scholarly journals Numerical simulation and industrial practice of inclusion removal from molten steel by gas bottom-blowing in continuous casting tundish

2011 ◽  
Vol 47 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Z. Meijie ◽  
G. Huazhi ◽  
H. Ao ◽  
Z. Hongxi ◽  
D. Chengji
Keyword(s):  
Numerical Simulation ◽  
Residence Time ◽  
Molten Steel ◽  
Volume Fraction ◽  
Dead Volume ◽  
Inclusion Removal ◽  
Industrial Practice ◽  
Bottom Blowing ◽  
Metallographic Images ◽  
Gas Blowing

Gas blowing at the bottom of tundish is an efficient metallurgy technique in clean steelmaking. In this paper, the removal of small size inclusions in the gas bottom-blowing tundish was studied by numerical simulation and industrial practice. The residence time distribution (RTD) of molten steel in the tundish was calculated by mathematical modeling. The content of small size inclusions in the slab was analyzed using a oxygen probing and metallographic images. The results show that the molten steel characteristics obviously change when applied gas bottom-blowing, the average residence time of molten steel in the tundish prolongs more than 100s and the dead volume fraction decreases about 5%. Therefore, the removal efficiency of small size inclusions greatly increases because of bubbles attachment and long moving path. Industrial experiment results show that the average inclusions content of less than 20?m decreases more than 24%, the average overall oxygen content decreases about 15% when controlling the reasonable blowing parameters.

Influence of Turbulence Controller on Flow Mode of Molten Steel in Tundish

2011 ◽  
Vol 189-193 ◽  
pp. 2411-2414
Author(s):  
Tian Fei Ma ◽  
Guo Qi Liu ◽  
Wen Gang Yang ◽  
Jian Bin Yu
Keyword(s):  
Fluid Flow ◽  
Residence Time ◽  
Molten Steel ◽  
Volume Fraction ◽  
Dead Zone ◽  
Plug Flow ◽  
Flow Mode ◽  
Water Modeling ◽  
Slab Caster ◽  
Numerical Computing

According to tundish for thin slab caster in a steel factory, 1:3 water modeling and numerical simulation were established. By measuring RTD(Residence time distribution) curves of fluid flow in tundish, real residence time, plug flow volume fraction and dead zone fraction were computed, influence of turbulence controller structure on flow mode of molten steel in tundish were studied. The results show that fluid flow in tundish can be improved, if turbulence controller has reasonable structure. A reasonable turbulence controller structure was obtained. Water modeling results agree with numerical computing results well.

scholarly journals Modelling of Fluid Flow and Residence Time Distribution in a Five-strand Tundish

2020 ◽  
Author(s):  
Dong-Yuan Sheng ◽  
Qiang Yue
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Volume Fraction ◽  
Fluid Dynamic ◽  
Flow Characteristics ◽  
Passive Scalar ◽  
Control Device ◽  
Dead Volume ◽  
Cfd Modelling

The quantified residence time distribution (RTD) provides a numerical characterization of mixing in the continue casting tundish, thus allowing the engineer to better understand the metallurgical performance of the reactor. This paper describes a computational fluid dynamic (CFD) modelling study for analyzing the flow pattern and the residence time distribution in a five-strand tundish. Two passive scalar transport equations are applied to separately calculate the E-curve and F-curve in the tundish. The numerical modelling results are compared to the water modelling results for the validation of the mathematical model. The volume fraction of different flow regions (plug, mixed and dead) and the intermixing time during the ladle changeover are calculated to study the effects of the flow control device (FCD) on the tundish performance. The result shows that a combination of the U-baffle with deflector holes and the turbulence inhibitor has three major effects on the flow characteristics in the tundish: i) reduce the extent of the dead volume; ii) evenly distribute the liquid streams to each strand and iii) shorten the intermixing time during the ladle changeover operation.

scholarly journals Modeling of Fluid Flow and Residence-Time Distribution in a Five-Strand Tundish

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1084 ◽  
Author(s):  
Dong-Yuan Sheng ◽  
Qiang Yue
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Volume Fraction ◽  
Fluid Dynamic ◽  
Flow Characteristics ◽  
Passive Scalar ◽  
Control Device ◽  
Dead Volume ◽  
Cfd Modeling

Quantified residence-time distribution (RTD) provides a numerical characterization of mixing in the continuous casting tundish-thus allowing the engineer to better understand the metallurgical performance of the reactor. This study describes a computational fluid dynamic (CFD) modeling study for analyzing the flow pattern and the residence-time distribution in a five-strand tundish. Two passive scalar-transport equations were applied to separately calculate the E-curve and F-curve in the tundish. The numeric modeling result were compared to water-modeling results to validate the mathematical model. The volume fraction of different flow regions (plug, mixed and dead) and the intermixing time during the ladle changeover were calculated to study the effects of the flow control device (FCD) on the tundish performance. From the results of CFD calculations, it can be stated that a combination of the U-baffle with deflector holes and the turbulence inhibitor had three major effects on the flow characteristics in the tundish: (i) to reduce the extent of the dead volume; (ii) to evenly distribute the liquid streams to each strand and (iii) to shorten the intermixing time during the ladle changeover operation.

