Modeling And Optimizing Of Bottom-argon-blowing Process For Ladle Furnace

The technology of Bottom-Argon-Blowing (BAB) becomes a pivotal procedure of refining processes of Ladle Furnace, because of its good metallurgical results, such as highly stirring, distributing ingredient and temperature, increasing the rate of chemical reaction, removing inclusions and so on. The current BAB technique has flaws such as ambiguous regulations, keeping unchanged pressure, lacking concise adjustment and limited adjusting range. In this thesis, based on the hydraulic model for result of blowing argon, mathematical models of stirring, mixing, influencing the rate of reaction, and removing inclusions properties of blowing argon were presented. Further, basing on some traditional process of blowing argon researches and analysis, a concise regulation of BAB of Ladle Furnace was made. Moreover, according to different metallurgical purposes of stages in regulation of blowing argon, the presented mathematical models were optimized by the multi-objective optimization method. Then the regulation of blowing argon was improved by optimizing the parameters of argon flow. Finally, the simulation research was done for validating the optimized regulation of blowing argon based on presented mathematical models. Main parts are as follows:(1) In the basis of researches and analysis of the hydraulic model of BAB of Ladle Furnace, mathematical models of stirring, mixing, influencing the rate of reaction, and removing inclusions properties of blowing argon were set up, proved and analyzed both in theory and in experiments.(2) For the current defects existing in BAB of Ladle Furnace, based on some traditional process of blowing argon researches and analysis, a clear regulation of BAB of Ladle Furnace was organized. The presented mathematical model was used as objectives of different metallurgical purposes of stages to optimize the regulation of blowing argon. Then the optimized regulation of blowing argon was attained by multi-objective optimization theory.(3) According to the real manufacturing conditions of Ladle Furnace, simulation experiments were conducted and the metallurgical results were analyzed. The experiments demonstrate that, on the basis of maintaining the pervious basic regulation, the regulation of blowing argon based on presented mathematical models has improved metallurgical performance in refining processes of Ladle Furnace.