(152c) Investigation of flow regimes in a spout-fluid bed with a draft tube using pressure fluctuation

Flow regimes in a semi-cylindrical spout-fluid bed of 0.10 m in diameter with a draft tube using spherical glass beads 1350 µm in diameter were investigated based on the pressure fluctuation signal within the draft tube, and also the effects of the gas velocity and the length of the entrainment region on the solid circulation rate and the solids loading ratio were examined from the point of view of the conveying of solid particles. As the results, the standard deviation and the cycle frequency of pressure fluctuation signal were found to be helpful in distinguishing various flow regimes, that is, spouting with aeration, intermittent spouting and fixed bed as the regions depending on the relative values of the central and auxiliary gas flow rates. Moreover, it was recognized that the solids circulation rate and the solids loading ratio can be varied over a wide range by adjusting the flow rate of auxiliary gas introduced through side distributor and the length of the entrainment region. Keywords: spout-fluid bed, draft tube, flow regime map, pressure fluctuation, solid loading ratio, solid circulation rate