摘要 |
Tubes 3 are provided substantially upright on an upper surface of a refrigerant container 2 by inserting lower end portions thereof into inserting holes 5 of the refrigerant container 2. The tube 3A, differed from the tubes 3B, has a trumpet shape which is suddenly increased in its passage cross section towards the lower end opening portion. Thus, most of refrigerant vapor boiled and evaporated in the refrigerant container 2 can be collectively introduced into the tube 3A located within the boiling area. The refrigerant vapor entered a header tank 4 from the tube 3A is diffused in the header tank 4, and is introduced into the tubes 3B located out of the boiling area. The condensate produced by cooling the refrigerant vapor upon passing through the tubes 3B can be circulated into the refrigerant container 2. |