| 摘要 |
PURPOSE:To realize freezing of a substance a short time by a method wherein liquid having an extremely low freezing point such as ethyl alcohol is kept at a prescribed temperature which is higher than its freezing point and the substance to be freezed is dipped into the liquid and then taken it out. CONSTITUTION:Liquid having a freezing point at least lower than -30 deg.C such as ethyl alcohol 3 is contained in a heat insulative liquid container 1. The ethyl alcohol 3 is cooled by a freezing circuit 4 through a heat exchanger 5 incorporated in the liquid container 1 down to a temperature lower than -20 deg.C which is lower than the freezing point of ethyl alcohol, for example, -70 deg.C. Further, solid carbon dioxide (dry ice) 10 is contained in the ethyl alcohol 3 in the liquid container 1 to promote cooling of the ethyl alcohol 3. In the case that the substance to be freezed, for example, a fresh fish such as fugu (swellfish) F is cooled, the fugu F is put into a packing bag and housed in a basket 13, which is then dipped into the ethyl alcohol 3, hung on a hanging part, 14 and left as it is about 5 minutes. By this a desired freezing state of the fugu F can be realized. |
