• 作者： Lu, Wei-Ming; Lee, Chen-Ming
• 中文摘要： 為了要確認在實驗室規格大小的三段攪拌翼攪拌槽中所觀測到之功率消耗不均勻現象是否亦存在於大型三段攪拌翼攪拌槽(槽徑5.6m、槽高13m、體積321m/sup 3/),本研究利用計算所得之流場來計算變形氣泡在攪拌槽中之運動。在轉速80rpm、通氣量0.156vvm的操作條件下計算結果發現進入中上段攪拌翼氣體量與原通氣量之比值與在小型攪拌槽實驗結果(轉速 250rpm、通氣量0.342vvm)相近,約為25-40%。而估計功率消耗比值得出在大槽中,中上段攪拌翼之功率消耗比值為2.03,上下段攪拌翼之比值為 1.82,顯示各段攪拌翼功率消耗不均勻現象依然存在於大型攪拌槽,此現象在設計大型攪拌槽時是必須要考慮的。
• 英文摘要： To examine the behavior of bubbles in plant scale multiple impeller stirred vessels, the motion of bubbles is simulated by coupling the calculated flow field. The results showed that the volume fraction of gas passing through the middle and the upper impellers were 30-40% of the original gas fed to the system. This result is in good agreement with the previous bench scale data. This model was extended to investigate the uniformity of power consumption in the plant scale agitated vessel with triple impellers. The ratio of the power consumptions of the middle to the lower impellers was 2 .03, and that of the upper to the lower impellers was 1.82. This result implied that non-uniform power consumption as seen in a bench scale vessel also exists in a plant scale vessel, and thus must be taken into consideration in the design of large scale stirred vessels.
• 中文關鍵字： 擾流; 擾拌槽; 動葉輪; 汽泡; 氣體滯留
• 英文關鍵字： Turbulent Flow; Stirred Tank; Impeller; Bubble; Gas Retention