利用梯度磁场的拦截作用富集氧气的研究

Oxygen enrichment from air by use of the interception effect of a gradient magnetic field on oxygen molecules

提出了一种利用梯度磁场对氧分子形成的拦截作用实现氧气富集的新方法。用两块相距一定距离的矩形钕铁硼永磁铁异极相对围成一个磁场空间,在磁场空间的边界处存在梯度磁场。当被引入磁场空间的空气穿过边界流出磁场空间时,氧分子受到梯度磁场的拦截作用,而氮分子则顺利流出,从而实现氧气富集。实验测得,当进出磁场空间的空气流量分别为40,20 mL/min,气体温度为298 K,磁感应强度与场强梯度乘积的最大值为563 T2/m(磁极间距为1 mm)时,氧气的富集量最大,达到了0.65%。当气体温度升高至343 K时,氧气的富集量降至0.32%;当磁感应强度与场强梯度乘积的最大值减小为101 T2/m(磁极间距为4 mm)时,氧气的富集量降至0.23%。实验结果显示进出磁场空间的空气流量存在一个最佳比值,使氧富集程度达到最大。本文实验条件下,该值在2.0左右。本文提出的方法被证明可以连续富集氧气,而且比其他磁分富氧方法具有更高的富集水平。

This paper presents a novel method for oxygen enrichment from air based on the interception effect of a gradient magnetic field on oxygen molecules. Placing opposite magnetic poles of two magnets with a certain distance between them forms a magnetic space having a field intensity gradient near its borders. When air inject- ed into the magnetic space flows out via its borders, oxygen molecules in the air will experience the interception effect of the gradient magnetic field, but nitrogen molecules will flow out from the magnetic space without hindrance. As a result, continuous oxygen enrichment is realized. The enrichment degree of oxygen reaches 0.65 % when the inlet and outlet air flows are 40 mL/min and 20 mL/min respectively and the gas temperature is 298 K and the maximum product of magnetic flux density and field intensity gradient is 563 T^2/m （the distance between two magnetic poles being 1 mm）. When the gas temperature rises to 343 K, the enrichment degree drops to 0.32 % ; when the maximum product of magnetic flux density and field intensity gradient drops to 101 T2/m （the distance between two magnetic poles being 4 mm）, the enrichment degree drops to 0.23 %. The experimental results show that there is an optimal ratio between the inlet air flow and the outlet air flow. Under the experimental conditions used in this work, the value of this ratio is about 2.0. It is demonstrated that the method presented here can continuously enrich oxygen and has a higher enrichment degree than other oxygenenrichment methods using magnetic separation.