Abstract: An improved dual-shaft preconditioner (10) of simplified design is provided giving increased moisturization and partial cooking of food or feed ingredients. The preconditioner (10) includes an elongated, tapered housing (12) presenting a pair of side-by-side, communicating housing sections (58, 60), with a corresponding pair of converging shafts (20, 22) within the sections (58, 60) and having a series of elongated, outwardly extending mixing elements (24, 26) secured to the shafts (20, 22). The preconditioner (10) is designed for use in a system including a downstream processing device, such as an extruder (146).

Abstract: Apparatus (20) for injection of fluid into extrusion system components such as a preconditioner (24) or extruder (100) is provided, preferably as a composite assembly including a fluid injection valve (52) and an interconnected static mixer section (54). Alternately, use may be made of the fluid injection valve (52) or static mixer section (54) alone. The invention greatly simplifies the fluid injection apparatus used in extrusion systems, while giving more efficient absorption of thermal energy with a minimum of environmental contamination, and the ability to inject multiple streams into the extrusion systems.

Abstract: Apparatus (20) for injection of fluid into extrusion system components such as a preconditioner (24) or extruder (100) is provided, preferably as a composite assembly including a fluid injection valve (52) and an interconnected static mixer section (54). Alternately, use may be made of the fluid injection valve (52) or static mixer section (54) alone. The invention greatly simplifies the fluid injection apparatus used in extrusion systems, while giving more efficient absorption of thermal energy with a minimum of environmental contamination, and the ability to inject multiple streams into the extrusion systems.

Abstract: Apparatus (20) for injection of fluid into extrusion system components such as a preconditioner (24) or extruder (100) is provided, preferably as a composite assembly including a fluid injection valve (52) and an interconnected static mixer section (54). Alternately, use may be made of the fluid injection valve (52) or static mixer section (54) alone. The invention greatly simplifies the fluid injection apparatus used in extrusion systems, while giving more efficient absorption of thermal energy with a minimum of environmental contamination, and the ability to inject multiple streams into the extrusion systems.

Abstract: Twin screw cooking extruders are provided requiring reduced specific mechanical energy inputs, through use of screw assemblies including first and second elongated, axially rotatable screws which are substantially coextensive in length, with the screw flighting presenting a pair of axially spaced apart sections of short pitch length and intermediate sections of greater pitch length. The intermediate sections have an axial length greater than about four times the length of the axially spaced apart sections.

Abstract: Screw assemblies are provided for cooking extruders characterized by operation using significantly reduced specific mechanical energy inputs, wherein the screw assemblies include first and second elongated, axially rotatable screws which are substantially coextensive in length, with the screw flighting presenting a pair of axially spaced apart sections of short pitch length and an intermediate section of greater pitch length. The intermediate section has an axial length greater than about four times the length of the axially spaced apart sections. The screw assemblies permit incorporation of significantly greater amounts of steam into comestible products during cooking thereof, as compared with prior art designs.

Abstract: An improved screw feeder assembly is provided for interconnection between the outlet of a preconditioner and the inlet of an extruder barrel. The assembly includes an upright housing with a pair of elongated shafts equipped with auger flighting within the housing and driven by means of motor. Preferably, the housing is mechanically coupled to the outlet and inlet with the shafts extending through the preconditioner vessel and downwardly to a point within the inlet and closely adjacent the screw(s) within the extruder barrel; the flighting is provided along the length of the housing, from a point closely adjacent the outlet and into the extruder inlet. This provides a positive conveyance of preconditioned material from the outlet to the inlet. Use of the assembly allows maintenance of superatmospheric pressures and temperatures above 212° F. within the preconditioner, which permits more efficient processing.

Abstract: Improved extruded starch-bearing products (e.g., starches, starch-bearing legumes, starch-bearing grains and formulations containing any of the foregoing) are provided having relatively high cook values and low cold water viscosities. The products are prepared by initial preconditioning to partially cook the starting material(s), followed by low shear extrusion cooking, with a total STE/SME ratio of at least about 4.

Abstract: Improved single screw extruders systems (40) are provided including a single screw extruder (42, 92) as well as an upstream preconditioner (44). The extruders (42, 92) include a single, internal, elongated, helically flighted, axially rotatable screw assembly (52) having one or more improved screw sections (74, 74a, 76). The screw sections (74, 74a, 76) include specially configured flighting (86) wherein adjacent flighting portions (86a, 86b) have smoothly arcuate surfaces (88) extending between the respective flighting portion peripheries (90a, 90b). This flighting design provides smooth, substantially surge-free operation while increasing SME and cook values. The preferred preconditioner (44) has independently controlled mixing shafts (106, 108) allowing the shafts (106, 108) to be rotated at different rotational speeds and/or directions.

Abstract: Improved extruded starch-bearing products (e.g., starches, starch-bearing legumes, starch-bearing grains and formulations containing any of the foregoing) are provided having relatively high cook values and low cold water viscosities. The products are prepared by initial preconditioning to partially cook the starting material(s), followed by low shear extrusion cooking, with a total STE/SME ratio of at least about 4.

