作　　者： ; ; ;

机构地区： 华南理工大学化学与化工学院

出　　处： 《现代化工》 2011年第11期64-67,69,共5页

摘　　要： 利用自主研发的超声鼓泡塔和双电导探针气泡特征参数测量仪测定了不同频率组合下超声场辐射对鼓泡塔内气泡Sauter直径随表观气速和鼓泡塔径向及轴向位置的分布情况。实验结果表明,在距气体分布板轴向距离250 mm、塔中心处气泡Sauter直径由于超声作用而显著减小,最大减幅达55%;在超声场作用下随着表观气速增大,气泡Sauter直径呈增大趋势,当表观气速大于0.06 m/s时,气泡Sauter直径趋于不变;大气泡在塔中心区域聚集倾向明显,小气泡分布在塔壁面附近,气泡Sauter直径(在径向位置)呈现中心峰分布趋势;随着距气体分布板轴向距离增加,气泡Sauter直径增大,在多频混响声场中,气泡Sauter直径增速小于单频声场中增速,即在多频混响超声场中易形成小气泡。实验结果证实,超声场有利于减小气泡体积,增大气泡比表面积,这对于加强气液相间传质、提高传质效果会有显著作用。 The bubble Sauter diameter distribution in radial and axial orientation versus the superficial gas velocity has been investigated in an air-water bubble column with a bubble feature measuring system called duplex conductivity probe under ultrasonic field of one frequency or multi-frequency. The results show that, the bubble Sauter diameters at the central line of the column are obviously reduced because of the remarkable effect of ultrasonic field. The maximmn reducing extent is about 55%. Under ultrasonic field,the bubble Sauter diameter increases as the superficial gas velocity rises until to 0. 06 m/s,then the diameter almost keeps constant. And the bigger bubbles are potentially concentrating in the central zone of the column, while the smaller bubbles appear near the wall of the column. The biggest bubble diameter appears at the central line of the column. The results also suggest that the bubble Sauter diameter distribution rises as the distance from the gas distributor increases and the frequency of the ultrasonic field has influence on the bubble Sauter diameters. The bubble Sauter diameters effected by multi-frequency reverbrating ultrasonic field are smaller than those by single frequency ultrasonic field. So multi-frequency reverbrating ultrasonic field such as produced from the combination of 20-50-100 kHz is favorable for generating smaller bubbles and more turbulent which can enlarge the bubble surface, then prolong the bubble residence time, and finally enhance the mass transfer between gas-liquid phases.

关 键 词： 鼓泡塔 超声场 气泡直径 分布特征

领　　域： [化学工程]