Abstract: Orthogonal experiment with 4 factors and 5 levels by using 120 t BOF geometric similarity 1：7 water model has been earned out to study the effect of height of oxygen lance from pool (200 -280 mm) , top lance flow rate (72. 5 ~ 99. 0 m³/h) , bottom blowing flow rate (0. 8 ~2. 4 m³/h) and distribution of bottom blowing holes (4 ~ 8 holes) position on BOF top and bottom combined blowing. Results show that distribution of bottom blowing holes position is most important factor to influence the mixing effect of liquid pool, with height of oxygen lance from pool h = 240 mm, top lance flow rate Q₁=99. 0 m³/h, bottom blowing flow rate Q₂=2. 4 m³/h and 6 holes bottom blowing position D)(4) , the mixing effect of liquid pool is best. The results of steel Q235B production application of 120 t BOF top and bottom combined blown obtain that with top blowing rate 25 000 m³/h, bottom blowing rate 560 ~ 800 m³/h and bottom blowing by 6 holes distribution the liquid end [ C] is 0. 14% 〜0. 18% and the carbon oxygen product is 0.002 3 ~0.002 5 by blowing for 14 ~ 16 min to get better pool mix effect.

摘要： 进行了120 t转炉几何相似比1:7的4因素5水平正交水模型实验,研究氧枪距离熔池高度（200~280 mm）、顶氧枪流量（72.5~99.0 m3/h）、底吹流量（0.8~2.4 m³/h）、底吹气孔（48孔）位置分布对转炉顶底复吹的影响。结果表明,底吹气孔位置分布是影响熔池搅拌效果的最重要的因素。当选取氧枪距熔池高度h=240mm,顶枪吹气体流量Q₁=99.0 m³/h,底吹气体流量Q₂=2.4 m³/h,底吹气孔（6孔）位置D（4）时,熔池搅拌效果最佳。120 t转炉顶底复吹生产Q235B钢应用结果得出,顶吹流量25 000 m³/h,底吹流量560~800 m³/h,底吹6孔布置吹炼14~16 min、钢水终点[C]0.14%~0.18%,碳氧积0.002 3~0.002 5,熔池搅拌效果良好。