Numerical Simulation on the Brake Effect of FAC-EMBr and EMBrRuler in the Continuous Casting Mold

Abstract

The brake effect of the freestanding adjustable combination electromagnetic brake (FAC-EMBr) and EMBr ruler on the behavior of molten steel flow and the level fluctuation were investigated with the numerical method. The effects of the horizontal magnetic pole position (EMBr ruler), magnetic induction intensity, and casting speed on two types of electromagnetic brakes were studied. The numerical simulation results show that the magnetic field caused by the EMBr ruler is mainly distributed under the submerged entry nozzle (SEN), and it is very weak nearby the meniscus area. After the FAC-EMBr is applied, the magnetic field is mainly distributed in the area below the submerged entry nozzle, the upper roll region, and in the meniscus region. The application of the electromagnetic brake can effectively suppress the impact of the jet and decrease the molten steel velocity in the meniscus area. The brake effect of the EMBr ruler on the behavior of the molten steel flow and the level fluctuation is significantly influenced by the horizontal magnetic pole position. The increasing of the magnetic flux density can significantly increase the velocity of molten steel in the upper roll region and lead to an intense fluctuation in the steel/slag interface, as the horizontal magnetic field cannot cover the three key regions. The brake effect of the FAC-EMBr is less influenced by the variation of the process parameters due to the addition of vertical magnetic poles. Additionally, the “secondary braking effect” of the vertical magnetic poles can help to lower the increase of velocity in the upper roll region caused by the excessive magnetic induction intensity and the high casting speed. Therefore, even under the high casting speed conditions, the application of a new type of FAC-EMBr is also an efficient way to suppress the molten steel flow and level fluctuation at the meniscus area and decrease the possibility of slag entrapment.

Influences of the Braking Effect of Ruler EMBr on Molten Steel Flow and Steel–Slag Interface Fluctuation in a Continuous Casting Mold

“…The top surface of the mold defined as a symmetrical boundary condition is a free surface, where the normal gradients of velocity component and other variables perpendicular to the free surface are set to a value of zero [14]. The central plane of mold width is a symmetrical plane with the same boundary condition as the free surface [21]. The mold wall is defined as the boundary condition of the non-slip insulation wall, in which the normal component of induced current and the normal gradients of other variables are set to a value of zero [23].…”

“…According to the above description, it is clear that the braking effect of EMBr technology has beneficial effects on the continuous casting process if applied correctly. In general, the braking effect exerted by the EMBr technology is greatly influenced by the processing and electromagnetic parameters [21]. By that, to achieve a desirable braking effect of the EMBr technology, the electromagnetic parameters should be matched with the variation of the processing parameters.…”

Asymmetric Flow Control in a Slab Mold through a New Type of Electromagnetic Field Arrangement

“…The behavior of molten steel flow and level fluctuation under the effect of steady electromagnetic field can be described by Navier-Stoke's equations and the VOF equation, together with Maxwell's equations, which can be found in References [23,24].…”

“…The mesh in the fluid region is shown in Figure 4 (mesh for Case 3). The procedures of the mesh independence test and mathematical model validation can be found in References [23,24].…”