| 摘要 |
PURPOSE: To obtain a non-azeotropic mixed cooling medium replaceable with a conventional non-azeotropic mixed cooling medium which is used for a refrigerator adapting a single-element ultralow temperature system. CONSTITUTION: This is a non-azeotropic mixed cooling medium obtained by mixing normal butane (n-C4 H10 :HC600), propylene (C3 H6 :HC1270) or propane (HC290), pentafluoroethane (C2 HF5 :HF125), and tetrafluoromethane (CF4 :FC14 ). This invention also provides a freezing process applying the non-azeotropic mixed cooling medium to a single-element ultralow temperature system. The cooling medium has zero O.D.P., no undesirable influence upon the ozonosphere and low toxicity and can be applied to a conventional freezing system in a retrofittable manner, which can keep the function without modifying the system. Further, the freezing system using the cooling medium enables the construction of a single-element ultralow temperature system with a gas that does not have an undesirable influence upon the ozonosphere and is harmless on human body. |
