Photographic study of solid‐gas fluidization

Abstract

Motion pictures at 2,000 frames/sec. were used to measure the movements of individual solid particles and gas bubbles in a fluidized bed. Air was used to fluidize 0.028‐in. glass spheres and 200‐mesh alumina in a 3.75‐in. glass column. Aggregates were very common, and each moved as a unit. Particles and aggregates near the wall showed pronounced alternations of fast and slow movements both upward and downward. Individual particles exhibited spin. Baffles increased the bed density and decreased the particle velocities. Small bubbles rose rapidly with little change in shape. Large cavities were slow and tended to collapse and reform elsewhere.