In order to supply the cryogenic test facilities operated in the building complex, the Leibniz Institute for Solid State and Material Research Dresden (Leibniz-Institut fuer Festkoerper- und Werkstoffforschung Dresden e.V., in short: IFW Dresden) has been using a L140 standard liquefaction plant since 2009. With the aid of this system, the IFW is nowadays largely independent of the purchase of helium by not only liquefying the helium itself, but also processing the return, which is fed from high-pressure cylinders to the liquefaction plant. To obtain the requested flexibility Linde Kryotechnik planned a modification of its exitsting L-Series L140 and designed a customized variation.
The cold box includes 2 operating modes:
- standard liquefaction mode of the L-Series into a 5000 liter dewar
- mode for filling the mobile dewar by means of a liquid helium decant pump
For the recovery of contaminated helium from the recycling plant of the IFW, the cold box was equipped with an internal cleaner as well as the design was planned for operation with and without nitrogen precooling.
At the time of commissioning the described installation represents the most efficient liquid helium plant of this size worldwide.