PURPOSE: To easily create a wide range of temps. by connecting the expansion mechanism in the cooling unit of the final stage to a refrigerant outlet side of one flow passage of an intermediate heat exchanger in the cooling unit of the final stage and constituting the expansion mechanism in such a manner that the opening degree thereof can be freely adjusted.
CONSTITUTION: An increases in the low-pressure side of the intermediate heat exchanger of the cooling unit is triggered by an increase in an evaporating pressure when the opening degree of the expansion mechanism 14 of the final stage is increased. The ratio of the condensing and liquefying of the high boiling refrigerant in a solvent mixture is lowered by this increase and the refrigerant flowing to an evaporator 9 becomes the refrigerant mixture contg. the high boiling refrigerant at a high ratio. A relatively high temp. is thus obtd. The temps. of a wide range from an ultra low temp. to a relatively high temp. is easily created by constituting the expansion mechanism 14 of the final stage in such a manner that the opening degree thereof can be freely adjusted.
YASUDA HIROSHI
TAGA AKIYOSHI
KATSUMATA NAOTO
HAYASHIDA TATSUO
