低密度循环流化床局部颗粒速度的轴径向分布的研究

在高8m,内径186mm的循环流化床中,利用光纤激光多普勒测速仪测量了FCC颗粒的局部速度沿轴径向的分布。实验结果表明:局部颗粒速度沿径向分布是不均匀的,床中心区域分布比较平坦,近壁环形区域分布较陡,颗粒沿轴向运动有较长的加速段。由实验数据回归得到预测低密度循环流化床局部颗粒速度的经验关联式。

Radial Distribution of Local Particle Velocity in a Dilute Circulating Fluidized Bed

This paper presents an experimental study on the radial and axial profiles of local particle velocity of fluidized catalyst (FCC) particles in a circulating fluidized bed of 8000 mm in height and 186 mm in inner diameter using a Fiber-Optic Probe Laser Doppler Velocimetry. It was found that the radial profiles of local particle velocity are parabolic, a plateau in the centre region and steep decreasing in the region near the bed wall, and that the length of particle acceleration along bed height is longer than that expected. A formula was recommended to correlate the local particle velocity with dilute gas-solid flow in the bed.