(165f) Fine Particle Classification Using Fluidized Beds in Series

Particle size classification is an important process for many industrial and academic applications. However, the behavior of very small particles (< 30 microns) is dominated by interparticle forces, and it becomes very difficult to classify them using sieving or other dry classification processes. As particle size decreases into this highly cohesive regime, hydro-separation methods, such as those used in water treatment processes, are typically found to work the best. A detailed study of the different separation techniques used in water treatment provides an insight into how particles behave under different fluid flow conditions and aids in the design of fluidized beds for particle separation. The fluidized beds used in this work function as hydro-separators, utilizing the settling velocities of particles to classify them based on their size. Many academic and industrial processes require that particles are accurately separated to a very narrow particle size distribution. The main objective of this project is to separate 10 micron glass spheres from a distribution of particles to within ± 1 micron using basic fluidization principles. We will investigate the effects of column length and cross-sectional shape on separation efficiency and will explore the role of reflux plates in the column.