Influence of air bubble size on float-sink of spheres in a gas-solid fluidized bed

Abstract

The float-sink of density adjusted spheres of different diameter (10-40 mm) in a gas-solid fluidized bed was investigated at various bed heights (50-200 mm). The maximum density of floating spheres (ρ float) and the minimum density of sinking spheres (ρ sink) were determined by the float-sink experiments. The fluidized bed density (ρ fb) was measured using the height and cross section of the fluidized bed and total weight of the fluidized media. The diameter of air bubbles at the bed surface was measured at each bed height, and was normalized by the sphere diameter. It was found that the value of ρ fb-ρ float approaches zero as the normalized bubble diameter decreases from 4 to 0.5 regardles..