Document Type : Regular Article
Author
Hamedan University of Technology
Abstract
The impact of bed loading on minimum spouting velocity (ums) of polydispersed TiO2 particles was studied in a conical fluidized bed. The experiments were performed at different bed loadings according to Gaussian and narrow-cut particle size distribution (PSD). The bed consisted of simple-agglomerates in size range of 30-90 µm belonging to Geldarts’ group A classification. The effect of PSD and interparticle force (IPF) on the predicted ums and hysteresis in the pressure profiles were studied through a combination of computational fluid dynamics and discrete element method (CFD-DEM). The experimental data showed that the choice of bed with Gaussian PSD-type led to more accurately predicting ums than the narrow-cut particle PSD. The impact of IPF on the expected ums became more critical than the PSD type because of an increase in bed loadings. The lowest deviations the results were obtained in the low bed loadings, which is confirmed the accuracy of simulation results. The simultaneous effects of PSD-type and IPF led to a change in the fluidization behavior of the bed. The bed with narrow-cut PSD has a hydrodynamic behavior similar to spouting and slugging regimes, while the fluidization quality of the bed improves by fine particles.
Keywords
- Fluidization
- Bed loading
- numerical modeling
- Interparticle force
- minimum spouting velocity
- Conical fluidized bed
Main Subjects
- Tanfara, H., Pugsley, T. and Winters, C., “Effect of particle size distribution on local voidage in a bench-scale conical fluidized bed dryer”, Technol., 20 (6), 1273 (2002).
- Das, J., Mahanta, P., Saikia, R. and Aamir, M. Sh., “Performance evaluation of drying characteristics in conical bubbling fluidized bed dryer”, Powder Technol., 374 (1), 534 (2020).
- Foroughi-Dahr, M., Sotudeh-Gharebagh, R. and Mostoufi, N., “Characterization of flow properties of pharmaceutical pellets in draft tube conical spout-fluid beds”, Ind. Eng. Chem., 68 (1), 274 (2018).
- Agu, C. E., Pfeifer, Ch. and Moldestad, B. M. E., “Prediction of void fraction and minimum fluidization velocity of a binary mixture of particles: Bed material and fuel particles”, Powder Technol., 349 (1), 107 (2019).
- Sun, G. L. and Grace, J. R., “Effect of particle-size distribution in different fluidization regimes”, AIChE J., 38 (1), 722 (1992).
- Yang, W. -Ch., Handbook of fluidization and fluid-particle systems, 1st, CRC Press, (2003).
- Zhong, W., Chen, X. and Zhang, M., “Hydrodynamic characteristics of spout-fluid bed: Pressure drop and minimum spouting/spout-fluidizing velocity”, Eng. J., 118 (1-2), 37 (2006).
- Ma, J., van Ommen, J. R., Liu, D., Mudde, R. F., Chen, X., Wagner, E. C. and Liang, C., “Fluidization dynamics of cohesive Geldart B particles, Part I: X-ray tomography analysis”, Eng. J., 359 (1), 1024 (2019).
- Shabanian, J. and Chaouki, J., “Local characterization of a gas-solid fluidized bed in the presence of thermally induced interparticle forces”, Eng. Sci., 119 (1), 261 (2014).
- Wang, X. S., Rahman, F. and Rhodes, M. J., “Nanoparticle fluidization and Geldart’s classification”, Eng. Sci., 62 (1), 3455 (2007).
- Wormsbecker, M., van Ommen, R., Nijenhuis, J., Tanfara, H. and Pugsley, T., “The influence of vessel geometry on fluidized bed dryer hydrodynamics”, Powder Technol., 194 (1), 115 (2009).
- Bahramian, A. R., “The mutual effects between the interparticle forces and mechanical properties on fluidization of TiO2 nanoparticle agglomerates in a conical fluidized bed: nanoindentation and pressure fluctuation analysis”, Nanopart. Res., 21 (1), 196 (2019).
- Castellanos, A., Valverde, J. M. and Quintanilla, M. A. S., “Agglomeration and sedimentation in gas-fluidized beds of cohesive powders”, Rev. E, 64 (1), 041304 (2001).
- Bahramian, A. R. and Olazar, M., “Fluidization of micronic particles in a conical fluidized bed: Experimental and numerical study of static bed height effect”,AIChE J., 58 (1), 730 (2012).
- Jiliang, M., Xiaoping, Ch. and Daoyin, L., “Minimum fluidization velocity of particles with wide size distribution at high temperatures”, Powder Technol., 235 (1), 271 (2013).
- Rao, A., Curtis, J. S., Hancock, B. C. and Wassgren, C., “The effect of column diameter and bed height on minimum fluidization velocity”, AIChE J., 56 (1), 2304 (2010).
- Liu, D., van Wachem, B. G. M., Mudde, R. F., Chen, X. and van Ommen, J. R., “An adhesive CFD-DEM model for simulating nanoparticle agglomerate fluidization”, AIChE J., 62 (1), 2259 (2016).
