Advantage of oxygen cluster jet in modern electric furnace steelmaking

(1) The original velocity, diameter, gas concentration and injection impact force can be maintained within the blowing distance of more than 70 times the nozzle diameter, which is much longer than any traditional supersonic oxygen lance;

(2) Compared with the traditional supersonic blowing, the amount of ambient air brought in is less than 90%;

(3) The expansion and attenuation of the air flow is small, so the cavities and splashes formed in the molten steel are much less.

The length of the cluster jet is much larger than the length of the supersonic jet, and the cluster jet can maintain a high cluster state over a long spray distance, which can better blow oxygen into the depth of the molten pool. In this way, more oxygen can enter the bath and the contact time with the bath is increased. Therefore, the utilization rate of oxygen will be increased accordingly.

The cluster jet oxygen lance is designed by applying the principle of gas mechanics. The main point is that the main oxygen flow in the center of the nozzle points to the molten pool. High kinetic energy and blowing speed are not enough to keep the jet in a long distance to maintain the state of convergence, in order to achieve the purpose of maintaining the state of convergence of the jet, it is necessary to use another medium to guide the oxygen, that is, the gas flow to the main oxygen flow plays the role of envelope, so that the main oxygen flow can maintain the diameter and velocity of the outlet in a long distance.

The key to the coherent jet lance technology is to design a special nozzle, which can input oxygen into the electric furnace at a supersonic rate. The exit Mach number of the cluster jet oxygen lance can reach

It has a high impact energy on the metal molten pool, and its jet condensation distance can reach 1.2~2.1m. Due to the concentrated energy of the cluster jet, it has a strong ability to penetrate the metal molten pool and increases the stirring intensity of oxygen to molten steel. Therefore, it is beneficial to promote steel slag inversion, uniform composition and temperature, reduce splashing, improve oxygen utilization rate, and improve metal yield and productivity. At the same time, with the enhancement of penetration ability, the gun position can be appropriately increased, so that the life of the oxygen gun can be improved.

For electric furnace steelmaking, multiple coherent jet nozzles can be arranged along the circumference of the furnace wall to make the chemical energy evenly distributed in the furnace. In addition to blowing oxygen, each nozzle can also be used as a furnace wall burner to melt scrap and shorten smelting Time; it can also be used as a source of oxygen for secondary combustion to make full use of the chemical latent heat in the furnace gas and increase the chemical energy input in the furnace. These functions can significantly improve the productivity of the electric furnace and reduce the power consumption. The application of cluster jet device in 60t electric furnace of MacSteel steel plant in the United States has achieved the following results: increasing output by 7.2, saving electricity by 0.7, reducing oxygen consumption by 36.7 and spraying material by 34.7.