TY - GEN

T1 - Mathematical modeling and optimization of hydrogen degassing in an argon-stirred ladle

AU - Karouni, F.

AU - Wynne, B. P.

AU - Talamantes-Silva, J.

PY - 2017/1/1

Y1 - 2017/1/1

N2 - A three-phase, transient model for hydrogen degassing of molten steel in an argon-stirred, slag-covered ladle has been developed based on the Eulerian method. The slag layer is treated as a separate phase with bubble coalescence and breakup accounted for using a discrete population balance model. A k-e turbulence model with a bubble induced source term is included along with drag, lift, turbulence dispersion, and wall lubrication submodels for the interfacial force terms. The model predictions are validated using industrial data from a vacuum arc degasser at Sheffield Forgemasters International Ltd. The effect of different ladle design and process parameters are subsequently investigated. Raising the argon injection rate from 0.07 to 0.21 m3min-1 is found to double the hydrogen degassing efficiency. The optimum efficiency is obtained for a porous plug placement at a radial distance of r/R=0.6, which is 24% more efficient than a central plug. A ladle aspect ratio of L/D=2 produces an increase in degassing efficiency of 32% compared to an aspect ratio of L/D=1.25, while the presence of a 10mm slag layer is shown to reduce efficiency by 26% in comparison to a slag free melt.

AB - A three-phase, transient model for hydrogen degassing of molten steel in an argon-stirred, slag-covered ladle has been developed based on the Eulerian method. The slag layer is treated as a separate phase with bubble coalescence and breakup accounted for using a discrete population balance model. A k-e turbulence model with a bubble induced source term is included along with drag, lift, turbulence dispersion, and wall lubrication submodels for the interfacial force terms. The model predictions are validated using industrial data from a vacuum arc degasser at Sheffield Forgemasters International Ltd. The effect of different ladle design and process parameters are subsequently investigated. Raising the argon injection rate from 0.07 to 0.21 m3min-1 is found to double the hydrogen degassing efficiency. The optimum efficiency is obtained for a porous plug placement at a radial distance of r/R=0.6, which is 24% more efficient than a central plug. A ladle aspect ratio of L/D=2 produces an increase in degassing efficiency of 32% compared to an aspect ratio of L/D=1.25, while the presence of a 10mm slag layer is shown to reduce efficiency by 26% in comparison to a slag free melt.

KW - degassing

KW - hydrogen

KW - modelling

KW - population balance

KW - slag

UR - http://www.scopus.com/inward/record.url?scp=85024926800&partnerID=8YFLogxK

M3 - Conference contribution book

AN - SCOPUS:85024926800

T3 - AISTech - Iron and Steel Technology Conference Proceedings

SP - 1479

EP - 1490

BT - AISTech 2017 - Proceedings of the Iron and Steel Technology Conference

T2 - AISTech 2017 Iron and Steel Technology Conference

Y2 - 8 May 2017 through 11 May 2017

ER -