System and ultrahigh pressure extrusion method for making extruded granular sorbent with post-extrusion cold-processing of extruded granular absorbent for size control

Patent metadata

Field	Value
Publication number	US-11083168-B2
Application number	US-201715445977-A
Country	US
Kind code	B2
Filing date	Feb 28, 2017
Priority date	Dec 29, 2015
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A post-extrusion extruded granular sorbent processing system having a pellet-collecting enclosure that receives pellets of granular sorbent extruded from a starch-containing admixture through a die at a discharge end of an extruder and transports the pellets in air from an air mover flowing from the enclosure through a pellet-conveying duct of a pneumatic conveyor cooling and drying the pellets. The system includes a subsystem configured for processing the pellets after extruding, cooling, and drying using a pellet processing machine configured for reducing a size of each pellet having a size greater than a size reduction setting of the machine. A preferred pellet processing machine has rotating horizontally and circumferentially corrugated rollers with a selectively variable gap between the rollers providing the size reducing setting and configuring the rotating rollers for reducing a size of the pellets passing between the rollers having a size greater than the gap between the rollers.

First claim

The invention claimed is:

1. A system for post-extrusion processing of extended granular sorbent comprising:
an extruder having a perforate extruder die at a discharge end of the extruder, the extruder receiving a starch-containing admixture gelatinized therein and extruding from the extruder die, sorbent pellets of granular sorbent comprised of starch;
a pellet-collecting enclosure disposed at the discharge end of the extruder, the pellet-collecting enclosure receiving the extruded sorbent pellets extruded from the extruder die;
a pneumatic conveyor comprised of an elongate pellet-conveying duct in air flow communicattion with the pellet-collecting enclosure and an air mover in air flow communication with the pellet-conveying duct and the pellet-collecting enclosure, the air mover flowing air through the pellet-conveying duct and the pellet-collecting enclosure transporting the extruded sorbent pellets discharged from the extruder die into the pellet-collecting enclosure away from the extruder and through the pellet-collecting enclosure and the pellet-conveying duct, the flowing air cooling and drying the extruded sorbent pellets during transport through the pellet-collecting enclosure and pellet-conveying duct; and
a granular sorbent processing subsystem configured for processing the extruded sorbent pellets after the extruding, the cooling, and the drying of the extruded sorbent pellets, the granular sorbent processing subsystem comprised of a post-extrusion pellet processing machine downstream of the pellet-conveying duct that receives the cooled and dried extruded sorbent pellets, the post-extrusion pellet processing machine configured to reduce a size of each one of the cooled and dried extruded sorbent pellets having a size greater than a predetermined particle size reduction setting of the post-extrusion pellet processing machine by removing a portion therefrom without increasing a bulk density thereof producing a size-reduced extruded sorbent pellet and a removed portion therefrom, the removed portion having the size smaller than the size-reduced extruded sorbent pellet, the post-extrusion pellet processing machine comprised of a pair of generally parallel generally horizontal rotating rollers, one of the rotating rollers comprising a horizontally corrugated roller and the other one of the rotating rollers comprising a circumferentially corrugated roller, the rotating rollers spaced apart by a gap therebetween that is selectively variable for (a) reducing a size of the extruded sorbent pellets having a size greater than a size of the gap between the rotating rollers during passage between the rotating rollers, and (b) allowing passage of the extruded sorbent pellets having the size smaller than the size of the gap between the rotating rollers without reducing the size thereof.

2. The post-extrusion processing system of claim 1 , wherein the extruder is a single screw extruder, and wherein the post-extrusion pellet processing machine is configured to reduce the size of the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine without one or more regions of compression or compaction being formed or otherwise induced in the size-reduced extruded sorbent pellets.

3. The post-extrusion processing system of claim 1 , wherein the post-extrusion pellet processing machine is configured to cut the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine in reducing the size of the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine.

4. The post-extrusion processing system of claim 1 , wherein the post-extrusion pellet processing machine is configured to shear the extruded sorbent pellets having size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine in reducing the size of the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine.

5. The post-extrusion processing system of claim 1 , wherein the post-extrusion pellet processing machine is configured to tear the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine in reducing the size of the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine.

6. The post-extrusion processing system of claim 1 , wherein the post-extrusion pellet processing machine is configured to pull apart the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine in reducing the size the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine.

7. The post-extrusion processing system of claim 1 , wherein the post-extrusion pellet processing machine is configured to twist apart the plurality of extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine in reducing the size of the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine.

8. The post-extrusion processing system of claim 1 , wherein the post-extrusion pellet processing machine is configured to reduce the size of the extruded sorbent pellets having the size greater than the predetermined particle size reduction setting of the post-extrusion pellet processing machine without substantially increasing the temperature of the extruded sorbent pellets during size reduction by the post-extrusion pellet processing machine.

9. The post-extrusion processing system of claim 1 , wherein the post-extrusion processing machine is configured so the extruded sorbent pellets have increased water absorption after size reduction by the post-extrusion processing machine.

10. The post-extrusion processing system of claim 1 , wherein the pellet-collecting chamber comprises a substantially airtight pellet quenching chamber in air-flow communication with the pellet-conveying duct where the air in the pellet quenching chamber (a) quenches by rapidly cooling the extruded sorbent pellets extruded from the extruder, and (b) flows from the pellet quenching chamber into the pellet-conveying duct transporting the extruded sorbent pellets into the pellet-conveying duct.

11. The post-extrusion processing system of claim 1 , wherein the post-extrusion pellet processing machine comprises one of a roll granulator and a granulating mill.

12. The post-extrusion processing system of claim 1 , wherein the pair of rotating rollers comprises a pair of counter-rotating rollers with the selectively variable gap therebetween controlling at least one of (a) the size of the smaller sized sorbent particles comprised of the removed portions produced from the extruded sorbent pellets having the size greater than the gap between the counter-rotating rollers being reduced in size during passage through the gap between the counter-rotating rollers, and (b) an amount of the smaller size sorbent particles comprised of the removed portions produced from the extruded sorbent pellets having the size greater than the gap between the counter-rotating rollers being reduce

Assignees

• Pioneer Pet Products Llc

Inventors

• Lipscomb John M
• Rodriguez Omar I
• Berge Chad C

Classifications

• B29B2009/166

  Deforming granules to give a special form, e.g. spheroidizing, rounding · CPC title

• B29B9/16

  Auxiliary treatment of granules · CPC title

• B29B9/12

  characterised by structure or composition · CPC title

• B29C48/92

  Measuring, controlling or regulating · CPC title

• B29B9/06

  in the form of filamentary material, e.g. combined with extrusion · CPC title