自來水淨水廠高速膠凝澄清池之操作與結構改進

A Construction Improvement and Operation in Water Treatment Blanket Clarifier

楊文傑(Wen-Jie Yang)

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(2007年)

https://doi.org/10.6846/TKU.2007.00817

摘要

研究內容是使用計算流體力學的FLUENT軟體，模擬板新淨水廠設備中的膠凝（反應）澄清池，首先建立澄清池的幾何結構和網格，並給與進水流速和濃度、葉輪旋轉和污泥毯層的操作條件，再使用Eulerian二相流模式，對淨水廠內的流場流動加以計算和分析。分別探討下列五種不同清況下的流場變化：一、葉輪不同轉速下的探討。二、不同進水濃度之影響。三、改變不同污泥毯層的濃度和高度。四、改變澄清池幾何結構。五、溫度變化的影響。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，葉輪在高轉速下，易造成槽底污泥毯層結構的懸浮翻騰。當不同的進水濃度時，其差異只在起始狀態下的出口通量值有明顯不同，當時間越久則沒有明顯差異。污泥毯層的高度和濃度，均與固體通量值成正比關係。在幾何結構的變化中，可以發現反應罩角度越小，其膠羽顆粒在反應罩內的時間越久。在每日相同處理水量的條件下，當進水管徑變大，可以提供更良好的出水品質。最後，溫度的影響加強了流力的循環，因此，在夏季的高溫情形下，易造成處理水量的困難。

關鍵字

污泥毯 ； 澄清池 ； 計算流體力學 ； 二相流

並列摘要

This study uses the software FLUENT(used for computational fluid dynamics) to simulate flocculation (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 model to calculate and analyze the flow field inside the water treatment plant. Next we explore flow field alterations resulting from changes in these five following variables: impeller rotational velocity, feed concentration, sludge blanket concentration and height, clarifier blanket structure, and temperature. Using the above calculations and analysis, we hope to obtain better water quality.
　　This study shows that high impeller rotational velocity causes the sludge blanket structure on the bottom of the tank to float and turn easily. With varying feed concentration, the only significant difference is in the initial effluent solid mass flux; Changes become less observable as time goes on. The height and concentration of the sludge blanket both correspond directly to the solid mass flux. Regarding changes in the geometric structure, we find that the smaller the angle of the reaction well, the longer the solid particles stay in the reaction well. Under the condition of constant daily water-processing quantity, larger feed diameter leads to better water quality. Lastly, temperature increases flow dynamic circulation. Thus, high temperature during the summer may lead to difficulties in processing water quantity.

並列關鍵字

sludge blanket ； clarifier ； CFD ； multiphase

參考文獻

李宗浩，「自來水淨水廠高速膠凝澄清池之模擬」，碩士論文，淡江大學，台北(2005)

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