气固下行流化床反应器 Ⅲ气、固混合

与气固并流上行提升管反应器相比，气固并流下行管反应器的轴向气固返混明显降低，而径向气固混和仍然相当大，因而有利于提高气固快速反应的转化率及选择性。本文在分析下行流化床反应器内气、固混合机理的基础上，比较了有关气、固混合的研究方法及结果，并比较了提升管和下行管的不同混合现象，旨在促进对这一课题更加深入系统地研究，以适应循环床下行管反应器设计、放大和模型化的迫切要求。

COCURRENT GAS SOLID DOWNFLOW FLUIDIZED BED (DOWNER) REACTORS

The axial gas and solids dispersions in the downer are much smaller than that in riser, while the radial gas solid mixing is comparable between the two, making downer reactor a far better candidate for short contact time reactions where the intermediates are the desired product. Available measurement techniques and reported experimental results of gas and solid mixing are summarized, and analysis is provided for the mixing mechanism in the downer reactor. The different mixing phenomena in risers and downers are also compared.