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CFD Simulation on the Hydrodynamics in Gas-Liquid Airlift Reactor

  • Shi Yan Liew EMAIL logo and Jolius Gimbun ORCID logo
Published/Copyright: August 3, 2017
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Abstract

Two-fluid model approach to simulate gas-liquid airlift reactors is widely implemented but have yet to reach a consensus on the closure model to account the gas-liquid interphase forces. Proper selection of a closure model is required in order to accurately capture the hydrodynamics in the complex of the two-phase system. Our work concerns the evaluation of the interfacial forces models (i. e. drag, lift and turbulent dispersion force) and their effects on local gas holdup and liquid velocity. A transient three-dimensional airlift reactor simulation was carried out using computational fluid dynamics by implementing the dispersed standard k-ε turbulence model. Four drag models governed by spherical bubble, bubble deformation and Rayleigh-Taylor were being evaluated in our work. The significance on the inclusion of the lift model on predictive accuracy on the flow field was also studied as well. Whereas, two turbulent dispersion force models were selected to evaluate on their performance in improving the predictive accuracy of the local hydrodynamics. Results showed that the drag governed by Rayleigh-Taylor which accounts the bubble swarm effect had better predictions on the gas holdup in the downcomer and improved predictions in radial gas holdup. The inclusion of the lift model improved local gas holdup predictions at higher heights of the reactor and shifted the bubble plume towards the centre region of the riser. Meanwhile, the turbulent dispersion models improved the overall results of predicted local gas holdup with closer agreement obtained when the drift velocity model was considered in the simulation. The axial liquid velocity was well predicted for all cases. The consideration of the drag, lift and turbulent dispersion forces resulted in a closer agreement with experimental data.

Funding statement: This work was supported by the University Malaysia Pahang; [GRS160329].

Acknowledgement

Liew SY thanks Ministry of Education Malaysia for MyMaster scholarship and the provision of a Master scholarship via Graduate Research Scheme. We also acknowledge funding from University Malaysia Pahang (No. GRS160329).

References

[1] Chisti MY, Moo-Young M. Airlift reactors: characteristics, applications and design consideration. Chem Eng Comm. 1987;60:195–242.10.1080/00986448708912017Search in Google Scholar

[2] Paul EL, Atiemo-Obeng VA, Kresta SM. Handbook of industrial mixing: science and practice. Hoboken, NJ: John Wiley and Sons, 2004.10.1002/0471451452Search in Google Scholar

[3] Chisti MY, Halard B, Moo-Young M. Liquid circulation in airlift reactors. Chem Eng Sci. 1988;43(3):451–457.10.1016/0009-2509(88)87005-2Search in Google Scholar

[4] Bello RA, Robinson CW, Moo-Young M. Gas holdup and overall volumetric oxygen transfer coefficient in airlift contactors. Biotechnol Bioeng. 1985;27(3):369–381.10.1002/bit.260270323Search in Google Scholar PubMed

[5] Choi KH. Hydrodynamic and mass transfer characteristics of external-loop airlift reactors without an extension tube above the downcomer. Korean J Chem Eng. 2001;18(2):240–246.10.1007/BF02698466Search in Google Scholar

[6] Chisti Y. Pneumatically agitated bioreactors in industrial and environmental bioprocessing: hydrodynamics, hydraulics and transport phenomena. Appl Mech Rev. 1998;51(1):33–112.10.1115/1.3098989Search in Google Scholar

[7] Šimčík M, Mota A, Ruzicka MC, Vicente A, Teixeira J. CFD simulation and experimental measurement of gas holdup and liquid interstitial velocity in internal loop airlift reactor. Chem Eng Sci. 2011;66(2011):3268–3279.10.1016/j.ces.2011.01.059Search in Google Scholar

[8] Mudde RF, Van Den Akker HE. 2D and 3D simulation of an internal airlift loop reactor on the basis of a two-fluid model. Chem Eng Sci. 2001;56(2001):6351–6358.10.1016/S0009-2509(01)00222-6Search in Google Scholar

[9] Talvy S, Cockx A, Liné A. Modeling hydrodynamics of gas-liquid airlift reactor. AIChE J. 2007;53(2):335–353.10.1002/aic.11078Search in Google Scholar

[10] Liao J, Ziegenhein T, Rzehak R. Bubbly flow in an airlift column: a CFD study. J Chem Technol Biotechnol. 2016;91:2904–2015.10.1002/jctb.4917Search in Google Scholar

[11] Schiller L, Naumann L. A drag coefficient correlation. Z Ver Deutsch Ing. 1935;77:318.Search in Google Scholar

[12] Law D, Battaglia F. Numerical simulations for hydrodynamics of air-water external loop airlift reactor flows with bubble break-up and coalescence effects. J Fluids Eng. 2013;135(8):081302.10.1115/1.4024396Search in Google Scholar

[13] Dhanasekharan KM, Sanyal J, Jain A, Haidari A. A generalized approach to model oxygen transfer in bioreactors using population balances and computational fluid dynamics. Chem Eng Sci. 2005;60(2005):213–218.10.1016/j.ces.2004.07.118Search in Google Scholar

[14] Grace JR, Wairegi T, Nguyen TH. Shape and velocities of single drops and bubbles moving freely through immiscible liquids. Trans Inst Chem Eng. 1976;54(3):167–173.Search in Google Scholar

