Drawdown mechanism of light particles in baffled stirred tank for the KR desulphurization process

doi:10.1016/j.cjche.2018.05.019

Chin.J.Chem.Eng. ›› 2019, Vol. 27 ›› Issue (2): 247-256.DOI: 10.1016/j.cjche.2018.05.019

• Fluid Dynamics and Transport Phenomena • Previous Articles Next Articles

Drawdown mechanism of light particles in baffled stirred tank for the KR desulphurization process

Meng Li¹, Yangbo Tan¹, Jianglong Sun^1,2,3, De Xie^1,2,3, Zeng Liu^1,2,3

1 School of Naval Architecture and Ocean Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;
2 Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration (CISSE), Shanghai 200240, China;
3 Hubei Key Laboratory of Naval Architecture and Ocean Engineering Hydrodynamics (HUST), Wuhan 430074, China

Received:2018-02-02 Revised:2018-05-02 Online:2019-03-18 Published:2019-02-28
Contact: Zeng Liu
Supported by:
Supported by the National Natural Science Foundation of China (51474109, 51609090, 51679097), and the Science Research Project of Huazhong University of Science and Technology (0118140077, 2006140115)

Drawdown mechanism of light particles in baffled stirred tank for the KR desulphurization process

Meng Li¹, Yangbo Tan¹, Jianglong Sun^1,2,3, De Xie^1,2,3, Zeng Liu^1,2,3

1 School of Naval Architecture and Ocean Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;
2 Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration (CISSE), Shanghai 200240, China;
3 Hubei Key Laboratory of Naval Architecture and Ocean Engineering Hydrodynamics (HUST), Wuhan 430074, China

通讯作者: Zeng Liu
基金资助:
Supported by the National Natural Science Foundation of China (51474109, 51609090, 51679097), and the Science Research Project of Huazhong University of Science and Technology (0118140077, 2006140115)

Abstract

Abstract: To improve the efficiency of the desulfurization process, the drawdown mechanism of light particles in stirred tank is studied in this paper. For both up and down pumping modes, the just drawdown speeds (N_jd) of floating particles in transformative Kanbara Reactor (KR) are measured in one and four baffled stirred tanks experimentally. Then numerical simulations with standard k-ε model coupled with volume of fluid model (VOF) and discrete phase model (DPM) are conducted to analyze the flow field at the just drawdown speed N_jd. The torques on the impeller obtained from experiments and simulations agree well with each other, which indicates the validity of our numerical simulations. Based on the simulations, three main drawdown mechanisms for floating particles, the axial circulation, turbulent fluctuation and largescale eddies, are analyzed. It's found that the axial circulation dominates the drawdown process at small submergence (S=1/4T and 1/3T) and the large-scale eddies play a major role at large submergence (S=2/3T and 3/4T). Besides, the turbulent fluctuation affects the drawdown process significantly for up pumping mode at small submergence (S=1/4T and 1/3T) and for down pumping mode at large submergence (S=2/3T and 3/4T). This paper helps to provide a more comprehensive understanding of the KR desulphurizer drawdown process in the baffled stirred tank.

Key words: Light particles, Drawdown mechanism, Baffled stirred tank, Submergence, Numerical simulations, KR impeller

摘要： To improve the efficiency of the desulfurization process, the drawdown mechanism of light particles in stirred tank is studied in this paper. For both up and down pumping modes, the just drawdown speeds (N_jd) of floating particles in transformative Kanbara Reactor (KR) are measured in one and four baffled stirred tanks experimentally. Then numerical simulations with standard k-ε model coupled with volume of fluid model (VOF) and discrete phase model (DPM) are conducted to analyze the flow field at the just drawdown speed N_jd. The torques on the impeller obtained from experiments and simulations agree well with each other, which indicates the validity of our numerical simulations. Based on the simulations, three main drawdown mechanisms for floating particles, the axial circulation, turbulent fluctuation and largescale eddies, are analyzed. It's found that the axial circulation dominates the drawdown process at small submergence (S=1/4T and 1/3T) and the large-scale eddies play a major role at large submergence (S=2/3T and 3/4T). Besides, the turbulent fluctuation affects the drawdown process significantly for up pumping mode at small submergence (S=1/4T and 1/3T) and for down pumping mode at large submergence (S=2/3T and 3/4T). This paper helps to provide a more comprehensive understanding of the KR desulphurizer drawdown process in the baffled stirred tank.

关键词: Light particles, Drawdown mechanism, Baffled stirred tank, Submergence, Numerical simulations, KR impeller

Meng Li, Yangbo Tan, Jianglong Sun, De Xie, Zeng Liu. Drawdown mechanism of light particles in baffled stirred tank for the KR desulphurization process[J]. Chin.J.Chem.Eng., 2019, 27(2): 247-256.

Meng Li, Yangbo Tan, Jianglong Sun, De Xie, Zeng Liu. Drawdown mechanism of light particles in baffled stirred tank for the KR desulphurization process[J]. Chinese Journal of Chemical Engineering, 2019, 27(2): 247-256.

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Drawdown mechanism of light particles in baffled stirred tank for the KR desulphurization process

Drawdown mechanism of light particles in baffled stirred tank for the KR desulphurization process

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