SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 56 ›› Issue (4): 203-214.DOI: 10.1016/j.cjche.2022.07.018

• Full Length Article • 上一篇    下一篇

Reduced power consumption in stirred vessel with high solid loading by equipping punched baffles

Xia Xiong1, Zuohua Liu1,2, Changyuan Tao1,2, Yundong Wang3, Fangqin Cheng4, Hong Li5   

  1. 1. School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China;
    2. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing 400044, China;
    3. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China;
    4. Institute of Resources and Environment Engineering, Shanxi University, Taiyuan 030006, China;
    5. Graduate School, Chongqing University, Chongqing 400044, China
  • 收稿日期:2022-04-30 修回日期:2022-07-17 出版日期:2023-04-28 发布日期:2023-06-13
  • 通讯作者: Zuohua Liu,E-mail:liuzuohua@cqu.edu.cn
  • 基金资助:
    The study was supported by the National Natural Science Foundation of China (22078030, Z20200804), National Key Research and Development Program of China (2019YFC1905802), Key Project of Independent Research Project of State Key Laboratory of Coal Mine Disaster Dynamics and Control (2011DA105287-zd201902), Hubei Three Gorges Laboratory Open/Innovation Fund (SK211009, SK215001).

Reduced power consumption in stirred vessel with high solid loading by equipping punched baffles

Xia Xiong1, Zuohua Liu1,2, Changyuan Tao1,2, Yundong Wang3, Fangqin Cheng4, Hong Li5   

  1. 1. School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China;
    2. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing 400044, China;
    3. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China;
    4. Institute of Resources and Environment Engineering, Shanxi University, Taiyuan 030006, China;
    5. Graduate School, Chongqing University, Chongqing 400044, China
  • Received:2022-04-30 Revised:2022-07-17 Online:2023-04-28 Published:2023-06-13
  • Contact: Zuohua Liu,E-mail:liuzuohua@cqu.edu.cn
  • Supported by:
    The study was supported by the National Natural Science Foundation of China (22078030, Z20200804), National Key Research and Development Program of China (2019YFC1905802), Key Project of Independent Research Project of State Key Laboratory of Coal Mine Disaster Dynamics and Control (2011DA105287-zd201902), Hubei Three Gorges Laboratory Open/Innovation Fund (SK211009, SK215001).

摘要: Solid–liquid suspension in stirred tank is a common operation in the chemical industry. The power consumption, flow pattern and flow field instability of three systems named as unbaffled stirred tank, traditional baffled stirred tank and punched baffled stirred tank (Pun-BST) were studied by using the computational fluid dynamic analysis. Results showed that perforating holes in the baffles could reduce power consumption of mixing. Meanwhile, the punched baffle system could maintain the solids in suspension as traditional baffle system. The results also showed that the baffles could increase the “effective flow” of stirred tank even though the whole velocity of the vessel is lower than un-baffled vessel. In addition, both the solid–liquid suspension and “effective flow” were related to instability of the flow field. Perfect solid–liquid suspension results always along with obvious instability of the flow field. But, the strengthening effect of punched baffle on flow field instability mainly happened in the near-wall area. It’s because the collision and aggregation among sub-streams induced by holes intensified the unstable fluid flow. On the whole, the Pun-BST system provided much better mixing characteristics and recommended to apply in the industrial process.

关键词: Solid-liquid suspension, Punched baffle, Energy conservation, Flow field instability, Effective fluxion

Abstract: Solid–liquid suspension in stirred tank is a common operation in the chemical industry. The power consumption, flow pattern and flow field instability of three systems named as unbaffled stirred tank, traditional baffled stirred tank and punched baffled stirred tank (Pun-BST) were studied by using the computational fluid dynamic analysis. Results showed that perforating holes in the baffles could reduce power consumption of mixing. Meanwhile, the punched baffle system could maintain the solids in suspension as traditional baffle system. The results also showed that the baffles could increase the “effective flow” of stirred tank even though the whole velocity of the vessel is lower than un-baffled vessel. In addition, both the solid–liquid suspension and “effective flow” were related to instability of the flow field. Perfect solid–liquid suspension results always along with obvious instability of the flow field. But, the strengthening effect of punched baffle on flow field instability mainly happened in the near-wall area. It’s because the collision and aggregation among sub-streams induced by holes intensified the unstable fluid flow. On the whole, the Pun-BST system provided much better mixing characteristics and recommended to apply in the industrial process.

Key words: Solid-liquid suspension, Punched baffle, Energy conservation, Flow field instability, Effective fluxion