CFD modeling of immiscible liquids turbulent dispersion in Kenics static mixers: Focusing on droplet behavior

doi:10.1016/j.cjche.2019.07.020

摘要/Abstract

摘要： The present study is concerned with the computational fluid dynamics (CFD) simulation of turbulent dispersion of immiscible liquids, namely, water-silicone oil and water-benzene through Kenics static mixers using the Eulerian-Eulerian and Eulerian-Lagrangian approaches of the ANSYS Fluent 16.0 software. To study the droplet size distribution (DSD), the Eulerian formulation incorporating a population balance model (PBM) was employed. For the Eulerian-Lagrangian approach, a discrete phase model (DPM) in conjunction with the Eulerian approach for continuous phase simulation was used to predict the residence time distribution (RTD) of droplets. In both approaches, a shear stress transport (SST) k-ω turbulence model was used. For validation purposes, the simulated results were compared with the experimental data and theoretical values for the Fanning friction factor, Sauter mean diameter and the mean residence time. The reliability of the computational model was further assessed by comparing the results with the available empirical correlations for Fanning friction factor and Sauter mean diameter. In addition, the influence of important geometrical and operational parameters, including the number of mixing elements and Weber number, was studied. It was found that the proposed models are capable of predicting the performance of the Kenics static mixer reasonably well.

关键词: CFD, Liquid-liquid dispersion, Kenics static mixer, Eulerian-Eulerian approach, Eulerian-Lagrangian approach

Abstract: The present study is concerned with the computational fluid dynamics (CFD) simulation of turbulent dispersion of immiscible liquids, namely, water-silicone oil and water-benzene through Kenics static mixers using the Eulerian-Eulerian and Eulerian-Lagrangian approaches of the ANSYS Fluent 16.0 software. To study the droplet size distribution (DSD), the Eulerian formulation incorporating a population balance model (PBM) was employed. For the Eulerian-Lagrangian approach, a discrete phase model (DPM) in conjunction with the Eulerian approach for continuous phase simulation was used to predict the residence time distribution (RTD) of droplets. In both approaches, a shear stress transport (SST) k-ω turbulence model was used. For validation purposes, the simulated results were compared with the experimental data and theoretical values for the Fanning friction factor, Sauter mean diameter and the mean residence time. The reliability of the computational model was further assessed by comparing the results with the available empirical correlations for Fanning friction factor and Sauter mean diameter. In addition, the influence of important geometrical and operational parameters, including the number of mixing elements and Weber number, was studied. It was found that the proposed models are capable of predicting the performance of the Kenics static mixer reasonably well.

Key words: CFD, Liquid-liquid dispersion, Kenics static mixer, Eulerian-Eulerian approach, Eulerian-Lagrangian approach

M. M. Haddadi, S. H. Hosseini, D. Rashtchian, G. Ahmadi. CFD modeling of immiscible liquids turbulent dispersion in Kenics static mixers: Focusing on droplet behavior[J]. 中国化学工程学报, 2020, 28(2): 348-361.

M. M. Haddadi, S. H. Hosseini, D. Rashtchian, G. Ahmadi. CFD modeling of immiscible liquids turbulent dispersion in Kenics static mixers: Focusing on droplet behavior[J]. Chinese Journal of Chemical Engineering, 2020, 28(2): 348-361.

