| 摘要 |
PURPOSE:To miniaturize a condensation heat exchanger and to facilitate the detachment of a freezer by using the tube provided with fins on the periphery and spiral grooves in the internal surface as the condensation heat exchanger. CONSTITUTION:A liquid reservoir 14 containing a cryogenic liquid 13 is contained in a vacuum container 18. Also, a condensation heat exchanger 12 is inserted in the liquid reservoir 14 through a port 15. This heat exchanger 12 comprises a double-structure composed of a rifle tube 30 provided with fins 31 on the periphery and spiral grooves 32 in the internal surface and an inner tube 40. The base end is connected to a freezer 10. The fins 31 enhance a surface area of the periphery of the tube 30 and the grooves 32 give a spiral flow to a cooling medium and enhance a surface area of the internal plane. Accordingly, an efficiency of the exchanger 12 is improved. Furthermore, this constitution facilitates a detachment of the exchanger 12. |
