Residence time distribution and particle dispersion in a longitudinal-flow fluidized bed

The solids dispersion in a longitudinal-flow fluidized bed with length 2.1 m has been experimentally investigated. Residence time distributions were measured for sand particles of three different sizes, and for apatite granules. The results showed that the solids flow could be described by the dispersed plug flow model. Dispersion coefficients in the range 2 × 10−4−23 × 10−4 m2/s were measured. The dispersion coefficient was found to increase with increasing bed height, gas velocity and bed flow velocity and decreasing particle size.