液池内气溶胶对孔板鼓泡体积影响的实验研究

Experimental Research on Effect of Aerosol in Liquid Pool on Size of Bubbles from Submerged Orifice

液池内的孔板鼓泡是安全壳内气体过滤排放过程中的重要现象。过滤过程中,孔板鼓泡体积直接影响气泡的上升速度与气液接触面积,因此是影响过滤器过滤效率的重要参数之一。随着过滤的进行,液池内滞留的气溶胶可能成为孔板鼓泡体积的影响因素之一。本文采用可视化实验,对含BaSO4和TiO2气溶胶液池内的孔板鼓泡过程进行研究,观察和分析孔板鼓泡体积的变化规律,进而获取气溶胶对孔板鼓泡体积的影响机制。研究表明,高温液池和TiO2会使得生成气泡体积增加,添加BaSO4的影响并不明显,实验还发现了生成气泡顶部含“小气腔”的情况,表面张力及“小气腔”的变化是气泡体积改变的主要机制。

The bubble formation from a submerged orifice in a liquid pool is an important phenomenon in the filtration and discharge process of gas in the containment.During filtration,the size of bubbles from the submerged orifice directly affects the rising speed and the gas-liquid contact area of the bubbles,and thus is one of the important parameters affecting the filter filtration efficiency.As the filtration proceeds,the aerosol content in the liquid pool,among others,may affect the bubble size.This paper conducts a visual experiment to study the bubble formation from a submerged orifice in a liquid pool containing BaSO4 or TiO2 aerosol and to observe and analyze the change law of the size of bubble from the submerged orifice,thus to gain the mechanism of the effect of aerosol on size of bubble from the submerged orifice.The results show that high temperature liquid pool and TiO2 can increase the bubble size,but adding BaSO4 has no obvious effect.Also,the experiment shows the presence of“small air cavity”on the top of the bubbles formed,and the changes of surface tension and“small air cavity”form the main change mechanism of bubble size.