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Please use this identifier to cite or link to this item:
https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/34771
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| Title: | 二氧化鈦奈米粒子溶液於無機管式薄膜過濾效能之研究 |
| Other Titles: | A study on filtration performance of titanium dioxide nanoparticle solution in inorganic tubular membrane. |
| Authors: | 林哲緯;Lin, Che-wei |
| Contributors: | 淡江大學化學工程與材料工程學系碩士班
鄭東文;Cheng, Tung-wen |
| Keywords: | 二氧化鈦;等電位點;氣液兩相流;濾速提升;Titanium dioxide;Isoelectric point;gas-liquid two-phase flow;flow enhancement |
| Date: | 2009 |
| Issue Date: | 2010-01-11 05:35:42 (UTC+8) |
| Abstract: | 本研究主要利用掃流式陶瓷膜過濾系統針對二氧化鈦奈米粒子水溶液進行濾速提升的探討，實驗操作參數有溶液之pH值、濃度、透膜壓差、液體速度、通氣速度以及膜管傾斜角度等，經由這些實驗操作的探討，找出提升二氧化鈦奈米粒子水溶液濾速之最佳操作條件。
實驗結果發現，當粒子所處的溶液環境為二氧化鈦之等電位點(pH=7)時粒子容易凝聚，其所受的剪應力之影響效應會較大，尤其在增加液體速度或通入氣體時，可以有效的造成擾動而提昇剪應力，因此對濃度極化現象的移除，有正面的幫助，而於等電位點下凝聚的粒子所受的剪應力效應會較明顯，因此濾速的提升會很顯著；至於提高透膜壓差對濾速的提升效果有限，由此可知若要提升二氧化鈦水溶液之濾速，如何減緩濃度極化現象，會比提高驅動力來的更為重要；至於改變膜管之傾斜角對濾速提升的效果也不大，但只要操作在容易掃除濃度極化效應的操作條件下，如高通氣速度時，不管是透膜壓差或傾斜角對濾速的提升效應就會慢慢顯現出來。實驗結果也發現氣液兩相流的操作方式對濾速之提升幫助最大，在液體速度介於0.1至0.5 m/s及通氣速度介於0.05至0.3 m/s，當pH=5時，最佳操作條件是液體速度為0.5 m/s及通氣速度為0.3 m/s，當pH=7時，液體速度為0.3 m/s及通氣速度為0.3 m/s時，濾速之值最大；這是因為於pH=5時，濾速會受總體速度影響，總體速度越大，得到的濾速便會越大；於pH=7時，除了受總體速度影響外，也會受注入因子(injection factor)的影響，從研究中顯示注入因子為0.5時，對濾速提升最為顯著。
In this study, the ceramic membranes were employed in a cross-flow filtration system to investigate the flux enhancement of the titanium dioxide nanoparticle solution. The parameters of experiment included pH value, concentration, transmembrane pressure, liquid velocity, gas velocity, and membrane inclination angle. By the experimental study, the method for improving the performance of filtration of the titanium dioxide nanoparticle solution can be obtained.
At the isoelectric point (pH=7), the titanium dioxide particles coagulate and form the larger particles, its migration is effected easily by the shear stress. By increasing the liquid or gas flow rate, the coagulated particles can be disturbed significantly. Therefore, the permeate flux of the filtration of titanium dioxide suspension at pH=7 can be enhanced apparently by increasing the shear stress. Relatively, the influences of transmembrane pressure or membrane inclination is not obvious on the permeate flux. It is noted that the operation with gas-liquid two-phase flow is an effective way to enhance the permeate flux. In the range of 0.1 to 0.5 m/s liquid velocity and 0.05 to 0.3 m/s gas velocity, the optimal condition for improving the flux is 0.5 m/s liquid velocity and 0.3 m/s gas velocity at pH=5, while 0.3 m/s liquid velocity and 0.3 m/s gas velocity for pH=7. At pH=5, the permeate flux is mainly affected by the total velocity. The higher total velocity, the higher permeate flux is obtained. At pH=7, the permeate flux is affected not only by the total velocity but also by the injection factor. Presented work implies that the best flux enhancement occurs at the 0.5 injection factor. |
| Appears in Collections: | [化學工程與材料工程學系暨研究所] 學位論文
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