16m高提升管中FCC颗粒固含率的研究

研究了 16m高循环床提升管中FCC颗粒固含率及其轴向分布 ,并与相同条件下 6m高提升管中固含率及其轴向分布进行了对比分析。结果表明 ,提升管高度对固含率及其轴向分布具有显著影响。提升管高度增加 ,提升管各高度截面上的平均固含率减小 ,其轴向分布也更加均匀。提升管下部浓相段和上部稀相段的固含率随操作条件的变化规律明显不同。在提升管稀相段截面上 ,固含率随颗粒循环量的提高呈线性增加 ,随表观气速的增加平缓下降 ;但在提升管浓相段 ,由于颗粒间相互作用较强 ,固含率随操作条件的变化更为显著。

Investigation on Solids Holdup of FCC Particles in a 16 m High CFB Riser

Experiments were conducted to investigate the axial distributions of solids holdup of FCC particles in a 16 m high CFB riser.The results were also compared with those in a 6 m high CFB riser under the same conditions.It is found that the riser height has a significant effect on the solids holdup and its axial distribution in the riser.With increasing riser height,the average solid holdup at various axial locations of the riser decreases and becomes more uniformly distributed along the riser height.Variations in solids holdup with operation conditions in the upper section of the riser are quite different from those in the bottom section.In the upper section,the increase in solids holdup varies with solids circulating rate in an obvious linear manner and the decrease with superficial gas velocity is relatively smooth;while in the bottom section,the effects of operating conditions on solids holdup are more significant because of stronger actions between particles.