针对大型鼓泡床反应器存在返混增强、物料流场分布不匀匀性趋强以及传质效率低等影响反应器安全稳定高效运行的突出问题，开发了一种径向展开的新型阻尼分布器，在冷模试验平台上探索阻尼分布器对气泡聚并及破碎行为的影响规律，考察大型反应器中不同阻尼分布器组合方式的流场流动特性，探究了阻尼分布器组合在工业反应器放大过程中的流场强化效果。结果表明：设置阻尼分布器后，鼓泡床反应器冷模试验装置中湍流涡尺度减小，气泡破碎概率提高，不同气泡群经阻尼分布器后气泡群平均直径从13.48～24.38 mm降至9.40～20.38 mm，表面积增幅为8.5%～71.9%。设置阻尼分布器可提高反应器局部气含率和液速分布均匀性，适当增加阻尼分布器层数有利于扩大流场的轴向影响范围。增大阻尼分布器直径有利于减小各高度平面间局部液速的差值并提高局部气含率径向分布均匀性，不同高度平面中心液速的差值由0.6 mm/s降至0.3 mm/s，同一高度平面局部气含率方差可降至未设置阻尼分布器时的15%。在反应器放大过程中，流体绕流的径向范围扩大，设置阻尼分布器后局部气含率和液速分布均匀性进一步提高，同一高度平面局部气含率方差可降低至未设置分布器时的7%，局部液速差值由1.3～2.7 mm/s降至1.0～1.1 mm/s。设置1/4倍塔径分布器并以安装间隔∶分布器直径=7∶1的方式设置阻尼分布器组合时，流场强化效果较好。

A new type of resistance internal with radial expansion was developed to overcome the major problems in large bubbling bed reactor, such as enhanced re-mixing, uneven distribution of  flow field and low mass transfer efficiency, which could affect the stable and efficient operation of the reactor and the safety of working conditions. The effect of resistance internal on bubble aggregation and fragmentation behavior was explored in cold model test platform, and the flow field flow characteristics of different combinations of resistance internals in a large reactor were investigated, and the flow field enhancement effect of resistance internal combinations in the industrial reactor amplification process was explored. The results show that the turbulent vortex scale is reduced and the bubble fragmentation probability is increased after the resistance internal is set in the cold model test device of bubble column reactor, and the average diameter of the bubble population decreases from 13.48-24.38 mm to 9.40-20.38 mm after different bubble populations pass through the resistance internal, and the surface area is increased by 8.5%-71.9%.The installation of the resistance internal can improve the uniformity of local gas holdup and liquid velocity distribution in the reactor, and the axial influence range of the flow field can be expanded by increasing the number of resistance internal layers. Increasing the diameter of the resistance internal is beneficial to reduce the difference of the local liquid velocity in each height plane and improve the uniformity of the radial distribution of the local gas holdup. The difference of the central liquid velocity in different height planes is reduced from 0.6 mm/s to 0.3 mm/s, and the variance of the local gas holdup in the same height plane can be reduced to 15% of that without the resistance internal. The radial range of fluid flow around the reactor is expanded during the process of reactor amplification, and the uniformity of local gas holdup and liquid velocity distribution is further reduced. The variance of local gas holdup in the same height plane can be reduced to 7% of that without the resistance internal, and the difference of local liquid velocity is reduced from 1.3-2.7 mm/s to 1.0-1.1 mm/s after setting the resistance internal combination. When a 1/4 times tower diameter distributor is set and the resistance internal combination is set in the way of installation interval :distributor diameter=7∶1, the flow field strengthening effect is better.

0 引言

1 试验方法

   1.1 鼓泡床反应器流场流动特性数值模拟

   1.2 气泡聚并及破碎行为

2 结果与讨论

   2.1 鼓泡床反应器放大对流场流动特性的影响

   2.2 阻尼分布器对气泡聚并及破碎行为的影响

   2.3 不同阻尼分布器组合对流场流动特性的影响

   2.4 鼓泡床反应器放大过程中阻尼分布器组合的流场强化效果

3 结论