薄板坯连铸中间包内抑湍器的模拟研究

控制中间包内钢液的合理流动对夹杂物的排除有重要影响,为此建立了模拟薄板坯连铸中间包流动情况的水模型。通过测定停留时间分布(RTD)曲线,研究了不同组合控流装置对中间包流体流动特性的影响。结果表明,结构及尺寸合理的抑湍器能延长水口响应时间及平均停留时间、提高活塞流区体积分数及降低死区体积分数;抑湍器与单坝组合的控流装置在控制流体流动方面效果极佳,而抑湍器与单墙单坝、单墙双坝组合的控流装置的控流效果不太理想。     

六流矩形坯连铸中间包结构优化的水模型研究

通过六流矩形坯连铸中间包的水模试验,研究了不同控流装置对其流动特性的影响。研究结果表明,稳流器和多孔挡墙能明显改善各流流动特性的一致性,在此基础上加设方形孔挡墙能有效减小死区体积。合理的中间包组合控流装置为稳流器＋多孔挡墙＋方形孔挡墙。     

三流Τ型中间包内控流装置优化的物理模拟

通过三流T型连铸中间包物理模拟实验,研究了直挡墙、V型挡墙及其与抑湍器组合控流装置对中间包流动特性的影响。结果表明,直挡墙控流装置的控流效果优于无控流装置的中间包,但不如设计合理的V型挡墙控流装置;V型挡墙与挡坝组合控流装置（方案Ⅴ）的控流效果较好,在其基础上加入抑湍器后控流效果并不理想。因此,提出了针对三流T型中间包控流装置的优化设计方案。     

八流方坯连铸中间包控流装置优化的水模研究

通过八流方坯连铸中间包水模实验,研究了不同控流装置对其流动特性的影响。研究表明:对比原挡墙,中间包的控流装置改为新挡渣墙后,表征中间包流动特性的流动特性因素有了明显的改善。在新挡墙的基础上,对稳流器和挡坝等控流装置关于控流效果的影响进行了实验研究,发现每个方案中的一个或者多个控流参数有利于进一步改善中间包的控流效果。通过对比和分析这几种控流方案对改善中间包内流体流动特性的效果,确定了最优方案。     

六流方坯连铸中间包结构优化水模实验

 通过六流方坯连铸中间包水模实验,研究了不同控流装置对其流动特性的影响。采用笔者提出的多流中间包流动特性分析模型及各流流动特性一致性的分析方法进行了定量描述。结果表明,带横墙和不带横墙的“V”型挡墙均能明显改善各流流动特性的一致性,与不带横墙的“V”型挡墙组合挡坝的数量、高度均对流动特性有影响,在较优的“V”型挡墙与挡坝组合控流装置基础上加入抑湍器后控流效果更佳。通过实验研究,提出了优化方案。     

四流大方坯连铸中间包结构优化水模实验研究

建立了4流中间包流体流动的物理模型,通过测定停留时间分布(RTD)曲线,研究不同的控流装置组成的中间包结构对流体流动特性的影响。     

两流板坯连铸中间包结构优化水模实验研究

通过两流板坯中间包水模实验,研究了抑湍器以及不同控流装置的组合对中间包流动特性的影响.结果表明,合理使用抑湍器能延长开始响应时间,提高平均停留时间和活塞流体积.抑湍器和垱坝组合控流效果良好,且结构简单.由抑湍器、垱坝和挡渣堰组成的控流装置使中间包流场更加合理,优化后的中间包平均停留时间由原先的188 s提高到218 s,活塞流体积分数由3.50%提高到15.41%,死区体积分数由41.57%降低到32.15%.     

