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Article
Publication date: 7 March 2008

D. Cepīte, A. Jakovičs, B. Halbedel and U. Krieger

To develop the mathematical model, which allows predicting the temperature and flow distribution of an opaque glass melt with the temperature‐dependent properties in case…

Abstract

Purpose

To develop the mathematical model, which allows predicting the temperature and flow distribution of an opaque glass melt with the temperature‐dependent properties in case it is generated by electromagnetic and thermal convection. Analysis has been done for geometry of the model crucible with the immersed rod electrodes. Numerical analysis is used as a tool for finding out the parameters of the system, which allow getting desiderated homogeneity of temperature field by EM action.

Design/methodology/approach

ANSYS CFX software is implemented for coupling of EM, thermal and HD processes in the modelled system. Usability of non‐inductive approximation is shown using a full harmonic analysis in ANSYS.

Findings

External magnetic field can impact the temperature distribution in the whole volume of the melt significantly, it relocates the hottest zones and changes the maximal temperature in the melt. Qualitative agreement between the numerical and experimental results has been obtained. Dependence of the potential difference between the electrodes on the velocity and temperature range has been examined. Impact of different thermal boundary conditions has been analysed.

Research limitations/implications

Effects analysed in the publication occur in each conducting media subjected to the impact of simultaneous electrical and magnetical field. The main limitation is non‐transparency of the melt.

Practical implications

The purpose is to develop a mathematical tool for parameter optimisation of real glass melting furnace.

Originality/value

In the present model temperature dependent properties of the melt have been taken into account, which has been neglected in previous models.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 13 September 2011

V. Geža, A. Jakovičs, U. Krieger and B. Halbedel

The purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.

Abstract

Purpose

The purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.

Design/methodology/approach

Numerical calculations in ANSYS and ANSYS CFX were used to study electromagnetic, thermal, hydrodynamic and chemical mixing processes, results are validated by comparison with experimental data.

Findings

Obtained results show that investigated approach can improve glass melt chemical homogeneity significantly – Lorentz force driven melt movement in conjunction with diffusion process ensures good mixing quality.

Research limitations/implications

The mixing in glass melt is present only in azimuthal direction (in cylindrical coordinate system associated with outlet tube axis) but the radial homogenization is determined by diffusion only.

Practical implications

The experiments in JSJ GmbH with soda lime glass were successful and showed mixing effect in output material, thus providing additional method for glass production.

Originality/value

Although the electrical conductivity of glass is very low, the melt motion is generated by EM forces in this equipment, thus this approach is innovative in glass production technology where typical motion source is buoyancy or mechanical mixing.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 7 January 2020

Ernests Platacis, Imants Kaldre, Ervins Blumbergs, Linards Goldsteins and Karlis Gailitis

The paper aims to optimize calcium difluoride electrical melting process towards creating titanium production with improved morphology by combining titanium reduction and…

Abstract

Purpose

The paper aims to optimize calcium difluoride electrical melting process towards creating titanium production with improved morphology by combining titanium reduction and electroslag melting processes. The study aims to explore optimal electrical heating power in the slag supplied via tungsten electrode and formation of a stable skull layer on water-cooled walls of a cylindrical stainless steel reactor, which is crucial for electroslag melting.

Design/methodology/approach

The multi-physical numerical modelling approach using commercial software COMSOL Multiphysics is presented in the paper by coupling electrical, heat transfer and fluid flow problems. The slag material phase change and corresponding changes of physical properties such as electrical conductivity and viscosity are modelled by step function, sharply changing value of parameter near the phase change temperature. A parametric study of applied electrical power has been carried out to find optimal conditions for the skull-layer formation.

Findings

The paper provides an estimation of necessary electrical power to avoid overheating or solidification of the top layer of slag, which is unacceptable for the combined Kroll process. The study also revealed important poloidal buoyancy flow with characteristic velocity of few cm/s of in the reactor, which governs the heat transfer process and formation of the skull layer.

Research limitations/implications

The presented simplification in numerical model offers high calculation speed but lacks fully developed phase change model, e.g. excluding latent heat. Also, heat transfer through radiation is neglected in the model.

Originality/value

The paper presents an original way to overcome the complexity of modelling slag electrical melting/solidification phenomena using temperature-dependent properties with step functions.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 17 January 2020

Maxim Khatsayuk, Viktor Timofeev and Viktor Demidovich

The purpose of this study is research and development of the magnetohydrodynamics (MHD)-vortex technology.

Abstract

Purpose

The purpose of this study is research and development of the magnetohydrodynamics (MHD)-vortex technology.

Design/methodology/approach

The main instruments of research are mathematical modeling. For mathematical modeling used numerical and analytical both methods. For verification was made small copy of facility with forming of vortex in rotating magnetic field.

Findings

The design and manufacture of the industrial unit for melting small metal waste in a gas-fired smelt furnace has been completed.

Originality/value

Here shows new algorithm for engineering calculation of arc induction systems with take into account longitudinal edge effect and discrete distribution of current layers. Also shows verification of numerical results. Presented new MHD-technology for forming vortex in electromagnetic field.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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