[15] Tomiyama A, Zun I, Sakaguchi T. Drag coefficient of single bubbles under normal and micro gravity conditions. JSME Int J Ser B. 1998;41:472–479.10.1299/jsmeb.41.472Search in Google Scholar

[16] Jiang X, Yang N, Yang B. Computational fluid dynamics simulation hydrodynamics in the riser of an external loop airlift reactor. Particuology. 2016;27:95–101.10.1016/j.partic.2015.05.011Search in Google Scholar

[17] Mohajerani M, Mehrvar M, Ein-Mozaffari F. CFD analysis of two-phase turbulent flow in internal airlift reactors. Can J Chem Eng. 2012;90(6):1612–1631.10.1002/cjce.20674Search in Google Scholar

[18] Liang XF, Pan H, Su YH. Luo ZH. CFD-PBM approach with modified drag model for the gas-liquid flow in a bubble column. Chem Eng Res Des. 2016;111(2016):88–102.10.1016/j.cherd.2016.06.014Search in Google Scholar

[19] Gimbun J, Liew SY, Nagy ZK, Rielly CD. Three-way coupling simulation of a gas-liquid stirred tank using a multi-compartment population balance model. Chem Prod Process Model. 2016;11(3):205–216.10.1515/cppm-2015-0076Search in Google Scholar

[20] Masood RM, Jovicic V, Delgado A. Numerical simulation of interfacial closures for 3D bubble column flows. Chem Eng Technol. 2015;38(5):777–786.10.1002/ceat.201400182Search in Google Scholar

[21] Pourtousi M, Sahu JN, Ganesan P. Effect of interfacial forces and turbulence models on predicting flow pattern inside the bubble column. Chem Eng Process. 2014;75(2014):38–47.10.1016/j.cep.2013.11.001Search in Google Scholar

[22] Masood RM, Delgado A. Numerical investigation of the interphase forces and turbulence closure in 3D square bubble column. Chem Eng Sci. 2014;108(2014):154–168.10.1016/j.ces.2014.01.004Search in Google Scholar

[23] Couvert A. Etude d’un réacteur airlift rectangulaire à recirculation interne. Toulouse, France: INSA, , 2000. Doctoral dissertation.Search in Google Scholar

[24] Cockx A. Modélisation de contacteurs gaz-liquide: application de la mécanique des fluides numérique aux airlifts. Toulouse, France: INSA, , 1997. Doctoral dissertation.Search in Google Scholar

[25] Sokolichin A, Eigenberger G, Lapin A. Simulation of buoyancy driven bubbly flow: established simplications and open questions. AIChE J. 2004;50(1):24–45.10.1002/aic.10003Search in Google Scholar

[26] Gimbun J, Rielly CD, Nagy ZK. Modelling of mass transfer in gas–liquid stirred tanks agitated by Rushton turbine and CD-6 impeller: a scale-up study. Chem Eng Res Des. 2009;87(4):437–451.10.1016/j.cherd.2008.12.017Search in Google Scholar

[27] Kolev NI. Multiphase flow dynamics 2: thermal and mechanical interactions. Berlin, Germany: Springer, 2005.Search in Google Scholar

[28] Fluent Inc. User’s Guide. Lebanon, NH, 2005.Search in Google Scholar

[29] Drew DA, Lahey JR. Application of general constitutive principles to the derivation of multidimensional two-phase flow equation. Int J Multiphas Flow. 1979;5:243.10.1016/0301-9322(79)90024-7Search in Google Scholar

[30] Zun I. The transverse migration of bubbles influenced by walls in vertical bubbly flow. Int J Multiphas Flow. 1980;6:583–588.10.1016/0301-9322(80)90053-1Search in Google Scholar

[31] Auton TR. The lift force on a spherical body in a rotational flow. J Fluid Mech. 1987;183:199–218.10.1017/S002211208700260XSearch in Google Scholar

[32] Tomiyama A, Tamai H, Zun I, Hosokawa S. Transverse migration of single bubbles in simple shear flows. Chem Eng Sci. 2002;57(2002):1849–1858.10.1016/S0009-2509(02)00085-4Search in Google Scholar

[33] Lucas D, Tomiyama A. On the role of the lateral life force in poly-dispersed bubbly flows. Int J Multiphase Flow. 2011;37:1178–1190.10.1016/j.ijmultiphaseflow.2011.05.009Search in Google Scholar

[34] Wellek RM, Agrawal AK, Skelland AH. Shape of liquid drops moving in liquid media. AIChE J. 1966;12:854–862.10.1002/aic.690120506Search in Google Scholar

[35] Lopez De Bertodano M. Turbulent bubbly flow in a triangular duct. Troy, NY: Rensselaer Polytechnic Institute, , 1991. Doctoral dissersation.Search in Google Scholar

[36] Yamaoh S, Matínez-Cuenca R, Monŕos G, Chiva S, Macián-Juan R. Numerical investigation of models for drag, lift, wall lubrication and turbulent dispersion forces for the simulation of gas-liquid two-phase flow. Chem Eng Res Des. 2015;98(2015):17–35.10.1016/j.cherd.2015.04.007Search in Google Scholar

[37] Simonin O, Viollet PL. Modelling of turbulent two-phase jets loaded with discrete particles. Phenom Multiphas Flows. 1990;1990:259–269.Search in Google Scholar

Received: 2017-5-10
Accepted: 2017-7-7
Published Online: 2017-8-3

© 2017 Walter de Gruyter GmbH, Berlin/Boston

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