Fluid dynamics of a fluidized-moving bed ( flumov)

Abstract

The fluid dynamics and other features of a gas–solid contactor based on a combination of FLUidized and MOVing beds (flumov) were studied. The fluidized zone is below the moving one; the mov/flu diameter ratio ranges between 2 and 3. The two zones are joined by means of a conical part and no mechanical elements are used between the bottom of the moving bed and the top of the fluidized bed. The gas is fed at the bottom of the fluidized bed; the solid is fed at the top of the moving bed and, consequently, it moves in countercurrent to the gas and in a continuous mode. The adequate regime is reached when a stable vault between the bottom of the moving bed and the top of the fluidized bed is formed and maintained. The solid circulation from the moving to the fluidized bed is controlled by injecting air pulses from the bottom of the moving bed, at different points of the conical zone. The study comprises the influence of both the contactor geometry and the solid type on the pressure drop profiles and the general flumov performance. The angle of the conical device joining the two zones is an important geometrical parameter and, in the range studied, the flumov performance does not depend on the tested solid size and type.