Cross-Flow Microfiltration of Soft Porous Submicron Particles

軟質多孔性次微米粒子之掃流微過濾

黃國楨(Kuo-Jen Hwang) ； 王雲生(Yun-Sheng Wang)

《Journal of the Chinese Institute of Chemical Engineers》 34卷1期 (2003/01) Pp. 161-169

https://doi.org/10.6967/JCICE.200301.0161

摘要

本研究旨在分析軟質多孔性次微米粒子之掃流微過濾中濾餅之成長及其性質。葡聚糖-二氧化錳粒子被製備並用以進行掃流過濾實驗。操作條件對過濾性能的影響被深入探討。實驗結果發現，增加過濾壓差和掃流速度皆會導致穩定濾速的提高。布朗動態模擬法被使用來模擬粒子的運動軌跡及濾面上之粒子輸送通量，而在各條件下之粒子附著機率則經由力平衡模式估計。計算結果顯示：提高濾壓差和掃流速度皆會增加濾餅成長速率與濾餅質量。基於濾餅延遲壓縮模式與濾餅性質之經驗式，本研究建立一動態解析方法來模擬濾餅局部性質之分佈。對於軟質多孔性次微米粒子而言，粒子內外之孔隙度皆須納入考慮。結果發現：有一表皮層在濾材表面生成，雖然其厚度僅佔全濾餅之10%，但此層卻佔總壓降之90%，並在過濾阻力上扮演相當重要的角色。

並列摘要

The formation and the properties of the filter cake in the cross-flow microfiltration of soft porous submicron particles are analyzed in this study. Dextran-MnO2 particles are prepared and used in experiments. The effects of operating conditions on the filtration performance are discussed. The results show that the pseudo-steady filtration rates increase with increasing the cross-flow velocity and the filtration pressure. The trajectories and the particle flux arriving at the membrane surface in cross-flow microfiltration are simulated using the Brownian dynamic simulation method. The probabilities of particle deposition under various conditions are estimated using the force balance model. The calculation results show that a higher cross-flow velocity or a higher filtration pressure leads to a higher cake growth rate and a larger cake mass. Based on the retardation cake compression model and the empirical equations for cake properties, a dynamic analysis method is developed for simulating the distributions of local properties in a filter cake, such as the solid compressive pressure, the porosity and the specific filtration resistance. For a soft porous particle, both the variations of internal and external porosities in the cake are take into consideration. It can be found that a skin layer controlled the filtration rate may form next to the membrane surface. Although the thickness of the skin layer is only about 10% of the whole cake, this layer has about 90% of the overall pressure drop through it , and it plays the major role on the filtration resistance.

並列關鍵字

Cross-flow microfiltration ； Submicron particles ； Soft particles Particle deposition ； Cake formation ； Filtration