旋转流管式微滤膜的流场探测及分离性能研究

Study on flow field and separation performance of tubular micro-filtration membrane with rotary flow

利用水力旋流器原理采用切向进料使膜器环隙产生旋转流,为探明旋转流场的特征,应用PIV(粒子图像测速技术)测试系统进行了实测,结果表明环隙中存在起强化过滤作用的类Taylor涡。在此基础上对旋转流场进行了过滤分离实验,以探讨旋转流场中的进料方式、悬浮液质量分数和操作压力对过滤的影响。研究发现由于存在旋转流和二次涡流的剪切强化作用使得在相同工况下旋转流过滤的稳定通量达到普通轴向流的4—10倍,这表明旋转流过滤是一种有效的膜过滤强化方法之一,由此为进一步探讨旋转流膜过滤强化机理,减少浓差极化和膜污染提供实验依据。

The fluid in membrane separator annular gap is dependent on the principle of the hydrocyclone to generate rotary flow. In order to find the flow field characteristics,the advanced PIV system was applied in the test. The test of separation performance was carried out and the influence factors of separation such as the operating pressure, the concentration of the feed, the injection ways and so on were discussed. The experimental results showed that the permeation flux of rotary flow is 4-10 times higher than that of conventional cross-flow at the same condition. Enhancement effect of rotary flow membrane micro-filtration is clear. The result can provide experimental basis for further research on enhancement mechanism and reducing polarization and pollution in membrane filtration.