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-12478034-B2
Application number	US-202117399040-A
Country	US
Kind code	B2
Filing date	Aug 10, 2021
Priority date	Dec 29, 2015
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

A method, system and machine for cold processing extruded starch-containing pellets by cold particle size reducing pellets of a size greater than a particle size reduction setting size enabling particle size reduction to be performed without compacting or compression any size reduced particle while doing so without heating them during particle size reduction thereby preserving their pores, internal liquid absorbing voids and starch matrix optimizing granular sorbent performance. Such a method, system and machine is selectively controllable enabling not only control of how many and a ratio of fines produced relative to the final product providing real time control of fines production but also is able to provide particle size distribution control as well. A preferred particle size reduction machine is a roll granulator that breaks larger size pellets into smaller sized particles and/or fines without compressing or compacting them with the spacing between the rolls selectively variably in a manner that regulates how much of different sized particles and/or particles falling within certain size ranges are produced advantageously enabling real time control of particle size distribution to be achieved during extruder line operation.

First claim

The invention claimed is:

1 . A method of making extruded granular sorbent comprising:
(a) providing a single screw extruder and a starch-containing admixture comprised of at least 40% starch and having a moisture content of no greater than about 25% by weight; (b) extruding the starch-containing admixture by (i) subjecting the starch-containing admixture in the single screw extruder to an extrusion pressure of at least 2000 PSI at an extrusion temperature of at least 100° C. for a residency time of no greater than twenty seconds gelatinizing at least some of the starch in the starch-containing admixture in the single screw extruder, at least some of the starch in the starch-containing admixture in the single screw extruder modified into a room-temperature water soluble binder, and (ii) discharging the starch-containing admixture from the single screw extruder as sorbent extrudate comprised of the room-temperature water soluble binder; (c) cold-processing the sorbent extrudate immediately upon being discharged from the single screw extruder by cooling the sorbent extrudate using air having (i) a temperature less than an initial temperature of the sorbent extrudate when discharged from the extruder, and (ii) a flow rate sufficient to cool the sorbent extrudate immediately upon being discharged from the extruder at a cooling rate of at least 5° C. per second for at least two seconds after discharge of the pellets of the sorbent extrudate from the extruder; and wherein, after the cold-processing step, the extruded granular sorbent is comprised of at least a plurality of pairs of pellets of the sorbent extrudate that form an agglutinated mass thereof within five seconds of being wetted with water, the agglutinated mass comprising a clump that is scoopable from a box of pellets within one minute of wetting the at least the plurality of pairs of pellets with water.

2 . The method of claim 1 , wherein the starch-containing admixture is comprised of one or more cereal grains, is comprised of at least 45% starch by weight, and has a moisture content of no more than about 20%.

3 . The method of claim 1 , wherein no moisture is added to the starch-containing admixture while the starch-containing admixture is in the extruder.

4 . The method of claim 1 , wherein the starch-containing admixture remains within the single screw extruder for a residency time of between eight seconds and twenty seconds before being discharged as sorbent extrudate from the extruder.

5 . The method of claim 4 , wherein the starch-containing admixture is subjected to an extrusion pressure of at least 2500 PSI within the single screw extruder during the extruding step.

6 . The method of claim 5 , wherein no moisture is added to the starch-containing admixture while the starch-containing admixture is in the single screw extruder during the extruding step.

7 . The method of claim 1 , wherein the starch-containing admixture is subjected to an extrusion pressure of at least 3000 PSI within the extruder during the extruding step.

8 . The method of claim 7 , wherein the sorbent extrudate comprises at least 5% by weight of the room-temperature water soluble binder, the room temperature water soluble binder comprised of a physically modified starch physically modified during the extruding step.

9 . The method of claim 1 , wherein the sorbent extrudate comprises at least 10% by weight of the room-temperature water soluble binder.

10 . The method of claim 1 , wherein the sorbent extrudate comprises at least 15% by weight of the room-temperature water soluble binder.

11 . The method of claim 1 , wherein the clump has a clump compressive crush strength of at least 500 PSI and a clump retention rate of at least 95% when the clump is dried to a moisture content of no greater than 12% by clump weight.

12 . The method of claim 1 , further comprising the step of providing a rotating cutter configured to cut the sorbent extrudate into pellets and cutting the sorbent extrudate into pellets during the extruding substep of discharging the sorbent extrudate from the extruder.

13 . The method of claim 1 , wherein the clump formed of the agglutinated mass of wetted extruded sorbent pellets has a crush strength of at least 400 PSI when the clump is dried to a moisture content of no greater than 12%.

14 . The method of claim 1 , wherein the clump formed of the agglutinated mass of wetted extruded sorbent pellets has a clump retention rate of at least 95%.

15 . The method of claim 1 , wherein the pellets of the sorbent extrudate has a water sorption capacity of at least five times pellet weight.

16 . The method of claim 1 , wherein the at least some of the other starch in the starch-containing admixture in the single screw extruder is modified during the extruding step into an enhanced liquid sorbent starch such that the pellets of sorbent extrudate have a water sorption capacity of at least four times pellet weight and sorb at least four times pellet weight in water within 30 seconds of being wetted with water.

17 . The method of claim 1 , further comprising the step of (1) providing a pneumatic conveyor in air-flow communication with (i) the single-screw extruder, and (ii) a pellet or particle size separating or classifying station, and (2) pneumatically transporting pellets of sorbent extrudate through the pneumatic conveyor to the pellet or particle size separating or classifying station.

18 . The method of claim 1 , wherein during the cold-processing step, air having a temperature of no higher than 37° C. is used to cool the sorbent extrudate immediately upon being discharged from the extruder.

19 . The method of claim 18 , wherein during the cold-processing step, air having a temperature of at least 37° C. less than the initial temperature of the sorbent extrudate is used to cool the sorbent extrudate immediately upon being discharged from the extruder and no heat is applied to the sorbent extrudate.

20 . The method of claim 1 , wherein during the cold-processing step, (i) the flow rate of the air is sufficient to cause the air to turbulently convectively cool the sorbent extrudate at a cooling rate of at least 10° C. per second for at least two seconds of the cold-processing step, (ii) both cooling and drying of the sorbent extrudate occurs, and (iii) the moisture content of the sorbent extrudate becomes less than 14% by weight.

21 . The method of claim 20 , wherein during the cold-processing step, (i) the flow rate of the air cooling the sorbent extrudate is at least 250 CFM, and (ii) the moisture content of the cooled and dried sorbent extrudate becomes less than 12% by sorbent extrudate weight.

22 . The method of claim 21 , wherein during the cold-processing step, (i) the flow rate of the air cooling the sorbent extrudate is at least 500 CFM, and (ii) the moisture content of the cooled and dried sorbent extrudate becomes less than about 10% by sorbent extrudate weight.

23 . The method of claim 1 , wherein the sorbent extrudate is configured to pick up and retain at least one times the weight of the sorbent extrudate of an aliphatic, hydrocarbon or petroleum-based liquid.

24 . The method of claim 23 , wherein the sorbent extrudate is configured to pick up and retain at least two times the weight of the sorbent extrudate of an aliphatic, hydrocarbon or petroleum-based liquid.

25 . The method of claim 23 , wherein the sorbent extrudate is f

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

• B29B9/12

  characterised by structure or composition · CPC title

• B29B9/16

  Auxiliary treatment of granules · 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