Terminal Velocity of Fluidizing Grains in a Vertical Pipe

It is necessary to know the characteristics of grain when grain is transferred and processed. In this research, in order to clarify the fundamental flow characteristics of grain, the flow state in a vertical pipe was investigated. Brown rice, BB shot (pellets) "BB's" and soybean were fluidized by the air style. We determined minimum fluidization velocity and terminal velocity, recorded the flow state, and observed the flow state with a video camera. The results of the experiment were as follows: 1) Minimum fluidization wind velocities were 1.6-2.1m/s in soybean, and 1.2-1.7m/s in BB's. This might be because of the shapes of soybean and BB's. 2)A fountain state appeared in brown rice, but not in either soybean or BB's. This might be because of the shapes of soybean and BB's. 3)Terminal velocity was 6.8m/s in brown rice, 9.5m/s in BB's, and 12.2m/s in soybean respectively.