Characteristic Simulation And Analysis Of Coherent Jet Oxygen Lance Of Converter

Oxygen lance plays a vital role in the modern steel making technology. Its performance influences the quality of the products directly. At present, most of the steel plants adopt the traditional lawal oxygen lance, and the coherent jet technology is being paid more attention by researchers because of its superior performance.The Fluent pre-processing software Gambit has been used to draw the three-dimensional model of traditional four-hole oxygen lance and four-hole coherent jet oxygen lance top-blown converter. Then imported into Fluent to establish the jet model and carry out the calculation. After that, postprocessing software Tecplot, Origin, etc. are used to make the velocity image, velocity streamline, numerical curve, etc. The single phase gas jet of traditional oxygen lance and coherent jet have been simulated. The axial and radial velocity distributions of the two jets are compared, and the influence of the variation of angle on gas jet velocity and spray area is analyzed. The VOF model is applied to simulate the two models, transient behavior of jet, distribution of gas phase velocity, flow state of liquid phase in the molten bath and the influence of oxygen lance position, the angle between nozzles and pressure on the interaction between oxygen lance jet and molten pool are all being analyzed, then making comparison on two aspects, impact depth and impact area. The influence of the change of lance position on these two aspects is verified by water model experiments. The results are in agreement with the numerical simulation.As is shown in the simulation, the supersonic section length of the traditional oxygen lance is about 0.7m, and that of the coherent jet oxygen lance is about 1.5m, which can provide more stirring energy and promote the reaction inside steel liquid. Although the central velocity of the coherent jet is larger, the radial attenuation is faster. Compared with the traditional jet, the jet diameter is increased, but not over expansion. It can be expected to ensure the impact effect when increasing the lance position by using the coherent jet oxygen lance, which is helpful to prolong the life of the oxygen lance. What’s more, the use of coherent jet oxygen lance can also ensure the spray area when decreasing the nozzle angle, which contributes to strengthen the impact in the bath center.