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.826. 北京科技大学学报 第29卷 Numerical simulation of inert gas flow in ladle furnace lid WEN Liangying,CHEN Dengfu,ZHA NG Shengfu;BAI Chenguang,LONG Zhanjun Materials Science and Engineering School,Chongqing University,Chongqing 400030,China ABSTRACI 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,respec- tively.When the bottom blowing rate is very small,argon cannot disperse on the top of the molten steel surface: as the Arbottom blowing rate increases to 20-50m3h,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 dis- tance 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. KEY WORDS furnace lid;gas flow:numerical simulation:inert gas;off -gas pressure (上接第784页) Water model study on the mechanism of inclusion removal in a continuous casting tundish ZHA NG Shengjun,ZHENG Shuguo,ZHU Miaoyong Materials and Metallurgy School.Northeastern University.Shenyang 110004.China ABSTRACI The effects of flow control devices,casting speed of liquid steel and inclusion size on inclusion re- moval in a continuous casting tundish were investigated by choosing emulsion drops to simulate inclusions in a water model.The results show that the efficiency of inclusion removal in the tundish with weir and dams is rela- tively high due to the collision and aggregation of inclusions in high turbulence region and the improvement of flow field in the tundish.Although adding turbulence inhibitor into the tundish changes fluid flow little in pour- ing region,it has not much effect on the efficiency of inclusion removal.It seems to be difficult to improve the efficiency of inclusion removal only by optimizing the flow control devices in the tundish with high casting speed of liquid steel. KEY WORDS continuous casting tundish;flow filed;inclusion;water modelingNumerical simulation of inert gas flow in ladle furnace lid WEN L iangyingCHEN Dengf uZHA NG Shengf uBAI ChenguangLONG Zhanjun Materials Science and Engineering SchoolChongqing UniversityChongqing400030China ABSTRACT Based on the coupling numerical solving methodthe 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 －250Pa and －120Parespectively．When the bottom blowing rate is very smallargon cannot disperse on the top of the molten steel surface； as the Ar-bottom blowing rate increases to20 50m 3·h －1argon can be dispersive and its flow distribution is similar near the molten steel surfacewhich is in favor of retaining inactive gas Ar．With the augment of the distance from the molten steel surface to the top ladle edgethe circulating region of Ar enlarges on the top of the molten steel surfacewhich is in favor of avoiding the increase of ［O］ or ［N］ in molten steel． KEY WORDS furnace lid；gas flow；numerical simulation；inert gas；off-gas pressure （上接第784页） Water model study on the mechanism of inclusion removal in a continuous casting tundish ZHA NG ShengjunZHENG ShuguoZHU Miaoyong Materials and Metallurgy SchoolNortheastern UniversityShenyang110004China ABSTRACT The effects of flow control devicescasting speed of liquid steel and inclusion size on inclusion removal in a continuous casting tundish were investigated by choosing emulsion drops to simulate inclusions in a water model．The results show that the efficiency of inclusion removal in the tundish with weir and dams is relatively high due to the collision and aggregation of inclusions in high turbulence region and the improvement of flow field in the tundish．Although adding turbulence inhibitor into the tundish changes fluid flow little in pouring regionit has not much effect on the efficiency of inclusion removal．It seems to be difficult to improve the efficiency of inclusion removal only by optimizing the flow control devices in the tundish with high casting speed of liquid steel． KEY WORDS continuous casting tundish；flow filed；inclusion；water modeling ·826· 北 京 科 技 大 学 学 报 第29卷