Transient Shielded Cryogenic Containers

Abstract

Transporting and storing industrial gases in the liquid phase is safer and more economical than in the high pressure gas phase. However, due to the extremely low liquid phase temperatures of the industrial gases and the present state of insulation techniques, the storage of these gases as liquids has been restricted to relatively short durations.

A totally new cryogenic container, utilizing a transient shield developed by engineers at Gardner Cryogenics, has improved the storage duration considerably and has been granted a patent. For cryogenic containers used for the storage of cryogenic liquids for occasional use as gas at ambient temperature, the heat leak can be substantially reduced by the use of a transient thermal shield. This transient thermal shield, through variations in its temperature with time, will extract, retain and release refrigeration from occasional or cyclical flow of fluid being warmed up. In such a process, the shield will intercept the heat leak into the storage and thus extend the storage time without the use of any energy to produce refrigeration for this purpose. Testing of a prototype container for liquid hydrogen storage has indicated an improvement of five hundred percent in storage time. Cryogenic containers with transient thermal shields are already finding applications in replacing high pressure gas storage, very low volume usage, storage of high purity cryogenic fluids, and in localities where venting of stored product is not allowed. This paper will describe the construction and the test results of a series of transient shielded cryogenic containers.