In this study, the liquid–liquid two-phase flow pattern and mass transfer rate in microchannels were investigated by an extraction experiment. Slug flow was observed at low flow velocities, which changed to annular and slug-annular flows at high flow velocities. The volumetric mass transfer coefficient (Ka) of the slug flow increased with increasing flow velocity; however, the flow pattern transition from slug to annular flow led to a discontinuous decline in Ka and reduced it to below that of slug flow. Since the difference in the specific interface areas (a) between the slug and annular flows was not large enough to address the difference in Ka for the slug and annular flows, it was suggested that the decrease in the mass transfer coefficient (K) was mainly responsible for the decrease in Ka with flow pattern transition. The highest Ka was obtained at the highest flow velocity within the slug flow region. Therefore, it was demonstrated that increasing the flow velocity as much as possible within the range where the stable slug flow is formed without causing the flow pattern transition from the slug to annular flows is an effective design strategy for minimizing the microchannel volume.

在这项研究中，通过萃取实验研究了微通道中的液-液两相流型和传质速率。在低流速下会观察到团状流，在高流速下会变成环形和团状环流。团状流的体积传质系数（Ka）随着流速的增加而增加；但是，流型从团状流向环形流过渡导致Ka的不连续下降，并将其减小到团状流以下。由于段塞流和环形流之间的特定界面区域（a）的差异不足以解决Ka的差异对于团状流和环形流，建议传质系数（K）的降低主要是随着流型转变而降低Ka的原因。在团状流区域内以最高流速获得最高Ka。因此，证明了在不引起从塞状流向环状流的流型过渡的情况下，在形成稳定的塞状流的范围内尽可能多地提高流速是使微通道容积最小化的有效设计策略。