INVESTIGATION OF THE MECHANISMS OF FORMATION AND CONTROL OF THE COLLIMATION OF THE “SUBMERGED” ARC COLUMN IN LADLE FURNACE USING SOLID AND HOLLOW ELECTRODES

Abstract

This paper investigates the fundamental mechanisms of formation and methods for controlling the geometric characteristics of a high-current electric arc discharge in ladle furnaces (LFs). The primary objective of the study is to develop a comprehensive analytical framework for the quantitative assessment of the plasma column spatial structure transformation under the specific conditions of a “submerged” arc. The article examines in detail the physical processes that govern the gas-dynamic configuration of the discharge during the transition from a conventional solid electrode to a hollow design operating beneath a layer of high-temperature molten slag. To address this challenge, the author developed a mathematical model based on the magnetic field intensity gradient functional and a rigorous radial force balance. The model accounts for the non-linear coupled effects of the molten slag hydrostatic pressure and internal electrodynamic phenomena on the arc column compression. Particular attention is given to the pressure redistribution effect, wherein the plasma flow transforms into an active shell surrounding a neutral gas stream. This approach provided a theoretical substantiation for the discharge collimation effect and identified the conditions for the arc shape transition from conical to cylindrical upon varying the axial hole diameter of the electrode. The scientific novelty of the work lies in establishing the relationship between electrode geometry and the localization of emission processes in the paraxial zone. The obtained results enable significant optimization of LF energy operating modes through arc burning stabilization and precision control over the directionality of heat fluxes. Practical implementation of the proposed model into the production cycle contributes to a reduction in specific electrical energy consumption, minimization of electrode consumption, and a substantial increase in the operational lifetime of the aggregate refractory lining.