FLUIDIZATION BEHAVIOR OF STICKY PARTICLES

ABSTRACT To obtain fundamental Information on the fluidization behavior of sticky particles, a visually observable fluidized bed, which can be operated under conditions in which agglomeration of the bed materials occurs, was designed and constructed. Polyethylene particles with a softening temperature of 117.2°C and melting temperature of 124.4°C, in sizes from 850 to 50 μm, were chosen as the bed material. Two types of fluidizing gas distributors were used: a porous plate and a porous plate with an independently fed jet at the center. The agglomeration rate was measured at different jet and bed temperatures, particle sizes, and residence times in the fluidized bed. The amount of agglomerates generated increased linearly with residence time and increased exponentially with either auxiliary air or jet air temperature. The agglomerates were formed from the whole range of particle sizes, but fine particles enhanced the agglomeration rate. A set of operating conditions must be properly chosen; otherwise, exce...