溶胀对中空纤维膜萃取器中的流动和传质性能的影响

溶胀是中空纤维膜萃取工业化必须要解决的关键问题之一。本文通过拍摄电镜照片，观察了溶胀前后中空纤维膜表面形态，孔隙率，膜孔径，膜孔道弯曲状况等微观结构的变化。结果表明，溶胀会使中空纤维膜孔隙率减小，膜孔径变小，弯曲因子增大，通过测量发现，溶胀后膜长度增加，而膜的内外径，膜厚基本不变。本文还研究了溶胀时间对中空纤维膜器中的流动及传质效果的影响，通过测量聚丙烯和聚砜中空纤维膜器管程和壳程的停留时间分布曲线表明，对于装填密度较高的膜器，溶胀时间对壳程和管程中的流动状况的影响可以忽略。此外，本文以正辛醇－苯胺－水为实验体系，在中空纤维膜器中进行了循环逆流传质实验。实验证明，由于溶胀使纤维膜阻增加，膜器的传质性能随时间的增加而下降。

Influence of Swelling on Flow and Mass Transfer in Hollow Fiber Membrane Extractor

The surface configuration, porosity, hole diameter and tortuosity of the hollow fiber membrane before swelling and after swelling were observed by the SEM method. It was found that the surface modality and the structure of the hollow fiber membrane were modified to some extent due to the swelling effect of the solvent. The outer diameter and the thickness remained constant but the porosity decreased and the tortuosity increased correspondingly. The influences of swelling on flow and mass transfer performance in hollow fiber membrane module was also studied. By measuring the residence time distribution (RTD) curves of the hollow fiber membrane module, it was shown that for the polypropylene and polysulfone hollow fiber modules with high packing factor, the influence of swelling time on the fluid flow in tube side and shell side of the extractor is negligible. Using octanol-aniline-water as experimental system, the mass transfer experiments was carried out by counter-currently recycling mode. It indicated that due to the swelling effect, the mass transfer performance was decreased.