scholarly journals Process Diagnosis of Liquid Steel Flow in a Slab Mold Operated with a Slide Valve

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1035
Author(s):  
Jafeth Rodríguez-Ávila ◽  
Carlos Rodrigo Muñiz-Valdés ◽  
Rodolfo Morales-Dávila ◽  
Alfonso Nàjera-Bastida
Keyword(s):  
Liquid Steel ◽  
Casting Process ◽  
Slide Valve ◽  
Heat Fluxes ◽  
Water Model ◽  
Process Diagnosis ◽  
Simulation Tools ◽  
Valve Opening ◽  
External Flows ◽  
Steel Flow

Slab molds receive liquid steel from the tundish through bifurcated submerged entry nozzles (SEN) using a slide valve as throughput control. Due to the off-centering position of the three plates’ orifices that conform to the valve to control the steel passage, the flow inside the nozzle and mold is inherently biased toward the valve opening side. In the practical casting, a biased flow induces inhomogeneous heat fluxes through the mold copper plates. The nozzle design itself is also a challenge, and has direct consequences on the quality of the product. A diagnosis of the casting process regarding the internal and external flows, performed through experimental and mathematical simulation tools, made it possible to reach concrete results. The mathematical simulations predicted the flow dynamics, and the topography and levels variations of the meniscus characterized through a full-scale water model. The flows are biased, and the meniscus level fluctuations indicated that the current nozzle is not reliable to cast at the two extremes of the casting speeds of 0.9 m/min and 1.65 m/min, due to the danger of mold flux entrainment. A redesign of the nozzle is recommended, based on the experimental and mathematical results presented here.

scholarly journals Evolution of the Numerical Model Describing the Distribution of Non-Metallic Inclusions in the Tundish

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2229
Author(s):  
Tomasz Merder ◽  
Jacek Pieprzyca ◽  
Marek Warzecha ◽  
Piotr Warzecha ◽  
Artur Hutny
Keyword(s):  
Numerical Model ◽  
Liquid Steel ◽  
Nonmetallic Inclusions ◽  
Steel Production ◽  
Cfd Modeling ◽  
Water Model ◽  
Working Space ◽  
Production Stages ◽  
Steel Flow ◽  
Flow Controllers

Continuous casting is one of the steel production stages, during which the improvement in the metallurgical purity of steel can be additionally affected by removing nonmetallic inclusions (NMIs). This can be achieved by means of various types of flow controllers, installed in the working space of the tundish. The change in the steel flow structure, caused by those flow controllers, should lead to an intensification of NMIs removal from the liquid metal to the slag. Therefore, it is crucial to understand the behavior of nonmetallic inclusions during the flow of liquid steel through the tundish, and particularly during their distribution. The presented paper reports the results of the modeling studies of NMI distribution in liquid steel, flowing through the tundish. CFD modeling methods—using different models and computation variants—were employed in the study. The obtained CFD results were compared with the results of laboratory tests (using a tundish water model). The results of the performed investigations allow us to compare both methods of modeling; the investigated phenomena were microparticle distribution and mass microparticle concentration in the model fluid. The validation of the CFD results verified the analyzed computation variants. The aim of the research was to determine which numerical model is the best for describing the studied phenomenon. This will be used as the first phase of a larger research program which will provide for a comprehensive study of the distribution of NMIs flowing through tundish steel.

scholarly journals New Insight on Liquid Steel Microalloying by Pulse-Step Method in Two-Strand Slab Tundish by Numerical Simulations

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 448
Author(s):  
Adam Cwudziński
Keyword(s):  
Liquid Steel ◽  
Mixing Time ◽  
Casting Process ◽  
Step Method ◽  
Flow Control Devices ◽  
Alloy Addition ◽  
Interesting Approach ◽  
Control Devices ◽  
Steel Flow ◽  
Alloy Concentration

