SYSTEM AND METHOD FOR RAPIDLY FREEZING COLD PACKS WITH A FLAT SIDE AND A CONVEX SIDE
A system and method for freezing cold packs. The system includes at least one plate containing a low-temperature refrigerant and a mechanical refrigeration system. The system is configured to receive a cold pack on the at least one plate and freeze the cold pack by contacting one of its major faces.
1 . A system for freezing a cold pack comprising:
a plate containing a low-temperature refrigerant; and
a mechanical refrigeration system, wherein the system is configured to receive a cold pack on top of the plate and freeze the cold pack with a uni-directional freeze gradient.
2 . The system of claim 1 , wherein the freezing of the cold pack produces a cold pack with one flat major face and one major face with a convex geometry.
3 . The system according to claim 1 , wherein the low temperature refrigerant is selected from the group consisting of ammonia, carbon dioxide, freon, chlorofluorocarbons, and combinations thereof.
4 . The system according to claim 1 , wherein the plate is made from a material selected from the group consisting of aluminum or aluminum alloys, stainless steel or steel alloys, copper or copper alloys, and combinations thereof.
5 . The system according to claim 1 , wherein a thermally conductive tray is used to convey the cold pack onto and off the plate.
6 . The system according to claim 5 , wherein the thermally conductive tray is made from a material selected from the group consisting of aluminum, copper, stainless steel, and combinations thereof.
7 . The system according to claim 1 , wherein an evaporator temperature setting for the refrigeration system is less than 0° C.
8 . The system according to claim 1 , wherein the cold pack is a water-based cold pack, comprising >50% water.
9 . The system according to claim 1 , wherein the cold pack is encapsulated in a flexible plastic material or flexible paper material.
10 . A method for freezing a cold pack, the method comprising:
placing a cold pack upon a plate, wherein the plate contains a low-temperature refrigerant; and
freezing the cold pack on one of its major faces with a freeze gradient emanating upward.
11 . The method of claim 10 , wherein the freezing of the cold pack produces a flat surface on a major face of the cold pack and a convex surface on the other major face of the cold pack.
12 . The method of claim 10 , further comprising placing the cold pack within a tray prior to placing the cold pack on the plate.
13 . The method of claim 10 , wherein the plate is oriented horizontally, and the cold pack is resting on the top surface of the plate under gravity loads.
14 . A method for keeping an item at a desired temperature the method comprising: placing at least one cold pack adjacent to the item, wherein the cold pack includes one flat surface and one convex surface opposite the one flat surface.
15 . The method of claim 14 , wherein the flat side of the cold pack is adjacent to the item.