Effects of Rolling Motion on Gas-Solid Flow in Circulating Fluidized Bed

A series of experiments were performed on a circulating fluidized bed (CFB) in order to investigate effects of the rolling motion on gas-solid flow in the CFB. Rolling period, superficial velocity, solids circulation flux, and particle size were changed in the experiments, while the amplitude of the rolling motion was maintained at ±16deg. The following results were obtained: (1)When the CFB stands upright, the gas-solid flow regime in the riser are affected by the superficial gas velocity and three types of flow regimes were observed: Bubbling fluidization, Turbulent fluidization, and Fast fluidization. (2)The solids circulation flux also affects gas-solid flow of the CFB at upright attitude. As the solid ciculation flux becomes larger, the total pressure drop throughout the CFB increases. (3)When the CFB undergoes the rolling motion, downflow of particles along the riser walls periodically changes, and falling particles accumulate on the distributor. As a result, total pressure drop throughout the CFB under rolling motion becomes larger than that of the upright attitude. (4)In our experiment, the rolling period has no influence on the total pressure drop throughout the CFB in the rolling motion. (5)When the superficial velocity is sufficiently large, the gas-solid flow in the riser is not affected very much by the rolling motion. And the total pressure drop throughout the CFB in rolling motion becomes nearly the same as that at the upright attitude.