Profiling solid volume fraction in a conical bed of dry micrometric particles: Measurements and numerical implementations

In order to develop predictive process models in conical fluidized beds, there is an ongoing search for experimental methods and simulation tools to measure and model hydrodynamics parameters. Accordingly, experiments carried out in a conical fluidized bed containing micrometric TiO2 particles with a wide particle size distribution. An optical fiber technique was employed to determine the effect of particles loading on the solid volume fraction. The axial and radial profiles of solid volume fraction have then been determined to evaluate the sensitivity of different models, including Syamlal-O΄Brien (1988), Arastoopour et al., (1990) and Gidaspow (1994) drag models. The Eulerian-Eulerian model with frictional stress models and three different boundary conditions (BCs), consisting of no-slip, partial-slip and free-slip have been used in the numerical simulations. The Gidaspow model with the partial-slip BC gives the best agreement with experimental data for different particle loadings.

The hydrodynamic behavior of TiO2 micrometric particles belonging to B/D boundary of Geldart's classification has been studied experimentally and numerically in a conical fluidized bed with different superficial gas velocities. The influence of static bed height on the axial and radial profiles of solid volume fraction has been experimentally determined using an optical fiber technique, while Eulerian-Eulerian approach and different boundary conditions have been applied in the numerical simulations.Figure optionsDownload as PowerPoint slideResearch highlights
► Experiments with Optical probe technique.
► Numerical analysis.
► Effect of boundary conditions.
► Conical fluidized bed.
► Simulation of Micrometric powders.