SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2015, Vol. 23 ›› Issue (6): 890-896.DOI: 10.1016/j.cjche.2014.11.030

• 流体力学与传递现象 • 上一篇    下一篇

Influence of impeller diameter on overall gas dispersion properties in a sparged multi-impeller stirred tank

Yuyun Bao, Bingjie Wang, Mingli Lin, Zhengming Gao, Jie Yang   

  1. State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
  • 收稿日期:2014-05-09 修回日期:2014-11-08 出版日期:2015-06-28 发布日期:2015-07-09
  • 通讯作者: Jie Yang
  • 基金资助:

    Supported by the National Natural Science Foundation of China (21121064, 21206002, 21376016).

Influence of impeller diameter on overall gas dispersion properties in a sparged multi-impeller stirred tank

Yuyun Bao, Bingjie Wang, Mingli Lin, Zhengming Gao, Jie Yang   

  1. State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2014-05-09 Revised:2014-11-08 Online:2015-06-28 Published:2015-07-09
  • Contact: Jie Yang
  • Supported by:

    Supported by the National Natural Science Foundation of China (21121064, 21206002, 21376016).

摘要: The impeller configuration with a six parabolic blade disk turbine below two down-pumping hydrofoil propellers, identified as PDT + 2CBY, was used in this study. The effect of the impeller diameter D, ranging from 0.30T to 0.40T (T as the tank diameter), on gas dispersion in a stirred tank of 0.48 m diameter was investigated by experimental and CFD simulation methods. Power consumption and total gas holdup were measured for the same impeller configuration PDT + 2CBY with four different D/T. Results show that with D/T increases from 0.30 to 0.40, the relative power demand (RPD) in a gas–liquid system decreases slightly. At low superficial gas velocity VS of 0.0078 m·s-1, the gas holdup increases evidently with the increase of D/T. However, at high superficial gas velocity, the systemwith D/T=0.33 gets a good balance between the gas recirculation and liquid shearing rate, which resulted in the highest gas holdup among four different D/T. CFD simulation based on the two-fluid model along with the Population Balance Model (PBM) was used to investigate the effect of impeller diameter on the gas dispersion. The power consumption and total gas holdup predicted by CFD simulation were in reasonable agreement with the experimental data.

关键词: Gas holdup, Mixing, Multiphase reactors, Relative power demand, CFD, Multi-impeller stirred tank

Abstract: The impeller configuration with a six parabolic blade disk turbine below two down-pumping hydrofoil propellers, identified as PDT + 2CBY, was used in this study. The effect of the impeller diameter D, ranging from 0.30T to 0.40T (T as the tank diameter), on gas dispersion in a stirred tank of 0.48 m diameter was investigated by experimental and CFD simulation methods. Power consumption and total gas holdup were measured for the same impeller configuration PDT + 2CBY with four different D/T. Results show that with D/T increases from 0.30 to 0.40, the relative power demand (RPD) in a gas-liquid system decreases slightly. At low superficial gas velocity VS of 0.0078 m·s-1, the gas holdup increases evidently with the increase of D/T. However, at high superficial gas velocity, the systemwith D/T=0.33 gets a good balance between the gas recirculation and liquid shearing rate, which resulted in the highest gas holdup among four different D/T. CFD simulation based on the two-fluid model along with the Population Balance Model (PBM) was used to investigate the effect of impeller diameter on the gas dispersion. The power consumption and total gas holdup predicted by CFD simulation were in reasonable agreement with the experimental data.

Key words: Gas holdup, Mixing, Multiphase reactors, Relative power demand, CFD, Multi-impeller stirred tank