Comparison between axial and radial melt stirring on purification of industrial aluminum during Ohno Continuous Casting

TY - JOUR

T1 - Comparison between axial and radial melt stirring on purification of industrial aluminum during Ohno Continuous Casting

AU - Fashu, S.

AU - Khan, R.

N1 - Publisher Copyright: © 2016 Karabuk University

PY - 2016/12

Y1 - 2016/12

N2 - With the purpose of enhancing the purity of a dilute industrial aluminum alloy during Ohno Continuous Casting (OCC) process, the melt mechanical stirring direction which can effectively and uniformly transport the accumulated solute rich liquid ahead of the solid-liquid interface into the bulk melt was numerically determined. Steady axial and transverse convective velocity cells were induced into the melt through mechanical stirring (at the same intensity) to produce rotational convective flow fields near the solid-liquid interface and their effect on solute transport were compared. For the same mechanical stirring intensity, axial stirring produced stronger melt velocity flow magnitudes than transverse stirring and these convective axial cells deeply penetrated the solute boundary layer. Due to the concave shape of the interface, axial stirring cells non-uniformly thinned the solute boundary layer producing a deep depression at the centre of the solute boundary layer whereas transverse stirring uniformly and weakly thinned the solute boundary layer. It was concluded that, with concave interfaces, the use of transverse stirring with higher velocity magnitudes in the melt is effective in uniformly thinning the solute boundary layer to produce pure, uniform and unidirectional ingots. For more flat interfaces, axial stirring was found to be a better method of uniformly thinning the solute boundary layer to produce uniform and ultrapure ingots without destabilizing the interface.

AB - With the purpose of enhancing the purity of a dilute industrial aluminum alloy during Ohno Continuous Casting (OCC) process, the melt mechanical stirring direction which can effectively and uniformly transport the accumulated solute rich liquid ahead of the solid-liquid interface into the bulk melt was numerically determined. Steady axial and transverse convective velocity cells were induced into the melt through mechanical stirring (at the same intensity) to produce rotational convective flow fields near the solid-liquid interface and their effect on solute transport were compared. For the same mechanical stirring intensity, axial stirring produced stronger melt velocity flow magnitudes than transverse stirring and these convective axial cells deeply penetrated the solute boundary layer. Due to the concave shape of the interface, axial stirring cells non-uniformly thinned the solute boundary layer producing a deep depression at the centre of the solute boundary layer whereas transverse stirring uniformly and weakly thinned the solute boundary layer. It was concluded that, with concave interfaces, the use of transverse stirring with higher velocity magnitudes in the melt is effective in uniformly thinning the solute boundary layer to produce pure, uniform and unidirectional ingots. For more flat interfaces, axial stirring was found to be a better method of uniformly thinning the solute boundary layer to produce uniform and ultrapure ingots without destabilizing the interface.

KW - Axial stirring

KW - Forced convection

KW - Solutes

KW - Transverse stirring

UR - http://www.scopus.com/inward/record.url?scp=85032979977&partnerID=8YFLogxK

U2 - 10.1016/j.jestch.2016.09.005

DO - 10.1016/j.jestch.2016.09.005

M3 - 文章

AN - SCOPUS:85032979977

SN - 2215-0986

VL - 19

SP - 2100

EP - 2108

JO - Engineering Science and Technology, an International Journal

JF - Engineering Science and Technology, an International Journal

IS - 4

ER -