Exterior insulation for pipe contg. liquid hydrogen at very low temp.

摘要

Cold liq. gas such as hydrogen runs through a pipe (1). The novelty is that the pipe is heat insulated by two or more sequential gas adjacent cavities (16,17) which are sealed by gas impermeable walls (10,13) and run roughly parallel to the main wall (6); and that the type and quantity of gases in the adjacent cavities (16,17) is such that their freezing point and freeze-out point are above that of the temperature of the colder dividing wall (10) and wall (6), respectively. Longitudinal profiles (21,22,23) prevent convection in the gas cavity (16). The first gas cavity (16) is filled with helium or argon, and the second gas cavity (17) is filled with nitrogen.