化学工业

化学工业

来源出版物：Chinese Journal of Chemical Engineering，2015，23（3）: 461-470

联系邮箱：Yuyun Bao，baoyy@mail.buct.edu.cn

Micromixing characteristics in a gas-liquid-solid stirred tank with settling particles

Wanbo Li，Xingye Geng，Yuyun Bao，et al.

The parallel-competing iodide-iodate reaction scheme was used to study the micromixing performance in a multi-phase stirred tank of 0.3m diameter. The impeller combination consisted of a half elliptical blade disk turbine below two down-pimping wide-blade hydrofoils，identified as HEDT+2WHD. Nitrogen and glass beads of 100 μm diameter and density 2500 kg·m-3were used as the dispersed phases. The micromixing could be improved by sparging gas because of its additional potential energy. Also，micromixing could be improved by the solid particles with high kinetic energy near the impeller tip. In a gas-solid-liquid system，the gas-liquid film vibrationwith damping，due to the frequent collisions between the bubbles and particles，led to the decrease of the turbulence level in the liquid and caused eventually the deterioration of themicromixing. A Damping Film Dissipation model is formulated to shed light on the above micromixing performances. At last，the micromixing time tm according to the incorporation model varied from 1.9 ms to 6.7 ms in our experiments.

Stirred tank； Gas-liquid-solid； Micromixing performance； Incorporation model