Experimental Study in a Short Circulating Fluidized Bed Riser

Experiments were performed with gas and solids flow in a 2.42m high circulating fluidized bed (CFB). This equipment has both solids and gas fed into the downer section. Local solids holdup was measured using an optical fiber probe. By the axial solids concentration distribution, it was verified that (1) the curve that precedes the entrance into the riser provides further acceleration to the flow and (2) the abrupt exit causes an increase in solids concentration in the top zone. Results of radial distributions in the bottom zone show that the flow is more concentrated near the wall. For the exit zone, the distributions show high values of solids holdup both near the wall and on the axis.