US2010062093A1PendingUtilityA1

Method and apparatus for producing fully cooked extrudates with significantly reduced specific mechanical energy inputs

62
Assignee: WENGER MFGPriority: Sep 11, 2008Filed: Sep 11, 2008Published: Mar 11, 2010
Est. expirySep 11, 2028(~2.1 yrs left)· nominal 20-yr term from priority
Inventors:Lavon WengerMarc WengerGalen J. RokeyAllan C. Spellmeier
B29C 48/40B29C 48/405B29C 48/03B29C 48/535B29C 48/402B29C 48/2526A23P 30/20B29C 48/395B29C 2948/92885B29C 48/686B30B 11/246B29C 2948/92952A23N 17/005B29C 48/80B29C 48/295B30B 11/243B29C 2948/9259B29C 48/54B29C 48/832B29C 48/06Y02P70/10
62
PatentIndex Score
0
Cited by
0
References
0
Claims

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. In preferred forms, the extruder ( 10 ) includes specially configured, intermeshed extrusion screws ( 18, 20 ) and a plurality of obliquely oriented steam inlets ( 48, 50 ), and an upstream, dual-shaft preconditioner ( 90 ) is used having individual variable frequency drives ( 98, 100 ) which allow infinite variablility in the speed and rotational direction of the preconditioner shafts ( 94, 96 ).

Claims

exact text as granted — not AI-modified
1 . A screw assembly for use in a twin-screw extruder and comprising;
 first and second elongated, axially rotatable screws each having an elongated shaft with outwardly extending helical flighting along the length of each shaft, the flighting of each shaft being intermeshed with the flighting of the other shaft,   the flighting of each of the first and second shafts presenting a pair of axially spaced apart sections of short pitch length, and an intermediate section having a pitch length greater than the pitch lengths of either of said short pitch length sections,   the flighting of said intermeshed intermediate sections having an axial gap distance therebetween of from about 0.1-0.4 inches.   
   
   
       2 . The screw assembly of  claim 1 , said gap distance being from about 0.15-0.35 inches. 
   
   
       3 . The screw assembly of  claim 1 , said screws having an  D S/R D  ratio of from about 1.9-2.5. 
   
   
       4 . The screw assembly of  claim 1 , the ratio of the pitch length of said intermediate section to the pitch lengths of either of said first and second sections being from about 1-7. 
   
   
       5 . The screw assembly of  claim 4 , said ratio being from about 3-6. 
   
   
       6 . The screw assembly of  claim 1 , the flighting of both of said first and second screws being single flight. 
   
   
       7 . The screw assembly of  claim 1 , said short pitch length sections having the same pitch lengths. 
   
   
       8 . The screw assembly of  claim 1 , the ratio of said long pitch length to the flight depth ratio in the long pitch length section being from about 0.4-0.9. 
   
   
       9 . A screw assembly for use in a twin-screw extruder and comprising:
 first and second elongated, axially rotatable screws each having an elongated shaft with outwardly extending helical flighting along the length of each shaft, the flighting of each shaft being intermeshed with the flighting of the other shaft,   the flighting of each of the first and second shafts presenting a pair of axially spaced apart sections of short pitch length, and an intermediate section having a pitch length greater than the pitch lengths of either of said short pitch length sections,   the ratio of the pitch length of said intermediate section to the pitch lengths of either of said first and second sections being from about 1-7.   
   
   
       10 . The screw assembly of  claim 9 , the flighting of both of said first and second screws being single flight. 
   
   
       11 . The screw assembly of  claim 9 , said short pitch length sections having the same pitch lengths. 
   
   
       12 . The screw assembly of  claim 9 , the ratio of said long pitch length to the flight depth ratio in the long pitch length section being from about 0.4-0.9. 
   
   
       13 . A screw assembly for use in a twin-screw extruder and comprising:
 first and second elongated, axially rotatable screws each having an elongated shaft with outwardly extending helical flighting along the length of each shaft, the flighting of each shaft being intermeshed with the flighting of the other shaft,   the flighting of each of the first and second shafts presenting a pair of axially spaced apart sections of short pitch length, and an intermediate section having a pitch length greater than the pitch lengths of either of said short pitch length sections,   the ratio of said long pitch length to the flight depth ratio in the long pitch length section is from about 0.4-0.9.   
   
   
       14 . The screw assembly of  claim 13 , the flighting of both of said first and second screws being single flight. 
   
   
       15 . The screw assembly of  claim 13 , said short pitch length sections having the same pitch lengths. 
   
   
       16 . A twin screw extruder comprising:
 an elongated barrel presenting a material inlet and a material outlet;   a restricted orifice die positioned adjacent said material outlet; and   a screw assembly situated within said barrel and comprising—   first and second elongated, axially rotatable screws each having an elongated shaft with outwardly extending helical flighting along the length of each shaft, the flighting of each shaft being intermeshed with the flighting of the other shaft,   the flighting of each of the first and second shafts presenting a pair of axially spaced apart sections of short pitch length, and an intermediate section having a pitch length greater than the pitch lengths of either of said short pitch length sections,   the flighting of said intermeshed intermediate sections having an axial gap distance therebetween of from about 0.1-0.4 inches.   
   
