本研究在掃流微過濾中通入氣體，並改變液體速度、氣體流量以及過濾壓差，討論這些操作條件對過濾通量、粒子附著機率、濾餅性質以及濾面上剪切力的影響。實驗中以平均孔徑為0.1 μm的醋酸纖維膜過濾具粒徑分佈的聚甲基丙烯酸甲酯。隨著氣體流量的提昇會出現不同流態，在氣泡流動的範圍下，作用於膜面上的剪切力能有效抑制濾餅生成，並且可以提高濾速，但隨著流態由氣泡流動轉變為團狀流動，剪切力迅速增加的結果，會造成粒徑5 μm以上的粒子之附著大幅減少，在小粒子填補空隙後導致孔隙度下降，與流體對濾餅壓縮的雙重作用下，使過濾比阻出現明顯的增加，濾速反而比未通氣的數值低。配合力分析的結果可以發現，氣體對粒子造成的作用力在過濾中扮演極重要的角色。本研究所提出基於力分析的粒子附著機構，可以用來預測濾餅中之粒徑分佈，粒子之附著機率與濾餅性質。

The effects of filtration flux、adhesion probability、cake properties and shear stress by changing liquid velocities、gas velocities and filtration pressures for air-sparging cross-flow microfiltration are studied. A filter membrane made of mixed cellulose ester with a mean pore size of 0.1 μm is used for filtering wide size distribution range particles, PMMA-7G. The flow behavior will change when gas velocity increases. Shear stress can restrain cake mass availability and improve filtration rates under bubble flow, but specific filtration resistance will increase clearly and filtration rates worse than no sparging filtration under slug flow。Because of shear stress increase rapidly。A great of particle decrease above 5μm. Smaller particle move in the void and the porosity become reduce. On the other hand, the cake layer compressed when fluid went past, so the specific filtration resistance increases glaringly. Communion with force analysis, we can find air-sparging force plays important role in filtration process, and we can use simulation analysis to forecast the tendency for particle distribution and adhesion property.

目錄
                                                 頁次 
中文摘要		Ⅰ
英文摘要	Ⅱ
目錄	Ⅲ
圖表目錄	Ⅵ


第一章	緒論	1
第二章	文獻回顧	6
     2-1掃流微過濾的特性	6
     2-2過濾的阻塞機制	7
     2-3剛性粒子的堆積特性	9
     2-4粒子粒徑對拉曳力的影響	9
     2-5過濾程序中通入氣體之影響	10
     2-6壓降對氣泡的影響	12
第三章	理論	13
     3-1掃流過濾模組的力分析	13
     3-2粒子堆積於膜面上之受力分析	15
     3-3粒子之附著機構	28
     3-4掃流微過濾之模式探討	33
第四章	實驗裝置與步驟	35
     4-1實驗物料與濾材	35
     4-2 掃流過濾裝置與懸浮液配製	37
     4-3分析儀器與軟體	38
     4-4 實驗步驟	39
第五章	實驗結果與討論	41
    5-1 單相流動下的掃流微過濾	42
    5-2 多相流動下的掃流過濾	46
    5-3 氣泡分析	68
    5-4 掃描式電子顯微鏡 (SEM)分析	72
    5-5 剪切力分析	77
    5-6 理論分析與計算	80
第六章	結論	91
符號說明	95
參考文獻	100
附錄	103
附錄A實驗物料之種類及物性	103
附錄B實驗數據計算式	105
附錄C.剪切力計算	107
附錄D.平均粒徑計算	108



