转炉底吹“小集团”非均匀供气对熔池混匀的影响

Effect of Inhomogeneous Air Supply of "Small Group"of Converter Bottom Blowing on Melting Pool Mixing

以某钢厂260 t转炉为对象,建立1/7的冷态试验模型,以死区占比、弱搅拌区占比和钢液平均流速为标准分析底吹供气模式下熔池内部流场特性,探讨底吹布置方式、供气模式对熔池混匀效果的影响。结果表明:在底吹条件下,在A3布置方式下按线性1:2:3:4流量分配的动力特性最好,其中混匀时间较均匀供气缩短18.42%,钢液死区占比与弱搅拌区占比均有所减少,钢液平均速度增大。流量不变时,距熔池底部越远,水平截面整体速度以及速度梯度越大,混合程度越均匀。

A 260 t converter of one steel plant is taken as the study object,1/7 cold-state test model is established,taking dead zone percentage,weak stirring zone percentage,and average flow rate of molten steel as the standard to analyze the internal flow field characteristics of melting pool under bottom blowing air supply model,it discussed the bottom blowing arrangement method,the effect of air supply model on melting pool mixing results.The results show that the dynamic characteristics are better when linear arrangement as per 1∶2∶3∶4 flow distribution with A3 arrangement under bottom blowing conditions,the mixing time is shorten 18.42%than uniform air supply,the dead zone percentage and weak stirring zone percentage of molten steel are all decreased,the average speed of molten steel is increased.When the flow rate is constant,the farther away from the bottom of the melting pool,the larger the overall velocity of the horizontal section and velocity gradient,the more homogeneous the mixing degree.