US 10,882,238 B2 · Method for making quenched granular absorbent

Abstract

A method of extruding self-clumping granular absorbent having cold water soluble amylopectin starch binder formed from starch-containing admixture sufficient for extruded sorbent pellets to produce flowable binder flowing between pellets clumping them together producing clumps of pellets that become hard when substantially dry that have a crush strength of at least 25 PSI and clump retention of at least 80% and preferably at least 90%. As a result, dried pellet clumps are easy to pick up leaving behind unspent pellets for continued sorbent use. A pellet quenching method rapidly cools and dries pellets before leaving the extruder preventing loss of cold water soluble starch and binder, preventing pellet shrinkage, and preventing pellet densification. An air conveyor transporting quenched pellets removed from the extruder further cools and dries the pellets producing pellets ready for sorbent use.

Claims34

Dependent claims

A method of making extruded granular sorbent comprising the following steps:

(a) providing an extruder, a starch-containing admixture for being extruded by the extruder into sorbent pellets, a pellet quenching apparatus comprised of a quenching gas supply that supplies quenching gas delivered to quench the sorbent pellets extruded from the extruder;
(b) extruding the starch-containing admixture from the extruder at or above (i) an extruder temperature, and (ii) an extruder pressure without adding any water or steam during extrusion forming sorbent pellets;
and
(c) quenching each sorbent pellet immediately upon extrusion from the extruder in a quenching gas that cools each sorbent pellet producing quenched sorbent pellets that form clumps of at least a plurality of pairs of the quenched sorbent pellets when wetted with water that each have a clump crush strength of at least 65 pounds per square inch and a clump retention rate of between 80% and 99%.

1 more element

A method of making extruded granular sorbent comprising the following steps:

(a) providing an extruder, a starch-containing admixture for being extruded by the extruder into sorbent pellets from a discharge end of the extruder, and a pellet quenching apparatus comprised of an air mover that delivers quenching air to a substantially air-tight quenching chamber disposed at the discharge end of the extruder into which the sorbent pellets extruded from the extruder are received;
(b) extruding sorbent pellets from the starch-containing admixture in the extruder without adding any water or steam during extrusion, the sorbent pellets having an initial pellet extrusion temperature upon extrusion from the extruder;
and
(c) quenching each sorbent pellet extruded from the extruder into the quenching chamber by the air mover delivering quenching air into the quenching chamber (i) cooling the sorbent pellets to a temperature at least 15 degrees Celsius cooler than the initial pellet extrusion temperature, and (ii) reducing the moisture of the sorbent pellets to no greater than 13% moisture by uncoated pellet weight.

1 more element

Dependencies are inferred from the claim text.

Method for making quenched granular absorbent

Life of this patent

Method for making quenched granular absorbent

Life of this patent

Abstract

Claims34