对具有扰流柱结构的微通道反应器内气液两相弹状流动进行了可视化实验研究。利用微粒子呈像测速技术(Micro-PIV)对微通道内两相流动流场进行在线测量;在不同气液流量条件下,研究了气弹经过扰流柱区域时气弹长度及气弹运动速度的变化规律,并对比了不同结构微通道内硝基苯催化加氢反应生成苯胺的产率。结果表明:具有扰流柱结构的微通道内速度场分布与无扰流柱微通道有较大区别;气弹经过扰流柱结构时气弹长度及气弹运动速度增加,并在扰流柱区域内出现震荡式波动;具有扰流柱结构微通道内进行的硝基苯催化加氢反应,其苯胺产率高于无扰流柱结构微通道。
In this paper, visualization experiments were carried out on the slug flow characteristics of nitrobenzene hydrogenation reaction in a microchannel with pin-fins configuration. Real-time two-phase flow fields were acquired with Micro-PIV technique. The influences of both gas and liquid flow rate, and the channel structure on the gas-slug length and moving speed in the mi- crochannel were investigated. Meanwhile, the effects of channel structures and configurations on the aniline yield of nitrobenzene hydrogenation were also discussed. The experimental results showed that the length and velocity of the gas slug were both increased when the slug passed through pin fin configuration. Besides, oscillations of gas slug interface were also observed. Moreover, with the assistance of designed pin fin configuration in the microchannel, higher aniline yield of nitrobenzene hydrogenation was achieved profitted form the enhancement of mass transfer efficiency.