scholarly journals Influence of Hydrodynamic Structure on Mixing Time of Alloy Additions with Liquid Steel in One Strand Tundish

2016 ◽  
Vol 61 (1) ◽  
pp. 295-300 ◽  
Author(s):  
A. Cwudziński
Keyword(s):  
Liquid Steel ◽  
Mixing Time ◽  
Hydrodynamic Conditions ◽  
Step Method ◽  
Ansys Fluent ◽  
Working Space ◽  
Alloy Addition ◽  
Steel Flow ◽  
Mixing Curves ◽  
Active Flow

The knowledge of the hydrodynamic pattern aids in designing new and modernizing existing tundishes. The device under examination is an one-strand tundish of a capacity of 30 Mg. Computer simulation of the liquid steel flow, tracer and alloy addition behaviour in turbulent motion conditions was done using the Ansys-Fluent®computer program. The hydrodynamic conditions of steel flow were determined based on the distribution of the characteristics of tundish liquid steel residence time distribution (RTD). The alloy addition was introduced to the liquid steel by the pulse-step method. Based on computer simulations carried out, steel flow fields and RTD and mixing curves were obtained, and the shares of stagnant volume flow and active flow and the mixing time were computed. Dispersion of the alloy addition in liquid steel during its flow through the tundish is a dynamic process which is determined by the hydrodynamic conditions occurring in the tundish working space.

scholarly journals Chemical Homogenization Of Liquid Steel Flowed Through Continuous Casting Slab Tundish During Alloying Process

2015 ◽  
Vol 60 (2) ◽  
pp. 561-565
Author(s):  
A. Cwudziński
Keyword(s):  
Liquid Steel ◽  
Mixing Time ◽  
Virtual Model ◽  
Ansys Fluent ◽  
Working Space ◽  
Continuous Casting Slab ◽  
Alloy Addition ◽  
Steel Flow ◽  
Mixing Curves ◽  
Metallurgical Processes

AbstractThis 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-ɛmodel 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.

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 Prediction of Hydrodynamic Conditions in one Strand Tundish. Influence of Thermal Conditions and Casting Speed/ Numeryczna Prognoza Warunków Hydrodynamicznych W Jednozyłowej Kadzi Posredniej. Wpływ Warunków Cieplnych I Predkosci Odlewania

2014 ◽  
Vol 59 (4) ◽  
pp. 1249-1256
Author(s):  
A. Cwudzinski
Keyword(s):  
Computer Simulations ◽  
Casting Speed ◽  
Liquid Steel ◽  
Thermal Conditions ◽  
Hydrodynamic Conditions ◽  
Ansys Fluent ◽  
Working Space ◽  
Flow Control Devices ◽  
Pattern Forming ◽  
Steel Flow

Abstract 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.

Optimization of Pulse-Step Method for Liquid Steel Alloying in One Strand Slab Tundish

2018 ◽  
Vol 941 ◽  
pp. 58-63 ◽  
Author(s):  
Adam Cwudziński
Keyword(s):  
Liquid Steel ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Computational Grids ◽  
Time Interval ◽  
Step Method ◽  
Ansys Fluent ◽  
Pulse Charge ◽  
Steel Alloying ◽  
Steel Flow

Introduction to the Fe-C-X system: Si, Mn, Al and Nb, Ti, V, B allow the ultimate tensile strength and ductility of steel to be increased at the same time. Therefore, multiphase steels of the TRIP, DP, MART and CP are the steels of the future. The scientific aim of the researches were to obtain new basic information on alloying process of liquid steel in a tundish with the use of the pulse–step method. The facility under investigation was a single outlet tundish being a component of a slab continuous casting machine. Computer simulations of the liquid steel flow and alloy behaviour in turbulent motion conditions were done using the Ansys-Fluent computer program. For generating the computational grids, Gambit program was used. For pulse–step method optimisation two aspects were considered. At first numerical simulations were performed for the selection of the time interval between the pulse feed of the first alloy batch and the continuous feed of subsequent alloy batches in order to maintain the required homogenisation level. Next simulations were done for determination of the mass of the pulse charge that ensures not only the attainment of the 95% homogenisation level, but also the limitation of alloy concentration peaks occurring in the liquid steel and going beyond the 95% homogenisation zone. On the basis of numerical investigations the mixing curves and time mixing for different variants of pulse-step method optimization were obtained.

scholarly journals Intensification of liquid steel active flow volume in one-strand tundish using a modified ladle shroud

