Numerical Study on the Effect of Electrode Polarity on Desulfurization in Direct Current Electroslag Remelting Process

Liu

et al. 2019

Metals

A slag treatment method was proposed to recycle rejected electrolytic manganese metal. To improve the sulfur removal ratio, computational fluid dynamics and experimental studies of the sulfur transfer behavior during the refining process were carried out. Experiments of slag-metal reaction for desulfurization were carried out using an electric resistance furnace at temperatures ranging from 1773 K to 1923 K. A transient three-dimensional coupled numerical model was established to represent the three-phase flow, heat and mass transfer in the experiment. The desulfurization rate was described by a metallurgical kinetics module, which was related to the slag composition, the interfacial tension coefficient, the flow and the temperature of the melt. The predicted sulfur content agreed reasonably well with the measured data. The temperature of the fluids at the outer side of the crucible was higher than that at the center, resulting in a larger sulfur partition ratio and a more vigorous flow. The sulfur transfer rate was higher at the outer edge of the molten slag–molten manganese interface. The sulfur removal ratio increased from 51.4% to 85.1% with a change in heating temperature from 1773 K to 1873 K, and slightly dropped to 83.3% when the heating temperature increased to 1923 K. The heating temperature of 1873 K is the optimal choice for recycling in the present work.

Section: Cfd Modeling Frameworkmentioning

confidence: 99%

“…As mentioned above, the temperature at the outer layer of the crucible is higher. A larger sulfur partition ratio is therefore created according to Equation (20). Furthermore, the higher temperature is able to promote the movement of the molten slag and the molten manganese.…”

Section: Flow Pattern and Temperature Distributionmentioning

confidence: 99%

Study on Sulfur Transfer Behavior during Refining of Rejected Electrolytic Manganese Metal

Liu

et al. 2019

Metals

“…At inlet and outlet, the magnetic flux density is continuous and equal to zero near the wall [13] and Mx = My = ∂Mz ∂z = 0; Wall: Mx = My = 0 and Mz = I 2πr . Evolution of the melting rate is solved by an iterative method, as follow [12]: (11) Here, the symbol ψ represents the power efficiency. It is hard to decide the power efficiency accurately as to the complex physical and chemical process.…”

Section: Boundary Conditions and Solution Proceduresmentioning

confidence: 99%

“…Kelkar et al [10] studied the effect of the various process parameters on temperature profiles, flow field, and pool shapes with flat electrode tip in the traditional ESR process. Wang Q et al [11] employed a transient 3D model to understand the role of slag thickness on the formation of metal bath with flat electrode tip in the ESR process. They found that changing the slag thickness could non-monotonically alter the slag temperature.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the effect of electrode tip on formation of metal droplets and temperature profile in a vibrating electrode electroslag remelting process

Baleta

Wang³

et al. 2019

Open Physics

Self Cite

In the present work, a transient full-coupled modelling approach has been put forward to study the effect of electrode tip on formation of metal droplets and temperature profile in the electromagnetically-controlled electroslag-remelting furnace with vibrating electrode. The electromagnetic field, momentum and energy conservation equations are solved simultaneously based on the finite volume method. The interface of slag and metal is traced using the volume of fluid approach. The results show that in the case of cone tip electrode the average dimension of metal droplets is smaller compared to the flat tip electrode. In addition, the bigger and stretched metal droplets are not observed with the cone tip electrode. The temperature fields with the cone tip electrode are distributed in a prominent periodic pattern compared to the case with flat tip electrode. The maximum temperature zone with the cone tip electrode is located along the z axial in the upper part of slag, not in the lower part. When the frequency changes from 0.17 Hz to 1 Hz, the maximum temperature reduces from 2050 K to 1985 K and the peak value of velocity decreases from 0.20 m/s to 0.125 m/s. When the vibration amplitude varies from 3mm to 6mm, the maximum temperature in the slag cover drops by 3.9% and the peak value of velocity rises by 16.7%.

“…The effect of electrode immersion depth, power control function, slag thickness, solidified slag, and current on multi-physical fields are also discussed. [33][34][35][36][37] Dong et al [38,39] investigated a novel singlepower two-circuit ESR process (ESR-STCCM) with currentcarrying mold via numerical simulation and experimental research. A 2D quasi-steady-state mathematical model was established to describe ESR-STCCM.…”

Section: Introductionmentioning

confidence: 99%

A Sequence‐Coupled Mathematical Model of Magneto‐Hydrodynamic Two‐Phase Flow and Heat Transfer in a Triplex‐Electrode Electroslag Remelting Furnace

Liu

2019

steel research int.

Self Cite

The triplex‐electrode electroslag remelting (TE‐ESR) furnace has the three‐phase equilibrium power supply which has the advantages of balanced load and reasonable short network structure, leading to a higher power factor. A transient three‐dimensional (3D) sequence‐coupled mathematical model is developed to explore the magneto‐hydrodynamic two‐phase flow and heat transfer in the TE‐ESR furnace. Compared to the traditional ESR process, the electromagnetic field, fluid flow, temperature, and solidification in the TE‐ESR system is completely different. Electric current has a tendency to gather beneath the top part of slag layer, with small amount entering the metal bath and the solidified ingot. The maximum Joule heating does not distribute beneath the interface of electrode and slag, but between adjacent electrodes. The thermal distribution in the TE‐ESR process is much more uniform than in the traditional ESR process, which is beneficial to improving ingot quality, especially heavy ingots. It can be observed that there is a pair of recirculation zones beneath the bottom of each electrode, caused by the formation and dripping of metal droplets. When the melting rate is increased to 0.03 kg s−1, the depth of the metal bath profile increases from 0.16 to 0.165 m.