Abstract
Particle growth in a tumbling fluidized bed coater, where a slurry or solution was being atomized, was investigated theoretically and experimentally. A growth rate equation of particles in the apparatus was derived assuming that spray droplets collided with individual particles of different sizes with a uniform mass rate per unit surface area of the particles at any instant and also assuming that the particles were coated with a constant proportion of coating substance in the droplets regardless of particle size and coating time. Individual seed particles with an equal size were found experimentally to have a scatter of coating mass unlike the assumption in the model. However, the theoretical relationship between the mean coating mass and the size of seed particles was in reasonably good agreement with the experiment. Consequently, the model proved to be useful for estimating the variation in the size distribution of coated particles with time.
