MINIMUM SPOUTABLE GAS FLOW RATE IN SIDE-OUTLET SPOUTED BED WITH INNER DRAFT-TUBE

Abstract

It has been found that the side-outlet spouted bed with inner draft-tube has the following advantageous characteristics stemming from the fact that simple rules hold at the beginning of spouting. When the gas velocity in the inner draft-tube increases and the ratio to terminal velocity of solid particles rises to a certain value, stable spouting begins. At the beginning of spouting the ratio of gas velocity in the gas inlet to terminal velocity of solid particles is also constant. These ratios do not change even if the size of the apparatus or the size of particles changes, as far as we have investigated on geometrically similar spouted beds. In addition, the gas streamlines are aproximately similar for geometrically similar spouted beds.
These characteristics of the side-outlet spouted bed with inner draft-tube facilitate the procedure for scale-up. For example, the minimum gas flow rate required for stable spouting can be easily predicted and the gas conversion can be easily estimated.