Studying the solids and fluid flow behavior in rotary drums based on a multiphase CFD model

Abstract The objective of this study is to analyze the solid and fluid flow behaviors inside a rotary drum using computational fluid dynamics (CFD). The CFD model developed was based on an Eulerian–Eulerian multiphase flow approach. The capability of the multiphase CFD model to predict the transverse and axial solid flow patterns, the fluid flow profile, and particle residence time was assessed. The model was used to study the effects of drum rotational speed, filling degree, feed rate, and drum inclination angle. It was verified using experimental results of particle and fluid velocities and residence time. The experiments were conducted on pilot scale rotary drums. As could be proved by measured and simulated results, the particle flow near the bed surface exerted a strong entrainment effect on the transverse air flow in the proximity of the bed surface. The study demonstrated the capability of the multiphase CFD model to predict the particle and fluid flow behaviors inside a rotary drum simultaneously.

[1]  Eckehard Specht,et al.  Predicting the fraction of the mixing zone of a rolling bed in rotary kilns , 2010 .

[2]  Mark E. Casada,et al.  Wheat Mill Stream Properties for Discrete Element Method Modeling , 2014 .

[3]  P. V. Barr,et al.  Granular flow behaviour in the transverse plane of a partially filled rotating cylinder , 1997, Journal of Fluid Mechanics.

[4]  Jpk Seville,et al.  Solids motion in rolling mode rotating drums operated at low to medium rotational speeds , 2001 .

[5]  Douglas W. Fuerstenau,et al.  Transport behavior of particulate solids in rotary drums: scale-up of residence time distribution using the axial dispersion model , 1980 .

[6]  D. Jeffrey,et al.  Kinetic theories for granular flow: inelastic particles in Couette flow and slightly inelastic particles in a general flowfield , 1984, Journal of Fluid Mechanics.

[7]  Leonard G. Austin,et al.  Axial transport of dry powders in horizontal rotating cylinders , 1974 .

[8]  Eckehard Specht,et al.  Prediction of rolling bed motion in rotating cylinders , 2004 .

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

[10]  Michele Marigo,et al.  A numerical comparison of mixing efficiencies of solids in a cylindrical vessel subject to a range of motions , 2012 .

[11]  Eckehard Specht,et al.  Experimental study of the lower and upper angles of repose of granular materials in rotating drums , 2005 .

[12]  T. Metzger,et al.  Moisture content and residence time distributions in mixed-flow grain dryers , 2011 .

[13]  Marcos A.S. Barrozo,et al.  Experimental and CFD study of the hydrodynamic behavior in a rotating drum , 2013 .

[14]  Carl Duchesne,et al.  Effect of friction coefficient and density on mixing particles in the rolling regime , 2011 .

[15]  Habib Kocabiyik,et al.  Porosity Rate of Some Kernel Crops , 2004 .

[16]  Jpk Seville,et al.  Granular motion in rotating drums: bed turnover time and slumping–rolling transition , 2002 .

[17]  Jochen Mellmann,et al.  The transverse motion of solids in rotating cylinders—forms of motion and transition behavior , 2001 .

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

[19]  Kefa Cen,et al.  Axial transport and residence time of MSW in rotary kilns: Part I. Experimental , 2002 .

[20]  R.L.C. Flemmer,et al.  Flow rates of dry powders in inclinded rotating cylinders under open-ended discharge conditions , 1978 .

[21]  Jpk Seville,et al.  Segregation of granular flow in the transverse plane of a rolling mode rotating drum , 2002 .

[22]  Masami Nakagawa,et al.  Steady particulate flows in a horizontal rotating cylinder , 1998 .

[23]  John F. Davidson,et al.  Flow of granular material through an inclined, rotating cylinder fitted with a dam , 2008 .

[24]  Haisheng Chen,et al.  Solids Motion and Segregation of Binary Mixtures in a Rotating Drum Mixer , 2007 .

[25]  François Bertrand,et al.  Characterization of Mixing and Size Segregation in a Rotating Drum by a Particle Tracking Method , 2013 .

[26]  Troy Shinbrot,et al.  Scaling surface velocities in rotating cylinders as a function of vessel radius, rotation rate, and particle size , 2002 .

[27]  Bakhtier Farouk,et al.  Modeling of Solid Particle Flow and Heat Transfer in Rotary Kiln Calciners , 1997 .

[28]  Evangelos Tsotsas,et al.  Mixing of particles in rotary drums: A comparison of discrete element simulations with experimental results and penetration models for thermal processes , 2006 .

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

[30]  Masami Nakagawa,et al.  Boundary effects on the angle of repose in rotating cylinders , 1998 .

[31]  Ke Wen Li,et al.  Entrainment in rotary cylinders , 1974 .

[32]  Hsiu-Po Kuo,et al.  Numerical studies of particle segregation in a rotating drum based on Eulerian continuum approach , 2013 .

[33]  A.A.H. Drinkenburg,et al.  SOLIDS MIXING AND RESIDENCE TIME DISTRIBUTION IN A HORIZONTAL ROTARY DRUM REACTOR , 1976 .

[34]  Jean Perron,et al.  Rotary cylinders: Solid transport prediction by dimensional and rheological analysis , 1990 .

[35]  François Bertrand,et al.  Comparison of DEM results and Lagrangian experimental data for the flow and mixing of granules in a rotating drum , 2014 .

[36]  Andrea C. Santomaso,et al.  Investigation of the Granular Behaviour in a Rotating Drum Operated over a Wide Range of Rotational Speed , 2003 .

[37]  Suresh K. Bhatia,et al.  Axial transport of granular solids in horizontal rotating cylinders. Part 1: Theory , 1991 .

[38]  Remko M. Boom,et al.  Granular mixing and segregation in a horizontal rotating drum: A simulation study on the impact of rotational speed and fill level , 2008 .

[39]  Mathieu Renouf,et al.  Euler-like modelling of dense granular flows: application to a rotating drum , 2008, 0803.0191.

[40]  Josephine M. Boac,et al.  MATERIAL AND INTERACTION PROPERTIES OF SELECTED GRAINS AND OILSEEDS FOR MODELING DISCRETE PARTICLES , 2010 .

[41]  M. Cross The transverse motion of solids moving through rotary kilns , 1979 .