Fluid and Solids Flow Affecting the Solids Circulation Rate in Spouted Beds with a Draft-Tube
In a spouted bed, the gas flow rates cannot be changed independently in either the spout or the annulus. In this study, an experimental spouted bed equipped with a draft-tube was made in such a way that each of the gas flow rates can be changed independently. The effect of the gas flow rate in the spout or in the annulus on the circulation rate of solids was examined for the three types of spouted bed. The relation between the solids circulation rate and the average gas velocity in the annulus differs among these three types of spouted beds. In the spouted bed with a gas inlet nozzle, the solids circulation rate initially sharply decreased with the average gas velocity in the annulus. It was found that an eddy motion of solid particles caused this sharp decrease in the solids circulation rate. The fluid flow that caused this eddy motion in the solids was confirmed by using a two-dimensional water flow model.
- Journal of chemical engineering of Japan
Journal of chemical engineering of Japan 37(9), 1085-1091, 2004-09-01