Elutriation and Circulation in a Concave-shaped Gas-solid Fluidized Bed

Abstract

An experimental study on the hydrodynamics of an internal circulation fluidiz ed bed was carried out on a cold three-dimensional model of a concave-shaped bed which was made from plexiglas. The experiments emphasized the elutriation of fine particles and the bed material gross circulation rate. The experimental operation for studying elutriation was batch. Seven kinds of reflectors placed above the dense bed were studied experimentally to examine their effects on the suppression of fines elutriation, and a correlation was developed, which was found to correlate with the data obtained without the reflector. The suppression efficiency of the reflector versus operating parameters and reflector structure was calculated. An experimental TV photography method was used to investigate the effects of operating parameters on the circulation rate, and a correlation was proposed. This paper also reveals the operating condition under which a steady circulation of bed particles was formed. The results obtained in this study are available for the design of an internal circulation fluidized bed combustor.