Influence of an external alternating electromagnetic field on convective flows in the bath of an ore-thermal furnace during the melting of oxide refractory materials

Abstract

Electric arc melting of oxide materials under the influence of an external electromagnetic field is a high-current and high-temperature technological process, accompanied by powerful electric and magnetic fields and complex structural motion of the melt. In the general case, the movement of the melt in the bath of an electric arc installation is determined by a combination of thermocapillary, thermal concentration, thermal and electromagnetic convections. In this work, based on the analysis of convective flows and the calculation of the integral vortex field of Archimedes forces and electromagnetic forces in the bath, using the OKB-2126A ore-thermal furnace for melting oxide refractory materials as an example, an assessment of thermal and electromagnetic convections was carried out. For the first time it has been established that the value of the integral vorticity of the field of electromagnetic forces in the depth of the bath exceeds the integral vorticity of the field of Archimedes forces by 3-4 times. In real objects, this difference is even greater, since, compared to those accepted in the calculations, the actual current density in the bath is higher, and the temperature difference is lower. Thus, electromagnetic convection in ore-thermal furnaces for melting oxide materials significantly exceeds thermal convection and makes a decisive contribution to the formation of the structure and intensity of melt movement.

Criterial dependencies of the movement of the melt refractory material in the bath of an ore thermal furnace under electromagnetic influence

“…As a result, the melting process is intensified, energy consumption is reduced, and the chemical and temperature homogeneity of the melt increases, which helps improve the quality of the final product. In this case, the effectiveness of the electromagnetic effect depends on both the structure and the speed of the resulting movement of the melt in the bath of the electric arc furnace [1][2][3].…”