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Keywords:

  • fluidization;
  • hydrodynamics;
  • CFD simulation;
  • conical fluidized bed;
  • drag models;
  • boundary conditions

Abstract

The numerical simulations and experimental data of bed hydrodynamics in a conical fluidized bed unit are compared. Experimental studies have been carried out in a bed containing TiO2 particles belonging to A/C boundary of Geldart's classification with a wide particle-size distribution. Thus, pressure measurements and an optical fiber technique allowed determining the effect of static bed height on the fluidization characteristics of micronic particles. Numerical simulations have then been performed to evaluate the sensitivity of gas-solids drag models. The Eulerian multiphase model has been used with different drag models and three boundary conditions (BC) consisting of no-slip, partial-slip, and free-slip. The numerical predictions using the Gidaspow drag model and partial-slip BC agreed reasonably well with the experimental bed pressure drop measurements. The simulation results obtained for bed expansion ratio show that the Gidaspow model with the free-slip BC best fit with the experimental data. © 2011 American Institute of Chemical Engineers AIChE J, 2012