Experimental and numerical investigation of the multiphase flow in the water model of a steel ladle as basis for the enhancement of multiphase flow models in computational fluid dynamics of metallurgical reactors

为了提高产品寿命，工业对高纯度和均匀的最佳技术性能的高性能钢的需求不断增加，需要对二次冶金工艺有全面的了解。这为提高工厂生产率和产品质量提供了机会。详细了解钢包水模型中不同参数的多相流，可以增强对该过程及其影响因素的基本认识。此外，所获得的数据可以作为进一步开发描述钢包内流动的数值模型的验证基础。在AOD转炉的研究过程中，cfd模型通过水模型试验得到了验证。结果表明，这些模型转移到实际过程后，能够较好地再现升力自由射流的特性。研究还表明，水模型中的影响参数对实际过程也有同样的影响。本研究项目旨在了解非均质升力自由射流的形成及其在钢包内流动的基本机理。这些知识将应用于多相流领域中描述反应器的数值模型的开发。特别是对冶金釜内多相流的数值描述进行全面的研究是十分必要的。用现代实验方法验证的数值模型在文献中并不常见。在研究项目中，对影响钢包水模型流动的各种因素进行了详细的实验研究。此外，在实验数据的基础上，进一步建立了能够从宏观上描述复杂过程的数值模型。这些模型为高级过程改进提供了基础。正确模拟气泡的大小分布、气泡的速度和非均匀升力自由射流的形状是建立所研究过程中能量和质量输运模型（例如化学反应模型）的关键因素。基于开发的模型，可以优化钢包和喷射系统的几何形状，使操作人员能够缩短工艺时间。这样可以节约能源和资源。

Increasing demands of the industry for high performance steels of highest purity and homogeneous optimal technological properties for components to increase the product life, require a comprehensive understanding of the processes in secondary metallurgy. This provides opportunities to improve the plant productivity and the product quality.A detailed knowledge of the multiphase flow in the water model of a ladle according to various parameters enhances the basic understanding of the process and its influencing factors. Furthermore, the achieved data can be used as a validation basis for the further development of numerical models describing the flow in the ladle. During investigations of an AOD converter CFD-models have been validated by water model experiments. It was found that after the transfer to the real process, these models are able to reproduce the characteristics of the lift free jet. It was also shown that influencing parameters in the water model affected the real process in the same way.This research project aims to understand the basic mechanisms of the formation of the heterogeneous lift free jet and the resulting flow in the ladle. This knowledge will be applied to the development of numerical models describing the reactor in the field of multiphase flow. Especially a comprehensive research of the numerical description of multiphase flows in metallurgical reactors is essential. Numerical models validated with modern experimental methods are not very common in literature.Within the research project various influencing factors on the flow in the water model of the ladle are experimentally investigated in detail. Moreover, based on the experimental data, numerical models, able to describe the complex process macroscopically, are further developed. These models provide a basis for advanced process improvements. A correct simulation of the bubble size distribution, the velocity of the bubbles and the shape of the heterogeneous lift free jet, are key factors for the development of models for energy and mass transport in the studied processes (eg modeling of chemical reactions). Based on the developed models the geometry of ladles and the injection systems can be optimized and enable the operator to shorten the process time. In this way, energy and resources can be saved.