Abstract:

For industrial applications, the parallel amplification of microreactors has become one of the most effective strategies, in which the study on the phase distribution in the parallel multiple microchannels is an important foundation. In this study, the influences of the subchannel interval and flow rates on distribution of liquid-liquid two-phase in comb parallel microchannels were investigated by the use of a high-speed camera. Results indicated that for low flow rates of dispersed and continuous phases (Q_c and Q_d), the dispersed phase volume fraction in the front branch microchannels was low, while it was high in the rear branch microchannels and the uniformity of daughter droplets was worse. With the increases of two-phase flow rates Q_c and Q_d, the dispersed phase volume fractions in three different configurations of microreactors were inclined to be consistent. At higher two-phase flow rate, the uniformity of droplets size in the branch microchannels could be significantly increased, and the variation coefficient is less than 0.15. Within the experimental range, the operating range of uniform droplet size distribution in the microreactor with the subchannel interval S = 0.6 mm is the largest.

Key words: parallel microchannels, microreactor, two-phase flow, droplet, distribution

摘要：

为了实现工业化应用，微反应器的并行放大已成为最有效的放大策略之一。在微反应器的放大过程中，相分布规律的研究是非常重要的。采用高速摄像仪研究了梳状并行微反应器的支通道间距和流量对液液两相分布的影响。当连续相和分散相流量Q_c及Q_d都较小时，不同支通道间距的微反应器内前方支通道的分散相含率较低，后方支通道的分散相含率较高，同时液滴长度的均匀性较差。随着Q_c与Q_d的增大，三种不同构型微反应器内分散相的体积相含率的数值分布逐渐趋于集中。在较高的两相流量下，支通道内液滴长度的均匀性显著提高，其变异系数小于0.15。在实验范围内，支通道间距S = 0.6 mm的微反应器中液滴尺寸均匀分布的操作范围最大。

关键词: 并行微通道, 微反应器, 两相流, 液滴, 分布