大方坯中间包控流装置及冶金效果的研究

以某炼钢厂五流大方坯连铸中间包为研究对象,采用数值模拟方法,研究不同控流装置及操作参数下的中间包内钢液流动特性。研究结果表明,设计结构合理的湍流器、挡墙和挡坝组合的中间包结构,对钢液流动状态具有重要影响,可延长中间包内钢液停留时间,达到去除夹杂物和均匀各流钢水温度的冶金效果。优化后的中间包结构能够更好地满足高品质特钢质量的要求。     

MYF型连铸机用中间包的流场测试和优化的水模研究

对ＭＹＦ型四流中间包的水模流动测试表明：包内各流股的流动特性值在较大的差异，对浇铸构成不利的影响。控流后，明显改善了中间包的流场条件，为现场提供了中间包控流的依据和方案。     

非对称大方坯连铸中间包内控流装置的对比研究

通过对5流T型非对称大方坯连铸中间包控流装置的水模研究,对比了不同控流装置对连铸中间包内流场的影响,发现结构合理的控流装置能够明显改善中间包内流体的流动特性。采用多流连铸中间包流动特性的评判方法,分析讨论各方案实验数据,得出了中间包内控流装置的优化设计方案,为中间包内控流装置的设计提供了参考。实验表明：直通孔过滤器能够更好地改善五流圆坯中间包内钢水的流动,并根据实验结果提出了最佳的过滤器结构。     

单流板坯中间包内湍流抑制器对流场的影响

通过水力学模型实验,研究了湍流抑制器对单流板坯中间包内钢液流动的影响,并比较了有无湍流抑制器时中间包内钢液流动的特性。湍流抑制器使钢液由长水口注入中间包后再返回,从而消除了中间包短路流,发展了表面流,延长了滞止时间和平均停留时间,有利于中间包内夹杂物的去除。湍流抑制器与单挡坝的结构在控制中间包内钢液流动方面效果较好。     

八流方坯连铸中间包结构优化研究

采用1:3水模型实验对钢厂的八流150 mm×150 mm坯连铸不同控流结构80 t中间包内钢液流场进行了研究,并通过数值模拟进行验证。研究结果表明,中间包仅加湍流抑制器后对改善钢液的流动效果不明显,加上"V"型挡墙后能明显改善各流流动特性,湍流抑制器、"V"型挡墙和单坝组合能进一步提高各流的流动特性一致性,平均停留时间增大到505.22 s,在挡坝的两侧分别形成了明显的环流区。将单挡坝改为双挡坝后,V_p/V_d平均由原来1.77提高到2.63,死区比例平均也减少了6.0%,且各水口的稳定性最好,各流RTD曲线吻合度也最好,且存在3个大环流区和1个小环流区,水模型实验与数值模拟结果一致。     

Fluid flow behaviour in slab continuous casting tundish with different configurations of gas bubbling curtain

Abstract

Fluid flow characteristics in a two strand slab continuous casting tundish with different configurations of argon gas bubbling curtain (GBC) were investigated in physical modelling experiments. It was found from this research that the GBC with a small flow rate acted as a gas dam and could greatly improve the flow characteristics in the tundish. It increased dramatically the peak concentration time and plug flow volume, decreased greatly the dead volume, created surface directed flow and eliminated short circuiting. Therefore, the fluid flow characteristics in a tundish with GBC were favourable to the floatation and separation of inclusions from molten steel. The flow characteristics with low gas flow rate and short distance of the bubbling curtain from the tundish outlet were better than those with high gas flow rate and large distance of the curtain to the outlet. The optimal configuration for the improvement in fluid flow characteristics was turbulence inhibitor (TI)–weir–dam–GBC (TI–W–D–GBC), followed by TI–channel weir (CW)–GBC, TI–W–GBC and TI–GBC.     

Water Modelling Experiments of Argon Bubbling Curtain in a Slab Continuous Casting Tundish

Fluid flow characteristics in a two‐strand slab tundish with Ar bubbling curtain were studied in water modelling experiments. It was found that the Ar bubbling curtain can greatly improve the flow characteristics in the tundish with a weir, a dam and a turbulence inhibitor. It dramatically increased the peak concentration time and plug volume and greatly decreased the dead volume, but hardly influenced the minimum residence time. Therefore, the fluid flow characteristics in a tundish with Ar bubbling curtain were favourable to the flotation and separation of inclusions from molten steel. The flow characteristics with low gas flow rate and short distance of the Ar bubbling curtain from the tundish outlet were better than those with high gas flow rate and large distance of the curtain from the outlet.     

