Mizrach, A., Agricultural Research Organization,, Volcani Cent, Bet Dagan, Isr, Agricultural Research Organization, Volcani Cent, Bet Dagan, Isr
Zaltzman, A., Agricultural Research Organization,, Volcani Cent, Bet Dagan, Isr, Agricultural Research Organization, Volcani Cent, Bet Dagan, Isr
Manor, G., Agricultural Research Organization,, Volcani Cent, Bet Dagan, Isr, Agricultural Research Organization, Volcani Cent, Bet Dagan, Isr
Nir, Z., Agricultural Research Organization,, Volcani Cent, Bet Dagan, Isr, Agricultural Research Organization, Volcani Cent, Bet Dagan, Isr

Agricultural crops which are mechanically harvested from the ground often contain a high percentage of foreign matter, usually soil clods and stones. Among the various methods of separation available, density difference has often been used. The most common manner of separating by density is to introduce the materials into an air flow. Spheres of different diameters and mass densities were dropped into a fluidized bed in which bed depth and drop height were varied. Acceleration of the bodies as a function of time was recorded, and velocities and distances traveled were calculated and plotted. The influence of the mass density, drop height of the spheres, and the bed depth on the motion are discussed.