Developing a technology for introducing alloy addition to liquid steel during the course of continuous casting process seems to be an interesting approach to enhancing the steelmaking process, especially as the effective introduction of micro-additives or non-metallic inclusion modifiers to the liquid steel is the key to the production of the highest-quality steel. This paper presents the results of investigation describing the process of liquid steel chemical homogenisation in the two-strand slab tundish. The alloy was fed to liquid steel by pulse-step method. Five tundish equipment variants with different flow control devices and alloy addition feeding positions were considered. The paper includes fields of liquid steel flow, alloy concentration vs. time curves, dimensionless mixing time, minimum time values and alloy concentration deviations at tundish outlets. The results pointed much more effectively with liquid steel mixing nickel than aluminium. For aluminium obtaining a 95% chemical homogenisation level requires three-fold more time. Moreover, it is definitely beneficial for chemical homogenisation to initiate the alloying process simultaneously in two sites. This procedure generates, among others, the least alloy deviation of concentration at tundish outlets.

scholarly journals Numerical Investigation of the Hydrodynamic Conditions in A Multi-Strand Cc Tundish with Closed Outlets

2014 ◽  
Vol 59 (3) ◽  
pp. 887-892 ◽  
Author(s):  
T. Merder
Keyword(s):  
Liquid Steel ◽  
Stokes Equations ◽  
Thermal Conditions ◽  
Casting Process ◽  
Navier Stokes ◽  
Hydrodynamic Conditions ◽  
Continuous Casting Process ◽  
Navier Stokes Equations ◽  
Steel Flow ◽  
Kinetics Of

Abstract In industrial conditions there are situations when the CC machine works under emergency. It can be result of mechanical or electrical causes, breakout of billet or problem with supplying new parts of liquid steel to the CC machine. As a consequence one or two outlets of the tundish should be closed. However, closing one of the outlets influences the hydrodynamic and thermal conditions occurring in the tundish. Thus, the important information is which of the outlets should be closed to conduct further continuous casting process correctly.The following research was conducted to analyze the influence of liquid steel flow behaviour in the multi-strand tundish when all outlets do not work. Such problem was solved by means of numerical methods based on Navier-Stokes equations (k–ɛ standard turbulence model). Numerical simulations were done using the educational version of CFD program (Computational Fluid Dynamics) – ANSYSFluent. As a result forecasted velocity fields and RTD curves (Residence Time Distribution) were obtained. RTD characteristics were used to determine kinetics of liquid steel mixing and also to calculate parts of particular flow areas for studied cases.

Mathematical Modeling of Behaviour a Liquid Steel Flow and a Non-Metallic Inclusions in the One Strand Wedge Type Tundish with a Subflux Turbulence Controller and a Low Dam

2012 ◽  
Vol 706-709 ◽  
pp. 1379-1384 ◽  
Author(s):  
Adam Cwudziński ◽  
Jan Jowsa
Keyword(s):  
Continuous Casting ◽  
Liquid Steel ◽  
Volume Fraction ◽  
Casting Process ◽  
Balance Model ◽  
Phase Volume Fraction ◽  
Metallic Inclusions ◽  
Rod System ◽  
The One ◽  
Steel Flow

The numerical modelling technique is successfully used for simulation of liquid metal movement and behaviour of non-metallic inclusions in the continuous casting devices. The CFD (Computational Fluid Dynamic) method allows information on physical, chemical and hydrodynamic phenomenon in the metallurgical processes to be obtained. In the continuous steel casting process, where the tundish performs the function of a device batching steel to the mould, the monitoring especially of non-metallic inclusions is very essential because a quantity of non-metallic inclusions in the liquid steel limit the quality of final steel product. The paper presents the results of computing simulation of behaviour a liquid steel flow and non-metallic inclusions in the one-strand tundish with stopper rod system. The subject of simulation was a one-strand tundish of a nominal capacity of 30 tons. The tundish is used in the polish steel mill to process of continuous casting slabs. In the paper authors analysed two tundish i.e. tundish with a low dam and tundish with a subflux turbulence controller and a low dam. The Ansys-Fluent® program was used for solved mathematical model of casting process. The computer simulations were performed for unsteady and nonisothermal conditions. The population balance model was used to description of non-metallic inclusions growth process. As a result of computations, fields of liquid steel flow, fields of secondary phase volume fraction, fields of volume fraction for particular bins and non-metallic inclusions growth curve were obtained.

