CFD Simulation of Immiscible Liquid-Liquid Dispersion in a Stirred Tank

化学工业与工程

Chemcial Industry and Engineering

2018, Vol. 35

Issue (2) :70-79 DOI: 10.13353/j.issn.1004.9533.20161024

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CFD Simulation of Immiscible Liquid-Liquid Dispersion in a Stirred Tank

Yan Yuefei, Wang Rijie, Yang Xiaoxia

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China

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Abstract

The mean droplet size and droplet size distribution are two important parameters for the description of immiscible liquid-liquid dispersion. They are closely related to the contact areas between the two phases which determine the rates of mass and heat transfer and chemical reactions. This work investigated the water-oil dispersion within a stirred tank using CFD method in detail. Results show the dispersion is significantly affected by the impeller speed, dispersed phase volume fraction and continuous phase viscosity. The increase of impeller speed and continuous phase viscosity is beneficial to dispersion when the composition of two phases was constant. The plots of mean droplet size versus impeller speed and that of mean droplet size versus dispersed phase volume fraction give good log-linear correlations, and the relative coefficients are up to 0.999. Besides, the droplet size distributions based on number are found to have bimodal distribution with the variation of impeller speed and continuous phase viscosity, while the droplet size distributions based on volume are unimodal distribution all the time.

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	Yan Yuefei
	Wang Rijie
	Yang Xiaoxia

Keywords： mean droplet size； droplet size distribution； immiscible liquid-liquid dispersion； stirred tank； CFD

Received 2016-03-15;

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Yan Yuefei, Wang Rijie, Yang Xiaoxia.CFD Simulation of Immiscible Liquid-Liquid Dispersion in a Stirred Tank[J] Chemcial Industry and Engineering, 2018,V35(2): 70-79

