Mixing and segregation in a bidisperse gas-solid fluidised bed: a numerical and experimental study

被引:258
作者
Bokkers, GA [1 ]
Annaland, MVS [1 ]
Kuipers, JAM [1 ]
机构
[1] Univ Twente, Fac Sci & Technol, NL-7500 AE Enschede, Netherlands
关键词
fluidisation; hydrodynamics; discrete particle modelling; particle image velocimetry;
D O I
10.1016/j.powtec.2004.01.018
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
In many industrial applications of dense gas-solid fluidised beds, mixing and segregation phenomena play a very important role. The extent of mixing and segregation is strongly influenced by the bubble characteristics. Therefore, the extent of mixing and segregation, induced by a single bubble injected in a monodisperse and bidisperse fluidised bed at incipient fluidisation conditions and in freely bubbling fluidised beds has been studied both with well-defined experiments and with a 3D Euler-Lagrangian model. Particle image velocimetry (PIV) was successfully applied to obtain the ensemble averaged particle velocity profile in the vicinity of the bubble in dense gas-solid fluidised systems. The bubble size of a single injected bubble in a fluidised bed at minimum fluidisation conditions calculated with a 3D discrete particle model (DPM) depended strongly on the selected gas-particle drag model. The widely used Ergun equation combined with the Wen and Yu [Powder Technol. 98 (1998) 38; Chem. Eng. Sci. 47 (1992) 1913] relations overpredicted the bubble size due to an overprediction of the drag force. The DPM with the drag model proposed by Koch and Hill [Annu. Rev. Fluid Mech. 33 (2001) 619], based on Lattice-Boltzmann simulations, gave much better agreement with the experimental findings. The segregation rates in a bidisperse freely bubbling fluidised bed predicted by the DPM agreed very well with the experimentally measured segregation rates by Goldschmidt [M.J.V Goldschmidt, Hydrodynamic modelling of fluidised bed spray granulation, PhD thesis, Twente University, 2001]. (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:176 / 186
页数:11
相关论文
共 14 条
[1]  
BIRD RB, 1960, TRANSPORT PHENOMENA, P198
[2]  
DEEN N, 2001, THESIS AALBORG U
[3]   Computer simulation of bubbles in large-particle fluidized beds [J].
Gera, D ;
Gautam, M ;
Tsuji, Y ;
Kawaguchi, T ;
Tanaka, T .
POWDER TECHNOLOGY, 1998, 98 (01) :38-47
[4]  
Gidaspow, 1994, MULTIPHASE FLOW FLUI
[5]  
GOLDSCHMIDT MJV, 2001, THESIS TWENTE U
[6]   Discrete particle simulation of bubble and slug formation in a two-dimensional gas-fluidised bed: A hard-sphere approach [J].
Hoomans, BPB ;
Kuipers, JAM ;
Briels, WJ ;
vanSwaaij, WPM .
CHEMICAL ENGINEERING SCIENCE, 1996, 51 (01) :99-118
[7]   Accurate measurement of particle impact parameters [J].
Kharaz, AH ;
Gorham, DA ;
Salman, AD .
MEASUREMENT SCIENCE AND TECHNOLOGY, 1999, 10 (01) :31-35
[8]   Inertial effects in suspension and porous-media flows [J].
Koch, DL ;
Hill, RJ .
ANNUAL REVIEW OF FLUID MECHANICS, 2001, 33 :619-647
[9]  
Kuipers J A M., 1998, Adv. Chem. Eng, V24, P227
[10]   A NUMERICAL-MODEL OF GAS-FLUIDIZED BEDS [J].
KUIPERS, JAM ;
VANDUIN, KJ ;
VANBECKUM, FPH ;
VANSWAAIJ, WPM .
CHEMICAL ENGINEERING SCIENCE, 1992, 47 (08) :1913-1924