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The submitted article deals with the use of physical and numerical modelling to study the process of the steel flow in an asymmetric five-strand tundish that continuously casts steel. For the purposes of physical modelling, a 1:4-scale plexiglass model was used as the operating tundish, and for numerical modelling, the geometry of the operating tundish was created on a 1:1 scale. A model liquid (water) was used in the physical modelling of the melt flow process, while liquid steel was used as the standard flowing medium in the numerical modelling. We assessed the relevant operating parameters influencing the characteristics of the flow of the bath in the tundish—the shape of the turbulence inhibitor, the position of the ladle shroud in relation to the turbulence inhibitor and the distance between the ladle shroud orifice and the bottom of the turbulence inhibitor. The preliminary results show that optimal steel flow characteristic results are achieved by using the TI3-C configuration. The results from both modelling methods achieved the same characteristics, therefore verifying the results of each other and demonstrating that when taken together, the results of physical and numerical modelling can be considered sufficiently informative. [ABSTRACT FROM AUTHOR]

The submitted article deals with the use of physical and numerical modelling to study the process of the steel flow in an asymmetric five-strand tundish that continuously casts steel. For the purposes of physical modelling, a 1:4-scale plexiglass model was used as the operating tundish, and for numerical modelling, the geometry of the operating tundish was created on a 1:1 scale. A model liquid (water) was used in the physical modelling of the melt flow process, while liquid steel was used as the standard flowing medium in the numerical modelling. We assessed the relevant operating parameters influencing the characteristics of the flow of the bath in the tundish—the shape of the turbulence inhibitor, the position of the ladle shroud in relation to the turbulence inhibitor and the distance between the ladle shroud orifice and the bottom of the turbulence inhibitor. The preliminary results show that optimal steel flow characteristic results are achieved by using the TI3-C configuration. The results from both modelling methods achieved the same characteristics, therefore verifying the results of each other and demonstrating that when taken together, the results of physical and numerical modelling can be considered sufficiently informative.

The article presents the results of research aimed at determining the nature of changes in the mixing of liquid steel in asymmetrical tundish due to the increase in casting speed and the possibility of limiting the use of Flow Control Devices (FCD). The tests were carried out on the water model of the Continuous Steel Casting (CSC) device equipped with the tundish model. Four variants of casting speed were analyzed. The analysis of the obtained results was divided into two stages: qualitative analysis of flow and mixing (visualization process) and quantitative analysis of flow and mixing (by analysis of mixing curves - Residence Time Distribution (RTD) type F).

The article presents the results of research aimed at determining the nature of changes in the mixing of liquid steel in asymmetrical tundish due to the increase in casting speed and the possibility of limiting the use of Flow Control Devices (FCD). The tests were carried out on the water model of the Continuous Steel Casting (CSC) device equipped with the tundish model. Four variants of casting speed were analyzed. The analysis of the obtained results was divided into two stages: qualitative analysis of flow and mixing (visualization process) and quantitative analysis of flow and mixing (by analysis of mixing curves - Residence Time Distribution (RTD) type F). [ABSTRACT FROM AUTHOR]

The ladle bottom argon blowing process has an important influence on the refining liquid steel. The effects of diameters, insertion depth of immersed cylinder and bottom gas flow rate on the flow state of liquid steel and the amplitude of liquid steel surface are numerically simulated for 150t ladle. The results show that the slag entrapment of liquid steel surface can be confined by changing the diameters and insertion depths of immersed cylinder. The effects of gas flow rate, diameter and insertion depth with immersed cylinder on the flow of molten steel in the ladle were analyzed.

In order to increase the efficiency and quality of the steel-making process a numerous studies are conducted at the various stages of the process, including continuous casting of steel. Researchers still search for new models and improve existing one, so that the specific of the process is accuratelly reproduced. One way to increase the accuracy of numerical simulation, is to apply the LES (Large Eddy Simulation) method to simulate steelmaking processes.

The way and speed of steel flux flowing into mould of continuous casting (CC) machine belong to the important parameters characterizing the steel continuous casting process. Such flux causes determined kinds of steel circulation, which together with simultaneous steel crystallization influence the creation of ingots primary structure and quality of its surface.

