LF精炼炉盖内惰性气氛的流动模拟

Numerical simulation of inert gas flow in ladle furnace lid

采用耦合数值求解的方法,计算并分析了LF精炼炉盖内气体流动的速度分布状态以及液面附近惰性气体氩(Ar)的流动行为和分布.结果表明:露弧加热期和埋弧加热期炉盖的合理抽气压力分别为-200^-250Pa和-120Pa;底吹氩气量过小不能在液面上部弥散,而增大到20~50m3.h-1,在液面附近弥散且流动分布状态相似,有利于液面附近惰性气氛的保持;液面距钢包上边缘的距离增大,氩气在液面上部回旋的区域扩大,可防止钢液增[N]或[O].

Based on the coupling numerical solving method, the velocity distribution and flow behavior of Ar in a ladle furnace lid was calculated and analyzed by numerical simulation. The results show that the appropriate off-gas pressures in the periods of emerged arc and submerged arc are - 200 ～ - 250 Pa and - 120 Pa, respectively. When the bottom blowing rate is very small, argon cannot disperse on the top of the molten steel surface; as the Ar-bottom blowing rate increases to 20 -- 50 m^3·h^- 1, argon can be dispersive and its flow distribution is similar near the molten steel surface, which is in favor of retaining inactive gas Ar. With the augment of the distance from the molten steel surface to the top ladle edge, the circulating region of Ar enlarges on the top of the molten steel surface, which is in favor of avoiding the increase of [O] or [N] in molten steel.