复吹转炉底吹非均匀供气对熔池搅拌混匀的影响

摘要：为了强化转炉熔池的搅拌，在200t复吹转炉1∶12的模型进行物理模拟试验，研究了底吹非均匀供气对转炉复吹和纯底吹熔池的搅拌混匀效果；采用数学模拟的方法计算了纯底吹条件下，转炉采用底吹非均匀供气时的熔池流体流动。研究结果表明，在所研究的不同的底吹非均匀供气方案中，与底吹均匀供气方案相比，线性底吹非均匀供气方案有利于改善转炉熔池搅拌效果，最佳的底吹非均匀供气方案的混匀时间比均匀供气降低了19%～25%。复吹时底吹非均匀供气的混匀时间降低程度要比纯底吹的非均匀供气大，即复吹条件下，底吹采用非均匀供气更有利于熔池搅拌混匀。采用线性底吹非均匀供气方案时，在熔池内形成了明显的大循环非对称流动，有利于整个熔池内的对流传质，从而缩短了混匀时间。

Influence of non-uniform bottom gas blowing on bath stirring and mixing in combined blown converter

In order to strengthen stirring of converter bath, physical simulation experiments were carried out in a 1∶12 model of the 200t combined blowing converter, and the effect of bottom blowing non uniform gas supply on the stirring and mixing in the converter bath with combined blowing or pure bottom blowing was studied.The fluid flow in the bath of the converter with non uniform bottom gas blowing was numerically calculated with a mathematical model under the condition of pure bottom blowing.The results show that compared with the uniform bottom blowing scheme, the linear non uniform bottom blowing schemes can improve the stirring effect in converter bath, and the mixing time of the optimal non uniform bottom blowing scheme is 19%-25% lower than that of the uniform bottom blowing scheme.The mixing time of non uniform bottom gas blowing in combined blowing is much lower than that in pure bottom blowing.Under the condition of combined blowing, non uniform bottom gas blowing is more favorable for bath stirring and mixing in the converter.When the linear non uniform bottom gas supply scheme is adopted, a large asymmetric circulation flow is formed in the bath, which is beneficial to the convection and mass transfer in the whole converter bath, thus shortening the mixing time.