Comparison of three vibrational modes (twist, vertical and horizontal) for fluidization of fine particles

The effects of three vibrational modes (twist, vertical and horizontal) on flow patterns are discussed. The particles used are four powders (glass beads, 6-100 μm), which are Geldart group A or group C. The fluidity of particles is evaluated with vibration strength (A), minimum fluidization velocity (umf), void fraction and flow patterns in the bed. The effect of vibrational mode on the flow patterns appears in whole bed motion, which is horizontal rotation or vertical rotation caused by twist or horizontal vibrational mode, respectively. For 60 and 100 μm particles, bubble behavior is dominant higher than umf. Thus, the effects of vibrational mode on the flow patterns in the bed and umf are not significant. For 30 μm particles, the horizontal rotation or vertical rotation are caused by twist or horizontal vibrational mode, respectively. For 6 μm particles, vertical rotation was not observed. When horizontal vibration is added to the bed, the lower limit of gas velocity for channel breakage for 6 μm is the lowest among the three vibrational modes. It is considered that the horizontal vibration affects channel breakage as the shear force.