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Study of Heat Transfer in the Poly Ethylene Fluidized Bed Reactor Numerically and Experimentally

Authors: Mahdi Hamzehei

Abstract:

In this research, heat transfer of a poly Ethylene fluidized bed reactor without reaction were studied experimentally and computationally at different superficial gas velocities. A multifluid Eulerian computational model incorporating the kinetic theory for solid particles was developed and used to simulate the heat conducting gas–solid flows in a fluidized bed configuration. Momentum exchange coefficients were evaluated using the Syamlal– O-Brien drag functions. Temperature distributions of different phases in the reactor were also computed. Good agreement was found between the model predictions and the experimentally obtained data for the bed expansion ratio as well as the qualitative gas–solid flow patterns. The simulation and experimental results showed that the gas temperature decreases as it moves upward in the reactor, while the solid particle temperature increases. Pressure drop and temperature distribution predicted by the simulations were in good agreement with the experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Also, the predicted time-average local voidage profiles were in reasonable agreement with the experimental results. The study showed that the computational model was capable of predicting the heat transfer and the hydrodynamic behavior of gas-solid fluidized bed flows with reasonable accuracy.

Keywords: Gas-solid flows, fluidized bed, Hydrodynamics, Heat transfer, Turbulence model, CFD

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1063328

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References:


[1] Gidaspow, D., Multiphase Flow and Fluidization, First ed. Academic press, London, 1994.
[2] Kunii, D., Levenspiel ,O., Fluidization Engineering, Second ed. Butterworth-Heinemann, Boston, 1991.
[3] Ranade, V.V., Computational Flow Modeling for Chemical Reactor Engineering, First ed, New York, 2002.
[4] Grace, J.R., Taghipour, F., Verification and validation of CFD models and dynamic similarity for fluidized beds. Powder Technology , 139, 99-110, 2004.
[5] Bird, R.B., Stewart, W.E., Lightfoot, E.N., Transport Phenomena. seconded . Wiley, New York, 2002.
[6] Taghipour, F., Ellis, N., Wong, C., Experimental and computational study of gas-solid fluidized bed hydrodynamics, Chemical Engineering Science, 60, 6857-6867, 2005.
[7] Kaneko Y., Shiojima, T., Horio, M., DEM simulation of fluidized beds for gas-phase olefin polymerization, Chemical Engineering Science, 54, 5809-5821, 1999.
[8] Rong. F., Marchisio. D.L., Fox. R.O., CFD Simulation of Polydisperse Fluidized-Bed Polymerization Reactors, Department of Chemical Engineering, Iowa State University, 2114 Sweeney Hall, Ames, IA 50010-2230, USA, Preprint submitted to Elsevier Science, August 2003.
[9] Gobin, H. Neau, O. Simonin, J. Llinas, V. Reiling, J.L. Selo, Fluid dynamic numerical simulation of a gas phase polymerization reactor, International Journal for Numerical Methods in Fluids, 43,1199-1220, 2003.
[10] Van Wachem, B.G.M., Schouten, J.C., Van den Bleek, C.M., Krishna, R., Sinclair, J.L., Comparative analysis of CFD models of dense gas- solid systems, AIChE Journal, 47, 1035-1051, 2001.
[11] Van Wachem, B.G.M., Schouten, J.C., Van den Bleek, C.M., Krishna, R., Sinclair, J.L., CFD modeling of gas-fluidized beds with a bimodal particle mixture, AIChE Journal, 47, 1292-1302, 2001.
[12] Chiesa, M., Mathiesen, V., Melheim, J.A.., Halvorsen, B., Numerical simulation of particulate flow by the Eulerian-Lagrangian and the Eulerian-Eulerian approach with application to a fluidized bed, Computers & Chemical Engineering, 29, 291-304, 2005.
[13] Syamlal, M., O-Brien, T.J., Computer simulation of bubbles in a fluidized bed. A.I.Ch.E., 85, 22-31,1989.
[14] Syamlal, M., O-Brien, T.J., Fluid dynamic simulation of O3 decomposition in a bubbling fluidized bed. A.I.Ch.E. Journal 49, 2793- 2801, 2003
[15] Huilin, L., Yurong, H., Gidaspow, D., Hydrodynamic modeling of binary mixture in a gas bubbling fluidized bed using the kinetic theory of granular flow, Chemical Engineering Science, 58, 1197-1205, 2003.
[16] Lun, C.K.K., and Savage, S.B., A Simple Kinetic Theory for Granular Flow of Rough, Inelastic, Spherical Particles, J. Appl. Mech., 54, 47-53, 1987.
[17] Zhong.W, Zhang.M, Jin.B, Zhang.Y, Xiao.R, Huang.Y, Experimental investigation of particle mixing behavior in a large spout-fluid bed, Chemical Engineering and Processing, 2007.
[18] Patankar, S.V., Numerical heat transfer and fluid flow, First ed. Hemisphere Publishing, Washington, DC, 1980.
[19] Gidaspow, D., Hydrodynamics of Fluidization and Heat Transfer: Supercomputer Modeling, Appl. Mech. Rev., 39, 1986.
[20] Hamzehei, M., Rahimzadeh, H., Experimental and Numerical Study of Hydrodynamics with Heat Transfer in a Gas-Solid Fluidized bed Reactor at Different Particle Sizes, Ind. Eng. Chem. Res., 48, 3177-3186, 2009.
[21] Hamzehei, M., Rahimzadeh, H., Ahmadi, G., Computational and Experimental Study of Heat Transfer and Hydrodynamics in a 2D Gas- Solid Fluidized Bed Reactor, Ind. Eng. Chem. Res., (Special Issue) 49, pp. 5110-5121, 2010.
[22] Hamzehei, M., Rahimzadeh, H., Ahmadi, G., Studies of gas velocity and particles size effects on fluidized bed hydrodynamics with CFD modeling and experimental investigation, Journal of Mechanics, 26, pp. 113-124, 2010.
[23] Hamzehei, M. and Rahimzadeh, H., "Investigation of a Fluidized Bed Chamber Hydrodynamics with Heat Transfer Numerically and Experimentally," Korean Journal of Chemical Engineering, 27, pp. 355.363, 2010.