参考文献

[1] T.F. Tadros, Emulsions:Formation, Stability, Industrial Applications, De Gruyter, Boston, 2016.
[2] M. Rayner, P. Dejmek, Engineering Aspects of Food Emulsification and Homogenization, CRC Press, New York, 2015.
[3] R.K. Thakur, Ch. Vial, D.P. Nigam, E.B. Nauman, G. Djelveh, Static mixers in the process industries-A review, Chem. Eng. Res. Des. 81(2003) 787-826.
[4] N.G. Anderson, Using continuous processes to increase production, Org. Process. Res. Dev. 16(2012) 852-869.
[5] A. Ghanem, T. Lemenand, D. Della Valle, H. Peerhossaini, Static mixers:Mechanisms, application, and characterization methods-A review, Chem. Eng. Res. Des. 92(2014) 205-228.
[6] D. Liang, S. Zhang, A contraction-expansion helical mixer in the laminar regime, Chin. J. Chem. Eng. 22(2014) 261-266.
[7] E.A. Mansur, Y.E. Mingxing, W. Yundong, D. Youyuan, A state-of-the-art review of mixing in microfluidic mixers, Chin. J. Chem. Eng. 16(2008) 503-516.
[8] L. Yuanfa, H. Gaohong, D. Luhui, D. Hong, J. Jia, L. Baojun, Experimental and CFD studies on the performance of microfiltration enhanced by a turbulence promoter, Chin. J. Chem. Eng. 20(2012) 617-624.
[9] H.Z. Li, C. Fasol, L. Choplin, Pressure drop of Newtonian and non-Newtonian fluids across a Sulzer SMX static mixer, Chem. Eng. Res. Des. 51(1996) 1947-1955.
[10] F. Theron, N.L. Sauze, Comparison between three static mixers for emulsification in turbulent flow, Int. J. Multiphase Flow 37(2011) 488-500.
[11] W.F.C. van Wageningen, D. Kandhai, R.F. Mudde, H.E.A. van den Akker, Dynamic flow in a Kenics static mixer:An assessment of various CFD methods, AICHE J. 50(2004) 1684-1696.
[12] J.O. Hinze, Fundamentals of the hydrodynamic mechanism of splitting in dispersion processes, AICHE J. 1(1955) 289-295.
[13] N. Kiss, G. Brenn, H. Pucher, J. Wieser, S. Scheler, H. Jennewein, D. Suzzi, J. Khinast, Formation of O/W emulsions by static mixers for pharmaceutical applications, Chem. Eng. Sci. 66(2011) 5084-5094.
[14] A.N. Kolmogorov, Equations of turbulence motion of incompressible fluid, Dokl. Akad. Nauk SSSR 30(1941) 299-303.
[15] E. Pitton, P. Ciandri, M. Margarone, P. Andreussi, An experimental study of stratified-dispersed flow in horizontal pipes, Int. J. Multiphase Flow 67(2014) 92-103.
[16] G.A. Farzi, N. Reza-Zadeh, A. Parsian-Nejad, Droplet formation study in emulsification process by KSM using a novel in situ visualization system, J. Dispers. Sci. Technol. 37(2015) 575-581.
[17] S. Middleman, Drop size distribution produced by turbulent pipe flow of immiscible fluids through a static mixer, Ind. Eng. Chem. Res. 13(1974) 78-83.
[18] P.D. Berkman, R.V. Calabrese, Dispersion of viscous liquids by turbulent flow in a static mixer, AICHE J. 34(1988) 602-609.
[19] M.P. Vasilev, R.Sh. Abiev, Intensity and efficiency of droplet dispersion:Pulsating flow type apparatus vs. static mixers, Chem. Eng. Res. Des. 137(2018) 329-349.
[20] M.P. Vasilev, R.Sh. Abiev, Turbulent droplets dispersion in a pulsating flow type apparatus-New type of static disperser, Chem. Eng. J. 349(2018) 646-661.
[21] K.D.P. Nigam, E.B. Nauman, Residence time distributions of power law fluids in motionless mixers, Can. J. Chem. Eng. 63(1985) 519-521.
[22] G. Montante, M. Coroneo, A. Paglianti, Blending of miscible liquids with different densities and viscosities, Chem. Eng. Sci. 141(2016) 250-260.
[23] M. Regner, K. Östergren, C. Trägårdh, Effects of geometry and flow rate on secondary flow and the mixing process in static mixers-A numerical study, Chem. Eng. Sci. 61(2006) 6133-6141.
[24] M. Coroneo, G. Montante, A. Paglianti, Computational fluid dynamic modeling of corrugated static mixers for turbulent applications, Ind. Eng. Chem. Res. 51(2012) 15986-15996.
[25] H. Meng, X. Jiang, Y. Yu, Z. Wang, J. Wu, Laminar flow and chaotic advection mixing performance in a static mixer with perforated helical segments, Korean J. Chem. Eng. 34(2017) 1328-1336.
[26] R.Sh. Abiev, A.S. Galushko, Hydrodynamics of pulsating flow type apparatus:Simulation and experiments, Chem. Eng. J. 229(2013) 285-295.
[27] Z. Jaworski, P. Pianko-Oprych, Two-phase laminar flow simulations in a Kenics static mixer:Standard Eulerian and Lagrangian approaches, Chem. Eng. Res. Des. 80(2002) 910-916.
