### Abstract

A comprehensive mathematical model for describing flow, turbulence and gas hold-up distribution in a bubble column reactor is developed. For large diameter bubble columns (>0.1 m), operated with the zero or low liquid throughput, sparged gas tends to pass preferentially through the central portion of the column. This non-uniform gas hold-up distribution leads to macroscale circulation and turbulence in the reactor. Two new mechanisms are proposed and modelled to explain such a non-uniform gas hold-up distribution in bubble columns. The influence of accompanying wakes and of the column wall on the motion of gas bubbles is accounted for for the first time. Turbulent, dispersed gas-liquid flow is described by the time averaged two phase momentum equations. The turbulent stresses are simulated using a k-ε model. Extra terms arising from the gas hold-up fluctuations and pressure gradients are included in the model. The predicted flow characteristics of the bubble column reactor are verified by comparison with the published experimental data over a wide range.

Original language | English |
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Pages (from-to) | 14-23 |

Number of pages | 10 |

Journal | Chemical Engineering Research and Design |

Volume | 75 |

Issue number | 1 |

Publication status | Published - 1997 |

Externally published | Yes |

### Keywords

- Bubble column
- CFD
- Gas-liquid flow
- Turbulence

### ASJC Scopus subject areas

- Polymers and Plastics