Elucidation of anomalous transport phenomena and its application to process intensification

在非平衡过程中，经常会观察到异常输运现象，即热和质量等物理性质的输运速率比正常扩散速率更快的输运现象。这项工作试图阐明反常质量传输现象的机制，并将这些现象应用到化学过程中，重点关注时间-特殊微扰的影响。本文研究了带涡轮叶轮的搅拌槽内泰勒涡流和层流中的反常传质现象。研究发现，流场中的拟序结构及其稳定性是导致异常输运现象的重要因素。如果对具有相干流动结构的共振频率的流场施加时间或特殊扰动，则流动结构稳定，异常输运被抑制。另一方面，施加破坏相干、对称或稳定结构的微扰，反常质量输运显著增强。本工作还提出了一种利用上述机理强化反常传质的新型中空膜分离过程。与普通中空纤维膜分离工艺相比，这种新型膜分离工艺不仅具有更高的抗污染性能，而且具有更高的渗透率和截留率。

Anomalous transport phenomena which give faster transport rate of physical properties such as heat and mass than its normal diffusion rate are often observed in non-equilibrium processes. This work tried to elucidate the mechanism of anomalous mass transport phenomena and apply these phenomena to chemical processes by focusing on the effect temporal-special perturbations. This work investigated anomalous mass transport phenomena in Taylor vortex flow and laminar flow in a stirred vessel with turbine impeller. It has been found that coherent structures in flow field and their steadiness are important factors for anomalous transport phenomena. If temporal or special perturbations are imposed a flow field with a resonant frequency with a coherent flow structure, the flow structure is stabilized and the anomalous transport is suppressed. On the other hand, perturbations breaking coherent, symmetry or steadiness structures are imposed, anomalous mass transport is dramatically enhanced. This work also proposed a novel hollow membrane separation process utilizing the above mechanism for enhancement of anomalous mass transport. This novel membrane separation process showed not only higher anti-fouling property but also higher permeability and rejection than an ordinary hollow fiber membrane separation process.