Investigation on the drying kinetics in a pulsed fluidized bed

For uniform drying of large particles, a modified fluidized bed with a continuous fluidizing air flow plus one stream of pulsing air, which is termed as a pulsed fluidized bed (PFB), was developed to eliminate some limitations of conventional fluidized beds (FB). The drying kinetics of activated alumina was investigated to assess the advantages of PFB, in comparison with the results obtained in the FB. At the same average air flow rate, the bed is easy to fluidize in the PFB operation and there is little temperature difference along the bed height. Due to the dispersion of particles by pulsing flow, the drying rate for activated alumina is higher to some extent in PFB than that in FB during the constant drying period even at low average superficial air velocity.