Abstract: An improved screw feeder assembly is provided for interconnection between the outlet of a preconditioner and the inlet of an extruder barrel. The assembly includes an upright housing with a pair of elongated shafts equipped with auger flighting within the housing and driven by means of motor. Preferably, the housing is mechanically coupled to the outlet and inlet with the shafts extending through the preconditioner vessel and downwardly to a point within the inlet and closely adjacent the screw(s) within the extruder barrel; the flighting is provided along the length of the housing, from a point closely adjacent the outlet and into the extruder inlet. This provides a positive conveyance of preconditioned material from the outlet to the inlet. Use of the assembly allows maintenance of superatmospheric pressures and temperatures above 212° F. within the preconditioner, which permits more efficient processing.

Abstract: Improved extruders and methods for the extrusion cooking of comestible products such as human foods or animal feeds are provided wherein the products may be produced with very low specific mechanical energy (SME) inputs as compared with conventional processing. The methods preferably involve introduction of very high levels of steam into the extruder barrel during processing, which concomitantly reduces necessary SME inputs required to achieve desired cook and expansion levels in the products. In accordance with the invention, fully-cooked pet foods can be fabricated with SME inputs of up to about 18 kWhr/T, whereas aquatic feeds can be fabricated with SME inputs of up to about 16 kWhr/T.

Abstract: Improved preconditioners (10) are provided for partial moisturization of human food or animal feed ingredients prior to downstream final processing thereof in an extruder (56) or pellet mill. The preconditioner (10) preferably includes an elongated housing (12) having a wall (14) with an inlet (20) and an opposed outlet (22). The housing (12) also has a larger diameter end wall (16) proximal to the inlet (20), a smaller diameter end wall (18) proximal to outlet (22), and a progressively converging housing wall (14) with a taper angle of from about 2-9°. A shaft (36) extends along the length of housing (14) and supports a plurality of outwardly extending mixing elements (46) positioned in axially and circumferentially spaced relationship along the length of the shaft (36). The outer margins (54) of the mixing elements (46) cooperatively define a taper along the length of the housing wall (14).

Abstract: A knife assembly (10) particularly adapted for coupling with an extruder barrel (26) is provided having a knife shaft (16) supporting a knife unit (14), with the knife shaft (16) axially rotatable and axially shiftable through fore and aft limits. The assembly (10) may be adjusted during operation without interrupting the axially rotation of shaft (16), using adjustment mechanism (24) located in a safely remote position from knife unit (14). The preferred assembly (10) includes axial shift limiting structure (114, 116, 124) serving to limit the extent of fore and aft axial movement of shaft (16). The mechanism (24) allows fine adjustment of the position of knife unit (14) relative to the extruder barrel (26), and also permits monitoring of the wear of knife unit (14).

Abstract: The present invention is directed to improved preconditioners (12) especially useful for the production of high meat-content pet foods. The preconditioners (12) include an elongated housing (16) with one or more elongated, axially rotatable mixing shafts (18, 20) therein, each having a plurality of outwardly extending mixing elements (42, 44). The preconditioner (12) is provided with apparatus (56) for directing relatively large quantities of heated non-steam gas into the preconditioner (12) in lieu of most or all of the steam normally used with preconditioners. This serves to heat material passing through the preconditioner (12) without the addition of substantial moisture.

Abstract: An improved extruder (10) is provided which permits successful introduction of very high quantities of injected steam into material being processed, on the order of 6-8% or more by weight steam. The extruder (10) includes an elongated extruder barrel (12) having at least one elongated, axially rotatable, helically flighted extrusion screw (16,18) therein. The barrel (12) is equipped with obliquely oriented steam injection ports (44, 46) along the length thereof, housing steam injectors (48, 50). The barrel (12) includes relatively high free volume steam injection heads (32 and 38, 40) having therein screw sections (78, 82) of relatively long pitch length, together with steam restriction heads (30, 34, and 42) on opposite sides of the injection heads (32, and 38, 40) having therein relatively short pitch length screw sections (76, 80, 84).

Abstract: The present invention is directed to improved preconditioners (12) especially useful for the production of high meat-content pet foods. The preconditioners (12) include an elongated housing (16) with one or more elongated, axially rotatable mixing shafts (18, 20) therein, each having a plurality of outwardly extending mixing elements (42, 44). The preconditioner (12) is provided with apparatus (56) for directing relatively large quantities of heated non-steam gas into the preconditioner (12) in lieu of most or all of the steam normally used with preconditioners. This serves to heat material passing through the preconditioner (12) without the addition of substantial moisture.

Abstract: Improved extruders and methods for the extrusion cooking of comestible products such as human foods or animal feeds are provided wherein the products may be produced with very low specific mechanical energy (SME) inputs as compared with conventional processing. The methods preferably involve introduction of very high levels of steam into the extruder barrel (12) during processing, which concomitantly reduces necessary SME inputs required to achieve desired cook and expansion levels in the products. In accordance with the invention, fully-cooked pet foods can be fabricated with SME inputs of up to about 18 kWhr/T, whereas aquatic feeds can be fabricated with SME inputs of up to about 16 kWhr/T.

Abstract: Improved extruded starch-bearing products (e.g., starches, starch-bearing legumes, starch-bearing grains and formulations containing any of the foregoing) are provided having relatively high cook values and low cold water viscosities. The products are prepared by initial preconditioning to partially cook the starting material(s), followed by low shear extrusion cooking, with a total STE/SME ratio of at least about 4.

Abstract: Improved extruded starch-bearing grain products (e.g., corn and wheat) are provided having relatively high cook values and low cold water viscosities. The products are prepared by initial preconditioning to partially cook the starting material(s), followed by low shear extrusion cooking, with a total STE/SME ratio of at least about 4.