炼钢 ›› 2022, Vol. 38 ›› Issue (4): 63-70.

• 凝固与浇铸 • 上一篇    下一篇

换包过程中连铸中间包内多相流动行为研究

钟  巍1, 2,徐  蕊3,王海军3,仇圣桃1, 3   

  1. 1.钢铁研究总院 连铸技术国家工程研究中心,北京 100081;
    2.新余钢铁股份有限公司 炼钢厂,江西 新余 338001;
    3.安徽工业大学 冶金工程学院,安徽 马鞍山 243002
  • 出版日期:2022-08-05 发布日期:2022-07-29

Multiphase flow behavior in a continuous casting tundish during ladle change

  • Online:2022-08-05 Published:2022-07-29

摘要: 为提高换包过程中钢水的洁净度,采用数值模拟和物理模拟研究了连铸中间包内钢水-渣相-气相多相流动行为,并进一步研究了液位上涨时间对换包过程中间包内多相流动行为的影响。结果表明:当液位上涨时间为97 s时,中间包内持续发生着二次氧化现象,换包初始时刻大量的气相被吸入冲击区内且冲击区上表面处钢水裸露面积分数迅速增大,5 s后气相的吸入量和钢水裸露面积分数保持稳定;钢水发生裸露的原因为换包初始时刻大包水口附近渣相受到钢水的直接冲击,此后表层渣相受到水平方向流动钢水的剪切作用,其厚度变薄;延长换包过程中液位上涨时间,不仅降低了钢水对大包水口附近渣相的冲击动能,也降低了渣钢界面处钢水对表层渣相的剪切作用,进而显著降低了中间包冲击区内气相的吸入量和钢水的裸露。为了提高换包过程中钢水的洁净度,建议中间包内液位上涨时间保持在184 s以上。

关键词: 中间包, 换包过程, 二次氧化, 液位上涨时间, 数值模拟

Abstract: In order to improve the steel cleanliness during ladle change, the steel-slag-air flow behavior in the tundish was investigated using numerical simulation and physical modeling. The effect of the refilling time on the multiphase flow behavior in the tundish during ladle change was also studied. The results showed that for the refilling time of 97 s the reoxidation was always occurred in the tundish during ladle change. A massive amount of gas phase was sucked into the impact zone at the start of pouring from the new ladle and the exposed area fraction of slag phase at the top surface was rapidly increased. After 5 s, the amount of sucked gas and the exposed area fraction of slag phase remained relatively stable. Reasons for the slag exposure mainly included: 1) the slag layer near the ladle shroud was directly impinged by the liquid steel at the start of pouring from the new ladle; 2) the thickness of the slag layer became thinner due to the shear effect of liquid steel flow. Increasing the refilling time during ladle change decreased not only the kinetic energy of liquid steel acting on the slag phase near the ladle shroud, but the shear effect at the slag-steel interface. Therefore, the amount of sucked gas and the slag exposure in the impact zone were significantly decreased. To improve the steel cleanliness during ladle change, the refilling time in the tundish should be larger than 184 s.

Key words: tundish, ladle change, reoxidation, refilling time, numerical simulation