Behavior of Jet from Nozzle Set on Side Wall of Lance

In a top-blowing converter, when a distance between the top-blowing lance and the molten metal surface increases, post-combustion ratio increases, but its heat transfer efficiency to the molten metal decreases. Therefore, a fundamental study of a gas jet behavior from the lance nozzles was carried out in order to develop a new oxygen top-blowing lance with side nozzles with the aim of achieving both higher post-combustion ratio and higher heat supply to the molten metal in converter. In order to design the shape of the side nozzles and blowing conditions, cold model experiments and numerical calculations were carried out to investigate the effect of the inclination angle of the side nozzles and the flow rate on the gas jet behavior of the nozzles. It was found that the gas jet from the side nozzles was deflected to the direction away from the side wall of the lance due to a difference in the pressure distribution at the nozzle outlet. The deflection angle can be estimated by an equation using the supply pressure, atmospheric pressure and inclination angle of the nozzle.