内构件对高密度提升管内流体力学及径向气体混合的影响

Effect of bluff internals on the hydrodynamics and lateral gas mixing was studied in a 0.186m ID high-density riser. With the bluff internals, the extremely non-uniform radial profiles of solid fraction and particle velocity become flat and the dense downflow layer near the wall disappears, indicating the significant enhancement of solid turbulence introduced by the internals. The fluctuation velocity and solid fraction transient signal analysis indicates a significant increase in fluctuation intensity near the wall region. The length influenced by the internals on the flow structure is about 1 meter. The lateral gas dispersion coefficient increases significantly as the bluff internals exist in the riser.     

内构件对高密度提升管颗粒浓度分布的影响

为改善工业高密度提升管反应器内颗粒浓度径向的不均匀分布 ,对加设钝体式内构件的提升管内颗粒浓度分布规律进行研究。试验结果表明 :由于钝体对回流颗粒的阻截 ,使床层底部颗粒浓相区的平均颗粒浓度有所下降 ,但对颗粒循环量没有影响。与传统提升管相比 ,颗粒浓度的径向分布变得均匀 ,在一些轴向位置甚至出现中心颗粒浓度高而边壁低的分布 ;钝体的约束使颗粒的湍动程度增加