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

doi:10.1016/j.cjche.2014.11.025

›› 2015, Vol. 23 ›› Issue (3): 461-470.DOI: 10.1016/j.cjche.2014.11.025

• 流体力学与传递现象 • 下一篇

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

Wanbo Li, Xingye Geng, Yuyun Bao, Zhengming Gao

State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China

收稿日期:2013-07-02 修回日期:2013-11-20 出版日期:2015-03-28 发布日期:2015-04-03
通讯作者: Yuyun Bao, Zhengming Gao
基金资助:
Supported by the National Natural Science Foundation of China (20990224, 21121064, 21206002).

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

Wanbo Li, Xingye Geng, Yuyun Bao, Zhengming Gao

State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China

Received:2013-07-02 Revised:2013-11-20 Online:2015-03-28 Published:2015-04-03
Supported by:
Supported by the National Natural Science Foundation of China (20990224, 21121064, 21206002).

摘要/Abstract

摘要： 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+2WH_D. Nitrogen and glass beads of 100 μm diameter and density 2500 kg·m^-3 were 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.

关键词: Stirred tank, Gas-liquid-solid, Micromixing performance, Incorporation model

Abstract: 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+2WH_D. Nitrogen and glass beads of 100 μm diameter and density 2500 kg·m^-3 were 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.

Key words: Stirred tank, Gas-liquid-solid, Micromixing performance, Incorporation model

Wanbo Li, Xingye Geng, Yuyun Bao, Zhengming Gao. Micromixing characteristics in a gas-liquid-solid stirred tank with settling particles[J]. , 2015, 23(3): 461-470.

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

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

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