Abstract: A tunnel freezer uses carbon dioxide snow to directly contact product carried on a conveyor belt passing through the freezer. Fans are provided above and below the upper conveyor belt run carrying the product, with the fans above and below having downwardly directed exhaust. Trough-shaped deflector plates are provided adjacent the lower fans to circulate a flow adjacent the underneath surface of the upper conveyor belt run. Preferably, circulation adjacent the upper conveyor belt run is generally parallel to the upper conveyor belt run, and turning vanes are provided to deflect the flow upwardly through the upper conveyor belt run. Freezers may be provided with one or more cooling zones arranged in series along the path of conveyor belt travel.

Abstract: Refrigeration apparatus for cooling or freezing products such as protein materials includes a drum through which heat transfer fluid is circulated. A belt is wrapped around part of the drum surface and the product to be refrigerated is applied to the drum surface, being pressed thereagainst by the belt. Either liquid or triple point carbon dioxide is circulated through the drum to cool the product in contact therewith. Other heat transfer fluids such as D-Limonene or DOWTHERM may also be circulated through the drum. A tank and related apparatus for cooling the heat transfer fluid is also disclosed.

Abstract: Refrigeration apparatus for cooling or freezing products such as protein materials includes a drum through which heat transfer fluid is circulated. A belt is wrapped around part of the drum surface and the product to be refrigerated is applied to the drum surface, being pressed thereagainst by the belt. Either liquid or triple point carbon dioxide is circulated through the drum to cool the product in contact therewith. Other heat transfer fluids such as D-Limonene or DOWTHERM may also be circulated through the drum. A tank and related apparatus for cooling the heat transfer fluid is also disclosed.