• 作者： Lu, Wei-Ming; Lin, Li-Chang
• 中文摘要： 在本文中,利用改良式光電毛細管法來測量雙攪拌翼系統通氣攪拌槽的通氣大小分布,並以所得到的氣泡大小分布曲線來預測單段系統中氣體分散之臨界轉速。在兩個攪拌翼中間的循環區,氣體分散和氣泡大小分布和Smith et al. (1987)在單段系統中所得的上循環區的結果非常相似,但在此兩個相同徑向攪拌翼所構成的系統氣泡結合現象較為嚴重。在雙段攪拌翼系統之上循環區,除了由槽壁和檔板處上升的氣泡增加了上循環區的平均氣泡大小外,其氣體分散的行為與中循環區並沒有多大的不同。我們亦觀察到對上段為軸向、下段為徑向之系統,增加轉速對氣泡平均大小有稍微的影響。
• 英文摘要： Bubble size distribution in aerated vessels with different dual impellers are determined by an improved photoelectric capillary method. The results of measurement show that characteristics of bubble size distribution curves can be used to predict the value of transitional rotation speed as it was observed in a single Rushton turbine system. In the circulation region between two impellers, the characteristics of gas dispersion and bubble size distribution are very similar to the upper circulation region of the results of Smith et al. (1987) in the single impeller system. However, more coalescence effect was found in the system I due to its two radial flow impellers. In the upper recirculation region, the performance of gas dispersion of the dual turbine system does not differ so much from the middle recirculation region except the average size of bubbles is larger than that of the middle recirculation region due to the coalescence effect of the upper impeller and rising bubble flow near the wall and baffle area. In the same region of the system with one Rushton impeller and one axial flow impeller, only slight effect of the increase in N on the average size of the bubble is observed.
• 中文關鍵字： 氣泡; 分散; 攪拌槽; 光電毛細管
• 英文關鍵字： Bubble; Distribution; Stirred Tank; Photoelecric Capillary