scholarly journals Analysis of Non-Symmetrical Heat Removal during Cast-ing of Steel Billets and Slabs

2021 ◽  
Author(s):  
Adán Ramirez-Lopez ◽  
Omar Davila-Maldonado ◽  
Alfronso Nájera-Bastida ◽  
Rodolfo Morales ◽  
Jafeth Rodríguez-Ávila ◽  
...  
Keyword(s):  
Liquid Steel ◽  
Cooling System ◽  
Liquid Core ◽  
Heat Removal ◽  
Casting Process ◽  
Steel Shell ◽  
Steel Ladle ◽  
Ingot Casting ◽  
Friction Forces ◽  
Steel Section

Steel is one of the essential materials in the world's civilization. It is essential to produce many products such as pipelines, mechanical elements in machines, vehicles, profiles, and beam sections for buildings in many industries. Until the '50s of the 20th century, steel products required a complex process known as ingot casting; for years, steelmakers focused on developing and simplifying this process. The result was the con-tinuous casting process (CCP); it is the most productive method to produce steel. The CCP allows producing significant volumes of steel sections without interruption and is more productive than the formal ingot casting process. The CCP begins by transferring the liquid steel from the steel-ladle to a tundish. This tundish or vessel distributes the liquid steel, by flowing through its volume, to one or more strands having wa-ter-cooled copper molds. The mold is the primary cooling system, PCS, solidifying a steel shell to withstand a liquid core and its friction forces with the mold wall. Further down the mold, the rolls drive the steel section in the SCS. Here the steel section is cooled, solidifying the remaining liquid core, by sprays placed in every cooling segment all around the billet and along the curved section of the machine. Finally, the steel strand goes towards a horizontal-straight free-spray zone, losing heat by radiation mechanism, where the billet cools down further to total solidification. A moving torch cutting-scissor splits the billet to the desired length at the end of this heat-radiant zone.

scholarly journals Numerical Modelling of Metal/Flux Interface in a Continuous Casting Mould / Modelowanie Numeryczne Powierzchni Międzyfazowej Metal/Ciekły Żużel W Krystalizatorze Do Ciągłego Odlewania Stali

2015 ◽  
Vol 60 (4) ◽  
pp. 2905-2912 ◽  
Author(s):  
J. Jowsa ◽  
M. Bielnicki ◽  
A. Cwudziński
Keyword(s):  
Liquid Steel ◽  
Steel Casting ◽  
Liquid Slag ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Continuous Steel Casting ◽  
Research Areas ◽  
Slab Casting ◽  
Metal Flux ◽  
Continuous Casting Mould

The behaviour of liquid slag in the mould is one of the key research areas of the continuous steel casting process. Numerical simulations of steel casting in the mould equipped with submerged entry nozzle, intended for slab casting, have been carried out within the study. For modelling the behaviour of the interfaces of the liquid steel - liquid slag - air system, the VOF method was employed. In the conducted simulations, seven different procedures for the discretization of the interface of individual phases were tested. The computation results have revealed that the “entrapment” of fine slag portions into liquid steel occurs in the system under investigation; the cause of this phenomenon is explicated by the Kelvin-Helmholtz theory.

Modelling of liquid steel flow with free surface

2004 ◽  
Vol 4 (1) ◽  
pp. 12 ◽  
Author(s):  
Marcela B. Goldschmit ◽  
Sergio P. Ferro ◽  
A. Heriberto Coppola Owen
Keyword(s):  
Free Surface ◽  
Liquid Steel ◽  
Steel Flow
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