[28] G.A. Farzi, N. Reza-Zadeh, A. Parsian-Nejad, Droplet size distribution in a Kenics static mixer:CFD simulation and experimental investigation of emulsions, J. Chem. Eng. Process. Technol. 5(2014) 201.
[29] F. Zidouni, E. Krepper, R. Rzehak, S. Rabha, M. Schubert, U. Hample, Simulation of gas-liquid flow in a helical static mixer, Chem. Eng. Sci. 137(2015) 476-486.
[30] N.G. Deen, M.V.S. Annaland, M.A.V.D. Hoef, J.A.M. Kuipers, Review of discrete particle modeling of fluidized bed, Chem. Eng. Sci. 62(2007) 28-44.
[31] P.J. Becker, F. Puel, R. Henry, N. Sheibat-Othman, Investigation of discrete population balance models and breakage kernels for dilute emulsification systems, Ind. Eng. Chem. Res. 50(2011) 11358-11374.
[32] H. Luo, H.F. Svendsen, Theoretical model for drop and bubble breakup in turbulent dispersions, AICHE J. 42(1996) 1225-1233.
[33] P. Pianko-Oprych, Z. Jaworski, CFD modeling of two-phase liquid-liquid flow in a SMX static mixer, Pol. J. Chem. Technol. 11(2009) 41-49.
[34] G.A. Farzi, N. Reza-Zadeh, A. Parsian-Nejad, Homogenization efficiency of two immiscible fluids in static mixer using droplet tracking technique, J. Dispers. Sci. Technol. 37(2015) 1486-1493.
[35] Z. Jaworski, P. Pianko-Oprych, D.L. Marchisio, A.W. Nienow, CFD modelling of turbulent drop breakage in a Kenics static mixer and comparison with experimental data, Chem. Eng. Res. Des. 85(2007) 753-759.
[36] P. Chen, J. Sanyal, M.P. Dudukovic, CFD modeling of bubble columns flows:Implementation of population balance, Chem. Eng. Sci. 59(2004) 5201.
[37] F. Sotiropoulos, Y. Ventikos, Flow through a curved duct using nonlinear twoequation turbulence models, AIAA J. 36(1998) 1256-1262.
[38] S.H. Hosseini, S. Shojaee, G. Ahmadi, M. Zivdar, Computational fluid dynamics studies of dry and wet pressure drops in structured packings, J. Ind. Eng. Chem. 18(2012) 1465-1473.
[39] F.R. Menter, Two-equation Eddy-viscosity turbulence models for engineering applications, AIAA J. 32(1994) 1598-1605.
[40] Ansys FLUENT, User's Guide, FLUENT Inc., Canonsburg, PA, 2011.
[41] D. Ramkrishna, Population Balances Theory and Applications to Particulate Systems in Engineering, Academic Press, San Diego, 2000.
[42] M.J. Hounslow, R.L. Ryall, V.R. Marshall, A discretized population balance for nucleation, growth, and aggregation, AICHE J. 34(1988) 1821-1832.
[43] J.D. Litster, D.J. Smit, M.J. Hounslow, Adjustable discretization population balance for growth and aggregation, AICHE J. 41(1995) 591-603.
[44] Y. Liao, D. Lucas, A literature review on mechanisms and models for the coalescence process of fluid particles, Chem. Eng. Sci. 65(2010) 2851-2864.
[45] Y.A. Çengel, J.M. Cimbala, Fluid Mechanics:Fundamentals and Applications, McGraw-Hill, New York, 2014.
[46] A. Hallanger, C. Michelsen, F. Soenstaboe, T.A. Knutsen, Simulation Model for ThreePhase Gravity Separators, SPE ATCE:Dallas, Texas, Paper 36644-MS, 1996.
[47] M.A. Sattar, J. Naser, G. Brooks, Numerical simulation of two-phase flow with bubble break-up and coalescence coupled with population balance modeling, Chem. Eng. Process. 70(2013) 66-76.
[48] S. Hard, F. Schönfeld, Laminar mixing in different interdigital micromixers:II. Numerical simulations, AICHE J. 49(2003) 578-584.
[49] D.A. Deglon, C.J. Meyer, CFD modelling of stirred tanks:Numerical considerations, Miner. Eng. 19(2006) 1059-1068.
[50] T. Lemenand, D. Della Valle, Y. Zellouf, H. Peerhossaini, Droplets formation in turbulent mixing of two immiscible fluids in a new type of static mixer, Int. J. Multiphase Flow 29(2003) 813-840.
[51] N.V. Rama Rao, M.H.I. Baird, A.N. Hrymak, P.E. Wood, Dispersion of high-viscosity liquid-liquid systems by flow through SMX static mixer elements, Chem. Eng. Sci. 62(2007) 6885-6896.
[52] S.J. Chen, D.R. Libby, Gas-liquid and liquid-liquid dispersions in a Kenics mixer, Presented at the 71th Annual AIChE Meeting, 1978.
[53] M. Stec, P.M. Synowiec, Study of fluid dynamic conditions in the selected static mixers part II-Determination of the residence time distribution, Can. J. Chem. Eng. 9999(2017) 1-13.
[54] K.A. Hweij, F. Azizi, Hydrodynamics and residence time distribution of liquid flow in tubular reactors equipped with screen-type static mixers, Chem. Eng. J. 279(2015) 948-963.