Fluidization of an inhomogeneous granular layer in a field of centrifugal forces (Q798108)

(From author's introduction.) The general theory of fluidization based on a continuum model of a rigid-plastic body and the condition of limiting equilibrium can be used to solve the problem of the transition to a suspended state of an inhomogeneous granular layer through which a liquid or gas flows in a field of centrifugal forces. Suspended layers of such type are used in chemical technology, to ignite carbon in rotating furnaces, and as one of the ways of fluidization of nuclear fuel in rocket motors. In the last case, in particular, the rotating fluidized bed provides a region in which there is more effective heat transfer to the working medium - usually hydrogen - than in the case of a fixed bed, and the thrust is increased accordingly. The intensification of the heat transfer between the solid and liquid phases and the possibility of raising the velocity of the fluidizing agent are the principle advantages of a rotating fluidized bed compared with an ordinary one in a gravity field. However, the presence of local inhomogeneities in the bed can seriously distort the fluidization and disturb the technological process. The authors show that, depending on the nature of the inhomogeneities and their position, there can either be uniform fluidization or else the formation of a discontinuity in the bed.