10.30544/458 ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 1-14
Author(s):  
Michał Bartosiewicz ◽  
Adam Cwudziński
Keyword(s):  
Numerical Simulations ◽  
Liquid Steel ◽  
Physical Simulation ◽  
Turbulence Models ◽  
Immersion Depth ◽  
Flow Volume ◽  
Ansys Fluent ◽  
The One ◽  
Steel Flow ◽  
Active Flow

This work presents the numerical and physical simulation results of the liquid steel flow in the one-strand tundish. The results obtained during the numerical simulations and the water modeling results were compared to each other. Six types of turbulence models were tested. Among tested turbulence models the BSL k-ω was turned out the best correlating with the results from the laboratory experiments. Besides, the ladle shroud modification was proposed by the authors and the influence of the modified ladle shroud immersion depth in the liquid steel on the hydrodynamic structure in the tundish was checked. The ladle shroud modification depended on the expansion, narrowing, and re-expansion of the liquid steel feed stream. The four tundish variants with the four different ladle shroud immersion depths (at 0.1, 0.2, 0.3 and 0.4 m) in the liquid steel were tested. The liquid steel flow volumes were calculated and according to the generated active flow volume, the most beneficial research case was indicated. The tundish variant with the ladle shroud immersion depth of 0.3 m in the liquid steel was characterized by the lowest stagnant flow volume. The numerical simulations were performed by using the Ansys-Fluent computer program.

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.

Mathematical Modeling and Industrial Experiment of Liquid Steel Flow in the Three Outlets Continuous Casting Bloom Tundish

2013 ◽  
Vol 58 (4) ◽  
pp. 1077-1083 ◽  
Author(s):  
A. Cwudzinśki
Keyword(s):  
Liquid Steel ◽  
Mass Scale ◽  
Correct Process ◽  
Ansys Fluent ◽  
Industrial Experiment ◽  
Flow Control Devices ◽  
Working Volume ◽  
The Subject ◽  
Control Devices ◽  
Steel Flow

Abstract The dynamic development of the continuous steel casting (CSC) process has resulted in the application of this technology to the casting of steel semi-finished products on a mass scale. In the CSC process, before the cooling and solidification of liquid steel commences, the liquid metal dynamically flows through the steelmaking ladle, the tundish and the mould. Therefore, the control of steel flow is the key to the correct process. One of the metallurgical device in which the control of steel flow hydrodynamics is of crucial importance is the tundish. The subject of investigation within the present study was a three-nozzle tundish designed for casting of blooms. The software program Ansys-Fluent R was employed for the analysis of tundish operation. For the verification of the correctness of obtained results, an industrial experiment was carried out. For modification of the hydrodynamic conditions within the working volume of the tundish, two flow control devices were proposed, namely: a dam and a dam with an overflow window. The outcome of performed computer simulations were liquid steel flow fields and residence time distribution curves.

Numerical Simulation of Behaviour a Non-Metallic Inclusions in an One-Strand Slab Tundish with Steel Flow Controll Devices

2011 ◽  
Vol 56 (3) ◽  
pp. 611-618 ◽  
Author(s):  
A. Cwudziński
Keyword(s):  
Numerical Simulation ◽  
Liquid Steel ◽  
Flow Reactor ◽  
Control Device ◽  
Discrete Phase Model ◽  
Internal Working ◽  
Working Space ◽  
Metallic Inclusions ◽  
Discrete Phase ◽  
Steel Flow

Numerical Simulation of Behaviour a Non-Metallic Inclusions in an One-Strand Slab Tundish with Steel Flow Controll DevicesAn effective refining of liquid steel can be carried out either in a tundish or in the mould of a CSC machine. Being a flow reactor, the tundish performs the function of a link between the steelmaking ladle and the mould. Owing to this fact, the liquid steel resides in the tundish for a specific time, which enables the tundish to be used for refining purposes. For modification oftundish internal working space, two types of flow control device (FCD), namely a ceramic gas-permeable barrier and a subflux turbulence controller (STC), were proposed. For simulation of movement of gas phase and non-metallic inclusions, a discrete phase model was used. The obtained results unambiguously indicate which of the proposed tundish equipment configurations will be more advantageous for intensifying the process of liquid steel refining from NMIs.

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.

scholarly journals Piv Method and Numerical Computation for Prediction of Liquid Steel Flow Structure in Tundish

2015 ◽  
Vol 60 (1) ◽  
pp. 11-17 ◽  
Author(s):  
A. Cwudziński
Keyword(s):  
Computer Simulations ◽  
Liquid Steel ◽  
Laboratory Experiments ◽  
Field Analysis ◽  
Ansys Fluent ◽  
Measuring Systems ◽  
Piv Method ◽  
Commercial Program ◽  
Flow Field Analysis ◽  
Steel Flow

AbstractThis 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.

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