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

doi:10.1016/j.cjche.2022.07.018

Chinese Journal of Chemical Engineering ›› 2023, Vol. 56 ›› Issue (4): 203-214.DOI: 10.1016/j.cjche.2022.07.018

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

Xia Xiong¹, Zuohua Liu^1,2, Changyuan Tao^1,2, Yundong Wang³, Fangqin Cheng⁴, Hong Li⁵

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:2023-06-13 Published:2023-04-28
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).

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

Xia Xiong¹, Zuohua Liu^1,2, Changyuan Tao^1,2, Yundong Wang³, Fangqin Cheng⁴, Hong Li⁵

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

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).

Abstract

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

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

Xia Xiong, Zuohua Liu, Changyuan Tao, Yundong Wang, Fangqin Cheng, Hong Li. Reduced power consumption in stirred vessel with high solid loading by equipping punched baffles[J]. Chinese Journal of Chemical Engineering, 2023, 56(4): 203-214.

References

[1] C. Carletti, G. Montante, T. Westerlund, A. Paglianti, Analysis of solid concentration distribution in dense solid–liquid stirred tanks by electrical resistance tomography, Chem. Eng. Sci. 119 (2014) 53–64.
[2] S. Wang, R. Parthasarathy, J. Wu, P. Slatter, Optimum solids concentration in an agitated vessel, Ind. Eng. Chem. Res. 53 (10) (2014) 3959–3973.
[3] J. Wu, Y. Zhu, P.C. Bandopadhayay, L. Pullum, I.C. Shepherd, Solids suspension with axial-flow impellers, AIChE J. 46 (3) (2000) 647–650.
[4] J. Wu, Y.G. Zhu, L. Pullum, Suspension of high concentration slurry, AIChE J. 48 (6) (2002) 1349–1352.
[5] J. Wu, S. Wang, L. Graham, R. Parthasarathy, B. Nguyen, High solids concentration agitation for minerals process intensification, AIChE J. 57 (9) (2011) 2316–2324.
[6] S. Wang, R. Parthasarathy, E.Y. Bong, J. Wu, P. Slatter, Suspension of ultrahigh concentration solids in an agitated vessel, AIChE J. 58 (4) (2012) 1291–1298.
[7] G.R. Drewer, N. Ahmed, G.J. Jameson, Suspension of high concentration solids in mechanically stirred vessels. IChemE Symp. Ser. No., 136 (41) (1994).
[8] A. Tamburini, A. Cipollina, G. Micale, A. Brucato, M. Ciofalo, CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of solid particle distribution, Chem. Eng. J. 223 (2013) 875–890.
[9] R. Alcamo, G. Micale, F. Grisafi, A. Brucato, M. Ciofalo, Large-eddy simulation of turbulent flow in an unbaffled stirred tank driven by a Rushton turbine, Chem. Eng. Sci. 60 (8–9) (2005) 2303–2316.
[10] O. Khazam, S.M. Kresta, A novel geometry for solids drawdown in stirred tanks, Chem. Eng. Res. Des. 87 (3) (2009) 280–290.
[11] A.K. Pukkella, R. Vysyaraju, V. Tammishetti, B. Rai, S. Subramanian, Improved mixing of solid suspensions in stirred tanks with interface baffles: CFD simulation and experimental validation, Chem. Eng. J. 358 (2019) 621–633.
[12] Y.Y. Shen, B. Qin, X. Li, Z.Y. Zhu, P.Z. Cui, J. Gao, Y.L. Wang, Investigation of the flow characteristics of liquid–liquid two-phase mixing in an agitator equipped with a “V-shaped” horizontal baffle, Environ. Dev. Sustain. 23 (2) (2021) 2298–2313.
[13] E.L. Paul, V.A. Atiemo-Obeng, S.M. Kresta, Handbook of Industrial Mixing, John Wiley & Sons Inc. New York (2003) 639–753.
[14] W.M. Lu, H.Z. Wu, M.Y. Ju, Effects of baffle design on the liquid mixing in an aerated stirred tank with standard Rushton turbine impellers, Chem. Eng. Sci. 52 (21–22) (1997) 3843–3851.
[15] A.L. Eken, M. Sahin, A parallel monolithic algorithm for the numerical simulation of large-scale fluid structure interaction problems, Int. J. Numer. Meth. Fluids 80 (12) (2016) 687–714.
[16] X.X. Duan, X. Feng, C. Peng, C. Yang, Z.S. Mao, Numerical simulation of micro-mixing in gas–liquid and solid–liquid stirred tanks with the coupled CFD-E-model, Chin. J. Chem. Eng. 28 (9) (2020) 2235–2247.
