This paper presents an investigation of a new method of purifying cryogenic liquid using sintered metallic wire-mesh filter,which has the advantages of high purifying efficiency and preferred strength at absolutely low temperature.Experiments are conducted to purify solid CO_2 particles from liquid nitrogen.Temperature and pressure in the upstream and downstream of the filter,and the flow rate of carbon dioxide(CO_2) gas and liquid nitrogen are measured,with the gas content of filtrate analyzed using a CO_2 concentration detector.It is illustrated that after filtration,the purity of liquid nitrogen(volume fraction) is higher than 99.99%,which means that the volume fraction of CO_2 is less than 0.01%.Effects of operation parameters on the performance of the filter,such as pressure drop△p and filtration efficiency E are analyzed quantitatively.The present conclusions will provide a guideline to the optimumal design and operation of sintered metallic wire-mesh filter in cryogenic application.
Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.
