Effect of Lance Structure on Behavior of Coherent Jet in EAF Steelmaking Process

Abstract

During the electric arc furnace steelmaking process, the coherent jet technology was widely used to protect the kinetic energy of the supersonic oxygen jet and achieve better mixing effects. Comparing with the conventional oxygen lance, the coherent lance could increase the surface area of impaction cavity, resulting in a better stirring effect and higher reaction rate. However, there was limited research about the effect of restriction structure for the coherent lance tip on the flow field characteristic of the main oxygen jet. In this research, three kinds of restriction structures have been investigated by numerical simulation and combustion experiment at room and high ambient temperature conditions. Then an optimum restriction structure would be tested in a 75 t electrical arc furnace steelmaking process to verify its metallurgical property.

Effect of Furnace Gas Composition on Characteristics of Supersonic Oxygen Jets in the Converter Steelmaking Process

“…Figure 5 and Figure 6 show the axial velocity and axial total pressure distribution of the supersonic oxygen jet in the numerical simulation and combustion experiment of Schemes 1 and 2 [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Table 4 and Table 5 shows the average and standard deviation of the axial velocity and the axial total pressure at the monitoring point, respectively.…”

“…Zhao et al [ 13 ] used a similar device to study the stirring ability of the supersonic combustion coherent jet in an electric furnace molten pool. Liu et al [ 14 ] used a cylindrical combustion device to study the influence of the lance structure on electric furnace steelmaking. During the high temperature experiment, they used pitot tubes and thermocouples to measure pressure and temperature, respectively [ 16 , 17 , 18 , 19 , 20 ].…”

“…In the numerical simulations, to explore the degree of dependence of the calculated results on the grid resolution, three grid resolutions were applied to monitor the velocity of the center plane of a supersonic jet formed by one Laval tube under the condition of the composition of the ambient gas in Scheme 2: 697,800 grid points (fine-resolution grid), 550,784 grid points (medium-resolution grid), and 330,730 grid points (coarse-resolution grid) [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Figure 4 indicates the variation of the area-weighted average velocity of the longitudinal section for the three grids.…”

“…The results show that the supersonic combustion coherent jet could be stably burned under high temperature environments, and the combustion flame is beneficial in protecting the flow characteristics of the main oxygen jet because the supersonic length of the coherent jet is increased. Liu et al [ 14 ] used numerical simulation and combustion experiments to study the characteristics of the lance structure on supersonic jets. The results show that the coherent lance is beneficial in increasing the surface area of the impact pit during the steelmaking process because the supersonic jet has better stirring ability for the molten pool and improves the efficiency of the reaction.…”

Supersonic jet characteristics of two parameter oxygen lance nozzle

“…The influences of different factors, such as structural forms, process parameters, and boundary conditions on the jet characteristics of an oxygen lance nozzle were studied. The main studies focused on the influences of orifice form, orifice arrangement, ambient temperature, and gas preheating temperature on the jet characteristics [6][7][8][9][10][11][12][13][14]. Yang et al [15] studied the variations of the supersonic jet characteristics of a swirl nozzle under different ambient and oxygen preheating temperatures.…”