Abstract: The influence of internals on 78.5L airlift loop reactor was studied and optimal values were obtained for theoretical guidance of industrial equipment. Fluent software was used to establish a mathematical model to compare with experiment result. The influence of height ratio between gas liquid separation zone and external tube, length ratio between diversion tube and external tube, and diameter ratio between diversion tube and external tube on flow behavior of airlift loop reactor was investigated. The error between simulation and experiment results was small, and the mathematical model could be used to predict flow behavior of airlift loop reactor. Circulation resistance became larger when length ratio between gas liquid separation zone and external tube was too large. Reactor flow achieved the best performance when the ratio was 0.34-0.36. Increasing length ratio between diversion tube and external tube could increase gas holdup and liquid circulation rate, but an overly large ratio would cause bubbles coalescence, which would affect flow performance. Reactor flow achieved the best performance when the ratio was 0.60-0.62. Increasing diameter ratio between diversion tube and external tube could improve flow. Loop resistance was larger when ring gap area was too small and reactor flow achieved the best performance when diameter ratio was 0.73-0.77.

Key words: loop reactor, internals simulation optimization, diversion tube, Fluent, gas liquid separation zone

摘要： 研究了78.5L气升式环流反应器内部结构对流动性能的影响规律, 并给出最佳区间来为工业装置提供理论指导。利用Fluent软件建立数学模型与实验装置作对比, 模拟了不同气液分离区高度与外筒高度比、导流筒长度与外筒长度比和筒内外直径比对流动行为的影响规律。结果表明:数学模型和实验结果误差较小, 可以用来预测气升式环流反应器流动行为。气液分离区高度与外筒高度比值过大会导致环流阻力增大, 从而不利于流动, 比值为0.34~0.36时流动性能最佳;导流筒长度与外筒长度的比值增大可增加气含率和环流液速, 但是比值过大会引起气泡的聚合, 从而影响流动性能, 当比值为0.60~0.62时流动性能最佳;在一定范围内增加内外筒直径比会改善流动效果, 但环隙面积过小会增加环形阻力, 内外筒直径比为0.73~0.77时流动效果比较理想。

关键词: 环流反应器, 内构件模拟优化, 导流筒, Fluent, 气液分离区