The term “Cryogenics” describes a system which helps maintain the temperature of an environment or a medium at extremely cold temperatures. In the case of cryogenic fluids, it facilitates the handling (storage and transportation) of those liquids, such as liquid hydrogen, liquid helium or liquid air.
Cryogenic temperatures are generally consider to be below -150 oF (-101oC), temperatures which are applicable in storing LNG (liquefied natural gases) such as helium, oxygen, hydrogen, nitrogen etc. The storing media is usually double wall vessel filled in most of the projects with evacuated expanded perlite. The basic driver for their design and construction is the low thermal conductivity achieved by the material applied inside the double wall, providing very good insulation properties. Raw Perlite is usually expanded at project site and online transferred into the cavities of the double wall tanks while vacuum is applied. The thermal conductivity of the expanded and evacuated perlite can reach levels of below 0,0007 W/m*K, depending on the raw perlite source used, the expansion technology applied, expanded perlite density achieved in combination with the expanded perlite grain size distribution obtained. Experience combined with expertise both in proper raw perlite quality/grain size selection and in the expansion technology applied guaranties successful project execution.
Special granulometries of Imerys Raw Graded Perlite are world-wide considered and recognized as THE reference raw material for the production of superior expanded perlite, complying with all economical and technical requirements for filling LNG tanks efficiently.