本研究音在討論操作條件對沉浸式薄膜過港之粒
子附著的影響。以孔洞大小為0.1 μm 之薄膜,過濾平均
粒徑為7μm 之聚甲基丙希酸甲酯(PMMA)粒子,探討不
同的過濾通量、過濾時間、通入空氣之曝氧量與氣泡大
小等操作條件對粒子的附著與過濾效能之影響。在定濾
迷過港、方式的研究結果顯示:當過濾通量增大三倍,最
終過濾差提高了近5 倍,而濾餅量則增加約7 倍。當
粒徑在l~m 以下時,粒子的附著會受到粒子間作用力
的影響,附著機率隨著粒徑的增大而下降,但大於l~m
後,粒子間的作用力之影響俊不再顯著,使得其附著機
率隨著粒徑的增大而土升。這是因為隨著粒子的增大,
切線方向的作用力也隨之加大,使得附著機率逐漸開始
下降。通入氣泡除了有助於掃除濾餅之外,還能使小粒
子易於附著,且通氧量越大,比現象就越為明顯,經比
較之後發現,改變氣泡大小的效果比通氧量來得顯著;加入通氣會使粒子在耳其面上的穩定性減小,進而導致
粒子不易附著,使其附著機率下降,且當粒徑越大,此現象就越為顯著。The effects of operated conditions, such as
flux, filtration time, particle size, aeration
, air bubble size on the deposition properties, cake
es, and the performance in submerged membrane
'on are studied. A particulate sample with a wide size
'on range is used in experiments. The properties of
deposition are analyzed based on force analysis
hydrodynamics. The results show that the interparticle
force plays a major role in particle . deposition for
submicron particles. Increasing filtration flux leads to a
large normal drag force exerted on depositing particles; as
a result, to increase particle deposition probability. An
increase in aeration intensity or reduction of bubble size
may decrease deposition probability for micron particles.
Furthermore, the estimated cake properties, such as mass,
porosity and average specific filtration resistance of cake
are compared with available experimental data .
Relation:
2008年輸送現象及其應用研討會論文摘要集 ( 2008 Symposium of transport phenomena and applications abstract book)