Design of a Laboratory Nitrogen Liquefier cum Cryostat Based on Closed Cycle Refrigerator

Abstract

Taking the CRYOMECH LNP 40 specifications as a reference, an attempt was made to design an integrated system consisting of a liquefying unit with a measurement cryostat. The dimensions were calculated in a very crude way though always taking the upper value. The dimensions for different parts were set with special care given to the sample chamber. Then a sample solid model was made. Heat transfer calculations were done to estimate the total heat going into the system from the major possible sources. Staying time of the cryogen was calculated. Encouragingly a reasonable value was obtained. And it was found out that with efficient cooling capacity liquefier, the system can be very handy both for measurement as well as transferring