| In a some iron and steel company, the low mixing efficiency for temperature andcomposition of molton steel and entrapment or overflow of the slag often occurred in the processof argon bottom blowing refining of70t ladle. In this paper, a three-dimensional mathematicalmodel with1:1ratio has been established. The effect of arrangement of porous plug and theargon gas flow rate on the70t ladle refining process have been investigated. The results usingoptimized process were tested by comparing with the results of physical model experiment. Theresults show that:(1) The flow field of molten steel in the ladle is uniform and reaches stable state quicklywhile using two porous plugs off-centered in the bottom, however, the loss of turbulent kineticenergy and the ratio of "dead zones" become larger compared with using single porous plugbecause of the collision of the two rising gas column.(2) While the position of porous plug in the bottom of ladle changes from0.4R to0.6R, thecollision angle between the molten steel and ladle wall became small. It can reduce the loss ofthe turbulent due to collision of molten steel with the ladle wall and increase the average speedof molten steel.(3) Adopting optimum process with single plug at0.5R off-centered in the bottom of ladleand the argon gas flow rate is200NL/min，the mixing time reduce50.9%and the ratio of the"dead zone" reduce8.31%.In addition, multiphase VOF model was applied to investigate the flowing behavior ofphase interface among the steel-slag-air-argon in the70t ladle. The result shows that:(1) Increasing the ratio of blowing argon or setting the porous plug near to the wall of theladle, the velocity of the surface of molten steel and the exposed area of liquid steel increases.(2) Compared with the standard atmosphere pressure condition, the flow rate of argon of theladle increases and the argon stirring ability enhancement under the67Pa pressure. The exposedarea of molten steel decreases owing to the reduced argon volume in the slag. |
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