Design and Development of Cryogenic Transfer Lines and Studies on Flow Phenomena

Abstract

Cryogenics refers to the field of science and engineering below 123 K (-150 ºC). Also it deals with the production, utilization and maintenance of the same. Below 123 K, the so called Permanent gases such as Argon, Oxygen, Nitrogen, Hydrogen and Helium can be liquefied. Because of their low boiling point and latent heat of vaporization, special storage and transfer systems are needed for storing these cryogens for end applications. Hence, it is necessary to use insulated cryogenic transfer lines to minimize the evaporation losses and enable maximum fluid collection during the transfer of the cryogens. Flexible transfer lines are manoeuvrable, easy to handle and can take care of differences in the heights between the storage and receiver tanks when compared to rigid transfer lines. On the other hand, the design and fabrication of flexible Cryogenic Transfer Lines (FCTLs) are more cumbersome than those of rigid cryogenic transfer lines. To the best of our knowledge, the procedure available to design and develop a FCTL is scanty in the open literature. The work presented in the thesis perhaps tries to fill the gap by detailing the theoretical background for the development of the super-insulated vacuum jacketed FCTLs. The minimum diameter and thickness of the inner line/tube for a particular flow rate and pressure have been estimated theoretically...