Numerical Study on the Combustion Phenomena in the Gas Region of a Top-Blown Converter With Single-Flow Post-Combustion Oxygen Lance

Post-combustion (PC) technology is a clean heat compensation method by introducing an additional amount of oxygen to further oxidize CO into CO 2 , and the heat produced by this process is effectively transferred to the scraps or molten bath. However, the combustion phenomena in the converter space with single-flow PC oxygen lance (SFPCL) have rarely been publicly reported. Herein, a 3D model is established to study the combustion characteristics in the gas region of a top-blown converter, and the velocity field, temperature distribution, mass fraction of each species, as well as the PC ratio (PCR) with the conventional four-hole lance (CL) and SFPCL are compared. The present study shows that oxygen jet flows down and forms a circulation in the converter space after impacting on the liquid surface. The coupling of primary and secondary jets for the SFPCL makes it have greater impact energy. The PC reaction is mainly concentrated at the jet boundary. Compared with the CL, the SFPCL obtains a larger combustion range due to the present of secondary jet. The area of combustion region at H = 0.15, 0.65, and 1.25 m is 1.12, 1.19, and 1.08 times than that with the CL, respectively. At the converter outlet, the mass fraction of CO with the CL is greater than that with the SFPCL, while the mass fraction of CO 2 is less than the SFPCL, and the PC ratio (PCR) is increased by 4.03 pct.