This paper presents the results of computer simulations (Ansys-Fluent) and laboratory experiments (physical water model) carried out to describe the motion of steel flow in the tundish. The facility under investigation is a single-nozzle slab tundish. The internal geometry of consider object was changed by flow control device i.e. subflux turbulence controller (STC). In order to obtain a complete hydrodynamic picture in the tundish furniture variants tested, the computer simulations were performed for both isothermal and non-isothermal conditions. From the performed computer simulations and laboratory experiments (physical modeling) it can be found that, the non-isothermal conditions occurring during continuous steel casting will definitely influence the hydrodynamic pattern forming in the tundishes with STC.

This paper presents the results of research on the behaviour of an alloy addition in steel flowing through the tundish used for casting slabs. The device under examination is a wedge-shaped single-nozzle tundish of a capacity of 30 Mg. Due to the complexity of alloy addition dissolution and dispersion in metallurgical processes, a decision was made to use the Species Model available within the Ansys-Fluent® program. For describing the turbulence, the Realizable k-ɛ model was chosen. By defining the heat losses on respective planes making up the virtual model, the non-isothermal conditions existing during the flow of liquid steel through the tundish were considered. From the performed numerical simulations, the fields of steel flow and steel temperature and alloy addition concentration in the tundish working space were obtained. In order to accurately illustrate the process of chemical homogenization in the tundish working space, mixing curves were recorded. Based on the obtained results (mixing curves), the mixing time needed for achieving the 95% level of chemical homogenization was calculated.

This paper presents the results of computer simulations and laboratory experiments carried out to describe the motion of steel flow in the tundish. The facility under investigation is a single-nozzle tundish designed for casting concast slabs. For the validation of the numerical model and verification of the hydrodynamic conditions occurring in the examined tundish furniture variants, obtained from the computer simulations, a physical model of the tundish was employed. State-of-the-art vector flow field analysis measuring systems developed by Lavision were used in the laboratory tests. Computer simulations of liquid steel flow were performed using the commercial program Ansys-Fluent¯. In order to obtain a complete hydrodynamic picture in the tundish furniture variants tested, the computer simulations were performed for both isothermal and non-isothermal conditions.

Inclusion behavior during a ladle teeming process is investigated. A Lagrangian method is used to track different-size inclusions and to compare their behaviors in steel flows, solved by the realizable k- ϵ model with SWF (Standard Wall Function), realizable k- ϵ model with EWT (Enhanced Wall Treatment), and RSM (Reynolds Stress Model). The results show that inclusion tracking based on the realizable k- ϵ model with SWF to predict the steel flow does not agree with the data from plant experiments. The predicted number of inclusions touching the wall shows almost no dependence on inclusion size. This is due to that the boundary layer is not resolved. The inclusion deposition predicted using the realizable k- ϵ model with EWT and the RSM model to predict the steel flow generally agrees with the experimental observations. However, the large size inclusion deposition is over-predicted when using the realizable k- ϵ model with EWT. More specifically, the prediction for 20 μm inclusions is three times larger than that with the RSM. This is due to that this model cannot calculate the anisotropic turbulence fluctuations. In summary, the turbulence properties in the near-wall boundary layer are found to be very important for a good prediction on inclusion deposition. [ABSTRACT FROM AUTHOR]

The article presents results of physical modelling of the steel continuous casting process in the tundish. Technological parameters of casting and constructive parameters of tundish were under study. Three different kinds of flow control devices were considered as well as their influence on the kinetics of steel flow and mixing in tundish. Created physical model enabled to conduct simultaneously visualization research and determine the RTD curves. According to the theory of flow in reactors the proper characteristics for estimating the flow are RTD curves E- and F-type, and they were obtained and discussed.

The startup of casting sequences in continuous casting of steel using three different turbulence inhibitors were modeled and simulated through the multiphase volume of fluid model (VOF) in a four-strand tundish. In the actual caster, one of the inhibitors released the liquid steel with a superheat high enough to avoid freezing problems in the outer strands. A second inhibitor improved the flow, yet it yielded steel freezing in these strands. A two-phase air–water system was used to model the liquid steel–air system and the interfaces were tracked by a donor–acceptor principle applied in the computational mesh. These activities led to the design of a third inhibitor. Experimental outcomes and the mathematical simulations agreed remarkably well regarding the velocity of the stream front in the tundish floor and the mass of steel reaching the outer strands. A larger steel mass and a faster stream front helped to completely prevent the steel from freezing in the outer strands. Finally, flow fields during the filling of the tundish using two of these inhibitors were simulated and the results explain the different performances observed experimentally.

