Conventional and modified fluidized bed: Comparison of the fluid dynamics and application in particle granulation

The goal of this study was to evaluate the fluid dynamic behavior of both conventional and draft tube fluidized beds, with and without injection of compressed air (at 68.95, 103.42 and 137.89 kPa) to assess their suitability for granulation. A 35% maltodextrin solution was sprayed on microcrystalline cellulose particles by a double-fluid nozzle. The tube heights tested indicate an 8 cm maximum height from the distribution plate. Beyond this value, fluidization is similar to that of a conventional bed. The growth occurred by nucleation and consolidation of particles and the post-granulation parameters analyzed were growth, angle of repose and granule circularity.