SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2022, Vol. 51 ›› Issue (11): 135-145.DOI: 10.1016/j.cjche.2021.10.001

• Full Length Article • 上一篇    下一篇

Analysis of the flow pattern and periodicity of gas–liquid–liquid three-phase flow in a countercurrent mixer-settler

Minghang Zhang1, Wangfeng Cai1, Pei Zhu1, Le Xie2, Yan Wang1   

  1. 1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China;
    2. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
  • 收稿日期:2021-06-22 修回日期:2021-10-06 出版日期:2022-11-18 发布日期:2023-01-18
  • 通讯作者: Le Xie,E-mail:xiele2018@csu.edu.cn;Yan Wang,E-mail:zhuwangyan@tju.edu.cn
  • 基金资助:
    In this work, we sincerely appreciated the National Natural Science Foundation of China (21978198) for financial support.

Analysis of the flow pattern and periodicity of gas–liquid–liquid three-phase flow in a countercurrent mixer-settler

Minghang Zhang1, Wangfeng Cai1, Pei Zhu1, Le Xie2, Yan Wang1   

  1. 1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China;
    2. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
  • Received:2021-06-22 Revised:2021-10-06 Online:2022-11-18 Published:2023-01-18
  • Contact: Le Xie,E-mail:xiele2018@csu.edu.cn;Yan Wang,E-mail:zhuwangyan@tju.edu.cn
  • Supported by:
    In this work, we sincerely appreciated the National Natural Science Foundation of China (21978198) for financial support.

摘要: In contrast to the concurrent mixer-settler, the interaction between the mixing and settling chambers have to be taken into account in the simulation of the countercurrent mixer-settler, and no work has been reported for this equipment. In this work, a three-phase flow model based on the Eulerian multiphase model, coupled with a sliding mesh model is proposed for a countercurrent mixer-settler. Based on this, the dispersed phase distribution, flow pattern, and pressure distribution are investigated, which can help to fill the gap in the operation mechanism. In addition, the velocity vector distribution at the phase port shows an intriguing phenomenon that two types of vectors with opposite directions are distributed on the left and right sides of the same plane, which indicates that the material exchange in the mixing and settling chambers is simultaneous. Analysis of this variation at this location by a fast Fourier transform (FFT) method reveals that it is mainly influenced by the mixing chamber and is consistent with the main period of the outlet flow fluctuations. Therefore, by monitoring the fluctuation of the outlet flow and then analyzing it by the FFT method, the state of the whole tank can be determined, which makes it promising for the design of control systems for countercurrent mixer-settlers.

关键词: Countercurrent mixer-settler, Three-phase flow, Sliding mesh model (SMM), Fast Fourier transform (FFT)

Abstract: In contrast to the concurrent mixer-settler, the interaction between the mixing and settling chambers have to be taken into account in the simulation of the countercurrent mixer-settler, and no work has been reported for this equipment. In this work, a three-phase flow model based on the Eulerian multiphase model, coupled with a sliding mesh model is proposed for a countercurrent mixer-settler. Based on this, the dispersed phase distribution, flow pattern, and pressure distribution are investigated, which can help to fill the gap in the operation mechanism. In addition, the velocity vector distribution at the phase port shows an intriguing phenomenon that two types of vectors with opposite directions are distributed on the left and right sides of the same plane, which indicates that the material exchange in the mixing and settling chambers is simultaneous. Analysis of this variation at this location by a fast Fourier transform (FFT) method reveals that it is mainly influenced by the mixing chamber and is consistent with the main period of the outlet flow fluctuations. Therefore, by monitoring the fluctuation of the outlet flow and then analyzing it by the FFT method, the state of the whole tank can be determined, which makes it promising for the design of control systems for countercurrent mixer-settlers.

Key words: Countercurrent mixer-settler, Three-phase flow, Sliding mesh model (SMM), Fast Fourier transform (FFT)