| Gas-solid fluidized beds are widely applied in many industries. Thehydrodynamic behavior of a2D and3D gas–solid fluidized bed with Geldart B magnetiteparticles having the diameter of0.2mm was investigated by applying computational fluiddynamics (CFD). Numerical simulation results from commercial CFD software packageFLUENT were validated against experimental results.A multifluid Eulerian model incorporating the kinetic theory of granular flow(KTGF) was applied for the simulation of unsteady gas-particles flow. Momentumexchange coefficients were computed by applying the Syamlal O'Brien and Gidaspowdrag models. A suitable numerical technique incorporating the finite volume method wasapplied to discretize the equations. Simulation results indicated that small bubbles weregenerated at the bottom of the bed. These small bubbles coalesce and grow in size as theypass through the bed, and by reaching the bed surface these large bubbles explode.The bed behavior was investigated by varying different parameters such asboundary conditions, granular temperature models, drag function models, geometryconfiguration, superficial velocities etc. The simulation predictions were reasonably ingood agreement with the experimental results and gas–particles flow patterns. By varyingbed parameters, various bed properties such as bed pressure drops, solid velocities, solidvolume fractions etc were investigated. The predicted pressure drops by the simulationswere in relatively good agreement with experimental results. Moreover3D simulations(not available in the literature for the specific case) were also conducted to get a muchrealistic picture of the flow behavior, and the results were satisfactory as the simulationswere carried for small time periods due to long time consumption by CPU whereas longersimulations are required for obtaining better results. More experimental and numericalefforts are required to completely understand the complex multiphase flow phenomena ofgas-solid fluidized beds. |
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