Oxygen gun technology can improve the dynamic conditions of slag-steel and dephosphorize fast. Meanwhile the use of oxygen gun can shield the radiation of arc light on furnace lining, that is beneficial to increase the electric heating efficiency and shorten the smelting time. There are coherentjet oxygen gun or EBT oxygen gun frequently used in EAF steelmaking process.
The coherentjet oxygen gun technology is mainly used to protect the main oxygen flow by using the envelope formed by medium combustion can solve the shortage of traditional supersonic oxygen gun jet distance, small impact force, low oxygen utilization rate. The exit Mach number of the coherentjet oxygen gun can reach about 2.0, and the jet distance of the technical state can reach 1.2~2.1m, which can be installed directly on the furnace wall to realize the functions of flux decarburization and so on.
The coherentjet oxygen gun has a variety of functions such as oxygen blowing, combustion and secondary combustion, and realize centralized automatic control, which can improve the utilization rate of oxygen and carbon spray powder and reduce energy consumption. The cluster oxygen gun cuts and melts the scrap steel more rapidly, and can blow oxygen into the melt pool more effectively, greatly improving the utilization rate of oxygen. First turn on the secondary oxygen system, delay a certain time to turn on the compressed air system, and then turn on the fuel oil (or gas) system after a certain delay, and at the same time carry out the main oxygen supply. When shutting down, fuel and main oxygen should be shut down first, and then compressed air and sub-oxygen should be shut down sequentially. Automatic alarm processing prevents serious safety accidents caused by oil pressure exceeding compressed air pressure.
Modern electric arc furnaces use the Eccentric Bottom Discharge (EBT) technology in order to achieve slag-free steel discharge. This not only reduces the amount of slag in the steel discharge process, but also shortens the smelting cycle and reduces the temperature drop of the steel discharge. However, it also makes the EBT zone one of the cold zones of the UHP-EAF, causing the scrap in this zone to melt slower and the melt pool composition to differ significantly from the central zone. In order to solve the problem of EBT cold zone, an EBT oxygen gun can be installed above the eccentric furnace side to blow oxygen to this zone. the EBT oxygen gun can promote the scrap melting in this zone, and after the emergence of the melt pool, increase the melt pool temperature in the EBT zone, even out the melt pool composition, and realize the re-combustion of CO.
In practice, the use of EBT oxygen gun completely solves the EBT area of the scrap in the steel is not yet melted and caused by the opening of the steel mouth can not be opened and other problems, while making the temperature and composition of the EBT area when the steel is discharged and the temperature and composition of the furnace door area error only 0.5% to 1.0%. EBT oxygen gun in the design needs to consider its impact. Due to the shallow melt pool in the EBT area, the penetration depth of the oxygen jet of the EBT oxygen gun should not exceed 2/3 of the depth of the melt pool in the EBT area in the design, and should avoid the steel outlet area. Considering the attenuation of the oxygen jet, the telescopic drive EBT oxygen gun is used, and the position of the gun is adjusted according to the smelting situation.