圖表目錄
                                                         頁次
圖目錄
第一章
Fig.1-1 The filtration spectrum	2   
Fig.1-2 The spectrum for each kind of filtrations	3   
Fig.1-3 Schematics of dead-end filtration and cross-flow filtration.	4  
第二章
Fig.2-1 Fouling schematics.(Belfort et al. 1993)	8   
Fig.2-2 Two-phase flowinsie pipes.(Cabassud et al. 2001)	12  
第三章
Fig.3-1 Schematics of momentum balance for a rectangular element in 
      cross-flow	13 
Fig.3-2 Force exerted on a depositing particle in the cross-flow system 	16 
Fig.3-3 Interaction energy of Van der Walls force and electrical double 
      layer repulsive force under different distance.	21  
Fig.3-4 Separated horizontal flow model. Simultaneous gas/liquid flow in 
(a)	is considered as the combination of gas and liquid flow，as(b)and (c)
	24.  
Fig.3-5 Force exerted on a depositing particle 	29 
Fig.3-6 One particle can deposit on another one for possible angle.	32  
Fig.3-7 Force exerted on a depositing particle. (Enlarge)	32  
Fig.3-8 The resistance of microfiltration	34  
第四章
Fig.4-1 Particle distribution for PMMA(7G)	35.
Fig.4-2 A schematic diagram of cross-flow filtration system	38
第五章   
Fig.5-1 Time courses of filtration rates during cross-flow microfiltration under   
       various filtration pressures .	43  
Fig.5-2  Filtration pressures courses of cake formation weights during cross-flow       
        microfiltration under various cross-flow velocities.	43
Fig.5-3  Time courses of filtration rates during cross-flow microfiltration under  
        various cross-flow velocities (after 6000 sec.).	45   
Fig.5-4  Filtration rate courses of cake formation weights during cross-flow 
        microfiltration under various filtration pressures.	45  
Fig.5-5  Analysis steps for Filtration process.		.	46  
Fig.5-6  Time courses of filtration rates during cross-flow microfiltration under 
        various gas velocities.	48   
Fig.5-7  Comparison of the pseudo steady state filtration rates during cross-flow 
        microfiltration under different gas velocities.	49  
Fig.5-8  Effect of the pseudo steady state filtration rates on the efficiency under 
        different gas velocities.	49   
Fig.5-9  The cake weight per unit area under different gas velocities.	52 
Fig.5-10 The cake weight per unit area courses of different filtration pressures under 
       different gas velocities.	52  
Fig.5-11 Frequency courses of different particle size under different filtration 
        pressures.	55   
Fig.5-12 Frequency courses of different particle size under different cross-flow 
       velocities.	55   
Fig.5-13 Frequency courses of different particle size under different gas 
       velocities.	56 
Fig.5-14 Particle size courses of cake weight per unit area under various filtration   
       pressures.	58  
Fig.5-15 Particle size courses of cake weight per unit area under various gas  
       velocities.	58  
Fig.5-16 Particle size courses of adhesion probability under various gas 
       velocities.	60 
Fig.5-17 Particle size courses of adhesion probability under various gas 
       velocities .	60
Fig.5-18 Gas velocities course of adhesion probability under various filtration 
       pressures.	61  
Fig.5-19 Comparison of resistance analyzes under different gas 
       velocities.	63 
Fig.5-20 Comparison of resistance analyzes under different gas 
       velocities.	63 
Fig.5-21 Effect of the average porosity of cake various different cross-flow velocities.	66 
Fig.5-22 Effect of the average porosity of cake various different 
       gas velocities.	66 
Fig.5-23 Effect of the average specific filtration resistance various different 
       cross-flow velocities. 	67
Fig.5-24 Effect of the average specific filtration resistance various different gas 
       velocities.	67  
Fig.5-25 Bubble size courses of frequency distribution under various gas velocities.	70 
Fig.5-26 Bubble size courses of frequency distribution under various filtration  
       pressure.	71  
Fig.5-27 Bubble size courses of frequency distribution under various 
       cross-flow rates.	71
Fig.5-28 The top view of membrane surface after filtration experiment.
       (Us=0.3,Ug=0 m/s ,TMP=20kPa)	73  
Fig.5-29 The top view of membrane surface after filtration experiment.
       (Us=0.3,Ug=0 m/s ,TMP=80kPa)	73  
Fig.5-30 The side view of membrane surface after filtration experiment.  
       (Us=0.3,Ug=0 m/s ,TMP=20kPa)	74  
Fig.5-31 The side view of membrane surface after filtration experiment. 
       (Us=0.3,Ug=0 m/s ,TMP=80kPa)	74  
Fig.5-32 The top view of membrane surface after filtration
       experiment.(Us=0.3,Ug=0.08 m/s ,TMP=20kPa)	75
Fig.5-33 The top view of membrane surface after filtration  
       experiment.(Us=0.3,Ug=0.49 m/s ,TMP=20kPa)	75 
Fig.5-34 The side view of membrane surface after filtration experiment.  
       (Us=0.3,Ug=0.08 m/s ,TMP=20kPa)	76  
Fig.5-35 The side view of membrane surface after filtration experiment. 
       (Us=0.3,Ug=0.49 m/s ,TMP=20kPa)	76  
Fig.5-36 Force exerted on particles with various diameters.	79  
Fig.5-37 Gas velocities course of shear stress under various cross-flow velocities.      	79 
Fig.5-38 Probability of particle deposition under different cross-flow velocities  
       (Theory)..	83  
Fig.5-39 Probability of particle deposition under different gas velocities (Theory).   	83  
Fig.5-40 Force exerted on particles with various diameters.	84  
Fig.5-41 Force ratio under various diameters.	84  
Fig.5-42 Probability of particle deposition under various cross-flow velocities
 	85  
Fig.5-43 Probability of particle deposition under various gas velocities	85
Fig.5-44 Average porosity of cake various different cross-flow velocities	86 
Fig.5-45 Average porosity of cake various different gas velocities	86  
Fig.5-46 Cake weights for theory and experiment values under various cross-flow  
       velocities.	87 
Fig.5-47 Cake weights for theory and experiment values under various gas velocities.
.	87  
Fig.5-48 Average particle size under various cross-flow velocities.	88  
Fig.5-49 Average particle size under various gas velocities	88  
Fig.5-50 Average specific resistance under various cross-flow velocities	89
Fig.5-51 Average specific resistance under various gas velocities.	89
Fig.5-52 Pseudo filtration rate under various cross-flow velocities	90
Fig.5-53 Pseudo filtration rate under various gas velocities.	90

附錄
Fig.A-1.1 The SEM of PMMA(7G)	103  
Fig.A-2.1 The top view of the mixed cellulose ester membrane by SEM.	104	  
Fig.B-3.1 The bubble image.	106  
Fig.D-1  Average particle size for different filtration pressure under various 
        cross-flow velocities.	108  

表目錄
Table.3-1  Values from Lockhart and Martineelli (Wilkes, 2006)
	26  
Table.3-2  Exponent for Two-Phase Correlation (Wilkes, 2006)	
	27   
Table.4-1  The operating conditions	40  
Table.5-1  The injection factor under different gas velocities.	70  
Table.5-2  True gas velocities values.	78  
Table.A-2.1 The characteristic of the mixed cellulose ester membrane.	104  
Table.C-1  Calculated shear stress	107  
Table.D-1  Average particle diameters.	108

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