Numerical Simulation Of Rotating Magnetic Field And Linear Magnetic Field On Electromagnetic Stirrer

Electromagnetic stirring technique has been widely used in steel industry,especially in continuous casting process. The mixing of liquid steel is relied onelectromagnetic stirrer inspires change magnetic, then generates Lorentz force. Toeach shape of steel in different positions, it uses different electromagnetic stirrers. Therotating electromagnetic stirrer used on billet and round bloom in mold, it is relied onelectromagnetic force to complete fully mixing of liquid steel, The linearelectromagnetic stirrer used on slab in secondary cooling zone, it is relied onelectromagnetic force to complete linear motion of liquid steel. Based on the theory ofelectromagnetic field, the electromagnetic stirring process for different positions havebeen simulated to study the change rules of magnetic flux density, electromagneticforce and flow velocity for the liquid metal with the help of the ANSYS software inthis paper.For350*350mm bloom continuous casting process, Lorentz force and flowingpatterns are investigated at the fixed condition of currents and dimension of the stirrer.From the simulation of different frequencies, when frequencies is at6Hz, themagnetic intension and Lorentz force are reaching maximum values and a peak valueof flowing rate is also appeared at this frequency. From all the results of2Hz to8Hz,there is an optimum value in this range of frequencies. Meanwhile, from the Lorentzforce distribution, it can be seen that, at the bottom of the stirrer, a vertical forcevector opposed to the casting direction is clearly displayed which could reduce thedepth of hot liquid steel running from nozzle. For200*200mm bloom continuouscasting process, it is numerically calculated and analyzed the magnetic flux densityand Lorentz force in Clem type winding electromagnetic stirrer under the conditionsof current variation and frequency variation, and conducted experimental comparison.Results show that the Lorentz force of Clem type winding electromagnetic stirrer isgreater than six poles electromagnetic stirrer, when frequency is3Hz, the Lorentzforce is maximum, the calculated values and experiment values are fitted. For roll type electromagnetic stirring in slab, it simulates on internal magneticfield changes of slab under different frequencies(5Hz、7Hz、10Hz), different ampereturns(400A/84N、360A/91N、320A/105N), different thickness(150mm、180mm、200mm), and researches change rules of internal slab in different arrangement. It isindicated that the magnetic flux density decreases with increasing frequency andLorentz force increases with increasing frequency; both of them increases withincreasing ampere turn; The thinner slab generates the greater magnetic inductionintensity and the greater the electromagnetic force along width direction of slab.Compared the arrangement of edge to edge and corner to corner, the area of magneticinduction intensity and electromagnetic force in arrangement of face to face is slightlysmaller, but the value is greater. This arrangement can obtain flow field distribution ofstability and stirring speed greater.