This paper presents the results of computer simulations and laboratory experiments carried out to describe the formation of the transient zone during continuous casting of slabs. The facility under investigation was a one strand tundish. Computer simulations of liquid steel flow were performed using the commercial program Ansys-Fluent. For the validation of the numerical model and verification of the hydrodynamic conditions occurring in the examined tundish furniture variants, obtained from the computer simulations, a water model of the tundish was employed. During laboratory tests simulating the process of steel flowing through the tundish, step type Residence Time Distribution curves were recorded. In order to obtain a complete hydrodynamic picture in the tundish furniture variants tested, the computer simulations were performed for both isothermal and non-isothermal conditions. In order to explain the phenomena occurring in the tundish working space, the Buoyancy number (Bu) has been calculated. [ABSTRACT FROM AUTHOR]

CC process has great importance on achieving high quality cast strands. On this stage of production last metallurgic interventions are wage, which regards to liquid steel and also primary structure of the solidifying steel ingots forms. This article presents results of the research, that applies to influence of the liquid steel mixing method in tundish on steel ingots’ primary structure. Study of the flow conducted on physical model of the triple-stranded tundish, which provided results formed as RTD curves. Generated curves were put together with primary structure’s metallographic test results of the individual cast strand’s cast in actual CCM. That listing allows to valuate influence of the liquid steel mixing method in tundish on steel ingots’ primary structure quality.

Article presents results of numerical simulation of steel flow and mixing in real two strand tundish working in on of polish steelworks. In calculation different casting flow rates were tested. They were analyzed taking into account their influence on the hydrodynamic conditions occurring in reactor. AnsysFluent code was used for numerical simulation of 3D turbulent steel flow in tundish for steady and transient conditions. As a result of calculation spatial velocity fields and steel turbulence intensity were obtained. Research was complemented by residence time distribution – typical for analyzed calculated. Whereas basing on F curves the kinetic of steel mixing were estimated.

Realizing the conservation and circulation of steel is of great significance to the global low-carbon and sustainable development, which requires the joint efforts from both the supply and demand sides. The first step for these efforts begins with the in-depth understanding of the steel use panorama, including steel flows in the production system and steel footprints in the consumption system. This study provides a unified methodological basis for tracing and analysing the steel use from production to consumption, taking China as a case study. By combing material flow analysis with the extended input-output approach, this study traced China's steel use from iron ore, intermediate products, end-use products to direct consumption, embodied consumption and final use in 2018. Based on this, policy implications for China's steel sustainable development were put forward from both supply and demand sides. The results indicate that investment drove 75.1% of China's steel production; construction accounted for 58.6% of China's direct steel consumption; the service industry's embodied steel consumption accounted for 6.8% of China's total steel consumption, although without direct steel consumption; and scrap accounted for 21.5% of China's steel sources, of which 56.7% entered basic oxygen furnaces rather than electric arc furnaces. Therefore, transforming economic growth model is crucial to reducing steel demand. Currently, construction should be the focus of efforts to improve material efficiency, while in the future, policies should guide the dematerialization of the service. From the perspective of production, the pathway lock-in should be broken for promoting China's steel recycling and low-carbon development. • Combining MFA with EIO to trace steel use from production to consumption. • Investment dominated the use of steel in China, driving 75.1% of steel production. • Construction accounted for 58.6% of China's direct steel consumption. • There are 6.8% of China's total steel consumption embodied in the services. • 56.7% of China's scrap entered the BOF rather than the EAF. [ABSTRACT FROM AUTHOR]

