| 摘要 |
<p>PURPOSE: To operate a thermal insulation device at less than 77 K by bringing one side thereof into contact with medium at a temperature of less than 77 K, letting the other side thereof adhere on a closed cell material of a substance which is 77 K or less and a solid, and making the closed cell material face a space including a thermal insulation material and nitrogen atmosphere. CONSTITUTION: A pipe line 2 is constituted by an inner surface 4 in contact with very low temperature liquid, for example, helium gas having a temperature of 70 K at the time of operation and an outer surface 6 coated by foaming polyurethane 8. The coating includes closed cells filled with carbon dioxide gas at an ambient temperature. A pipe 2 is arranged in an outer sleeve 10, and an annular space between an inner surface of the sleeve 10 and a coating outer surface 6 of the pipe 2 is filled with mineral thermal insulation powders such as pearlite. As a result, effective thermal insulation becomes possible at a temperature of about 70 K without necessitating vacuum thermal insulation.</p> |
