scholarly journals Analysis of the Depth of Immersion of the Submerged Entry Nozzle on the Oscillations of the Meniscus in a Continuous Casting Mold

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 596 ◽  
Author(s):  
F. Saldaña-Salas ◽  
E. Torres-Alonso ◽  
J.A. Ramos-Banderas ◽  
G. Solorio-Díaz ◽  
C.A. Hernández-Bocanegra

In this study the effects of the depth of immersion of the Submerged Entry Nozzles (SEN) on the fluid-dynamic structure, oscillations of the free surface and opening of the slag layer, in a continuous casting mold for conventional slab of steel were analyzed. For this work, a water/oil/air system was used in a 1:1 scale model, using the techniques of Particle Image Velocimetry (PIV), colorimetry and mathematical multiphase simulation. The results of the fluid dynamics by PIV agree with those obtained in the mathematical simulation, as well as with the dispersion of dye. It was observed that working with immersion depths of 100 mm or less could be detrimental to steel quality because they promote surface oscillations of a higher degree of Stokes with high elevations and asymmetry in their three dimensions. In addition, this generates an excessive opening of the oil layer which was corroborated through the quantification of the F index. On the other hand, with depths of immersion in the range of 150–200 mm, lower oscillations were obtained as well as zones of low speed near the wall of the SEN and a smaller opening of the oil layer.

2017 ◽  
Vol 36 (5) ◽  
pp. 551-565 ◽  
Author(s):  
Peng Zhao ◽  
Qiang Li ◽  
Shi Bo Kuang ◽  
Zongshu Zou

AbstractThe slag behaviors, directly relating with the qualities of the final cast products, are influenced by the transient surface flow of liquid steel in a continuous casting mold. A one-half scale model is used to investigate the slag behaviors and their droplets entrainment. The model based on Volume of Fluid (VOF) multiphase coupled with Large Eddy Simulation (LES) is established to further illuminate the phenomena of the liquid oil layer fluctuation, the slag “eye” regions, and the slag entrainment observed in water experiment. The effects of casting speeds on the slag behaviors and their entrained droplets are investigated. The results show that the fluctuation of the oil layer is influenced by the transient flow. The calculations for the oil layer profile, the accumulation, and protrusions of oil layer are consistent with the water experiment. The asymmetry of the slag “eye” regions is also influenced by the asymmetry of free surface and transient turbulent flow. The “eye” regions near the narrow wall show distinct asymmetric change at different casting speeds. At a lower casting speed, the slag “eye” regions change irregularly and display the alternate process of open and collapse at the two sides of the narrow walls of the model. While at a relative higher casting speed, the slag layer gathers toward the nozzle, and the slag “eye” regions gradually grow and always open. The simulation model can reveal that the mechanism of the slag entrainment includes two main modes: the cutting or dragging mode and shear layer instability. The average diameter and amount of the entrained droplets are calculated through the UDF codes of ANSYS FLUENT software, and the size distribution of the entrained droplets is also counted. When the casting speed is lower, the dominant diameters of the entrained droplets range between 2 and 3 mm. With casting speed increase, the distribution of the droplets becomes wider, and there is a gradually increase in the percentage of larger droplets with a size of 4–6 mm.


Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1375
Author(s):  
Alexander Vakhrushev ◽  
Abdellah Kharicha ◽  
Menghuai Wu ◽  
Andreas Ludwig ◽  
Yong Tang ◽  
...  

Continuous casting (CC) is one of the most important processes of steel production; it features a high production rate and close to the net shape. The quality improvement of final CC products is an important goal of scientific research. One of the defining issues of this goal is the stability of the casting process. The clogging of submerged entry nozzles (SENs) typically results in asymmetric mold flow, uneven solidification, meniscus fluctuations, and possible slag entrapment. Analyses of retained SENs have evidenced the solidification of entrapped melt inside clog material. The experimental study of these phenomena has significant difficulties that make numerical simulation a perfect investigation tool. In the present study, verified 2D simulations were performed with an advanced multi-material model based on a newly presented single mesh approach for the liquid and solid regions. Implemented as an in-house code using the OpenFOAM finite volume method libraries, it aggregated the liquid melt flow, solidification of the steel, and heat transfer through the refractory SENs, copper mold plates, and the slag layer, including its convection. The introduced novel technique dynamically couples the momentum at the steel/slag interface without complex multi-phase interface tracking. The following scenarios were studied: (i) SEN with proper fiber insulation, (ii) partial damage of SEN insulation, and (iii) complete damage of SEN insulation. A uniform 12 mm clog layer with 45% entrapped liquid steel was additionally considered. The simulations showed that parasitic solidification occurred inside an SEN bore with partially or completely absent insulation. SEN clogging was found to promote the solidification of the entrapped melt; without SEN insulation, it could overgrow the clogged region. The jet flow was shown to be accelerated due to the combined effect of the clogging and parasitic solidification; simultaneously, the superheat transport was impaired inside the mold cavity.


2020 ◽  
Vol 51 (6) ◽  
pp. 2862-2870
Author(s):  
Meijuan Gan ◽  
Weijie Pan ◽  
Qiangqiang Wang ◽  
Xubin Zhang ◽  
Shengping He

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 428
Author(s):  
Yang Wang ◽  
Jie Feng ◽  
Shufeng Yang ◽  
Jingshe Li

Surface velocity in the continuous-casting mold needs to be studied to better control the quality of steel products. In this paper, the measurement of surface velocity in a 150 mm × 1270 mm slab continuous-casting mold was investigated. Taking the slag layer into consideration, a numerical simulation was performed which was validated by a particle image velocimetry test. A nail-board experiment was also conducted to measure surface velocity in the continuous-casting mold. The effect of nail diameter used in nail-board experiment on the measurement of the surface velocity was also discussed to improve the precision of nail-board experiment result. The results showed that the maximum surface velocity was 0.739 m/s around the mid-section of the free surface, and the results of nail-board experiments were more accurate when the steel nail diameter was 10 mm.


JOM ◽  
2012 ◽  
Vol 64 (9) ◽  
pp. 1080-1086 ◽  
Author(s):  
Yongfeng Chen ◽  
Lifeng Zhang ◽  
Shufeng Yang ◽  
Jingshe Li

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