Droplet Heat Transfer in Oxygen Steelmaking

Bloated droplet phenomena play a vital role in the refining kinetics of basic oxygen steelmaking. Previous studies have developed extensive models to understand the kinetics of bloated droplets. However, no studies in the open literature address the thermal behavior of bloated droplets for a BOF (Basic oxygen furnace). The present work aims to develop a bloated droplet heat transfer model by incorporating the dynamic and chemical aspects taking place during the time of flight. The calculations were carried out with reasonable assumptions for a single droplet interacting with the slag/emulsion zone. The model was developed with the input experimental data (initial droplet temperature as 1853 K, initial diameter as 6.4 mm with a mass of 1 g, and a slag composition of 32 pct CaO, 35 pct SiO2, 17 pct Al2O3, 16 pct FeO) from Gu et al. Gu et al. and the results were validated. The study highlights the significance of how the chemical kinetics is influenced by the thermal characteristics of a droplet in a real BOF compared to the experimental scenario. The predicted results infer that the heat transfer contributed by radiation is 6 times greater than the convective heat transfer in a droplet. Moreover, by computing the droplet heat transfer efficiency, it was found that a droplet ejected from the hotspot losses approximately 73 pct of maximum heat to the surrounding.