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

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