A Separated two stage helium liquefier using a 4 K GM cryocooler

27th International Cryogenics Engineering Conference and International Cryogenic Materials Conference 2018

Liu, Mengyu^1 ; Zuo, Huakun^1 ; You, Jun^1 ; Li, Liang^1 ; Wang, Shaoliang^1

Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Hongshan District, Wuhan and 430074, Hubei, China^1

关键词: Cryocoolers;    G-m cryocooler;    Liquid helium;    Liquid helium temperature;    Precooling process;    Scientific experiments;    Small scale;    Working pressures;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/502/1/012079/pdf
DOI  :  10.1088/1757-899X/502/1/012079

来源: IOP

【 摘 要 】

A small-scale helium liquefier using a GM cryocooler (1.5 W @ 4.2 K) is designed and built. The helium gas to be liquefied is precooling by the cryocooler with natural convention loop and the precooling process inside the liquefier is separated to two stages by the first stage cold head of the cryocooler. Liquid nitrogen is used for cooling helium gas before entering the liquefier and cooling the radiation shield as well. The liquefier can start producing liquid helium within 7.5 hours after running from room temperature. A liquefaction rate of 18.57 L/day is obtained at a working pressure of about 115 kPa. Simply designed with high performance makes this helium liquefier appropriate to be used directly with cryostats for scientific experiments of liquid helium temperature range.Published under licence by IOP Publishing Ltd.