Micromixing Performance of a Miniaturized Annular Rotating Flow Mixer (MARFM)

Miniaturization of mixers is becoming an increasingly significant topic in process intensification. In this work, we develop a novel miniaturized annular rotating flow mixer (MARFM) by integrating the rotating flow field and micro-scale effect. The micromixing performance of MARFM is evaluated by the Villermaux/Dushman reaction system. Effects of various structural parameters on the micromixing performance are investigated. Two flow regions named stratification region and entrainment region have been firstly distinguished. Increasing rotational speed can remarkably improve micromixing performance under the stratification region rather than the entrainment region. In addition, the mixing performance at extreme flow conditions including high fluid viscosity and high flow rate ratio can be substantially improved in the MARFM. Segregation index is at least an order of magnitude smaller than that without the rotating flow field. Moreover, the micromixing time could range from 10(-5) to 10(-3) s in the MARFM, which is 1-3 orders of magnitude smaller than that of conventional mixers. Relationship between micromixing time and mean energy dissipation rate is established, which shows that higher energy utilization efficiency has been reached.