Numerical Analysis and Study of Factors Affecting the Hydrodynamic Behavior of a Gas-Solid Bubbling Fluidized Bed with Particle Granular Behavior

Document Type : Original Article

Authors

Department of Mechanical engineering , Imam Khomeini International University, Qazvin, Iran

Abstract

In recent years, fluidized bed reactors have attracted much attention due to a number of features such as uniform temperature distribution, proper mixing phases, and high heat transfer rates. The high heat transfer rate in the fluidized bed depends on the hydrodynamic factors of the bubbling bed. Therefore, in this study, the effects of particle diameter variations, the inlet air velocity change, and the drag model alteration on the performance of Geldart Group B particles in a bubbling fluidized bed are examined by studying the mean axial velocity distribution of particles and the mean volume fraction distribution of particles in the bubbling fluidized bed. Thus, the Eulerian multiphase flow approach and the kinetic theory of granular flow are employed in this study. In this regard, particles with the diameters of 500 μm, 530 μm, 570 μm, and 600 μm are considered. As can be seen in the results, increasing the diameter of solid particles from 500 μm to 600 μm decreases the average velocity of the solid particles around the bed core by approximately 45% and increases the accumulation of solid particles in the bed bottom by 14%. Moreover, as the particle diameters increase, an approximate increase in the granular temperature is witnessed. In addition, three different drag models have been studied in this paper. Compared to other drag models, the Syamlal-O'Brien model predicts the lowest downward velocity (negative velocity) near the walls, the lowest upward velocity (positive velocity) near the bed core, and the highest average volume fraction of solid particles. Furthermore, this study has investigated the effect of change in the inlet air velocity. As can be seen in the result of this study, increasing the velocity from 0.550 m/s to 0.587 m/s increases the average velocity of particles around the bed core by approximately 40%.

