• 作者： Lu, Wei-Ming; Wu, Ming-Tzung
• 中文摘要： 為了研究通氣攪拌槽中,攪拌翼之葉片數目,對通氣攪拌效果的影響,本研究以四葉、六葉、八葉之盤狀垂直透平翼為探討對象,並以 Smith等人所提的「空穴」觀念為基礎,了解各攪拌翼中氣泡分散之機構。並以熱膜測速儀測量槽中通氣時液體流態及紊流波動速度,最後以「亞硫酸鈉」法,測量各攪拌翼於通氣時之液相質量係數,供探討各種不同設計之依據。從消耗功率測定所得的結果,顯示各攪拌翼的消耗功率深受氣泡分散機構的影響。同時由紊流理論及紊流強度測定的結果證實各攪拌翼之平均紊流波動速度於通氣而氣泡有效分散時與操作變數具有下式關係: =K(N/sup 3.15/D/sup 6.85//P/sup 0.1/Q/sup 0.252/T/ sup 2/H)/sup 1/3/ 氣泡有效分散時本研究結果亦顯示,於一定之通氣量時,各種不同攪拌翼只要值相同.該通氣攪拌系即具有相同之K/sub L/a值,且K/sub L/a與/sup 1.4/ 成正比,更證實確可作為規模放大之基準。
• 英文摘要： In order to study the effect of blade number on the performance of gas dispersion in an aerated stirred tank, the cavity concept had been used to understand the dispersive mechanism of bubble for Rushton turbine with blade numberof 4, 6 and 8. The flow pattern as well as the turbulent fluctuating velocity was measured with a hot-film anemometer and the volumetric mass transfer coefficient was also measured by sodium sulfite method simultaneously. Both theoretical and experimental results show that the average turbulent fluctuating velocity which represents the mixing intensity of the system can be correlated as =K(N/sup 3.15/D/sup 6.85//P/sup 0.1/Q/sup 0.252/T/ sup 2/H)/sup 1/3/ The results of this study also indicate that at constant gas flow rate, equal value of will produce the equal value of K/sub L/a for impellers of different type, and the value of K/sub L/a is proportional to /sup L4/.
• 中文關鍵字： 通氣攪拌槽; 混合; 紊流; 葉片數目; 空穴; 氣泡; 分散機構
• 英文關鍵字： Aerated Stirred Tank; Mixing; Turbulence; Blade Number; Cavity; Bubble; Dispersive Mechanism