多孔分布板对气升式环流反应器内流动和传质的影响

Effect of Perforated Plate on Flow and Mass Transfer in Airlift Loop Reactor

为改善环隙进料气升式环流反应器内气相分布状况,提高气含率,强化传质,在反应器上升段设置了多孔分布板,然后采用计算流体力学(CFD)模拟方法,对工业规模气升式环流反应器进行了数值模拟研究。考察了多孔分布板对环流反应器内流动和传质的影响规律,并研究了不同表观气速下分布板开孔率对气含率和传质系数的影响。冷漠实验结果表明:添加分布板能够提高气相径向分布的均匀性,对气泡进行有效破碎,降低气泡直径,增加反应器的整体气含率,强化气液传质效果。对多孔分布板开孔率进行了优化,确定了工业规模气升式环流反应器的分布板最佳开孔率。模拟结果为环流反应器的放大设计和优化提供了依据。

In order to improve the gas phase distribution in the annular feed airlift loop reactor,increase the gas holdup and enhance the mass transfer,perforated plate was set in the rising section of the reactor.Firstly,the cold model experiment showed that the perforated plate could significantly improve the gas holdup.Then,the computational fluid dynamics simulation was carried out to investigate the influence of the perforated plate on flow and mass transfer in the loop reactor,and the influence of the aperture ratio on the gas holdup and mass transfer coefficient at different superficial gas velocities were studied.The results showed that perforated plate could improve the uniformity of gas radial distribution,effectively break the bubble,reduce the bubble diameter,increase the overall gas holdup,and strengthen the gas-liquid mass transfer.The aperture ratio of perforated plate was optimized,and the optimal aperture ratio of porous plate in industrial scale airlift loop reactor was determined.The simulation results provide a basis for the scale-up design and optimization of the loop reactor.