Katsumi Nakao

Coalescence and breakup of bubbles in liquids

Abstract Coalescence and breakup in a swarm of bubbles were directly observed by using the high speed cinematography. It was designed so that three dimensional motion of bubbles could be continually followed. Influence of operating conditions and liquid properties on the frequencies of bubble passing, coalescence and breakup was examined. It was seen that there was the critical distance at which the leading bubble began to exert an noticeable influence on, the following one. The distance was about 3- to 4-fold diameter of the leading bubble. Coalescence was found to take place when more than about a half of the projected area of the following bubble was overlapped with that of the leading bubble at the critical distance. On the contrary, breakup occurred in the case of the overlapping less than about a half of the projected area of the following bubble. The increment of the following bubble velocity induced by the leading one was empirically correlated with the bubble distance and the angle between the straight line joining the centers of bubbles and the vertical axis. The Reynolds numbers had no appreciable effect on the velocity increment within the range examined.

Dynamico of a Mukiplate Gas-liquid Reactor

多段気液反応装置の動特性を検討するため, 総括反応速度および装置流動特性のプロセス変量依存性を同時に考慮して転達関数を求めた。実験的に求めた反応装置動特性と, 実験に伴う非線型性の効果を考慮して, この伝達関数から模擬した装置動特性とは, ほぼ一致する。また先に報告したこの種の装量に対する効果的な制御系の設計方法は, 本報告で求めた伝達関数により, その動特性を表わせる反応装置に対しても適用できる。

Kinetic Study of Gas-Liquid Reaction using Continuous Stirred Tank Reactor with Known Interfacial Area

定常吸収理論が適用できるように, 流通式自由表面撹拌槽を用いて, 酢酸第2水銀 (50%酢酸水溶液) によるエチレンの反応吸収実験を行なった。そして, 溶解ガスの液境膜内での反応量が無視される実験条件を明らかにし, この条件下のデータを用いて反応速度を解析した。さらに, 流通操作における正味総括反応速度と操作因子との関係を検討するため正味反応係数φを定義し, これを用いて実験データを整理した。