固阀塔板上密集鼓泡区气泡的运动行为特征

利用双头电导探针测定了固阀塔板上密集鼓泡区气泡的运动速度,考察了密集鼓泡区不同轴向高度的气泡速度分布规律及其分形特征,分析了塔板上密集鼓泡区的气泡运动行为。研究结果表明:不同轴向高度处气泡速度沿同方向的分布具有相似性,近塔中心区域气泡速度变化平缓,呈弱双峰分布;塔板上气泡速度分布具有分形特征,分形维数为1.04~1.25,且随轴向高度的增加均先减小后增大;深层鼓泡区内气泡速度分布的分形维数可以较好地表征气泡运动的湍动强度,两者之间存在线性关系,气泡流湍动强度及分形维数与泡沫层高度间存在指数函数关系。

Bubble Movement Behavior in Dense Bubbling Zone of Fixed Valve Tray Plate

The bubble velocity in dense bubbling zone of the fixed valve tray plate was measured by the double-sensor conductivity probe. The fractal characteristics and distribution of bubble velocity in different vertical heights, as well as the behavior of bubble movement in different foam zones, were also investigated. The results showed that the distribution of bubble movement in different vertical heights along the same direction was similar. The change of bubble velocity showed a weak double peak shape, and was not fluctuant near the tower center. The bubble velocity distribution on the tray plate was of fractal characteristics with a fractal dimension ranged from 1.04 to 1.25, which reduced at first, and then increased along the vertical height. In the deep foam zone, the turbulent intensity of the bubble motion could be characterized very well by the fractal dimension of bubble velocity distribution, which showed the linear relation between them. There existed an exponential function relationship between turbulent intensity, fractal dimension of bubble flow and the height of foam.