Tube type freezing unit and in-tube freezing method

摘要

A tube type freezing unit of the present invention employs as a low-temperature heat accumulating material an aqueous solution of bromide of a low concentration. A plurality of thin tubes are accommodated in a shell, and a non-freezing liquid or a refrigerant is passed into the shell around the tubes. A sherbet-like slush is generated in a freezing mode by filling the tubes with the aqueous solution of bromide of a low concentration which serves as the low-temperature heat accumulating solution and then by passing a non-freezing liquid having a temperature of about -5 DEG C. or a refrigerant whose vaporization temperature is about -5 DEG C. around the tubes which contain the aqueous solution of bromide in a stationary state. The aqueous solution of bromide does not freeze. So, the sherbet-like slush is generated in the solution. An aqueous solution of bromide of a low concentration has a freezing point of about -1 DEG C. In consequence, a non-freezing liquid or a refrigerant can be used as a relatively high temperature.