Mixing Behaviors of Wet Granular Materials in Gas Fluidized Beds

Authors: Eldin Wee Chuan Lim

Abstract:

The mixing behaviors of dry and wet granular materials in gas fluidized bed systems were investigated computationally using the combined Computational Fluid Dynamics and Discrete Element Method (CFD-DEM). Dry particles were observed to mix fairly rapidly during the fluidization process due to vigorous relative motions between particles induced by the flow of gas. In contrast, due to the presence of strong cohesive forces arising from capillary liquid bridges between wet particles, the mixing efficiencies of wet granular materials under similar operating conditions were observed to be reduced significantly.

Keywords: Computational Fluid Dynamics, Discrete Element Method, Gas Fluidization, Mixing, Wet particles

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1072044

References:

[1] C. Gao, F. Vejahati, H. Katalambula, R. Gupta, "Co-gasification of biomass with coal and oil sand coke in a drop tube furnace", Energy & Fuels, vol. 24, pp. 232-240, 2010.
[2] J. Hernandez, G. Aranda-Almansa, C. Serrano, "Co-gasification of biomass wastes and coal - coke blends in an entrained flow gasifier: an experimental study", Energy & Fuels, vol. 24, pp. 2479-2488, 2010.
[3] S. Kajitani, Y. Zhang, S. Umemoto, M. Ashizawa, S. Hara, "Cogasification reactivity of coal and woody biomass in high-temperature gasification", Energy & Fuels, vol. 24, pp. 145-151, 2010.
[4] K. Li, R. Zhang, J. Bi, "Experimental study on syngas production by cogasification of coal and biomass in a fluidized bed", International Journal of Hydrogen Energy, vol. 35, pp. 2722-2726, 2010.
[5] M.L. Mastellone, L. Zaccariello, U. Arena, "Co-gasification of coal, plastic waste and wood in a bubbling fluidized bed reactor", Fuel, vol. 89, pp. 2991-3000, 2010.
[6] M.W. Seo, J.H. Goo, S.D. Kim, S.H. Lee, Y.C. Choi, "Gasification characteristics of coal/biomass blend in a dual circulating fluidized bed reactor", Energy & Fuels, vol. 24, pp. 3108-3118, 2010.
[7] E.W.C. Lim, C.H. Wang, and A.B. Yu, "Discrete Element Simulation for Pneumatic Conveying of Granular Material", AIChE Journal, vol. 52(2), pp. 496-509, 2006.
[8] E.W.C. Lim., Y. Zhang, and C.H. Wang, "Effects of an Electrostatic Field in Pneumatic Conveying of Granular Materials through Inclined and Vertical Pipes", Chemical Engineering Science, vol. 61(24), pp. 7889-7908, 2006b.
[9] E.W.C. Lim, and C.H. Wang, "Diffusion Modeling of Bulk Granular Attrition", Industrial and Engineering Chemistry Research, vol. 45(6), pp. 2077-2083, 2006.
[10] E.W.C. Lim, Y.S. Wong, and C.H. Wang, "Particle Image Velocimetry Experiment and Discrete-Element Simulation of Voidage Wave Instability in a Vibrated Liquid-Fluidized Bed", Industrial and Engineering Chemistry Research, vol. 46(4), pp. 1375-1389, 2007.
[11] E.W.C. Lim, "Voidage Waves in Hydraulic Conveying through Narrow Pipes", Chemical Engineering Science, vol. 62(17), pp. 4529-4543, 2007.
[12] E.W.C. Lim, "Master Curve for the Discrete-Element Method", Industrial and Engineering Chemistry Research, vol. 47(2), pp. 481- 485, 2008.
[13] E.W.C. Lim, "Vibrated Granular Bed on a Bumpy Surface", Physical Review E, vol. 79, pp. 041302, 2009.
[14] E.W.C. Lim, "Density Segregation in Vibrated Granular Beds with Bumpy Surfaces", AIChE Journal, vol. 56(10), pp. 2588-2597, 2010.
[15] E.W.C. Lim, "Granular Leidenfrost Effect in Vibrated Beds with Bumpy Surfaces", European Physical Journal E, vol. 32(4), pp. 365- 375, 2010.
[16] R. Di Felice, "The Voidage Function for Fluid-Particle Interaction Systems", International Journal of Multiphase Flow, vol. 20, pp. 153- 159, 1994.
[17] T. Mikami, H. Kamiya, and M. Horio, "Numerical Simulation of Cohesive Powder Behavior in a Fluidized Bed", Chemical Engineering Science, vol. 53(10), pp. 1927-1940, 1998.