Downstream pneumatic recirculation comminuting apparatus

An apparatus for comminuting severable waste material into pieces, comprising:

• a frame having an enclosure with an entrance opening for receiving the waste material;
• a recycle manifold inclined along a recycled material delivery direction extending from a lowered entrance end to an elevated exit end including a substantially horizontal spillway lip edge along an inclined side wall of the recycle manifold at the exit end to provide a lateral outlet therealong;
• a pair of overlapping scissor rolls provided beneath the recycle manifold and communicating with the entrance end of the recycle manifold, the scissor rolls rotatably carried by the frame with one of the scissor rolls elevated relative to another of the scissor rolls, the one scissor roll configured to draw solid waste material beneath the one scissor roll and up between the pair of scissor rolls and into the recycle manifold and operative to shear the waste material into smaller subdivided pieces as the material is passed between the scissor rolls, the another scissor roll communicating with the lateral outlet to draw material underneath the another scissor roll;
• a shear outtake manifold carried by the frame beneath the one scissor roll and the another scissor roll and configured to collect the subdivided pieces of waste material;
• a screen carried between the scissor rolls and the shear outtake manifold, and configured to permit undersized smaller pieces of a size less than the predetermined size to pass therethrough and collect in the shear outtake manifold and to prevent oversized smaller pieces of a size greater than the predetermined size from passing therethrough such that the oversized smaller pieces are drawn up between the pair of scissors rolls for further subdividing and delivery to the recycle manifold;
• and
• a pneumatic duct communicating with an upstream end of the shear outtake manifold and operative to entrain and remove the undersized smaller pieces from the shear outtake manifold.

An apparatus for comminuting solid waste material, comprising:

• a frame having an enclosure with an entrance for receiving solid waste material.
• a set of overlapping scissor rolls having horizontal axes provided in a common, inclined plane and rotatably mounted within the enclosure so as to shear the waste material into subdivided pieces as the material is passed from beneath and up between the scissor rolls;
• a recycle manifold elevated above the scissor rolls having a bottom entrance end and an inclined exit end above the bottom end providing a material spillway that delivers recycled material alongside one of the scissor rolls and beneath the pair of scissor rolls;
• a shear outtake manifold configured to collect the subdivided pieces;
• a separator screen carried by the frame between the scissor rolls and the shear outtake manifold, and having a plurality of apertures for separating subdivided pieces having a size less than a predetermined size which pass through to the shear outtake manifold for separation while preventing large subdivided pieces having a size greater than the predetermined size from passing therethrough;
• a source of air flow carried by the frame and communicating with a downstream end of the shear outtake manifold and operative to generate an airstream;
• and
• a pneumatic duct carried by the frame, communicating at one end with the source of air flow and at an opposite end with an upstream end of the shear outtake manifold, and operative to provide an airstream of sufficient velocity to deliver the subdivided pieces from the shear outtake manifold through an outlet at a downstream end.

A comminuting apparatus, comprising:

• a frame having an enclosure with an entrance for receiving waste material;
• a set of overlapping scissor rolls with one scissor roll elevated relative to another scissor roll, and the scissor rolls carried for co-rotation within the enclosure to provide an entrance nip from below and an exit nip from above and operative to comminute the waste material into subdivided pieces by drawing new waste material from the entrance and beneath the one scissor roll and up between the pair of scissor rolls and recirculating subdivided pieces around and beneath the another scissor roll for further subdividing between the scissor rolls;
• a recycle manifold elevated above the scissor rolls having a bottom entrance end and an inclined exit end above the bottom end providing a material spillway that delivers recycled material alongside one of the scissor rolls and beneath the pair of scissor rolls;
• a shear outtake manifold provided beneath the set of overlapping scissor rolls and configured to collect the subdivided pieces of waste material;
• a screen interposed between the set of scissor rolls and the shear outtake manifold and operative to permit undersized smaller pieces of a size less than a predetermined size to pass therethrough and to prevent oversized pieces of a size greater than a predetermined size from passing therethrough;
• and
• a pneumatic conveyor comprising a centrifugal fan and a pneumatic duct communicating with an upstream end of the shear outtake manifold, the centrifugal fan having a first outer volute duct for ejecting undersized smaller pieces from the pneumatic conveyor and a second outer volute duct downstream of the first outer volute duct and communicating with the pneumatic duct to deliver an airstream from the centrifugal fan into the shear outtake manifold that entrains the subdivided pieces and removes the subdivided pieces from the shear outtake manifold.

A method for subdividing and sorting pieces of solid waste material, comprising:

• providing a frame with an enclosure having an entrance, a set of overlapping scissor rolls carried within the enclosure, a shear outtake manifold provided beneath the scissor rolls, a sorting screen interposed between the scissor rolls and the shear outtake manifold, a tilted recycle manifold above the scissor rolls, having an elevated, lateral outlet including a horizontal lip edge, a recycle flow path downstream of the recycle manifold, a recirculation cavity downstream of the recycle flow path, and a pneumatic conveyor having a source of airflow external of the enclosure and a pneumatic duct communicating with the shear outtake manifold;
• receiving solid waste material into the entrance of the enclosure;
• directing the waste material via one of the scissor rolls between the one scissor roll and the separator screen, and between the scissor rolls to subdivide the waste material;
• accumulating the subdivided waste material within the recycle manifold above the scissor rolls;
• cascading the accumulated subdivided material over the lip edge via the recycle flow path from the recycle manifold section into the recirculation cavity;
• directing the subdivided material from the recirculation cavity between another of the scissor rolls and the separator screen;
• while directing the subdivided waste material between the another scissor roll and the separator screen, impinging the subdivided pieces against the screen to direct small subdivided pieces that are of a size less than a predetermined size through the screen and into the shear outtake manifold and delivering the subdivided pieces that are of a size greater than the predetermined size between the set of overlapping scissor rolls for further subdividing;
• collecting the small subdivided pieces of waste material in the shear outtake manifold;
• and
• delivering an air stream from the source of air flow into the shear outtake manifold to entrain the small subdivided pieces and remove the small subdivided pieces from the shear outtake manifold.