Numerical Simulation Of Coherent Jet Oxygen Lance For Converter Steelmaking

The structure of coherent jet oxygen lance, a new type of oxygen lance, is created by adding side holes surrounding the nozzle. The high temperature and low density fire generated by combustion reaction of concomitant gas in holes can protect the main oxygen jet. Compared with traditional supersonic oxygen lance, coherent jet oxygen lance has lots of features such as slow attenuation of main oxygen jet and long potential core length. Coherent jet is widely concerned quickly as soon as pushed out and it is successfully applied to the electric furnace steelmaking, but it is rarely applied to converter. The research of coherent jet oxygen lance on converter becomes more and more important because of converter steelmaking difficulty.In the paper the converter capacity is 120 t.The forming reason of coherent jet was studied fundamentally by using Fluent software to simulate and calculate. The reasonable structure of nozzle of coherent jet oxygen lance was confirmed by analyzed simulated result of coherent jet flow field. Different kinds of concomitant gas were selected and choosing reasonable gas by analyzed simulated result of coherent jet flow field. Analyzing the impact of change of concomitant gas pressure and ambient temperature on fire length and flow field.The simulation of traditional supersonic oxygen lance and coherent oxygen lance blow molten pool was done and the results were analyzed, it offers theoretical reference for applying coherent jet oxygen lance on converter steelmaking.The fire generated by combustion reaction of concomitant gas in holes can protect the main oxygen jet, it reduces the entrainment effect between oxygen jet and jet field effectively, the velocity attenuation of main oxygen jet is slow, the potential core length is 4~5 times than potential core length of traditional supersonic jet. When traditional supersonic oxygen lance and coherent jet oxygen lance blow molten pool,coherent jet obtains better result to molten pool compared with traditional supersonic jet. The result help improve the dynamic condition during the steelmaking process and increase the oxygen utilization and get more metal. The maximal depth of penetration and the average depth of penetration of Coherent jet oxygen lance at 40 times of De lance height are deeper than that of traditional oxygen lance at 20 times of De lance height. Coherent jet oxygen lance at high lance height blow the molten pool can replace traditional supersonic oxygen lance at low lance height.