Solids mixing in an expanded top fluid bed

This study investigated solids mixing of a group A fine powder in a 0.15 m ID expanded top fluid bed with a ferromagnetic tracer. The superficial gas velocity was raised from 0.075 to 1.1 m/s, causing the bed to go through bubbling, slugging, and turbulent fluidization regimes. A countercurrent flow model described the data well at low gas velocities. The bed assumed a more homogeneous appearance at higher gas velocities; a one‐dimensional axial dispersion model was used to correlate the data. Axial dispersion coefficients increased with gas velocity. The data agree well with literature data for low gas velocities.