Behavior of Top-Blown Jet under a New Cyclone Oxygen Lance during BOF Steelmaking Process

Abstract

An oxygen lance is the operation unit that generates supersonic oxygen jets, controls their behavior, and acts as a vital role in the steelmaking process. It is thought that airflow similar to a tornado may suppress upward splashing because of part of the jet pressure shifting from the axis of the oxygen lance to the tangential direction. Therefore, a new oxygen lance is designed to form a tornado jet, and the numerical simulation consequences are verified by the physical model. The structure of the new oxygen lance is optimized by numerical simulation results, and the comparison of simulation results before and after optimization is analyzed. On this basis, the effect of the cyclone oxygen lance on the upward splashing behavior, penetrating depth, turbulent kinetic energy, turbulent dissipation rate, and rotation of molten bath is investigated. The conclusions present that, compared with the conventional oxygen lance, the upward splashing with the cyclone oxygen lance decreases, and the penetrating depth and reaction area increase. In other words, for obtaining the same penetrating depth, the cyclone lance height can be higher than that of a conventional oxygen lance, which leads to a better protective effect on the refractories of the oxygen lance. Moreover, the average value of the turbulent kinetic energy of the cyclone nozzle is larger than that of the traditional Laval nozzle at the interface between oxygen and slag, which improves the effect of steelmaking.

Simulating and Evaluating the Multiphase Jet Flow Characteristics of a Five‐Hole Oxygen Lance under Nonisothermal Conditions

“…[1][2][3] As a result of the Laval nozzle's impact, an impact cavity is formed on the liquid surface of the molten metal. [4] The shape and motion of this impact cavity depend on the parameters of the top nozzle, which directly influence the gas-liquid reaction interface, splashing behavior, and stirring ability of the molten pool. [5][6][7] Therefore, understanding the motion characteristics of the supersonic jet and its interaction with the molten pool is crucial for promoting the mixing and chemical reaction rate of molten metal, which promotes the homogenization of the molten metal temperature and composition and prolongs the service life of the oxygen lance.…”

Comparison of Different Approaches to the Creation of a Mathematical Model of Melt Temperature in an LD Converter

“…Mathematical methods and models are widely applicable for calculating measured process variables in various technological processes. These models are based on different approaches to their creation, e.g., Li et al [1] proposed a new cyclone oxygen lance for the steelmaking process. The physical model and various hydrodynamic and mathematical methods were used to optimize the structure of the new oxygen lance.…”