Convective solids transport in large diameter gas fluidized beds

It is demonstrated that the convective solids transport occurring in large diameter gas fluidized beds can be predicted quantitatively on the basis of measured properties of the bubble phase. Based on the fundamental findings of Rowe and co-workers [5], who have shown the solids mixing in gas fluidized beds for particle diameters greater than 100 μm to be caused solely by the action of rising bubbles, an equation has been derive from extensive measurements of the bubble development in a 1 m diam. fluidized bed of quartz sand which relates the convective solids mass flow due to solids transport in the bubble wakes to easily determinable parameters. The predictions of this relationship are found to bein good agreement with direct measurements of the convective solids transport carried out by Schmalfeld [21] on a pilot scale in a semicylindrical bed of 0.8 m diam.