Abstract: A receptacle for maintaining perishables, such as food, at a reduced temperature features an exterior shell joined to an interior shell so that a space occupied by a vacuum exists between them. The junction of the inner and outer shells is located on the exterior of the receptacle. Phase change material is disposed within compartments in the bottom of the receptacle and is covered by a false bottom. A cryogenic liquid, such as liquid nitrogen, is poured down the interior walls of the receptacle and into the compartments containing the phase change material so that the phase change material is frozen in situs. A liquid absorbing material may be substituted for the phase change material.

Abstract: An insulated container that is open on top and contains phase change material travels along a conveyor. The container initially stops under an infrared sensor whereat its initial interior temperature is determined. A microprocessor uses the temperature data to determine the amount of cryogenic liquid that must be added to the container so that its phase change material will be frozen to a predetermined temperature. A cryogenic liquid dispenser charges the container with an amount of cryogenic liquid determined by the microprocessor. The cryogenic liquid dispenser includes a phase separator which depressurizes cryogenic fluid received from a bulk storage tank. Once the container is charged, it may be loaded with perishables, examples of which include food, blood or chemicals.