鼓泡塔流动特性与表面活性剂迁移规律耦合的实验及建模

Bubble columns are widely used in industrial processes, such as oxidation, chlorination, hydrogenation, biochemistry and wastewater treatment. In real processes, the liquid phase always consists of mixture with various substances, and more or less contains surfactants. Therefore, investigating hydrodynamics in bubble columns with surfactants is the scientific foundation for the design and scale-up of this kind of reactors. In this project, particle image velocimetry and high speed camera will be used to capture the influence of surfactants on bubble rising, coalescence and breakage processes under the turbulent condition. Then the interfacial drag model and bubble coalescence and breakage kernels will be established. Concurrently, with respect to surfactant migration between the liquid bulk and interface, the corresponding surfactant transport models will be developed, and coupled with CFD and PBM model to establish multi-scale CFD-PBM-STM model. The model will be validated with experimental data. The findings of the project will reveal the mechanism of the coupling effects between hydrodynamics in bubble columns and surfactant migration, deepen scientific understanding about gas-liquid multiphase flow with surfactant and provide guidelines for the design and scale-up of bubble column reactors with surfactants.

鼓泡塔广泛运用于氧化、氯化、加氢、生化、废水处理等工业过程，实际运用时液相经常是由多种物质组成的混合物，或多或少含有表面活性剂，因此，研究含表面活性剂鼓泡塔的流体力学是此类反应器设计放大的科学理论基础。本项目结合粒子成像测速及高速摄像实验技术，拍摄湍流条件下表面活性剂对气泡浮升以及聚并破碎过程的影响，并建立相应条件下的相间曳力模型以及气泡聚并破碎核模型。同时，针对表面活性剂在体相和相界面之间的迁移现象，发展相应的表面活性剂传输模型，与计算流体力学和群体平衡模型耦合，建立多尺度的CFD-PBM-STM模型，并对模型进行多层次的实验验证。本项目的实施将揭示鼓泡塔流体动力学与表面活性剂迁移的耦合作用机制，有助于深化对含表面活性剂气-液两相流的科学认识，对含表面活性剂鼓泡塔反应器的设计放大具有重要的指导性意义。

表面活性剂广泛应用于生化、乳化、选矿、采油等多相过程工艺，研究表面活性剂的作用机制是含表面活性剂过程工艺强化的科学基础。本项目采用LBM数值模拟方法研究了单液滴的破碎行为，形成了液滴破碎相图。同时，针对表面活性剂在体相和相界面之间的迁移现象，发展相应的表面活性剂传输模型，与计算流体力学和群体平衡模型耦合用于高压均质器和鼓泡塔的模拟，模型预测的尺寸分布和相含率与实验结果符合良好。本项目的实施揭示了流动规律与表面活性剂迁移的耦合作用机制，深化了对含表面活性剂体系多相流的科学认识，对含表面活性剂工艺的设计和强化具有重要的指导性意义。