Research on Flow Field of Double-Nozzles Bottom Blowing CAS Process with Properties of Liquid Metal through Numerical Simulation

2013 ◽  
Vol 675 ◽  
pp. 129-134
Author(s):  
Meng Zhou
Keyword(s):  
Numerical Simulation ◽  
Liquid Metal ◽  
Flow Field ◽  
Mixing Time ◽  
Simulation Method ◽  
Refining Process ◽  
Transmission Process ◽  
Dimensionless Analysis ◽  
Bottom Blowing ◽  
Gas Blowing

The Fluid Flow of Liquid Metal in Ladles of CAS-OB Refining Process Is a Complicated Turbulent Transmission Process. it Behaves much More Complicated than in Traditional Ladle because of Immersion Snorkel. this Paper Describes Properties of Liquid Metal Based on Full Buoyancy Model. the Author Analyzes the Characteristics of Flow Field in Single and Double-nozzles Bottom Blowing Condition through Numerical Simulation Method. Double-nozzles Bottom Blowing Could Improve Blending Effect in the Region where Is Weak Mixing. this Paper Also Draws an Empirical Formula which Tells how Gas Blowing and Immersion Depth Influence Mixing Time in CAS-OB Ladle through Dimensionless Analysis.

Assessment of the Design Parameters for Wastewater Treatment by Reverse Osmosis

1999 ◽  
Vol 40 (4-5) ◽  
pp. 269-276
Author(s):  
D. Van Gauwbergen ◽  
J. Baeyens
Keyword(s):  
Reverse Osmosis ◽  
Residence Time ◽  
Volume Fraction ◽  
Transport Model ◽  
Dead Volume ◽  
Design Parameters ◽  
Flow Profile ◽  
Modelling Procedure ◽  
Mass Transport Model ◽  
Spiral Wound

A modelling procedure is presented to predict the fluxes and solute concentrations in different flows for reverse osmosis (RO) spiral-wound modules. Important underlying factors for this procedure are the osmotic pressure for various solutions, the hydrodynamic flow profile in the concentrate channel, and the intrinsic separation characteristics of the membrane material. Experiments were carried out using a flat sheet test cell to determine the parameters of the mass transport model. Results of residence time distribution (RTD)-measurements on an industrial spiral-wound module were used to determine macroscopic fluid flow regimes resulting in the definition of dead volume fraction, average residence time and Pe-number. The evaluation of the modelling procedure has been based on experimental data of an industrial membrane plant system.

scholarly journals Design Optimization of a Single-Strand Tundish Based on CFD-Taguchi-Grey Relational Analysis Combined Method

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1539
Author(s):  
Dong-Yuan Sheng
Keyword(s):  
Residence Time ◽  
Grey Relational Analysis ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Volume Fraction ◽  
Single Strand ◽  
Dead Volume ◽  
Analysis Method ◽  
Relational Analysis ◽  
Grey Relational

A novel digital design methodology that combines computational fluid dynamics (CFD) modelling and Taguchi-Grey relational analysis method was presented for a single-strand tundish. The present study aimed at optimizing the flow control device in the tundish with an emphasis on maximizing the inclusion removal rate and minimizing the dead volume fraction. A CFD model was employed to calculate the fluid flow and the residence-time distribution of liquid steel in the tundish. The Lagrangian approach was applied to investigate the behavior of non-metallic inclusions in the system. The calculated residence-time distribution curves were used to analyze the dead volume fraction in the tundish. A Taguchi orthogonal array L9(3^4) was used to analyze the effects of design factors on both single and multiple responses. Moreover, for the purpose of meeting the multi-objective target functions, grey relational analysis and analysis of variance were used. The optimum positions of the weir and the dam were obtained based on the design targets. A special focus of this study was to demonstrate the capabilities of the Taguchi-Grey relational analysis method as a powerful means of increasing the effectiveness of CFD simulation.

scholarly journals Effect of Thermal Buoyancy on Fluid Flow and Residence-Time Distribution in a Single-Strand Tundish

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1906
Author(s):  
Dong-Yuan Sheng ◽  
Pär G. Jönsson
Keyword(s):  
Fluid Flow ◽  
Residence Time ◽  
Molten Steel ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Volume Fraction ◽  
Heat Losses ◽  
Single Strand ◽  
Cfd Model ◽  
Thermal Buoyancy

