Prediction of Droplet Generation and Blowing Parameters Helps for Interface Reaction During BOS Processes

Droplet generation phenomenon and its dependence on process parameters have been determined using a predictive numerical model, which predict droplet generation rate based on the blowing number. Evaluation of blowing number is performed depending on lance dynamics, oxygen flow rate and surface tension. The developed model considers surface tension as a function of oxygen, carbon and sulphur content of bath and bath temperature. Bath temperature is predicted using the enthalpy change of oxidation reactions and change of specific heat in each component present in the bath. Predicted end blow carbon concentration and bath temperature correspond well with the experimental values obtained from steel plant. The effect of lance angle and lance height on droplet generation is also taken in account. It has been found that the rate of droplet generation in melt increases with increases of blowing number (NB) and jet momentum onto the metal bath. Bath temperature is found to be more dominating factor for droplet generation process compared to lance height.