[1] Luo H, Svendsen H F. Theoretical model for drop and bubble breakup in turbulent dispersions[J]. AIChE Journal, 1996, 42(5):1225-1233
[2] Edward L P, Atiemo-Obeng V A, Kresta M S. Handbook of industrial mixing:Science and practice[M]. New Jersey:John Wiley & Sons, Inc, 2004
[3] Eastwood C D, Armi L, Lasheras J C. The breakup of immiscible fluids in turbulent flows[J]. Journal of Fluid Mechanics, 2004, 502:309-333
[4] Sechremeli D, Stampouli A, Stamatoudis M. Comparison of mean drop sizes and drop size distributions in agitated liquid-liquid dispersions produced by disk and open type impellers[J]. Chemical Engineering Journal, 2006, 117(2):117-122
[5] Chen H T, Middleman S. Drop size distribution in agitated liquid-liquid systems[J]. AIChE Journal, 1967, 13(5):989-998
[6] Calabrese R V, Wang C, Bryner N P. Drop breakup in turbulent stirred-tank contactors:Ⅲ. Correlations for mean size and drop size distribution[J]. AIChE Journal, 1986, 32(4):677-681
[7] Wang C, Calabrese R V. Drop breakup in turbulent stirred-tank contactors:Ⅱ. Relative influence of viscosity and interfacial tension[J]. AIChE Journal, 1986, 32(4):667-676
[8] Desnoyer C, Masbernat O, Gourdon C. Experimental study of drop size distributions at high phase ratio in liquid-liquid dispersions[J]. Chemical Engineering Science, 2003, 58(7):1353-1363
[9] El-Hamouz A, Cooke M, Kowalski A, et al. Dispersion of silicone oil in water surfactant solution:Effect of impeller speed, oil viscosity and addition point on drop size distribution[J]. Chemical Engineering and Processing, 2009, 48(2):633-642
[10] Boxall J A, Koh C A, Sloan E D, et al. Measurement and calibration of droplet size distributions in water-in-oil emulsions by particle video microscope and a focused beam reflectance method[J]. Industrial & Engineering Chemistry Research, 2010, 49:1412-1418
[11] Wang W, Chen W, Duan J, et al. Effect of dispersed holdup on drop size distribution in oil-water dispersions:Experimental observations and population balance modeling[J]. Chemical Engineering Science, 2014, 105:22-31
[12] Colella D, Vinci D, Bagatin R, et al. A study on coalescence and breakage mechanisms in three different bubble columns[J]. Chemical Engineering Science, 1990, 54:4767-4777
[13] Olmos E, Gentric C, Vial C, et al. Numerical simulation of multiphase flow in bubble column reactors:Influence of bubble coalescence and breakup[J]. Chemical Engineering Science, 2001, 56:6359-6365
[14] Lehr F, Millies M, Mewes D. Bubble-Size distributions and flow fields in bubble columns[J]. AIChE Journal, 2002, 48:2426-2443
[15] Ramkrishna D, Mahoney A W. Population balance modeling. Promise for the future[J]. Chemical Engineering Science, 2002, 57:595-606
[16] Chen P, Sanyal J, Dudukovic M P. Numerical simulation of bubble columns flows:Effect of different breakup and coalescence closures[J]. Chemical Engineering Science, 2005, 60:1085-1101
[17] Ljungqvist M, Rasmuson A. Numerical simulation of the two phase flow in an axially stirred reactor[J]. Chemical Engineering Research and Design, 2001, 79:533-546
[18] Schiller L, Naumann A. A drag coefficient correlation[J]. Z Ver Deutsch Ing, 1935, 77:318-325
[19] Kasat G R, Khopkar A R, Ranade V V, et al. CFD simulation of liquid-phase mixing in solid-liquid stirred reactor[J]. Chemical Engineering Science, 2008, 63:3877-3885
[20] Blazek J. Computational fluid dynamics:Principles and applications[M]. Amsterdam:Elsevier Ltd., 2005
[21] Tsouris C, Tavlarides L L. Breakup and coalescence models for drops in turbulent dispersions[J]. AIChE Journal, 1994, 40:395-406
[22] Alopaeus V, Koskinen J, Keskinen K I. Simulation of the population balances for liquid-liquid systems in a non ideal stirred tank. Part 1.Description and qualitative validation of the model[J]. Chemical Engineering Science, 1999, 54:5887-5899
[23] Lasheras J C, Eastwood C, Martinez-Bazan C, et al. A review of statistical models for the break-up of an immiscible fluid immersed into a fully developed turbulent flow[J]. International Journal of Multiphase Flow, 2002, 28:247-278
[24] Liao Y, Lucas D. A literature review of theoretical models for drop and bubble breakup in turbulent dispersions[J]. Chemical Engineering Science, 2009, 64:3389-3406
[25] Wang T, Wang J, Jin Y. A novel theoretical breakup kernel function for bubbles/droplets in a turbulent flow[J]. Chemical Engineering Science, 2003, 58:4629-4637
[26] Liao Y, Lucas D. A literature review on mechanisms and models for the coalescence process of fluid particles[J]. Chemical Engineering Science, 2010, 65:2851-2864
[27] Abrahamson J. Collision rates of small particles in a vigorously turbulent fluid[J]. Chemical Engineering Science, 1975, 30:1371-1379
[28] Higashitani K, Yamauchi K, Matsuno Y, et al. Turbulent coagulation of particles dispersed in a viscous fluid[J]. Journal of Chemical Engineering of Japan, 1983, 16(4):299-304
[29] Pacek A W, Man C C, Nienow A W. On the Sauter mean diameter and size distributions in turbulent liquid-liquid dispersions in a stirred vessel[J]. Chemical Engineering Science, 1998, 53:2005-2011
[30] Deglon D A, Meyer C J. CFD modeling of stirred tanks:Numerical considerations[J]. Minerals Engineering, 2006, 19:1059-1068
[31] Feng X, Cheng J, Li X, et al. Numerical simulation of turbulent flow in a baffled stirred tank with an explicit algebraic stress model[J]. Chemical Engineering Science, 2012, 69:30-44
[32] Feng X, Li X, Cheng J, et al. Numerical simulation of solid-liquid turbulent flow in a stirred tank with a two-phase explicit algebraic stress model[J]. Chemical Engineering Science, 2012, 82:272-284
[33] Roudsari S F, Turcotte G, Dhib R, et al. CFD modeling of the mixing of water in oil emulsions[J]. Computers & Chemical Engineering, 2012, 45:124-136
[34] Zhou G, Kresta S M. Evolution of drop size distribution in liquid-liquid dispersions for various impellers[J]. Chemical Engineering Science, 1998, 53(11):2099-2113
[35] Liu C, Li M, Liang C, et al. Measurement and analysis of bimodal drop size distribution in a rotor-stator homogenizer[J]. Chemical Engineering Science, 2013, 102:622-631
[36] Ruiz M C, Lermanda P, Padilla R. Drop size distribution in a batch mixer under breakage conditions[J]. Hydrometallurgy, 2002, 63:65-74
[37] Vankova N, Tcholakova S, Denkov N D, et al. Emulsification in turbulent flow. 1. Mean and maximum drop diameters in inertial and viscous regimes[J]. Journal of Colloid and Interface Science, 2007, 312:363-380
[38] Stamatoudis M, Tavlarides L L. The effect of continuous-phase viscosity on the unsteady state behavior of liquid-liquid agitated dispersions[J]. Chemical Engineering Journal, 2007, 35:137-143
[39] Vankova N, Tcholakova S, Denkov N D, et al. Emulsification in turbulent flow. 1. Mean and maximum drop diameters in inertial and viscous regimes[J]. Journal of Colloid and Interface Science, 2007, 312:363-380