中文摘要：

在直径80mm、高度8000mm的液固循环床提升管中，采用脉冲磷光示踪技术对颗粒停留时间和扩散特性进行了研究。考察了表观液速和颗粒循环速率对颗粒停留时间分布和扩散特性的影响，并对液固循环床提升管和气固循环床提升管中颗粒停留时间分布进行了比较。结果表明：在液固循环床提升管中，颗粒停留时间分布为一尖而窄且对称无拖尾的单峰分布，颗粒停留时间分布相对均匀，颗粒扩散相对较小，液固流动接近于平推流；颗粒轴向扩散从入口到出口逐渐增大，而颗粒径向扩散从中心到边壁较为均匀；颗粒轴向Peclet数随表观液速和颗粒循环速率变化较小。

英文摘要：

The particle residence time distribution （RTD） and dispersion behavior were investigated in the riser of a liquid-solid circulating fluidized bed （LSCFB） with a diameter of 80 mm and a height of 8000 mm by using impulse phosphor tracer technique. The influences of superficial liquid velocity and particle circulation rate were examined. Furthermore, comparison on characteristics of particle RTD in LSCFB and gas-solid circulating fluidized bed （GSCFB） was also made. The experimental results show that compared with the gas-solid system, the profile of the particle RTD in the LSCFB has a sharp narrow symmetrical peak without tail, which indicates that particle RTD is rather uniform, particle dispersion is weak, and flow ap- proaches to a plug pattern. Axial particle dispersion increases from the bottom to the exit of the riser, while the radial dispersion is relatively uniform at the same axial section, The particle axial Peclet number in the riser varies insignificantly with superficial liquid velocity and particle circulation rate.