Natural convection of molten steel flow in a tundish occurs due to the temperature variation of the inlet stream and heat losses through top surface and refractory walls. A computational fluid dynamics (CFD) model was applied to study the effect of thermal buoyancy on fluid flow and residence-time distribution in a single-strand tundish. The CFD model was first validated with the experimental data from a non-isothermal water model and then applied to both scale-down model and prototype. The effects of flow control devices, including weir, dam and turbulence inhibitor, were compared and analyzed. Parameter studies of different heat losses through the top surface were performed. The results show that thermal buoyancy has a significant impact on the flow pattern and temperature distributions of molten steel in the tundish. The increase of heat loss through the top surface shortens the mean residence time of molten steel in the tundish, leading to an increase in dead volume fraction and a decrease in plug flow volume fraction.

scholarly journals Physical and mathematical modeling of inclusion removal with gas bottom-blowing in continuous casting tundish

2011 ◽  
Vol 47 (1) ◽  
pp. 37-44 ◽  
Author(s):  
M.J. Zhang ◽  
H.Z. Gu ◽  
A. Huang ◽  
H.X. Zhu ◽  
C.J. Deng
Keyword(s):  
Mathematical Modeling ◽  
Removal Efficiency ◽  
Scale Model ◽  
Inclusion Removal ◽  
Large Size ◽  
Residence Time Distributions ◽  
Continuous Casting Tundish ◽  
Bottom Blowing ◽  
Physical And Mathematical Modeling ◽  
Gas Blowing

Gas blowing at the bottom of tundish is an efficient metallurgy technique in clean steelmaking and has been widely concerned. In this paper, spherical alumina particles were selected to model inclusions, 1:3 scale model was utilized, the removal efficiency of inclusions with the gas bottomblowing in the tundish was studied by physical and mathematical modeling. The mathematical model is validated by comparing the predicted and measured residence time distributions and dye flow patterns of tracer. The results show that while the removal efficiency of large size particles has no obvious changes, the gas bottom-blowing has great contribution to the removal of small particles.

scholarly journals Numerical Simulation of Bottom-Blowing Stirring in Different Smelting Stages of Electric Arc Furnace Steelmaking

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 799
Author(s):  
Hang Hu ◽  
Lingzhi Yang ◽  
Yufeng Guo ◽  
Feng Chen ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Molten Steel ◽  
Steel Slag ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Simulation Software ◽  
Model Verification ◽  
Smelting Process ◽  
Arc Furnace ◽  
Bottom Blowing

Electric arc furnace (EAF) steel bottom-blowing can effectively improve the temperature and composition uniformity of the molten pool during smelting process. To explore the effect of molten-steel characteristics on bottom-blowing at various stages of smelting, we divided the smelting process of the EAF into four stages: the melting stage, the early decarburization stage, the intermediate smelting stage, and the ending smelting stage. The numerical simulation software ANSYS Fluent 18.2 was used to simulate the velocity field of molten steel under the condition of bottom-blowing stirring in different stages in EAF steelmaking process. The properties of bottom-blowing and the kinetic conditions of the steel-slag at this interface were investigated. Our results showed that at a bottom-blowing gas flow rate of 100 L/min, the average flow rates of the four stages were v1 = 0.0081 m/s, v2 = 0.0069 m/s, v3 = 0.0063 m/s, and v4 = 0.0053 m/s. The physical model verification confirmed the results, that is, the viscosity of molten steel decreased as the smelting progressed, and the flow velocity of the molten steel caused by the agitation of bottom-blowing also decreased, the effect of bottom-blowing decreased. Based on these results, a theoretical basis was provided for the development of the bottom-blowing process.

scholarly journals Analysis of Optimization Weights for Flow Field of Internal Rotation Stabilizer Coupled with Porous Retaining Wall

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1208
Author(s):  
Ziyu Liu ◽  
Yan Jin ◽  
Feifang Gan ◽  
Peng Lin ◽  
Jingyu Huang ◽  
...  
Keyword(s):  
Flow Field ◽  
Internal Rotation ◽  
Residence Time ◽  
Molten Steel ◽  
Volume Fraction ◽  
Removal Rate ◽  
Retaining Wall ◽  
Wall Structure ◽  
Average Residence Time ◽  
Opening Method

In this paper, the flow field of the approximate T-shaped tundish and the removal rate of fine inclusions are improved by changing the parameters of the flow control device of the SCB (stabilizer coupling baffle) structure. Studies have shown that the synergistic effect of the DPRW (double porous retaining wall) structure and the IRS (internal rotation stabilizer) structure has excellent performance in mixing the temperature composition of the molten steel, increasing the average residence time of the molten steel, reducing the volume fraction of the dead zone, and improving the removal rate of fine inclusions. The opening method and diameter of the double-layer retaining wall have a greater impact on the flow field parameters. The larger the diameter, the more conducive to increasing the average residence time, and the smaller the diameter, the more conducive to increasing the removal rate of fine inclusions.

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