# Maximising heat transfer efficiency in the cold crucible induction melting process

Pericleous, K.A., Bojarevics, V., Djambazov, G., Harding, R.A. and Wickins, M.
(2005)
*Maximising heat transfer efficiency in the cold crucible induction melting process.*
In: EUROTHERM Seminar 82. Numerical Heat Transfer 2005 [Proceedings].
Institute of Thermal Technology, Silesian University of Technology, Gliwice, Poland, pp. 405-414.
ISBN 8392238125

## Abstract

Induction heating is an efficient method used to melt electrically conductive materials, particularly if melting takes place in a ceramic crucible. This form of melting is particularly good for alloys, as electromagnetic forces set up by the induction coil lead to vigorous stirring of the melt ensuring homogeneity and uniformity in temperature. However, for certain reactive alloys, or where high purity is required, ceramic crucibles cannot be used, but a water-cooled segmented copper crucible is employed instead. Water cooling prevents meltdown or distortion of the metal wall, but much of the energy goes into the coolant. To reduce this loss, the electromagnetic force generated by the coil is used to push the melt away from the walls and so minimise contact with water-cooled surfaces. Even then, heat is lost through the crucible base where contact is inevitable.

In a collaborative programme between Greenwich and Birmingham Universities, computer modelling has been used in conjunction with experiments to improve the superheat attainable in the melt for a,number of alloys, especially for y-TiAl intermetallics to cast aeroengine turbine blades. The model solves the discretised form of the turbulent Navier-Stokes, thermal energy conservation and Maxwell equations using a Spectral Collocation technique. The time-varying melt envelope is followed explicitly during the computation using an adaptive mesh. This paper briefly describes the mathematical model used to represent the interaction between the magnetic field, fluid flow, heat

transfer and change of phase in the crucible and identifies the proportions of energy used in the melt, lost in the crucible base and in the crucible walls. The role of turbulence is highlighted as important in controlling heat losses and turbulence damping is introduced as a means of improving superheat. Model validation is against experimental results and shows good agreement with measured temperatures and energy losses in the cooling fluid throughout the melting cycle.

Item Type: | Conference Proceedings |
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Title of Proceedings: | EUROTHERM Seminar 82. Numerical Heat Transfer 2005 [Proceedings] |

Additional Information: | [1] This paper was first presented at EUROTHERM Seminar 82. Numerical Heat Transfer 2005 held from 13-16 September 2005 in Cracow, Poland. |

Uncontrolled Keywords: | induction heating, melting, mathematical modelling |

Subjects: | Q Science > QA Mathematics T Technology > TJ Mechanical engineering and machinery |

Pre-2014 Departments: | School of Computing & Mathematical Sciences School of Computing & Mathematical Sciences > Centre for Numerical Modelling & Process Analysis School of Computing & Mathematical Sciences > Centre for Numerical Modelling & Process Analysis > Computational Science & Engineering Group School of Computing & Mathematical Sciences > Department of Computer Systems Technology School of Computing & Mathematical Sciences > Department of Mathematical Sciences |

Related URLs: | |

Last Modified: | 14 Oct 2016 09:02 |

URI: | http://gala.gre.ac.uk/id/eprint/883 |

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