Analysis of the effect of particle size distributions on the fluid dynamic behavior and segregation patterns of fluidized, vibrated and vibrofluidized beds

In this work, the effects of particle size distribution on the dynamics and segregation patterns in fluidized, vibrated and vibrofluidized beds were investigated. Four particle size distributions composed of glass spheres were tested: binary, flat, Gaussian and a reference one, all of them with a mean Sauter diameter equal to 2.18 x 10(-3) m. The experimental setup consisted basically of a circular glass chamber with a height of 0.50 m and diameter of 0.114 m and was operated in different modes: as a fluidized bed (Gamma = 0), or either as vibrated or vibrofluidized beds (Gamma = 2). The pressure drops in the fluidized and vibrofluidized beds were not significantly affected by the particle size distributions. Well-defined segregation patterns were observed in fluidized and vibrated beds, with the small particles concentrated at the top and the large particles at the bottom in the fluidized bed, and with a reversed pattern in the vibrated bed. Segregation patterns in the vibrofluidized bed depended on the values of the vibration parameters. Segregation in vibrofluidized and vibrated beds was minimized by operating at high amplitudes of vibration. (C) 2007 Curtin University of Technology and John Wiley & Sons, Ltd.