The ladle bottom argon blowing process has an important influence on the refining liquid steel. The effects of diameters, insertion depth of immersed cylinder and bottom gas flow rate on the flow state of liquid steel and the amplitude of liquid steel surface are numerically simulated for 150t ladle. The results show that the slag entrapment of liquid steel surface can be confined by changing the diameters and insertion depths of immersed cylinder. The effects of gas flow rate, diameter and insertion depth with immersed cylinder on the flow of molten steel in the ladle were analyzed. [ABSTRACT FROM AUTHOR]

A new tundish is designed with the aim to produce a swirling flow in a tundish SEN by an economical way of using the steel flow potential as the required power. This design is easily obtained by adding a cylindrical part of the tundish onto a traditional tundish. The results show that a swirling flow in the SEN of the new tundish is successfully obtained, also, that the tangential velocity in the SEN can reach around 1.6 m s−1. The installation of weirs in the cylindrical tundish can contribute to stabilize the steel flow at the top of the tundish. However, this reduces the swirling flow intensity in the SEN around 30%. In addition, the possibility of slag entrainment at the top of the tundish is analyzed. The calculated Weber Number is around 5.0 for no weir case and 2.8 for the weir case, which means that the risk of slag entrainment is small. A high value of shear stress is found on the SEN wall due to the swirling flow in SEN. A further investigation shows that a smooth transition of SEN inlet can reduce the maximum shear stress level in the SEN, without decreasing the swirling flow intensity. [ABSTRACT FROM AUTHOR]

This paper reports the results of computer simulations of the flow of liquid steel in a single-nozzle tundish, which describe the flow hydrodynamics, depending on the thermal conditions and casting speed. In this paper, five casting speeds, namely 0.3, 0.6, 0.9, 1.2 and 1.5 m/min., have been examined. In view of the fact that tundishes are being equipped with various flow control devices and the process of creating specific hydrodynamic conditions is influenced also by the temperature gradient, computer simulations of liquid steel flow under isothermal and non-isothermal conditions were performed. Computer simulations of liquid steel flow were performed using the commercial program Ansys-Fluent®. In order to explain the phenomena occurring in the tundish working space, the buoyancy number (Bu) has been calculated. The next research step in the analysis of the flow pattern forming in different casting conditions was to record the E and F-type RTD characteristics and to describe the pattern of flow. [ABSTRACT FROM AUTHOR]

This paper presents the results of a computer simulation and laboratory experiments carried out to describe the hydrodynamics of steel active flow in the tundish. One of the parameters describing the correct influence of FCDs on the tundish operation is the description of the active flow zone (dispersed plug flow and well mixed volume flow). The facility under investigation is a single-nozzle tundish designed for casting concast slabs. Computer simulations of liquid steel flow were performed using the commercial program Ansys-Fluent. For the validation of the numerical model and verification of the hydrodynamic conditions occurring in the examined tundish furniture variants, obtained from the computer simulations, a physical model of the tundish was employed. During laboratory tests simulating the process of steel flowing through the tundish, E type RTD curves were recorded, which were then juxtaposed with results obtained from computer simulations. In order to obtain a complete hydrodynamic picture in the tundish furniture variants tested, the computer simulations were performed for both isothermal and non-isothermal conditions. [ABSTRACT FROM AUTHOR]

The article presents results of physical modelling of the steel continuous casting process in the tundish. Technological parameters of casting and constructive parameters of tundish were under study. Three different kinds of flow control devices were considered as well as their influence on the kinetics of steel flow and mixing in tundish. Created physical model enabled to conduct simultaneously visualization research and determine the RTD curves. According to the theory of flow in reactors the proper characteristics for estimating the flow are RTD curves E- and F-type, and they were obtained and discussed. [ABSTRACT FROM AUTHOR]

The paper reports the results of studies on the validation of a numerical model of the flow of liquid steel through the tundish used for continuous casting of steel. The facility under investigation is a single-nozzle tundish designed for casting concast slabs. For the description of the turbulence of steel flow through the tundish, the k-ε, RNG k-ε and Realizable k-ε turbulence model were adopted. Computer simulations of liquid steel flow were performed using the commercial program Ansys-Fluent®. For the validation of the numerical model and verification of the hydrodynamic conditions occurring in the examined tundish furniture variants, obtained from the computer simulations, a physical model of the tundish was employed. During laboratory tests simulating the process of steel flowing through the tundish, E and F-type RTD (Residence Time Distribution) curves were recorded, which were then juxtaposed with results obtained from computer simulations. In order to obtain a complete hydrodynamic picture in the tundish furniture variants tested, the computer simulations were performed for both isothermal and non-isothermal conditions. [ABSTRACT FROM PUBLISHER]

