| The oxygen lance is the essential equipment for modern oxygen steelmaking process whose performance is decided by oxygen jet characteristic that is sprayed out by oxygen lance nozzle. In view of coherent jet technology characteristic which is used in electric furnace, jet test experiment, high temperature simulating experiment and numerical simulation study were carried on in this article. In order to provide theoretical basis for using coherent jet technology in the steel-making, jet characteristic of traditional supersonic oxygen lance and coherent jet oxygen lance were studied systematically.Physical simulation experiment was carried out by using rapid scanning oxygen lance examination system with the microcomputer control hydraulic servo'multi- spots pressure in laboratory. The cold experiment testing to traditional supersonic oxygen lance and coherent jet oxygen lance with helium side was carried on by this equipment to test, and regarding to coherent jet that was formed by propane and pure oxygen burning, high temperature simulation test was carried on as well as by using coherent jet oxygen lance. Weakening rule of middle line speed for traditional supersonic oxygen lance and velocity distribution rule of coherent jet flow field with low density helium were obtained by cold experiment test. The process and phenomenon of high temperature simulation indicated that because external main jet was surrounded by high temperature burning flame, there was more rigidity to coherent jet, thus one kind of jet likes to laser-beam could be formed, which makes the central oxygen jet could keep relative coherent state on a certain degree.In the part of numerical simulation,according to computational fluid dynamics principle, Laval nozzle oxygen lance head , traditional supersonic oxygen lance and mathematical model of coherent jet oxygen lance were established separately by GAMBIT software, and numerical simulation research on oxygen lance jet characteristic was also carried out by using FLUENT software. Such as flowing situation in Laval nozzle under different operating mode condition, flow characteristic of traditional supersonic jet when operating pressure and ambient temperature was different and the effect of different craft parameters to flowing characteristic of coherent jet flow field with helium side were discussed mainly. Numerical simulation results indicated that the axis speed weaken of supersonic coherent oxygen lance jet is much slower than traditional supersonic jet, and the length of core area and supersonic area length increased obviously, which makes the central jet could keep initial velocity and impact momentum in a long distance from nozzle outlet. |
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