Particle mixing near the grid region of fluidized beds.

Abstract

Experiments were conducted in a three-dimensional fluidized bed to investigate the presence of stagnant zones near the grid region. It was found that the formation of the dead zone above the distributor was influenced by the orifice gas velocity, orifice pitch, orifice diameter, particle size and particle density. The effect of bed height on the critical orifice gas velocity required for the elimination of the dead zone was insignificant within the range of bed heights investigated. Empirical correlations are proposed to calculate the critical orifice gas velocity required to eliminate the dead zone as a function of pitch, orifice diameter, particle size and particle density for a perforated plate distributor and for two different arrangements of a cap plate distributor. (A)