the trough 40 by means of a flexible connection 47. An adjustable baffle 61 is provided across the trough 40 between the screens 43 and 44 to control the distribution of the smaller sized particles into the chute 57. The direction of the air blast from the blower 63 is controlled by a grid 66 which comprises vertical and horizontal louvres which are laterally and vertically adjustable, Fig. 4 (not shown). The trash wheel 103 has fixed or radially adjustable blades. The sizes of the inlets 120, 121, 122 to the bins 88, 90, 91 may be varied by angularly adjustable baffles 117, 118. The screen 167 is disposed in a trough 164 which is mounted and vibrated in the same manner as the trough 40.