40t单流中间包控流装置的优化配置

采用水模型和工业验证的方法针对40 t单流中间包的控流装置进行优化配置研究.通过对单独湍流抑制器控流装置、湍流抑制器+下挡墙组合控流装置、湍流抑制器+下挡墙+上挡墙组合控流装置的研究表明,下挡墙在改善钢液流动形态和减少中间包内死区方面所起的作用大于上挡墙.平均停留时间随下挡墙与长水口的距离增加呈先增大后减小的趋势.确定了单流中间包以湍流抑制器+下挡墙的优化组合形式,死区比例由原来的25.9%降低到了13.6%.通过系统取样分析发现优化后中间包内T.O和N含量大幅降低,正常坯中的大型夹杂物质量分数也由原来的8.4×10-7降低到3.2×10-7.      

Flow Control in Six-Strand Billet Continuous Casting Tundish With Different Configurations

A 1∶2.5 scale tundish model was set up in laboratory for a six-strand billet continuous casting tundish with different configurations to investigate fluid flow characteristics under different operational conditions by measuring residence time distribution curves.It was found that minimum residence time,maximum concentration time and average residence time of the three strands on the same side of the tundish with the former configuration under normal operation,that is,six strands were open,were small and non-uniform and the tundish had large dead volume fraction.Vortexes easily formed on the liquid surface in the pouring zone of the tundish.The fluid flow characteristics in the tundish with the optimal turbulence inhibitor and baffles were improved and became less non-uniform among the strands.Vortexes were not found on the pouring zone surface in the optimal tundish.For non-normal operation,that is,one strand was close,it was important to choose which strand to be closed for maintaining flow characteristics of the rest two strands.It was found from this investigation that fluid flow characteristics in the optimal configuration tundish with closing strand 2 were better than those with closing strand 3 on the same side.     

Flow Control in Six-Straud Billet Continuous Casting Tundish With Different Configurations

 A 1:2.5 scale tundish model was set up in laboratory for a six-strand billet continuous casting tundish with different configurations to investigate fluid flowing characteristics under different operational conditions by measuring residence time distribution curves. It was known from the investigation that minimum residence time, maximum concentration time and average residence time of the three strands in the same side of the tundish with the former configuration under normal operation, that is, 6 strands were open, were small and non-uniform and the tundish had large dead volume fraction. Vortexes easily formed on the liquid surface in the pouring zone of the tundish. The fluid flow characteristics in the tundish with the optimal turbulence inhibitor and baffles were improved and became less non-uniform among the strands. Vortexes were not found on the pouring zone surface in the optimal tundish. Under un-normal operation, that is, one strand was close, it was important to choose which strand should be closed for flowing characteristics of the rest two strands. It was found from this investigation that fluid flowing characteristics in the optimal configuration tundish with closing strand 2 were better than those with closing strand 3 at the same side.     

中间包湍流控制器结构优化的水力学模拟

通过水力学模拟实验,研究了湍流控制器结构对中问包内流体流动特性的影响.结果表明:湍流控制器的结构埘巾间包流体流动特性有较大的影响.湍流控制器内腔形状为槽形,顶缘长度为30mm且其底部形状为平底时,流体在中间包内的斤始响应和平均停留时间最长,死区体积分数最小,活塞流与死区体积的比值最大,而且最有利于中问包内的夹杂物上浮去除.同时,相对于湍流控制器的内腔形状和底部形状,其顶缘长度对中间包内的流场影响最大.     

侧孔长水口两流非对称中间包流场优化

 中间包流体流动直接影响连铸坯的质量,为了缩小非对称中间包两流之间的流动差异,利用水模型和数值模拟方法,研究了侧孔长水口中间包流体流动特性。研究结果表明：直通型长水口、圆形湍流控制器和单挡墙结构中间包两出口流体差异较大,侧孔长水口和多孔挡墙结构中间包两流之间平均停留时间差异是直通型长水口中间包的3/4,且近长水口侧出口的平均停留时间延长7.7%。