Study on inclined jetting and splashing phenomenon in electric arc furnace steelmaking

In Electric Arc Furnace (EAF) steelmaking, scrap metal is melted by using electric arc and oxy-fuel burner inside the furnace. After that the molten metal is purified by blowing oxygen supersonically into the molten metal which in turn results in splashing of liquids melt on the wall of the furnace. The splashed metal droplets cause wear of furnace wall and loss of production. Optimization of the operating condition (lance angle, lance height and flow rate) may allow less splashing and increase productivity. In the present study, air was injected on water surface in a small-scale model at different lance angles, lance heights and flow rates. Splashed liquid in the forward direction was collected and measured in each case. The forward splashing rate was found to increase with the increase of lance angle from the vertical and flow rate. But the splashing rate is not a monotonous function of lance height. Splashing rate increases with lance height up to a critical distance and after that splashing rate decreases with the increase of lance height. The shape of the cavity was carefully observed by using a video camera and it was found that the splashing was minimum when the cavity was operating in penetrating regime. The critical depth of penetration of water at different lance angle was measured at constant lance height. The critical depth of penetration was found to decrease with the lance angle. A correlation was obtained to determine the critical depth of penetration at different lance angles. Using the values of critical depth of penetration at different lance angle, the Blowing number equation can be corrected to calculate the blowing number at different lance angles. The present study shows that the Blowing number on liquid surface increases with jet angle.