连铸结晶器内气泡群粒径分布的实验研究

Experimental Study of Bubble Size Distribution in Continuous Casting Mold

为了获得结晶器内的气泡粒径及其分布规律,建立了一套水模型实验系统.为模拟真实上水口的吹氩过程,采用莫来石制作水模型的环状吹气装置,利用激光片光源和高速摄像机捕捉气泡的瞬时分布,并采用Image J软件分析和计算气泡的粒径.结果发现:气泡平均粒径随水流量、水口插入深度的增加而增大,随吹气量、水口倾角的增大而减小;莫来石弥散砖产生的气泡初始粒径较小且分布均匀.气泡粒径在结晶器宽面一侧水平方向上呈先增大后减小的趋势.随水流量的增大,气泡分布更加分散;随吹气量的增加,气泡分布规律无明显区别,但粒径增大.

In order to obtain the bubble size distribution in the mold,a water model system was developed with air blowing through a circumferential inlet chamber made of specially-coated mullite porous brick,which is used as the actual upper nozzle. The transient bubble distributions in the mold were captured by a high-speed video camera under a laser light beam. Then,the location and size of bubbles were measured using the image analysis software of Image J. The results showthat the average bubble size increases with increasing the water flowrate and SEN immersion depth,decreases with increasing the gas blowing rate and nozzle port angle. The initial bubble size obtained from the mullite brick is small and uniform. The bubble size along the horizontal direction of wide wall increases first and then decreases. With the increase of water flowrate,the bubble distribution is more dispersed. With the increase of gas blowing rate,there is no obvious difference for the bubble distribution; however,the bubble size was increased.