Abstract In the laboratory, or for other limited refrigeration purposes, the cooling effect of a liquid refrigerant may be used for a limited period of time without recompressing and reliquifying the refrigerant. The present disclosure teaches how to accomplish this feat with maximum efficiency by placing the specimen to be cooled in proximity to the liquid, thereby permitting heat transfer directly to the gaseous refrigerant which is vaporizing from the liquid. Further, the rate of cooling is variable, in accordance with the need for cooling, by warming the liquid to vaporize more liquid, thereby increasing the vapor density above the liquid. With greater vapor density (or, we might say, by making the fog thicker) the heat exchange rate (cooling rate) is increased. Conversely, when heat is not supplied to the liquid, and the vapor density is decreased, the rate of heat exchange (cooling rate) is decreased. The rate of cooling, and the minimum temperature obtainable, may be varied further by adjustable pressure relief means to control the ''''boiling'''' point of the refrigerant. Vacuum may be applied to the container if desired to lower the boiling point even lower to achieve a lower temperature.
Apparatus for refrigerating an item comprising a container in which the item is to be placed, liquid and gas refrigerant in said container in close proximity to each other, means to produce heating of the liquid to increase the vapor density adjacent to the liquid and surrounding the item to be cooled to thereby increase the rate of cooling, means automatically responsive to an increase in the temperature of the item being cooled to increase the temperature of the heat-producing means to thereby increase the cooling rate, pressure release means to limit pressure buildup in said container, said pressure release means being adjustable whereby the pressure and boiling point of the liquid may be raised to thereby raise the vapor density and increase the cooling rate while conserving cooling liquid and vapor, and said pressure release means being completely closable to stop all loss of vapor and liquid from said container.
Claim 2
Dependent Claim
151 words
Apparatus for refrigerating an item comprising a container in which the item is to be placed, liquid and gas refrigerant in said container in close proximity to each other, means to produce heating of the liquid to increase the vapor density adjacent to the liquid and surrounding the item to be cooled to thereby increase the rate of cooling, means automatically responsive to an increase in the temperature of the item being cooled to increase the temperature of the heat-producing means to thereby increase the cooling rate, pressure release means to limit pressure buildup in said container, said pressure release means being adjustable whereby the pressure and boiling point of the liquid may be raised to thereby raise the vapor density and increase the cooling rate while conserving cooling liquid and vapor, and said pressure release means being completely closable to stop all loss of vapor and liquid from said container.