   
       17 . The extruder of  claim 16 , said gap distance being from about 0.15-0.35 inches. 
   
   
       18 . The extruder of  claim 16 , said screws having an S D /R D  ratio of from about 1.9-2.5. 
   
   
       19 . The extruder of  claim 16 , the ratio of the pitch length of said intermediate section to the pitch lengths of either of said first and second sections being from about 1-7. 
   
   
       20 . The extruder of  claim 19 , said ratio being from about 3-6. 
   
   
       21 . The extruder of  claim 16 , the flighting of both of said first and second screws being single flight. 
   
   
       22 . The extruder of  claim 16 , said short pitch length sections having the same pitch lengths. 
   
   
       23 . The extruder of  claim 16 , the ratio of said long pitch length to the flight depth ratio in the long pitch length section being from about 0.4-0.9. 
   
   
       24 . A twin screw extruder comprising:
 an elongated barrel presenting a material inlet and a material outlet;   a restricted orifice die positioned adjacent said material outlet; and   a screw assembly situated within said barrel and comprising—
 first and second elongated, axially rotatable screws each having an elongated shaft with outwardly extending helical flighting along the length of each shaft, the flighting of each shaft being intermeshed with the flighting of the other shaft, 
 the flighting of each of the first and second shafts presenting a pair of axially spaced apart sections of short pitch length, and an intermediate section having a pitch length greater than the pitch lengths of either of said short pitch length sections, 
 the ratio of the pitch length of said intermediate section to the pitch lengths of either of said first and second sections being from about 1-7. 
   
   
   
       25 . The extruder of  claim 24 , the flighting of both of said first and second screws being single flight. 
   
   
       26 . The extruder of  claim 24 , said short pitch length sections having the same pitch lengths. 
   
   
       27 . The extruder of  claim 24 , the ratio of said long pitch length to the flight depth ratio in the long pitch length section being from about 0.4-0.9. 
   
   
       28 . A twin screw extruder comprising:
 an elongated barrel presenting a material inlet and a material outlet;   a restricted orifice die positioned adjacent said material outlet; and   a screw assembly situated within said barrel and comprising—
 first and second elongated, axially rotatable screws each having an elongated shaft with outwardly extending helical flighting along the length of each shaft, the flighting of each shaft being intermeshed with the flighting of the other shaft, 
 the flighting of each of the first and second shafts presenting a pair of axially spaced apart sections of short pitch length, and an intermediate section having a pitch length greater than the pitch lengths of either of said short pitch length sections, 
 the ratio of said long pitch length to the flight depth ratio in the long pitch length section is from about 0.4-0.9. 
   
   
   
       29 . The extruder of  claim 28 , the flighting of both of said first and second screws being single flight. 
   
   
       30 . The extruder of  claim 28 , said short pitch length sections having the same pitch lengths. 
   
   
       31 . (canceled) 
   
   
       32 . (canceled) 
   
   
       33 . (canceled) 
   
   
       34 . (canceled) 
   
   
       35 . (canceled) 
   
   
       36 . (canceled) 
   
   
       37 . (canceled) 
   
   
       38 . (canceled) 
   
   
       39 . (canceled) 
   
   
       40 . (canceled) 
   
   
       41 . In a method of processing comestible materials in order to produce a substantially fully cooked extrudate selected from the group consisting of pet feeds and aquatic feeds, said method comprising the steps of passing a comestible material including a starch-bearing ingredient through a cooking extruder having an elongated, tubular barrel with an inlet and an outlet and presenting a longitudinal axis, a restrictive orifice die plate disposed across said outlet, and an elongated, axially rotatable, helically flighted screw within said barrel, said passing step comprising the step of imparting an SME to said material, the improvement which comprises imparting an SME of up to about 18 kWhr/T to a pet food extrudate, and up to about 16 kWhr/T to an aquatic feed extrudate. 
   
   
       42 . The method of  claim 41 , said imparted SME being from about 10-18 kWhr/T for said pet food extrudate, and from about 8-16 kWhr/T for said aquatic feed extrudate. 
   
   
       43 . The method of  claim 41 , including the step of injecting steam into said material during passage of said material through said barrel. 
   
   
       44 . The method of  claim 41 , said extrudate being as least about 75% cooked, as measured by the extent of gelatinization of starch-bearing materials in the extrudate. 
   
   
       45 . The method of  claim 44 , said extrudate being from about 75-98% cooked. 
   
   
       46 . The extruder of  claims 16 ,  24 , or  28 , said barrel equipped with a plurality of steam injection ports at an area of the barrel adjacent said intermediate long pitch sections of said screws. 
   
   
       47 . The extruder of  claim 46 , said injection ports oriented at an angle relative to the longitudinal axes of said screws.

Join the waitlist — get patent alerts

Track US2010062093A1 — get alerts on status changes and closely related new filings.

We store only your email — no account needed. See our privacy policy.