- Shabanian, J., Fotovat, F., Chaouki, J. and Bouffard, J., “Fluidization behavior in a gas-solid fluidized bed with thermally induced inter-particle forces”, Proceedings of 10th International Conference on Circulating Fluidized Beds and Fluidization Technology, Sun River, Oregon, USA, (2011).
- Bahramian, A. R. and Olazar, M., “Evaluation of elastic and inelastic contact forces in the flow regimes of Titania nanoparticle agglomerates in a bench-scale conical fluidized bed: A comparative study of CFD-DEM simulation and experimental data”, Eng. Res. Des., 176 (1), 34 (2021).
- Feng, , Li, J., Cheng, Zh., and Fang, Y., “Influence of particle size distribution on minimum fluidization velocity and bed expansion at elevated pressure”, Powder Technol., 320 (1), 27 (2017).
- Gauthier, D., Zerguerras, S. and Flamant, G., “Influence of the particle size distribution of powders on the velocities of minimum and complete fluidization”, Chem. Eng. Japan, 74 (1), 181 (1999).
- Tsuji, T., Yabumoto, K. and Tanaka, T., “Spontaneous structures in three-dimensional bubbling gas-fluidized bed by parallel DEM–CFD coupling simulation”, Powder Technol., 184 (1), 132 (2008).
- Yang, S., Luo, K., Fang, M., Fan, J. and Cen, K., “Influences of operating parameters on the hydrodynamics of a 3-D spout-fluid bed based on DEM modelling approach”, Eng. J., 247 (1), 161 (2014).
- Xu, Y., Li, T., Musser, J., Liu, X., Xu, G. and Rogers W. A., “CFD-DEM modeling the effect of column size and bed height on minimum fluidization velocity in micro fluidized beds with Geldart B particles”, Powder Technol., 318 (1), 321 (2017).
- Groger, U., and Heyes, , “Modelling and measuring of cohesion in wet granular materials”, Powder Technol., 133 (1-3), 203 (2003).
- Fan, X. and Zhou, Ch., “Estimation of bed expansion and separation density of gas-solid separation fluidized beds using a micron-sized-particle-dense medium”, Separations, 8 (242),1 (2021).
- Liu, P., LaMarche, C. Q., Kellogg, K. M. and Hrenya, Ch. M., “Fine-particle defluidization: Interaction between cohesion, Young's modulus and static bed height”, Eng. Sci., 145 (1), 266 (2016).
- Galvin, J. E. and Benyahia, S., “The effect of cohesive forces on the fluidization of aeratable powders”, AIChE J., 60 (1), 473 (2014).
- Bahramian, A. R., Olazar, M. and Ahmadi, G., “Effect of slip boundary conditions on the simulation of micro-particle velocity fields in a conical fluidized bed”, AIChE J., 59 (1), 4502 (2013).
- McKeen, T. and Pugsley, T., “Simulation and experimental validation of a freely bubbling bed of FCC catalyst”, Powder Technol., 129 (1), 139 (2003).
- Endresa, S. Ch., Ciacchi, L. C. and Mädler, L., “A review of contact force models between nanoparticles in agglomerates, aggregates, and films”, Aerosol Sci., 153 (1), 105719 (2021).
- Castellanos, A., “The relationship between attractive interparticle forces and bulk behaviour in dry and uncharged fine powders”, Adv Phys., 54 (4), 263 (2005).
- Visser, J., “An invited review: van der Waals and other cohesive forces affecting powder fluidization”, Powder Technol., 58 (1), 1 (1989).
- Ye, M., van der Hoef, M. A. and Kuipers, J. A. M., “The effects of particle and gas properties on the fluidization of Geldart A particles”, Eng. Sci., 60 (16), 4567 (2005).
- Kobayashi, T., Tanaka, T., Shimada, N. and Kawaguchi, T., “DEM-CFD analysis of fluidization behavior of Geldart Group A particles using a dynamic adhesion force model”, Powder Technol., 248 (1), 143 (2013).
- Dong, Y., Perez, D., Voter, A. F. and Martini, A., “The roles of statics and dynamics in determining transitions between atomic friction regimes”, Tribology Let., 42 (1), 99 (2011).
- Cundall, P. A. and Strack, O. D. L., “A discrete numerical model for granular assemblies”, Geol., 29 (1), 47 (1979).
- Galvin, J. E. and Benyahia, S., “The effect of cohesive forces on the fluidization of aeratable powders”, AIChE J., 60 (1), 473 (2014).
- Tsinontides, S. C. and Jackson, R., “The mechanics of gas-fluidized beds with an interval of stable fluidization”, Fluid Mech., 255 (1), 237 (1993).
- Grace, J. R. and Sun, G., “Influence of particle-size distribution on the performance of fluidized-bed reactors”, J. Chem. Eng., 69 (1), 1126 (1991).
- Peng, Z., Doroodchi, E., Luo, C. and Moghtaderi, B., “Influence of void fraction calculation on fidelity of CFD-DEM simulation of gas-solid bubbling fluidized beds”, AlChE J., 60 (1), 2000 (2014).
', './data/ijche/coversheet/cover_en.jpg'))