Spiral freezer
AssigneeAir Products and Chemicals, Inc.
InventorsEdward F. Kiczek, David J. Klee, Kevin S. McAfee, Roger A. Howells
Life of this patent
Estimating the term…
Abstract
A spiral type freezer constructed and operated to introduce refrigerated atmosphere into the bottom of the insulated chamber and circulate the atmosphere in a circulation flow from the bottom of the chamber to an exit on top of the chamber, the refrigerated atmosphere producing a thermal gradient from the bottom to the top of the chamber so that the freezer is operated non-isothermally.
Claims7
In a freezer of the type having a spiral conveyor disposed within an insulated chamber, said spiral adapted to move items to be refrigerated and from a lower inlet in said chamber to an elevated outlet in said chamber said spiral conveyor having an axis of rotation, the improvement comprising:
- means for introducing a source of refrigerated atmosphere into a lower portion of said chamber;
- and
- means to circulate said refrigerated atmosphere inside said chamber from the point of introduction to a point of egress at an upper location in said chamber, said means to circulate refrigerated atmosphere is effected by including at least two circulating fans disposed generally perpendicular to the axis of rotation of said conveyor and directed to circulate refrigeration around said chamber, an inner solid cage disposed inside said spiral conveyor, said chamber having a cross-sectional shape perpendicular to the axis of rotation of a five sided irregular polygon with only two of the included angles being right angles, said chamber being disposed around said conveyor to effect circulation of refrigeration around said conveyor generally parallel to the direction of movement of said conveyor whereby, when in use, said insulated chamber is operated under non-isothermal conditions.
A method of operation a spiral cryogenic freezer containing a spiral conveyor to freeze articles wherein the refrigeration capacity is increased from 3 to 4 times comprising the steps of:
- modifying said spiral freezer by incorporating a solid cage inside said spiral conveyor and providing a chamber having a cross-sectional shape in a plane disposed perpendicular to an axis of rotation of said spiral conveyor of a five sided irregular polygon with only two of the included angles being right angles, said chamber disposed around said conveyor to effect circulation of refrigeration inside said freezer around said conveyor generally parallel to the direction of movement of said conveyor;
- introducing refrigerated air at approximately -250.degree. F. into the bottom of said freezer below said conveyor;
- circulating said refrigerated air around said spiral conveyor to permit exchange of refrigeration between said air and articles or conveyor in said freezer;
- and
- exhausting air from said freezer at about -100.degree. F.
Dependencies are inferred from the claim text.