Screw extruder for the production of an expanded dry feed for foodstuff

{
  "publication_number": "US4039168A",
  "country": "US",
  "kind": "A",
  "title": "Screw extruder for the production of an expanded dry feed for foodstuff",
  "abstract": "Proteinaceous raw materials, possibly mixed with starchy raw materials are extruded into an expanded dry feed or foodstuff by extruding a starting mix with at least 12 but not more than 20 percent by weight of moisture in a short time, while keeping the extruder permanently filled with raw material mixture. Preferably not more than 7 percent of fat should be present. The inventive apparatus for extruding this material has grooves in the extrusion casing extending in longitudinal direction, and the extrusion screw ends at the outlet side in a nose cone. Preferably one pitch length is present between a screw seal and the feed inlet, and also one pitch length is present between the feed inlet and a compression section of the screw.",
  "claims": [
    "1. A screw extruder for the production of an expanded dry feed or foodstuff, comprising: a stationary casing having an inner wall defining an axially extending bore; a screw mounted for rotation within said casing; the latter and said screw defining a push zone, a filling and transport zone, a compression zone and a final zone; said casing have a lateral filler opening at the beginning of said transport zone, and further having an outlet at one end thereof; said screw includes an end portion near said outlet, said end portion having the shape of a cone, said bore in the casing having an end portion surrounding said end portion of the screw and also having the shape of a cone, said casing and said screw extending in said push zone beyond said filler opening over a distance equal to at least one pitch length of said screw in a direction opposite to said outlet; said screw being sealed with respect to said casing at the end of said push zone; said filler opening being positioned at a distance of said compression zone which is at least equal to one pitch length of said screw; said casing having spaced-apart internal grooves extending in the longitudinal direction, said grooves having in cross-section the shape of a rectangular trapezium including a radially extending rectangular edge and a bevelled edge, said rectangular edge being the front edge and said bevelled edge being the rear edge when seen in the direction of rotation of said screw.",
    "2. The screw extruder as defined in claim 1, wherein said screw has inner channels for the passage of a coolant."
  ],
  "cpc": [
    "A23K 40/30",
    "A23K 40/20",
    "A23K 40/25",
    "A23P 30/34",
    "B30B 11/24",
    "B30B 11/248"
  ],
  "assignees": [
    "TROUW & CO NV"
  ],
  "filing_date": "1975-01-03",
  "publication_date": "1977-08-02",
  "grant_date": "1977-08-02",
  "priority_date": "1974-01-08",
  "application_number": "US-53841875-A",
  "family_id": "19820526",
  "citations": [
    "US2838794A",
    "US3827841A",
    "US3850415A"
  ]
}