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 mum), which are Geldart group A or group C. The fluidity of particles is evaluated with vibration strength (Lambda), minimum fluidization velocity (u(mf)), 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 mum particles, bubble behavior is dominant higher than u(mf). Thus, the effects of vibrational mode on the flow patterns in the bed and u(mf) are not significant. For 30 mum particles, the horizontal rotation or vertical rotation are caused by twist or horizontal vibrational mode, respectively. For 6 mum 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 Irm is the lowest among the three vibrational modes. It is considered that the horizontal vibration affects channel breakage as the shear force.