Effects of Coarse Particle Addition on Solids Distribution of CFB with Air-Staging

To study the influence of coarse particle addition on solids distribution of circulating fluidized bed (CFB), some experiments has been done on a 0.25m×0.25m×6.07m square circulating fluidized bed in this paper. The axial pressure drop, local solids holdup and coarse particle fraction in the CFB system was measured and analyzed. Experimental results show that the pressure drop increases with the increasing of initial coarse particle fraction (X_c0) no matter with or without air staging. Comparatively, the pressure drop is larger for the case with air-staging. With same initial coarse particle fraction X_c0, the coarse particle fraction is larger in the bottom bed but smaller in the upper bed and external circulating system when air-staging is adopted.