PURPOSE: To enable mixed refrigerant to be efficiently separated in a short period of time, and to adjust a mixture ratio in accordance with the conditions of a load and an external air temperature by connecting a refrigerant return pipeline for returning adsorbed refrigerant to the suction side of a compressor to an adsorber, and by forming a refrigerant storage part, which is provided for storing a portion of condensed refrigerant and for pushing out the adsorbed refrigerant in the adsorber with the stored refrigerant when the refrigerant is returned, in a pipe passage connecting a heat exchanger to a storage tank.

CONSTITUTION: When R114 refrigerant gas adsorbed in an adsorber 8 is brought into a saturated state, the adsorber 8 and a refrigerant return pipeline 14 are connected with each other by changing over a three-way valve 7. By this method, the adsorber 8 is connected to the low pressure side of a refrigerating cycle, and the R114 refrigerant is desorbed from an adsorbent material, while R22 refrigerant stored in a refrigerant storage part 10 is gasified due to negative pressure and flows into the adsorber 8 to effect purge within the adsorber 8. As a result, the R114 refrigerant adsorbed on the adsorbent material is completely desorbed by the effect of reduced pressure and the purging action and is returned to a compressor 1 through the refrigerant return pipeline 14 and via an evaporator 6.