A mathematical model has been developed to analyze the mass transfer in the sequence continuous casting process with the static magnetic field. The induced electromagnetic force is obtained by solving simultaneous equations for the momentum and the electromagnetic field. The application of static magnetic field affects the mass transfer by changing the flow field in the strand. The results of numerical calculation show a reasonable agreement of the calculated relative concentration of mixed steel with the measured one. The mixing of molten steel in the low part of the mold is significantly suppressed by the static magnetic field, and composition of new grade steel along the slab length in the transition zone increases significantly. The distribution of relative concentration averaged at cross section changes from parabolic to integral symbolic-like along the slab length, and the transition length is reduced about 50% by applying the magnetic field of 0.5 T.

A mathematical model has been developed to analyze the circulating flow characteristics in RH Degassing vessel designed for two-and multi-legs system. The homogeneous model with the spatially variable density was used to simulate gas-liquid flow in up-legs. The difference of density between pure liquid and gas-liquid was considered to be a driving force of circulation flow. The volume fraction of gas was obtained by modifying the gas plume model of the stirred ladle. The complicated geometry including ladle, vacuum, up-legs, and down-leg was considered by incorporation of blockage technique. Numerical calculations of the circulating flow have been conducted for the water model of RH degassing vessel with twoand multi-legs with changing the air flowrates from 5 to 35 l/min. Computed velocities at the exit of downleg agree well with the observed data available in the literature. The momentum transport in RH degassing vessel with multi-legs will be larger than that with two-legs. This is justified based on fact that the velocities in RH degassing vessel with multi- legs tend to be uniform, i.e. the mean velocity of bulk in a ladle is remarkably larger than that in two-legs. Simulated transient concentration profile of the tracer from top surface to interior shows clearly the difference of flow characteristics between two-and multi-legs RH degassing vessels.

Fluid flow and mixing process in a bottom stirring electrical arc furnace (EAF) with the single-and multiplug are experimentally and numerically studied. A homogeneous fluid with a spatially variable density is used to model the gas-liquid flow. k-e turbulence model is employed to calculate the effective viscosity. The five layouts are selected to examine the mixing times. The mixing time is defined as the function of the diameter, number, location of plugs and the tracer injection point. The results show that the variation of mixing time is not obvious with the increasing of plug diameter, but the stirring efficiency is getting better when plug number is increased and distributed in deep and off-central region in vessel. This is because the angular velocities occur and the more stirring energy is obtained in such layouts.