关键词: 气-固环流混合, 导流筒, 烧焦管, 石油焦燃烧器, 轴向密度分布

Abstract: A large-scale cold experimental equipment which can adapt to combustion demands of petroleum coke was established by using the combined structure of gas-solid annular flow and riser transporter reactor. The pressure gradients of air-sand two-phase flow along the axial direction of the annular flow unit were measured by differential pressure transmitters under different operation conditions. The axial distributions of solids density in two regions of the annular flow mixing unit, namely internal annular and external annular regions, were investigated. The results show that the axial distributions of solids density in the internal annular region have two modes, namely the bottom dense phase and the upper turbulent flow diffusion phase. The solids flux has little effect on the density distributions in the bottom dense region, but significant effect on the upper turbulent flow diffusion region. The solids density in the whole internal annular region decreases with increasing the superficial gas velocity. The axial distribution of solids density in the external annular region is directly relative to the superficial gas velocity, solids flux in the internal annular region and the solids dense phase level in the external annular region. The empirical models for axial distributions of solids density in the internal and external annular regions have been established based on the experimental data. The model predictions are in good agreement with the experimental data.

Key words: gas-solid annular flow mixing, draft tube, coke-burning riser, combustor for petroleum coke, axial distribution of solids density