Radial Distribution of Local Concentration Weighted Particle Velocities in High Density Circulating Fluidized Beds

An extensive experimental investigation of radial profiles of concentration -weighted particle velocities was carried out by simultaneously measuring local transient particle velocity, solids concentration and solids flux using a three-fibre optical probe at five axial levels and seven radial locations in a 0.2 m diameter riser operating over a wide range of solids circulation fluxes (198 to 350 kg/m 2s) and superficial gas velocities (6 to 8 m/s). Particle velocities averaged over time and concentration-weighted particle velocities were compared and found to differ from each other, the latter being smaller than the former at most radial locations. The difference, which results from the correlation between velocity and voidage fluctuations, was more pronounced for high -density conditions