Distributor Induced Hydrodynamics in a Conical Fluidized Bed Dryer

The hydrodynamics induced by perforated, punched, and mesh (Dutch weave) distributor plates have been studied using dry placebo pharmaceutical granule in a conical fluidized bed dryer at inlet superficial gas velocities of 0.5 to 3.5 m/s. For superficial gas velocities up to 2.0 m/s, the punched plate design leads to improved hydrodynamics based on reduced bubble frequencies and limited segregation. Beyond 2.0 m/s, the influence of gas velocity supersedes that of distributor design, as coalescence dominates the hydrodynamic behavior resulting in low-frequency, high-intensity spectral density distributions for all distributor designs.