磁场作用下低温氧氮传质的可视化实验研究

Visualized Study on Mass Transfer Characteristics of Cryogenic Nitrogen and Oxygen Under Magnetic Field

氧分子具有顺磁性,因而在梯度磁场中会受到磁场力作用。低温精馏是空气分离的主要方法之一,也是氧的顺磁性的一个潜在应用领域,本文通过设计搭建的低温氧氮传质可视化实验装置,研究了两块永磁体磁缝处的梯度磁场对液氧液氮扩散传质过程的影响,借助自行研制的激光干涉测量系统,实时观察和测量磁场作用区域液氧液氮浓度的变化.实验结果表明,在传质过程中氧分子受到磁场力的作用,会依附在磁场较强的区域。同时,与传质方向相反的磁场力减慢了氧分子沿浓度梯度的传质,使得传质过程更加稳定。

Oxygen is paramagnetic, which is subjected to magnetic forces in the gradient magnetic field. The paramagnetism of oxygen is greatly enlarged under low temperatures, but is studied by very few researchers. Cryogenic distillation is one of the main methods for air separation, and is a potential application for the paramagnetism of oxygen. In this paper, the influence of gradient magnetic field on diffuse process between liquid oxygen and nitrogen is studied, through the visualization experimental setup we designed. The concentration of liquid oxygen and nitrogen of within the magnetic field is observed and measured dynamically by a self-designed laser interferometry system. The results show that oxygen will cling to the area where the magnetic field is the strongest, due to the magnetic force during the diffuse process. Also, mass transfer process of oxygen is reduced both in speed and in quantity due to the magnetic force which is in the direction opposite to the diffuse direction of oxygen. For this reason, the mass transfer process is more stable.