Study on the Formation of Open‐Eye and Slag Entrainment in Gas Stirred Ladle

Thunman, Mikael; Eckert, Sven; Hennig, O.; Björkvall, Johan; Sichen, Du

doi:10.1002/srin.200706297

Cited by 24 publications

(26 citation statements)

References 8 publications

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“…In contrast, the viscosity of the top liquid and interfacial tension between the two liquids has only a slight effect on the open‐eye size. Similar work has been by Thuman et al where they used Ga–In–Sn alloy with a melting temperature of 283 K (10 °C) to simulate the liquid steel and an MGCL 2 ‐Glycerol (87%) solution to simulate the slag. It was found that no open‐eye formed at lower flow rates, but did occur when the gas flow reached a critical rate.…”

Section: Introductionmentioning

confidence: 82%

“…Studies related to studying the open‐eye in a gas‐stirred ladle through physical modeling and numerical simulation have been performed extensively in the past three decades. Yonezawa and Schwerdtfeger carried out cold model measurements using mercury and silicone oil to represent liquid metal and slag, respectively, for investigating the open‐eye size in the ladle.…”

Section: Introductionmentioning

confidence: 99%

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Modeling of the Effect of the Gas Flow Rate on the Fluid Flow and Open‐Eye Formation in a Water Model of a Steelmaking Ladle

Ramasetti

Visuri

Sulasalmi

et al. 2018

steel research int.

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In ladle metallurgy of steelmaking, the role of gas injection into the metal bath is been studied to a great extent as it improves the quality of steel. The size of the open‐eye is associated with higher emulsification of top slag, which intensifies metal–slag reactions, and information about the position and size of the open‐eye is important for effective alloying practice. Moreover, the open‐eye has an effect on the energy balance since it increases heat losses. In this work, experimental measurements and numerical simulations are performed to study the effect gas flow rate on the formation of the open‐eye in a steelmaking ladle. A one‐fifth scale water model is constructed for studying gas injection with single and dual plug configurations. For the numerical modeling, the Multiphase Volume of Fluid (VOF) model is used for simulating the system including the behavior of the slag layer. The physical modeling results show that the open‐eye area changes from 9.22 to 198.34 cm2 when the gas flow rate varies from 0.75 to 15 SLM using a single plug. The effect of the number of plugs on the open‐eye area for the same range of flow rates mentioned above is also studied. The two open‐eye areas generated due to the gas injected through the dual plugs change from 37.59 to 231.1 cm2 when the gas flow rate is increased from 0.75 to 7.5 SLM for each plug in the physical modeling. The numerical simulation results of the open‐eye area are found to be in good agreement with the experimental data obtained from the water model. During the gas stirring process, the slag layer is deformed such that the thickness of the slag becomes thick near to the wall and thin near the slag eye at high gas flow rates. In dual plug system, the two open‐eyes tends to merge and form a huge open‐eye at high flow rates that suits for better alloying purposes. The high‐flow velocity near the surface, which could damage the ladle refractory, tends to be reduced in dual plug system when compared to single plug system.

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Section: Introductionmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Modeling of the Effect of the Gas Flow Rate on the Fluid Flow and Open‐Eye Formation in a Water Model of a Steelmaking Ladle

Ramasetti

Visuri

Sulasalmi

et al. 2018

steel research int.

View full text Add to dashboard Cite

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“…There are only a few works about physical models of the ladle furnace that considered the three phase system gas-steel-slag [3][4][5][6]. These works evaluate several issues, being one of the most important to quantify how much is the mixing time increased by the presence of the slag layer.…”

Section: Introductionmentioning

confidence: 98%

Effect of Slag on Mixing Time in Gas-Stirred Ladles Assisted with a Physical Model

2012

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A 1/6 th water physical model of a 140 tons gas-stirred steel ladle is used to evaluate mixing times ( m at 95% of chemical uniformity) in a two phase system without slag (air-water) and in a more realistic three phase system (air-water-oil) to simulate the argon-steel-slag system and quantify the effect of the slag layer on the mixing time. Slag layer is kept constant at 0.004 m. Mixing times are estimated through measured changes in pH due to the addition of a tracer (NaOH 1 M). The effect of the following variables on the mixing time is evaluated for a single injector: gas flow rate (7, 17 y 37 l/min) and the injector position (R/r= 0, 1/3, , 2/3 and 4/5). Experimental results obtained in this work show good agreement when compared against mixing time correlations reported by Mazumdar for the two phase air-water case (no slag considered). Another comparison is done using the new concept called "effective bath height" proposed by Barati, where the mixing time is a function of the size of the slag layer since this layer dissipates part of the total amount of stirring energy introduced into the ladle by the injection of gas. Agreement is not good in this case. Finally, an estimation of the percentage of the stirring energy dissipated by the slag is computed, including other factors that govern the dissipation of stirring energy. Percentage of energy dissipated by the slag is found to be between 2.7 to 12 % depending on the process conditions.

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“…However, a bare metal surface region, called the "open-eye", will be observable when the velocity of argon bubbles is large enough and the slag layer is relatively thin. The open-eye region increases the amount of oxygen dissolvable in molten steel, therefore resulting in re-oxidation and slag entrapment [8,9]. In addition, the heat loss will escalate due to the argon gas having a comparatively lower temperature than the molten steel.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study on Flow, Temperature, and Concentration Distribution Features of Combined Gas and Bottom-Electromagnetic Stirring in a Ladle

Deng

et al. 2018

Metals

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Abstract:A novel method of combined argon gas stirring and bottom-rotating electromagnetic stirring in a ladle refining process is presented in this report. A three-dimensional numerical model was adopted to investigate its effect on improving flow field, eliminating temperature stratification, and homogenizing concentration distribution. The results show that the electromagnetic force has a tendency to spiral by spinning clockwise on the horizontal section and straight up along the vertical section, respectively. When the electromagnetic force is applied to the gas-liquid two phase flow, the gas-liquid plume is shifted and the gas-liquid two phase region is extended. The rotated flow driven by the electromagnetic force promotes the scatter of bubbles. The temperature stratification tends to be alleviated due to the effect of heat compensation and the improved flow. The temperature stratification tends to disappear when the current reaches 1200 A. The improved flow field has a positive influence on decreasing concentration stratification and shortening the mixing time when the combined method is imposed. However, the alloy depositing site needs to be optimized according to the whole circulatory flow and the region of bubbles to escape.

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Study on the Formation of Open‐Eye and Slag Entrainment in Gas Stirred Ladle

Cited by 24 publications

References 8 publications

Modeling of the Effect of the Gas Flow Rate on the Fluid Flow and Open‐Eye Formation in a Water Model of a Steelmaking Ladle

Modeling of the Effect of the Gas Flow Rate on the Fluid Flow and Open‐Eye Formation in a Water Model of a Steelmaking Ladle

Effect of Slag on Mixing Time in Gas-Stirred Ladles Assisted with a Physical Model

Numerical Study on Flow, Temperature, and Concentration Distribution Features of Combined Gas and Bottom-Electromagnetic Stirring in a Ladle

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