Method and device for vacuum-pressure shock freezing using liquefied gas

摘要

In this method, the material to be frozen is first subjected to a vacuum action and then gas acting as coolant and pressurising medium is fed in against it. For this purpose, liquefied gas is introduced into an evacuated container containing a material to be frozen. Using direct evaporation volume expansion, the container pressure exceeds the filling pressure, so that the suppliable cooling capacity is not sufficient for freezing. The features according to the invention make it possible to introduce the necessary total liquid-gas quantity in a single step into the liquid-gas absorber in the container and cause its automatic distribution to the material to be frozen, so that the cryogenic gas resulting from the expansion occurring in parallel with the direct evaporation acts as a sufficient and meterable coolant and pressurising medium in use with organic tissue parts, such as living-cell products, plant and animal foodstuffs.