Solid Particles Feeding and Classification under Microgravity

　A study of solid particles feeding and classification processes had been carried out under microgravity in drop shaft experiments and also under normal gravity conditions. The feeding of fine powder was accomplished by a piston type feeder connected with a linear motor. The feeding process was observed directly through a CCD camera with a video timer. Hebb type cyclone was used as a particles classifier. Two kinds of particles, fly ash and glass beads with average diameter about four microns were used in this work. In each experiment coarse and fine particles were collected and their size distributions were measured. The results revealed a small difference in size distributions of fine particles between normal-and microgravity condition.