Interferometric study on the mass transfer in cryogenic distillation under magnetic field

Cryogenic Engineering Conference 2017

材料科学;物理学

Bao, S.R.^1 ; Zhang, R.P.^1 ; Rong, Y.Y.^1 ; Zhi, X.Q.^1 ; Qiu, L.M.^1

Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou

310027, China^1

关键词: Comprehensive utilizations;    Concentration distributions;    Cryogenic distillations;    Gradient magnetic field;    Mass transfer characteristics;    Mass transfer efficiency;    Nonuniform magnetic fields;    Susceptibility differences;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012135/pdf
DOI  :  10.1088/1757-899X/278/1/012135

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Cryogenic distillation has long been used for the mass production of industrial gases because of its features of high efficiency, high purity, and capability to produce noble gases. It is of great theoretical and practical significance to explore methods to improve the mass transfer efficiency in cryogenic distillation. The negative correlation between the susceptibility of paramagnetic oxygen and temperature provides a new possibility of comprehensive utilization of boiling point and susceptibility differences in cryogenic distillation. Starting from this concept, we proposed a novel distillation intensifying method by using gradient magnetic field, in which the magnetic forces enhance the transport of the oxygen molecules to the liquid phase in the distillation. In this study, a cryogenic testbed was designed and fabricated to study the diffusion between oxygen and nitrogen under magnetic field. A Mach-Zehnder interferometer was used to visualize the concentration distribution during the diffusion process. The mass transfer characteristics with and without magnetic field, in the chamber filled with the magnetized medium, were systematically studied. The concentration redistribution of oxygen was observed, and the stable stratified diffusion between liquid oxygen and nitrogen was prolonged by the non-uniform magnetic field. The experimental results show that the magnetic field can efficiently influence the mass transfer in cryogenic distillation, which can provide a new mechanism for the optimization of air separation process.