Fluidized beds have gained prominence in many process in dustries (including chemicals, petroleum, metallurgy, food and pharmaceuticals) as a means of bringing particulate solids into contact with gases and/or liquids. Many fluidized bed operations are physical in nature (e.g. drying, coating, classification, granulation, and rapid heat transfer as in quenching or annealing). Other operations involve chemical reactions including the cata lytic cracking of hydrocarbons, the manufacture of acry10nitrite and phthalic anhydride, the roasting of metallurgical ores, and the regeneration of spent...