US 4,018,675 AGranted

Waste sorting machine

OwnerBen G. Petrucciinventor

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Abstract

A hexagonal-in-section trommel is rotatably mounted on a frame with the axis of rotation inclined downwardly from a waste material input end to a discharge end. The walls of the trommel include panels formed of screens having various predetermined mesh sizes, some relatively large, others relatively small. Inwardly projecting rods mounted on the interior walls of the trommel are spaced apart in such a way that larger pieces (such as old corrugated paper board, or cardboard, long strips of paper and plastic sheets) are engaged by the rods and are lifted up the side walls of the trommel, thereby allowing smaller pieces of waste material not lifted by the rods to pass downwardly through the screen mesh for removal by a subjacent conveyor. Concurrently, as the larger pieces approach the top of the trommel, they are disengaged from the rods by gravity; and as the larger pieces fall toward the bottom of the trommel, they concurrently move toward the discharge end owing to the trommel's inclination. As the corrugated board, long strips of paper and plastic sheets fall toward the bottom of the trommel, the heavier, more compact, corrugated board with rigid sharp corners tends to force any underlying light flexible plastic sheets or paper strips downwardly against the screen and poke them through the wider meshes for removal by the subjacent conveyor. Any pieces of light plastic or paper which might still be intermingled with the corrugated board at the discharge end of the trommel are removed by an air blast. Thus, both small, undersized particles and large, yet light, pieces of paper and plastic are efficiently separated from the desired panels and flattened cartons of old corrugated board.

A waste sorting machine comprising:

a. a frame:
b. an elongated, polygonal in cross-section trommel extending from an input end to an output end, the walls of said trommel being formed of screen having a predetermined mesh size incapable of supporting waste material smaller than said mesh size,
1. each side of said polygonal in cross-section trommel including a plurality of panels covered by said screen and extending consecutively between said input end and said output end, said predetermined mesh size on at least some of said panels varying in dependence upon the distance from said input end and the side of said trommel on which said panel is located,
2. at least some of said panels adjacent said input end carrying screen of relatively large mesh size and the remaining panels adjacent said input end carrying screen of relatively small mesh size,
3. at least some of said panels adjacent said output end carrying screen of relatively large mesh size and the remaining panels adjacent said output end carrying screen of relatively small mesh size;
c. means for mounting said trommel on said frame for rotation about the longitudinal axis of said trommel, said axis being inclined downwardly from said input end toward said output end in order gravitally to advance waste material entering said input end as said trommel is rotated, and to discharge through said output end material larger than said mesh size;
d. means for rotating said trommel;
e. a plurality of rods mounted on said trommel, said rods projecting into the interior of said trommel and being capable of engaging said material larger than said mesh size in the floor portion of said trommel and elevating the same as said trommel is rotated, said rods being incapable of supporting said material larger than mesh size when said rods approach an inverted position adjacent the ceiling portion of said trommel,
1. said material larger than said mesh size including rectangular panels of relatively heavy and rigid corrugated board plus sheets of pliable light gauge material, and wherein said relatively large size mesh provides a plurality of openings through which a substantial portion of the corners of said rectangular panels can protrude as said material larger than said mesh size falls away from said rods when said rods approach said inverted position, said corners of said relatively rigid corrugated board panels being capable of engaging and poking subjacent ones of said pliable sheets downwardly through respective ones of said openings to a location outside said trommel while said relatiely ridgid corrugated board panels remain inside said trommel;
f. conveyor means located adjacent said output end for carrying away said material larger than said mesh size advancing through said trommel and discharging through said output end;
and,
g. means below said trommel for removing said material smaller than said mesh size passing downwardly through said screen in the vicinity of said floor portion of said trommel.

9 more elements

Abstract

Claims5