A PRACTICAL GUIDE TO THE OPTIMUM UTILIZATION OF COOLING CAPACITY OF BOIL- OFF GAS FROM CRYOGENIC APPARATUS

Technical Report · Mon Apr 29 04:00:00 EDT 1963

DOI:https://doi.org/10.2172/4707287· OSTI ID:4707287

Chamberlain, W.; Maseck, H.

The loss rate of a liquid helium container was calculated by a method which includes the important effect of interception of heat conducted down the neck by boil-off gas flowing up the neck. The results indicated an optimum neck geometry for given flask design beyond which added neck length is not effective in reducing boil-off. A radiation shield is introduced between the liquid helium flask and the liquid nitrogen shield. This intermediate shield is thermally tied to, and cooled by, the flask neck. Its effectiveness in reducing loss rate is demonstrated. It is further shown that when the intermediate shield is employed, large increases in the emissivity of the liquid helium flask have a negligible effect on loss rate. A graph is presented which permits direct determination of loss rates with and without the intermediate shield for containers of known geometry and materials. The effect of instrument leads and supports either down the neck or through the vacuum can be included. (auth)

• Research Organization: California Univ., Berkeley, CA (US). Lawrence Radiation Lab.
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-17-025869
• OSTI ID: 4707287
• Report Number(s): UCRL-10805
• Country of Publication: United States
• Language: English

Related Subjects

CONFIGURATION
COOLING
CRYOGENICS
DIAGRAMS
GASES
HEAT TRANSFER
HELIUM
LIQUIDS
LOSSES
NITROGEN
PHYSICS
PLANNING
RADIATIONS
SHIELDING
VACUUM
VESSELS