[17] Y.Y. Liang, Z.M. Gao, D.E. Shi, W.L. Zhao, Z.Q. Cai, Coupling simulation of fluid structure interaction in the stirred vessel with a pitched blade turbine, Chin. J. Chem. Eng. 26 (5) (2018) 922–929.
[18] A. Tamburini, A. Cipollina, G. Micale, A. Brucato, M. Ciofalo, CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of suspension curves, Chem. Eng. J. 178 (2011) 324–341.
[19] A. Tamburini, A. Cipollina, G. Micale, A. Brucato, M. Ciofalo, CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of the minimum impeller speed for complete suspension, Chem. Eng. J. 193-194 (2012) 234–255.
[20] D.Y. Gu, X.H. Shi, Z.H. Liu, Intensification on drawdown process of floating particles by circle package fractal impellers, J. Taiwan Inst. Chem. Eng. 106 (2020) 62–73.
[21] D.Y. Gu, M. Ye, X.M. Wang, Z.H. Liu, Numerical investigation on mixing characteristics of floating and sinking particles in a stirred tank with fractal impellers, J. Taiwan Inst. Chem. Eng. 116 (2020) 51–61.
[22] D.Y. Gu, C. Cheng, Z.H. Liu, Y.D. Wang, Numerical simulation of solid–liquid mixing characteristics in a stirred tank with fractal impellers, Adv. Powder Technol. 30 (10) (2019) 2126–2138.
[23] D.Y. Gu, Z.H. Liu, F.C. Qiu, J. Li, C.Y. Tao, Y.D. Wang, Design of impeller blades for efficient homogeneity of solid–liquid suspension in a stirred tank reactor, Adv. Powder Technol. 28 (10) (2017) 2514–2523.
[24] D.Y. Gu, Z.H. Liu, Z.M. Xie, J. Li, C.Y. Tao, Y.D. Wang, Numerical simulation of solid–liquid suspension in a stirred tank with a dual punched rigid-flexible impeller, Adv. Powder Technol. 28 (10) (2017) 2723–2734.
[25] L. Liu, M. Barigou, Numerical modelling of velocity field and phase distribution in dense monodisperse solid–liquid suspensions under different regimes of agitation: CFD and PEPT experiments, Chem. Eng. Sci. 101 (2013) 837–850.
[26] X.K. Li, Multiphase flow and fluidization, continuum and kinetic theory descriptions, J. Non Newton. Fluid Mech. 55 (2) (1994) 207–208.
[27] O.P. Klenov, A.S. Noskov, Solid dispersion in the slurry reactor with multiple impellers, Chem. Eng. J. 176-177 (2011) 75–82.
[28] S. Hosseini, D. Patel, F. Ein-Mozaffari, M. Mehrvar, Study of solid–liquid mixing in agitated tanks through computational fluid dynamics modeling, Ind. Eng. Chem. Res. 49 (9) (2010) 4426–4435.
[29] N.N. Qi, H. Zhang, K. Zhang, G. Xu, Y.P. Yang, CFD simulation of particle suspension in a stirred tank, Particuology 11 (3) (2013) 317–326.
[30] J.P. Torré, D.F. Fletcher, T. Lasuye, C. Xuereb, An experimental and computational study of the vortex shape in a partially baffled agitated vessel, Chem. Eng. Sci. 62 (7) (2007) 1915–1926.
[31] A. Tamburini, A. Cipollina, G. Micale, M. Ciofalo, A. Brucato, Dense solid–liquid off-bottom suspension dynamics: Simulation and experiment, Chem. Eng. Res. Des. 87 (4) (2009) 587–597.
[32] X. Xiong, Z.H. Liu, C.Y. Tao, Y.D. Wang, W.Y. Fei, Study on instability strengthening of flow field in stirred tank, J. Taiwan Inst. Chem. Eng. 134 (2022) 104284.

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

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

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[3]	Seyed Mostafa Hosseinalipour, Hadiseh Karimaei, Ehsan Movahednejad. Droplets diameter distribution using maximum entropy formulation combined with a new energy-based sub-model [J]. Chin.J.Chem.Eng., 2016, 24(11): 1625-1630.
[4]	WANG Jianlin, XUE Yaoyu, YU Tao, ZHAO Liqiang. Run-to-run Optimization for Fed-batch Fermentation Process with Swarm Energy Conservation Particle Swarm Optimization Algorithm [J]. , 2010, 18(5): 787-794.
[5]	Huang Kejin, Zhan Dezhi, Nakaiwa Masaru, Nakane Takashi, Takamatsu Takeichiro. Modeling and Analysis of Internal Heat Integrated Distillation Columns [J]. , 1999, 7(1): 67-76.
[6]	CHENG Dazhuang, WANG Yingchen, LIN Mengliu, WU Dejun, SHI Litian. SOLID-LIQUID SUSPENSION SYSTEM IN AGITATED TANK WITH DRAFT TUBE [J]. , 1993, 1(2): 84-93.