The Dynamics of Fluidized Particles

When a bed of rigid particles, supported below by a porous plate, is subjected to an increasing upward flow of air, at first nothing happens. Then as the flow increases, the bed can expand slightly and particles can move in relative motion. At higher velocities, large voids (bubbles) can appear which rise like bubbles to the top of the bed, upon which solid objects can float. Such a state is called fluidization and is the subject of this excellent monograph by one of the world's leading figures in the field. Such systems have enormous industrial application in fields as diverse as combustion, pneumatic transport, sedimentation and breakfast cereal manufacture.