气泡细化过程中气含率的实验研究

Experimental Research on Gas Holdup in Bubble Disintegration Process

应用压差法测定局部气含率,用膨胀法测定平均气含率.分别讨论了中心和偏心搅拌模式下气体流量、搅拌转速等因素对局部气含率和平均气含率的影响,以及局部气含率沿径向的变化规律.结果表明,中心双向搅拌和偏心单向搅拌均可显著提高气含率,且后者更有效;在筒内壁附近的气含率无论何种搅拌方式均随着气体流量的增大而增大;中心搅拌下的气含率随着径向距离的增大而下降,但偏心搅拌则在不同的位置气含率沿径向的变化表现出不同的变化趋势;平均气含率无论中心和偏心搅拌均随流量增加,但随转速的增加中心搅拌模式下气含率变小而偏心搅拌模式下的则增大.

Pressure difference method with the sudden-stoppage technique was applied to examine respectively the effects of different factors on local gas holdup under centric and eccentric stirring,and the changes of local gas holdup along the radial under centric and eccentric stirring. The results showed that centric forward-reverse and eccentric stirring modes could improve gas holdup,and the latter more effectively. Local gas holdup could be improved by forward-reverse rotation under centric stirring. Gas holdup near water model wall increased with increasing of gas flow rate under any kind of stirring mode. Local gas holdup decreased with increasing of radial distance under centric stirring,but fluctuated with radial distance under eccentric stirring. Average gas holdup increased with increasing of gas flow rate under both centric and eccentric stirring. Average gas holdup increased with increasing of rotation speed under eccentric stirring,but decreased with increasing of rotation speed under centric stirring.