淨水廠反應澄清池之模擬

Modeling of a Reaction Clarifier of Water Treatment Plant

溫鉦晏(Jheng-Yan Wen)

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(2009年)

https://doi.org/10.6846/TKU.2009.00911

摘要

使用計算流體力學的FLUENT軟體，模擬板新淨水廠設備的反應澄清池，先建立澄清池幾何結構和網格，給與進水流速和濃度、葉輪轉速和污泥毯的操作條件，再使用Eulerian二相流紊流模式，對淨水廠內的流場流動加以計算分析。分別探討不同清況下的流場變化並與過去澄清池層流研究做比較：一、進水濃度不同下的探討比較。二、不同葉輪轉速之影響比較。三、不同污泥毯層的厚度的影響與比較。四、使用離散相（DPM）模式模擬顆粒走向。五、改變澄清池結構的影響與比較。六、使用自定義黏度公式模擬澄清池流場。藉由以上分析和計算的結果，以求得更良好的出水品質。
本研究的結果顯示，紊流模式比層流模式較穩定且不易擾動。高轉速的葉輪，污泥毯易懸浮翻騰。高進水濃度，泥毯翻騰速度快，長時間後出水品質衰退小。污泥毯厚，泥毯翻騰快，出水品質衰退多。改變幾何結構上，膠羽顆粒在反應罩內的時間變久。在自定義黏度公式上，得知黏度計算被參數particle dissipation energy控制。

關鍵字

污泥毯 ； 澄清池 ； 計算流體力學 ； 多相流 ； 紊流

並列摘要

This study uses the software FLUENT(used for computational fluid dynamics) to simulate reaction clarifier blanket inside Bansin water treatment plant. We first establish the geometric structure and mesh of the clarifier blanket, then provide feed velocity, concentration, impeller rotation, and operation conditions for the sludge blanket. Then we use the Eulerian multiphased turbulent model to calculate and analyze the flow field inside the water treatment plant. Next we explore flow field alterations and compare it with the clarifier researches in the past. 1.the compare in different feed concentration 2.the compare in different impeller rotational velocity 3.the compare in sludge blanket height, 4 simulate particle’s path by DPM 5.the compare in clarifier blanket structure 6.simulate the flow field in the clarifier by the viscosity function defined myself. Using the above calculations and analysis, we hope to obtain better water quality.
This study shows that turbulent model isn’t easy agitate than laminar model. High impeller rotational velocity causes the sludge blanket easily to agitate. With high concentration feed, the sludge blanket to agitate fast.; The height blanket the sludge blanket to agitate fast.; Regarding changes in the geometric structure, we find the longer the solid particles stay in the reaction well. A parameter called particle dissipation energy control the viscosity calculation that the defined viscosity function.

並列關鍵字

blanket ； clarifier ； CFD ； multiphase ； turbulent

參考文獻

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Annadurai, G., Sung, S. S., and Lee, D. J. “Floc characteristics and removal of turbidity and humic acid from high-turbidity storm water” Journal of Environmental Engineering, 129, 571-575 (2003).

Annadurai, G., Sung, S. S., and Lee, D. J. “Optimization of floc characteristics for treatment of highly turbid water” Separation Science and Technology, 39, 19-42 (2004a).

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