Study of the conditions of gas-liquid flow formation during the tapping of the melt from the converter

The study of the conditions for the formation of a gas-liquid flow during the tapping of molten metal from the converter is based on low-temperature modeling, aimed at analyzing the impact of the structural characteristics of the steel tapping channel. The use of inert gas (argon) enabled the creation of a protective gas shell that reduces the contact of the metal with atmospheric oxygen, lowering its content in the flow to 1–3%. Based on the experiments, a classification of blowing regimes and empirical dependencies were developed to describe the interaction between the gas and the liquid. It was established that the minimum oxygen concentration in the gas phase (1–3%) is achieved with an argon flow of 10–20% of the maximum. This maintains the efficiency of the protective shell at 95%. Further increases in the argon flow lead to the expansion of the flow's opening angle, negatively impacting its organization. Increasing the number of nozzles improves flow stability: with six nozzles, the oxygen concentration remains below 10.5%, even with high gas flow rates. Experiments on a flat tapping channel model revealed a dependence between the gas flow, liquid level, and the depth of the vortex. Increasing the gas flow with a high liquid level contributes to the stability of the interfacial surface, whereas reducing the liquid level leads to an increase in vortex depth and deterioration of the flow organization. The experiments were conducted on a laboratory setup simulating the tapping process, accounting for geometric and dynamic similarity. Technically pure argon with an oxygen content of up to 0.7% was used. The main parameters for analysis included gas flow rate, liquid level, relative vortex depth, and flow opening angle. To assess the effectiveness of the gas shell, oxygen concentration was analyzed using a gas analyzer. The proposed optimal conditions include controlling the argon flow rate, liquid level, and the number of nozzles. It was established that an argon flow rate of 0.05–0.125 m³/min ensures effective protection of the melt, and an optimal flow opening angle of up to 3° contributes to efficiency levels of 92–99%. The obtained results are of significant practical importance for improving the tapping process, refining, and reducing steel oxidation. The developed dependencies allow for more accurate determination of blowing parameters and optimization of the tapping channel design, thereby enhancing the efficiency of metallurgical processes