Numerical study of segregation using multiscale models

Segregation occurs ubiquitously and is an important process in mineral processing. Numerical simulation of the segregation phenomena can improve the understanding of the mechanisms and hence helps the optimisation of equipment and process designs. In this article, a multi-fluid model and a hybrid model are presented. Their capabilities of addressing various aspects of segregation problems in gas–solid flows are demonstrated. Specifically, the multi-fluid model treats both particles and fluid at the macroscopic continuum level. It can be employed to simulate segregation, given different particle types are treated as different solid phases. The hybrid model is derived using a concurrent multiscale modelling approach, where the discrete element method for solid particles is coupled with continuum fluid mechanics for the fluid phase. It is demonstrated to be able to capture segregation, which may be difficult to be predicted by the current multi-fluid model in some cases.

[1]  C. Rhie,et al.  A numerical study of the turbulent flow past an isolated airfoil with trailing edge separation , 1982 .

[2]  V. Swaaij,et al.  Hydrodynamic modeling of dense gas-fluidised beds using the kinetic theory of granular flow: effect of coefficient of restitution on bed dynamics , 2000 .

[3]  M. Syamlal,et al.  MFIX documentation theory guide , 1993 .

[4]  Madhava Syamlal,et al.  Hydrodynamics of particle segregation in fluidized beds , 2004 .

[5]  Syamlal.  The particle-particle drag term in a multiparticle model of fluidization , 1987 .

[6]  Jam Hans Kuipers,et al.  Digital image analysis measurements of bed expansion and segregation dynamics in dense gas-fluidized beds , 2003 .

[7]  C. Medaglia,et al.  A Numerical Study , 2005 .

[8]  Francine Battaglia,et al.  Hydrodynamic modeling of particle rotation for segregation in bubbling gas-fluidized beds , 2006 .

[9]  Yuqing Feng,et al.  Discrete particle simulation of gas fluidization of particle mixtures , 2004 .

[10]  Xiaolong Yin,et al.  Drag law for bidisperse gas-solid suspensions containing equally sized spheres , 2009 .

[11]  David G. Schaeffer,et al.  Instability in the evolution equations describing incompressible granular flow , 1987 .

[12]  J. Jenkins,et al.  Kinetic theory for identical, frictional, nearly elastic spheres , 2002 .

[13]  S. Sundaresan,et al.  The role of meso-scale structures in rapid gas–solid flows , 2001, Journal of Fluid Mechanics.

[14]  R. Jackson,et al.  The Dynamics of Fluidized Particles , 2000 .

[15]  Aibing Yu,et al.  Microdynamic modelling and analysis of the mixing and segregation of binary mixtures of particles in gas fluidization , 2007 .

[16]  Yuqing Feng,et al.  Assessment of model formulations in the discrete particle simulation of gas-solid flow , 2004 .

[17]  C. Rhie,et al.  Numerical Study of the Turbulent Flow Past an Airfoil with Trailing Edge Separation , 1983 .

[18]  Francine Battaglia,et al.  Dynamics and structures of segregation in a dense, vibrating granular bed. , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.

[19]  M. G. RUSBRIDGE,et al.  Kinetic Theory , 1969, Nature.

[20]  Madhava Syamlal,et al.  MFIX documentation numerical technique , 1998 .

[21]  H. Rusche.  Computational fluid dynamics of dispersed two-phase flows at high phase fractions , 2003 .

[22]  G. Grest,et al.  Granular flow down an inclined plane: Bagnold scaling and rheology. , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.

[23]  B.P.B. Hoomans,et al.  Granular dynamics simulation of segregation phenomena in bubbling gas-fluidised beds , 2000 .

[24]  R. Ocampo-Pérez,et al.  Adsorption of Fluoride from Water Solution on Bone Char , 2007 .

[25]  M. Goldschmidt,et al.  Hydrodynamic Modelling of Fluidised Bed Spray Granulation , 2001 .

[26]  A. W. Jenike,et al.  A theory of flow of particulate solids in converging and diverging channels based on a conical yield function , 1987 .

[27]  Steve Plimpton,et al.  Fast parallel algorithms for short-range molecular dynamics , 1993 .

[28]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[29]  Syamlal.  A review of granular stress constitutive relations , 1987 .

[30]  John Garside,et al.  Velocity-Voidage Relationships for Fluidization and Sedimentation in Solid-Liquid Systems , 1977 .

[31]  Alex C. Hoffmann,et al.  PARTICLE SEGREGATION IN FLUIDISED BINARY MIXTURES , 1993 .