An Experimental Investigation of Particle Motion in a Liquid Fluidized Bed.

A laboratory study was made on particle motion in liquid fluidized beds. Experiments made in a bed of 4-inch inside diameter with a large length-to-diameter ratio of 24 to 1 are described. Particle motion in the bed was found to be essentially a diffusion process. Diffusion coefficients for motion in the vertical direction were measured for glass beads of .236-inch diameter at a range of average bead concentrations. Verticle diffusion was independent of radial position in the bed. The experimental findings on particle diffusion in the bed were compared to principles of diffusion of a turbulent fluid. Steady and quasi-steady patterns of particle circulation were observed in both a cylindrical bed with a length-to-diameter ratio of 5 to 1 and in beds of conical shape, and are described. Author