| Abstract: | Particle motion and gas distribution have been measured in 0.3 m spouted beds with porous and solid wall draft-tubes. Particle velocity in the annulus varied with gas rate and bed geometry. Narrow particle residence time distributions were observed under all conditions. Annular gas flow with the porous tubes exhibited a characteristic maximum in the lower part of the bed. A computer model has successfully simulated this phenomenon. The porous tube had a higher annular airflow than the solid tube at low separation distances, and a lower pressure drop for a given annular flow. A composite porous and solid wall tube offers improved performance. |
