椭圆形钢包底吹氩的流动特征
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摘要
以一种150t椭圆形钢包为原型建立1∶4的钢包水模型,在相似原理基础上,以氮气模拟现场用氩气进行底吹,以水模拟钢液,进行水模型实验.分析了底吹气孔位置、吹气量对钢液混匀及流动的影响.结果表明:原型方案两吹气孔位置距离近,相互干扰性强,动能耗散大,影响钢液搅拌效果.底吹气量存在临界值(327.6L·h-1),超过临界值后气量增加的动能主要消耗在鼓动液面和吹开渣面上,对钢液混匀的效果较小.优化后两底吹气孔分别位于长轴0.6R处,呈180°分布,优化后钢液混匀时间整体下降,相同吹气量下混匀效果更好.采用优化后方案,相同吹气量下钢液面裸露面积大大降低,减少了钢液二次氧化,钙处理过程全氧从58×10-6降低到47×10-6,软吹过程平均增N量<3×10-6.
The blowing hole location and the gas flow in a 150 t elliptic ladle were optimized by establishing a 1∶ 4 water model.Based on the similarity criterion,high pressure nitrogen was used to simulate argon in the water modelling experiment. Experimental results show that the mixing of liquid steel is weak in the original ladle because the two blowing holes are close to each other. A critical gas flow exists at different locations. Beyond the critical value,the increase in kinetic energy mainly is used to stir liquid steel and blow the slag surface. After optimization,the two blowing holes distribute in 180° and are arranged at the 0. 6 radius of the major axis respectively. The mixing time of liquid steel shortens and the exposed area of liquid steel reduces greatly compared with the original ladle with the same gas flow. Moreover,the total oxygen decreases to 47 × 10- 6from 58 × 10- 6during calcium treatment,and the average nitrogen pick-up amount is less than 3 × 10- 6during the soft stirring process.
The blowing hole location and the gas flow in a 150 t elliptic ladle were optimized by establishing a 1∶ 4 water model.Based on the similarity criterion,high pressure nitrogen was used to simulate argon in the water modelling experiment. Experimental results show that the mixing of liquid steel is weak in the original ladle because the two blowing holes are close to each other. A critical gas flow exists at different locations. Beyond the critical value,the increase in kinetic energy mainly is used to stir liquid steel and blow the slag surface. After optimization,the two blowing holes distribute in 180° and are arranged at the 0. 6 radius of the major axis respectively. The mixing time of liquid steel shortens and the exposed area of liquid steel reduces greatly compared with the original ladle with the same gas flow. Moreover,the total oxygen decreases to 47 × 10- 6from 58 × 10- 6during calcium treatment,and the average nitrogen pick-up amount is less than 3 × 10- 6during the soft stirring process.
引文
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[8]He P,Hu X H,Liang X J.Analysis on some problems about argon bottom-blowing in ladle.Steelmaking,1992,8(4):35(何平,胡现槐,梁泽基.钢包底吹氩一些问题的分析.炼钢,1992,8(4):35)
[9]Kim S H,Fruehan R J.Physical modeling of gas/liquid mass transfer in a gas stirred ladle.Metall Trans B,1987,18:673
[10]Zhou Y,Dong Y C,Wang H C,et al.Mathematical simulation on blowing argon at bottom of ladle on external refining.J Anhui Univ Technol,2002,19(2):91(周云,董元篪,王海川,等.炉外精炼中钢包底吹氩流场的数学模拟.安徽工业大学学报,2002,19(2):91)
[2]Guo D,Irons G A.A water model and numerical study of the spout height in a gas-stirred vessel.Metall Mater Trans B,2002,33(3):377
[3]Wang L T,Zhang Q Y,Peng S H,et al.Mathematical model for growth and removal of inclusion in a multi-tuyere ladle during gasstirring.ISIJ Int,2005,45(3):331
[4]Han J J,Li S Q,Wu L.Characteristic number equation about describing mixing effect of steel stirred by argon in the ladle.J Chonqing Univ,2012,35(1):76(韩建军,李士琦,吴龙.描述底吹氩钢包内钢液混合效果的特征数方程.重庆大学学报,2012,35(1):76)
[5]Sahai Y,Emi T.Melt flow characterization in continuous casting tundishes.ISIJ Int,1996,36(6):667
[6]Chattopadhyay K,Sengupta A,Ajmani S K,et al.Optimisation of dual purging location for better mixing in ladle:a water model study.Ironmaking Steelmaking,2009,36(7):537
[7]Fan Y J,Yang M S.Application of argon stirring in ladle for converter steelmaking.Iron Steel,2001,36(4):20(范英俊,杨明生.钢包底吹氩在转炉生产中的应用.钢铁,2001,36(4):20)
[8]He P,Hu X H,Liang X J.Analysis on some problems about argon bottom-blowing in ladle.Steelmaking,1992,8(4):35(何平,胡现槐,梁泽基.钢包底吹氩一些问题的分析.炼钢,1992,8(4):35)
[9]Kim S H,Fruehan R J.Physical modeling of gas/liquid mass transfer in a gas stirred ladle.Metall Trans B,1987,18:673
[10]Zhou Y,Dong Y C,Wang H C,et al.Mathematical simulation on blowing argon at bottom of ladle on external refining.J Anhui Univ Technol,2002,19(2):91(周云,董元篪,王海川,等.炉外精炼中钢包底吹氩流场的数学模拟.安徽工业大学学报,2002,19(2):91)