管式膜過濾之薄膜表面受力與薄膜阻力之分析模擬

Simulation of force on membrane surface and resistance of membrane in a tubular membrane filtration system

林佑儒(Yu-Ju Lin)

指導教授 ： 吳容銘

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2008年)

https://doi.org/10.6846/TKU.2008.00333

摘要

管式膜過濾已廣泛的被使用在固液分離程序上，管式膜過濾模組之改良將有助於提高分離效率，並且節省操作成本。實驗方面，採用平均孔徑為3.5 um的複合陶瓷膜，過濾平均粒徑為15 um的聚甲基丙烯酸甲酯(PMMA)粉體，探討懸浮液濃度、過濾壓力、掃流速度等操作變數對濾速之影響。同時，配合流體力學軟體加以模擬，分析膜面上之剪應力的變化情形，進而找出提升濾速之方法。亦即，外加側流之管式膜過濾模組。並探討反洗操作對濾速之影響。側流膜過濾，可使膜面上之剪應力增加，清除薄膜表面之結垢；反洗操作，則可使薄膜表面的濾餅脫落，亦可清洗膜孔內部所沈積的粒子。

關鍵字

管式膜過濾 ； 側流 ； 反洗 ； 模擬 ； 結垢

並列摘要

Tubular filtration is commonly used in solid-liquid separation processes. The improvement of tubular filtration models helps raise separation efficiency and saves operation cost. This experiment uses a filter membrane, made of Zirconia, with a mean pore size of 3.5 um is used to filter 15 um PMMA particles. We study the effects of changes in suspension concentration, transmembrane pressure, cross-flow velocity, etc. on filtration rate. Also, we use Computational Fluid Dynamics, CFD, Software Fluent 6.2 to simulate changes in shear-stress on the surface of the membrane to discover tubular-membrane filtration with side-stream, which raises filtration rate and shear-stress on the membrane, also removing fouling on the membrane surface. We then explored the effects of backwash on filtration rate, discovering that backwashing causes the cake to peel off on the membrane surface and cleans the accumulated particles inside the membrane pores.

並列關鍵字

tubular-membrane filtration ； side-stream ； backwash ； simulation ； fouling

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