Abstract
Segregation and dynamic behavior of air bubbles and binary particles in 2-D gas-solid fluidized beds were investigated by recording video movies of fluidization, rising air bubbles and the movement of a plastic disk immersed in the fluidized beds. Four types of binary particles of different sized glass beads were employed. Segregation occurred in all four cases; flotsam and jetsam almost completely separated into upper and lower layers. When binary particles with large particle size diffrences were employed, the boundary surface between the flotsam and jetsam layers swelled near the side-walls and air bubbles generated frequently at the swell. In the upper layer of flotsam, particles rose up at the center of the column and fell down near the side-walls. However, at the lower layer of the flotsam, particles rose up near the side-walls and fell at the center. These results indicate that complicated particle flow can occur in fluidized bed of binary particles, which is dependent on the shape of boundary surface between the flotsam and jetsam layers.
