Effect of Electromagnetic Field on an Aluminum Billet in the Rotary Casting Machine

Abstract

The article provides analytical and numerical solutions to the problem of calculating the electromagnetic forces acting on a continuously crystallizing aluminum ingot in a rotary casting machine when exposed to an alternating magnetic field of an inductor. Depending on the adopted assumptions, 2D and 3D computational models are constructed. The analytical solution was obtained on the basis of the 2D computational model with a larger number of assumptions. The numerical solution was obtained on the basis of the 3D computational model that takes into account the actual geometric dimensions and current load. The electromagnetic forces normal to the ingot surface are used to press the ingot melt against the crystallizer’s wheel annular groove. Tangential forces ensure mixing of the crystallizing ingot’s liquid core and contribute to improving the ingot structure. It is shown that the ratio of normal and tangential forces can be controlled by changing the phase shift angle between the currents in the grooves of a three-phase inductor. The obtained analytical expressions show that the relative electromagnetic forces acting on the crystallizing ingot are governed by only three parameters. Based on these parameters, a rapid analysis of electromagnetic forces can be quickly performed for a wide range of equipment items. The dependences of electromagnetic forces on the phase shift angle between the currents in adjacent slots of the inductor are presented. As a result of comparing the analytical and numerical solutions of the problem, a conclusion has been drawn about the validity of analytical expressions for electromagnetic forces. The use of electromagnetic forces makes it possible to achieve more efficient production of continuously cast billets made of non-ferrous metals and alloys.