Abstract: Based on olefin reduction technology with auxiliary reactor for FCC naphtha upgrading, a large-scale cold model experimental setup with a riser-airlift loop fluidized bed coupled reactor was established. The distributions of solids hold-up in the upper airlift loop fluidized bed were investigated. The effects of superficial gas velocity and outer solids flux on the radial distribution of local solids hold-up were analyzed. The fluidization quality of coupled airlift loop fluidized bed and coupled conventional one was compared in radial non-uniformity index. The results show that the solids hold-up of airlift loop fluidized bed decreased with increasing superficial gas velocity, and the solids hold-up in the bottom of draft tube increased with increasing outer solids flux, while outer solids flux had little effect on that in the middle-upper part of draft tube. The solids hold-up of annulus decreased slightly with increasing outer solids flux. When Ug,d<0.85 m/s, the uniformity of radial distributions of local solids hold-up in the draft tube gradually became well along axial direction; when Ug,d≥0.85 m/s, firstly the uniformity became well along axial direction, then became worse in the exit of draft tube. The uniformity extent of distributions of solids hold-up in the annulus is middle part of annulus > bottom part of annulus > upper part of annulus. In the same condition, the radial non-uniformity index of distributions of solids hold-up of airlift loop fluidized bed was less than that of conventional fluidized bed.

Key words: coupled reactor, gas-solid airlift loop fluidized bed, radial non-uniformity index, distribution of solids hold-up

摘要： 针对催化汽油辅助反应器改质降烯烃技术，在提升管-环流床耦合反应器大型冷模实验装置上，研究了上部环流床内局部固含率分布及操作条件的影响，采用径向不均匀指数分析比较了提升管上端耦合环流床及耦合常规流化床的流化质量. 结果表明，环流床内固含率随表观气速增加而减小，导流筒底部固含率随外循环强度增加而增加，中上部固含率受外循环强度影响较小，环隙内固含率随外循环强度增加略有降低. 当导流筒内表观气速Ug,d<0.85 m/s时，固含率径向分布的均匀性沿轴向向上逐渐变好，当Ug,d≥0.85 m/s时，则沿轴向向上先变好，在导流筒出口处又变差；环隙内固含率分布趋于均匀的程度依次为环隙中部>环隙下部>环隙上部. 相同条件下，环流床内固含率分布的径向不均匀指数小于常规流化床.

关键词: 耦合反应器, 气-固环流床, 径向不均匀指数, 固含率分布