Research on the Gas-Solid Jet Flow and Erosion Wear Characteristics in Bottom Injecting Lance Used for Oxygen-Lime Powder Bottom Blowing Converter

Oxygen-lime powder bottom blowing converters have significant advantages in metallurgical performance, and have drawn more attention in recent studies. The key for oxygen-lime powder bottom blowing converter applications is to solve the problem of the furnace life. Erosion wear of the bottom injecting lance induced by a high velocity gas-solid jet inside the lance is an important factor for the furnace life but has rarely been studied. To reveal the gas-solid jet flow and erosion wear characteristics in the bottom injecting lance, a computational fluid dynamic model coupled with a discrete phase erosion model was established in the present work. The geometric dimension and boundary conditions of the lance were consistent with a commercial bottom injecting lance applied on a 120 ton converter. The simulated results were validated via a jet measurement experiment and an industrial experiment. The results show that the pressure loss in the lance of the gas-solid jet is much higher than that of pure gas jet, and the gas velocity at the lance outlet decreases after powder addition. Mixing powder into the gas has an obvious influence on the pressure variation curve and the velocity variation curve of the gas in the lance. The effect of the lance structure on jet flow and erosion wear was discussed in detail. On the premise that the total length of the lance remains constant, prolonging the shrink pipe length is helpful for reducing the pressure loss in lance. Simultaneously, the value of the maximum erosion wear and the area of the high wear rate region can be significantly reduced by prolonging the shrink pipe, which is vitally important for protecting the lance from being worn out by powder particles. The results of this work provide meaningful explorations and references for the design of converter bottom injecting lance.