Article presents results of numerical simulation of steel flow and mixing in real two strand tundish working in on of polish steelworks. In calculation different casting flow rates were tested. They were analyzed taking into account their influence on the hydrodynamic conditions occurring in reactor. Ansy sFluent code was used for numerical simulation of 3D turbulent steel flow in tundish for steady and transient conditions. As a result of calculation spatial velocity fields and steel turbulence intensity were obtained. Research was complemented by residence time distribution -- typical for analyzed calculated. Whereas basing on F curves the kinetic of steel mixing were estimated. [ABSTRACT FROM AUTHOR]

CC process has great importance on achieving high quality cast strands. On this stage of production last metallurgic interventions are wage, which regards to liquid steel and also primary structure of the solidifying steel ingots forms. This article presents results of the research, that applies to influence of the liquid steel mixing method in tundish on steel ingots' primary structure. Study of the flow conducted on physical model of the triple-stranded tundish, which provided results formed as RTD curves. Generated curves were put together with primary structure's metallographic test results of the individual cast strand's cast in actual CCM. That listing allows to valuate influence of the liquid steel mixing method in tundish on steel ingots' primary structure quality. [ABSTRACT FROM AUTHOR]

The paper presents computation results from the simulation of liquid steel flow in a one-strand slab tundish used in a Polish steel plant. This is a wedge type tundish with a depression in the bottom of the discharge zone. Fluent software was used for solving the mathematical model of the casting process, and Euler–Lagrange description was chosen for the description of interactions between the continuous phase (liquid steel) and the discrete phase (inert gas). To verify the mathematical model and the numerical simulation results, test results obtained from industrial experiments were applied. The internal geometry of the facility under consideration was changed by two types of flow control devices, a subflux turbulence controller and a gas permeable barrier mounted on the tundish bottom. A number of variants were tested including flowrate and position of the argon. For all variants of modification, the quantity of non-metallic inclusions removed from liquid steel has been obtained. [ABSTRACT FROM AUTHOR]

This paper addresses surface/subsurface quality (slivers, pipe, pinholes, blowholes, inclusion content) and diversion rate (slab casting abnormality codes) of products cast on high or low throughput thick slab machines. Examples from LTV, NKK and TKS pertaining to curved mould and vertical/bending casters are reviewed, which make apparent the important effect of steel flow stability and steel flow pattern in the mold on defect occurrence. The first conclusion, which pertains mostly to slow speed or wide slab machines, is that creating or maintaining a stable double roll flow is key to eliminating slab defects. The second conclusion, relating mostly to high speed casters, is that the intensity of the double roll flow pattern must not be excessive. With this in mind, the efficiency of an existing versatile electromagnetic based technology that allows accelerating, slowing down, and stirring the liquid steel was examined. The analysis shows good response of the liquid steel to various imposed magnetic fields, presents corresponding slab/coil quality improvements, and demonstrates the relevance of the proposed hydrodynamic and metallurgical concepts. [ABSTRACT FROM AUTHOR]

The startup of casting sequences in continuous casting of steel using three different turbulence inhibitors were modeled and simulated through the multiphase volume of fluid model (VOF) in a four-strand tundish. In the actual caster, one of the inhibitors released the liquid steel with a superheat high enough to avoid freezing problems in the outer strands. A second inhibitor improved the flow, yet it yielded steel freezing in these strands. A two-phase air–water system was used to model the liquid steel–air system and the interfaces were tracked by a donor–acceptor principle applied in the computational mesh. These activities led to the design of a third inhibitor. Experimental outcomes and the mathematical simulations agreed remarkably well regarding the velocity of the stream front in the tundish floor and the mass of steel reaching the outer strands. A larger steel mass and a faster stream front helped to completely prevent the steel from freezing in the outer strands. Finally, flow fields during the filling of the tundish using two of these inhibitors were simulated and the results explain the different performances observed experimentally. [ABSTRACT FROM AUTHOR]