Abstract: | A mechanism of bubble formation in a nonhomogeneous fluidized bed, based on instability theory, is suggested. In this mechanism it is assumed that the “bubbles” are formed at the bottom of the bed by the growth of prominences appearing because of the instability to perturbations of the lower surface of the bed. A bubble breaks off when the volume of the prominence becomes sufficiently large so that the buoyant force equals the sum of the bed resistance opposing its growth and the inertial forces. An equation for the diameter of the departing bubble is established. |