Numerical modelling studies of flow and mixing phenomena in gas stirred steel ladles

Abstract

A three-dimensional computational fluid dynamics (CFD) model was developed to simulate the fluid flow and mixing phenomena in a gas stirred ladle. Particular attention was paid to incorporate the effect of slippage between rising gas bubbles and surrounding fluid in the numerical model, to capture the relevant flow physics in a more effective manner. Various parametric studies were undertaken to examine the effects of gas flow rate, bottom nozzle configurations and tracer addition locations on mixing time. It was observed that the arrangement of bottom nozzles has a great effect on the mixing behaviour in a gas stirred ladle, with off centric gas injection producing shorter mixing time. Mixing time was found to be sensitive to the tracer addition position, particularly for the axisymmetric bottom gas injection system. The predicted results were compared with reported experimental observations and a very good agreement was observed in this regard, thereby establishing the authenticity of the proposed formulation.

Numerical Simulations of Inclusion Behavior and Mixing Phenomena in Gas-stirred Ladles with Different Arrangement of Tuyeres

“…1 effect on the transport phenomena in gas-stirred systems, 13) were not well considered in these mathematical model. 14,16,18) Furthermore it is worth noting that there is still no such work published to study the optimization of bottom tuyeres from the viewpoints of improving both inclusion removal and mixing efficiency. In gas-stirred systems, the inclusion removal occurring mainly in bubbly plume region and liquid surface, is directly related to the degree of turbulence and bubble dispersion in these regions, while the mixing phenomena is mainly directly related to the uniformity of liquid velocity and turbulence, and distribution of dead zone in the whole metallurgical reactor.…”

“…On the other hand, there were also many physical and mathematical investigations been carried out to study the effect of different arrangement of bottom tuyeres on the mixing phenomena, [14][15][16][17][18][19] but the bubble turbulent dispersion force and bubble-induced turbulence, which have important ISIJ International, Vol. 54 (2014), No.…”

“…It is well known that gas blowing has been widely applied in metallurgical processes to enhance the inclusion removal and metallurgical reaction rates and to homogenize the temperature and composition of the melt, and the number, arrangement and gas flow rate of bottom blowing have a great impact on these transport phenomena. Hence, the study of inclusions removal behavior and mixing phenomena under different arrangement of gas blowing in gas-stirred system is necessary and has received considerable attention [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] over the years. Inclusion behavior in gas-stirred system involves complex phenomena, such as inclusion transport due to liquid flow, inclusion growth due to inclusion-inclusion collision and inclusion removal due to flotation and attachment to bubbles, and some models have been proposed to describe these behaviors.…”

A CFD and Experimental Investigation of Slag Eye in Gas Stirred Ladle

“…Liu et al (9) measured slag eye area in a water model for different gas flow rates, slag layer thickness and porous plug locations. Several numerical simulation models [10][11][12][13] have been proposed for investigating the fluid flow and mixing phenomena in gas stirred ladles. Mazumdar et al (14) made an extensive review of physical modelling, combined physical and mathematical modelling and mathematical modelling studies.…”

Effect of Inert Gas Flow Rate on Homogenization and Inclusion Removal in a Gas Stirred Ladle

“…In the ladle process, very often argon stirring is applied. Many studies addressing refining are found in the literature 1–15.…”