Keywords

Smiley face

References

  1. Van Wachem, B.G.M., Schouten, J.C., Van den Bleek, C.M., Krishna, R., and Sinclair, J.L. “Comparative analysis of CFD models of dense gas–solid systems” ,AIChE J. Vol. 47, No. 5, pp. 1035-1051, 2001.
  2. Behjat, Y., Shahhosseini, S., and Hashemabadi, S.H. “CFD modeling of hydrodynamic and heat transfer in fluidized bed reactors”, Int. Commun. Heat Mass Transf. Vol. 35, No. 3, pp. 357-368, 2008.
  3. Passalacqua, A., and Marmo, L. “A critical comparison of frictional stress models applied to the simulation of bubbling fluidized beds” ,Chem. Eng. Sci. Vol. 64, No. 12, pp. 2795-2806, 2009.
  4. Loha, C., Chattopadhyay, H., and Chatterjee, P.K. “Assessment of drag models in simulating bubbling fluidized bed hydrodynamics” ,Chem. Eng. Sci. Vol. 75, pp. 400-407, 2012.
  5. Zinani, F., Philippsen, C.G., and Indrusiak, M.L.S. “Numerical study of gas–solid drag models in a bubbling fluidized bed” ,Part. Sci. Technol. 36, No. 1, pp. 1-10, 2018.
  6. Wang, L., Xie, X., Wei, G., and Li, R. “Numerical simulation of hydrodynamic characteristics in a gas–solid fluidized bed”, Part. Sci. Technol. Vol. 35, No. 2,  pp. 177-182, 2017.
  7. Varghese, M.M., and Vakamalla, T.R. “Effect of Turbulence Model on the Hydrodynamics of Gas–solid Fluidized Bed” ,RTFDR. pp. 47-61, 2022.
  8. Esfahani, M., Rahimi, R., and Hosseini, S.H. “Investigation of Fluidized Bed Hydrodynamics using CFD”, NICEC11. Tehran, Iran, 1385. (In Persian)
  9. Lindborg, H., Lysberg, M., and Jakobsen, H.A. “Practical validation of the two-fluid model applied to dense gas–solid flows in fluidized beds” , Eng. Sci.Vol. 62, No. 21, pp. 5854-5869, 2007.
  10. Benyahia, S., Syamlal, M., and O'Brien, T.J. “Study of the ability of multiphase continuum models to predict core‐annulus flow” ,AIChE J. Vol. 53, No. 10, pp. 2549-2568, 2007.
  11. Guo, Y., Deng, B., Ge, D., and Shen, X. “CFD simulation on hydrodynamics in fluidized beds: assessment of gradient approximations and turbulence models” ,Heat Mass Transfer. Vol. 51, No. 8, pp. 1067-1074, 2015.
  12. Khezri, R., Wan Ab Karim Ghani, W. A., Masoudi Soltani, S., Awang Biak, D. R., Yunus, R., Silas, K., and Rezaei Motlagh, S. “Computational Fluid Dynamics Simulation of Gas–Solid Hydrodynamics in a Bubbling Fluidized-Bed Reactor: Effects of Air Distributor, Viscous and Drag Models”,Processes. Vol. 7, No. 8, 2019.
  13. Loha, C., Chattopadhyay, H., and Chatterjee, P.K. “Euler-Euler CFD modeling of fluidized bed: Influence of specularity coefficient on hydrodynamic behavior” ,Particuology. Vol. 11, No. 6, pp. 673-680, 2013.
  14. Loha, C., Chattopadhaya, H., and Chatterjee, P.K. “Effect of coefficient of restitution in Euler–Euler CFD simulation of fluidized-bed hydrodynamics” , Particuology. Vol. 15, pp. 170-177,
  15. Kshetrimayum, K.S., Park, S., Han, C., and Lee, C.J. “EMMS drag model for simulating a gas–solid fluidized bed of geldart B particles: Effect of bed model parameters and polydisperity” ,Particuology. Vol. 51, pp. 142-154, 2020.
  16. Verma, V., Padding, J.T., Deen, N.G., and Kuipers, J.A.M. “Effect of bed size on hydrodynamics in 3‐D gas–solid fluidized beds”,AIChE J. Vol. 61, No. 5, pp. 1492-1506, 2015.
  17. Ghasemi, H., Amini, Hassan., and Khayat, Morteza. “Experimental study of solid particle mixing in a fluidized bed using image processing method” ,Fluid Mech Aero J. Vol. 3, No. 1, 1393. (In Persian)
  18. Gelderbloom, S.J., Gidaspow, D., and Lyczkowski, R.W. “CFD simulations of bubbling/collapsing fluidized beds for three Geldart groups” ,AIChE J. Vol. 49, No. 4, pp. 844-858, 2003.
  19. Gidaspow, D., Bezburuah, R., and Ding, J. “Hydrodynamics of circulating fluidized beds: kinetic theory approach” ,Illinois Inst of Tech. Chicago, USA, 1991.
  20. Syamlal, M., & O’Brien, T.J. “Computer simulation of bubbles in a fluidized bed”, AICHE Symp. Ser. Vol. 85, No. 1, pp. 22-31, 1989.
  21. Wen, C.Y. “Mechanics of fluidization” , Chem. Eng. Prog. Symp. Ser. Vol. 62, pp. 100-111, 1966.
  22. Ogawa, S., Umemura, A., and Oshima, N. “On the equations of fully fluidized granular materials” , Vol. 31, No. 4, pp. 483-493, 1980.
  23. Syamlal, M., Rogers, W., and OBrien, T.J. “MFIX documentation theory” , United States, 1993.
  24. Lun, C.K.K., Savage, S.B., Jeffrey, D.J., and Chepurniy, N. “Kinetic theories for granular flow: inelastic particles in Couette flow and slightly inelastic particles in a general flowfield” , J. Fluid Mech. Vol. 140, pp. 223-256, 1984.
  25. San Jose, M. J., Olazar, M., Benito, P. L., and Bolbao, J. “Hydrodynamics and expansion of fluidized beds of coarse particles” ,Trans. Inst. Chem. Eng. vol. 73A, pp. 473-479, 1995.
  26. Johnson, P.C., and Jackson, R. “Frictional–collisional constitutive relations for granular materials, with application to plane shearing” , J. Fluid Mech. Vol. 176, pp. 67-93, 1987.
  27. Inc, ANSYS. “ANSYS FLUENT 12.0 (theory Guide)” ,United States, 2009.
  28. Kuwagi, K., Utsunomiya, H., Shimoyama, Y., Hirano, H., and Takami, T. “Direct numerical simulation of fluidized bed with immersed boundary method” , The 13th Conf. fluidization eng. Gyeong-ju, Korea, 2010.
  29. Hoomans, B. P. B. “Granular dynamics of gas-solid two-phase flows” , Universiteit Twente, Netherlands, 2000.
  30. Peltola, J. “Dynamics in a circulating fluidized bed: Experimental and numerical study” ,MS thesis, Tampere University of Technology, Faculty of Automation, Mechanical and Material Technology, 2009. 
  31. Jung, J., Gidaspow, D., and Gamwo, I.K. “Measurement of two kinds of granular temperatures, stresses, and dispersion in bubbling beds” , Ind. Eng. Chem. Res. Vol. 44, No. 5, pp. 1329-1341, 2005.

 

Fluid Mechanics & Aerodynamics
Volume 11, Issue 1 - Serial Number 29
October 2022
Pages 115-132

Files

History

  • Receive Date: 05 January 2022
  • Revise Date: 15 April 2022
  • Accept Date: 18 May 2022
  • Publish Date: 21 September 2022

Share

How to cite

Statistics