透气砖布置和吹氩流量对钢包内钢液流动行为的影响

针对攀钢200t钢包,采用物理模拟与数值模拟相结合的方式,研究了透气砖布置方式和吹氩流量对钢液流动行为的影响规律。结果表明,当两透气砖呈120°布置在距包底中心0.62R(R为包底半径)处时,钢液的平均流速和平均湍动能大,"死区"范围小,混匀时间短,是合理的透气砖布置方式,其临界吹氩流量为27m3/h;与单透气砖相比,双透气砖喷吹的能量利用率高,"死区"范围小,单透气砖的吹氩流量需控制到45m3/h才能达到与双透气砖吹氩流量为27m3/h时相同的搅拌效果。实践证明,研究得到的透气砖布置方式和吹氩流量能保证熔池的搅拌效果,使转炉钢水经吹氩处理后,钢包不同位置温差小于10℃,Δw[C],Δw[Si],Δw[Mn]小于0.03%;在一定的软吹氩流量条件下,吹氩时间大于等于8min,可以使钢中wT[O]小于25×10-6。研究表明,用离散相模型对钢包底吹氩过程进行数值模拟,可以得到与物理模拟试验和生产实践较为吻合的结果。

Effect of Porous Plugs Arrangement and Argon Blowing Flow Rate on Flow Behavior of Molten Steel in Ladle

The effect of porous plugs arrangement and argon blowing flow rate on flow behavior of molten steel in Pansteel 200t ladle was discussed by physical simulation combined with numerical simulation. The results show that when two porous plugs are 120° arrange at 0. 62R (R is the radius of ladle bottom) away from the center of ladle bottom, the average velocity and average turbulent kinetic energy of molten steel are large, the range of “dead zone” is small and the mixing time is short, it is the reasonable porous plugs arrangement, and its critical argon blowing flow rate is 27m3/h; compared with single porous plug, the energy utilization rate of double porous plugs is higher, and the range of “dead zone” is smaller, to achieve the same stirring effect of double porous plugs with argon blowing flow rate being 27m3/h, the argon blowing flow rate of single porous plug needs to get 45m3/h. Practice has proved that the porous plugs arrangement and argon blowing flow rate obtained from the study can ensure the stirring effect of molten pool, making the temperature deviation less than 10℃ and the composition deviation of ［C］, ［Si］, ［Mn］ less than 0. 03% at different positions in ladle after the converter molten steel treating with argon blowing, it also can make the wT［O］ of steel less than 25×10-6 when argon blowing time is more than or equal to 8min in some soft argon blowing conditions. The research shows that using discrete phase model for numerical simulation of the ladle bottom argon blowing process can get tallies with the physical simulation experiment and production practice result.