Abstract: A mixed refrigerant comprising one member selected from R-23, R-116 and a mixture thereof and one member selected from propane, butane and a mixture thereof. The mixed refrigerant allows cooling the inside of a freezer to a super low temperature, particularly to a temperature of −60° C. or lower, with a compressor of a conventional freezer. The mixed refrigerant not only has a low boiling point similar to those of R-23 and R-116, but also can be liquefied in a room temperature surrounding due to propane or butane contained therein, and further has good miscibility with a lubricating oil or the like so that a freezer unit using the refrigerant is free from the problem of clogging therein. Additionally, the mixed refrigerant has no ability to deplete ozone and is significantly low with respect to greenhouse effect.

Abstract: A mixed fluorocarbon refrigerant comprising 1,1,1,2-tetrafluoroethane and trifluoromethane provides a refrigeration temperature of −30° C. or less. The composition can also contain a refrigerator oil and an additive. The additive is selected from the group consisting of saturated hydrocarbons, unsaturated hydrocarbons and aromatic hydrocarbons.

Abstract: A brine refrigerating apparatus includes a cooling chamber which is divided into a plurality of cooling sections by shelves provided in the cooling chamber, each shelf having a brine pipe in which a cold brine flows.