Oxygen gun
The structure and performance of oxygen guns largely determine the effect of oxygen steelmaking. Especially for the top-blowing oxygen converter steelmaking process, the oxygen gun plays a leading role. It dominates the contact area between the oxygen jet and the molten pool, the penetration depth of the oxygen jet, the stirring state of the molten pool, the oxidation degree of the elements, the heating rate of the molten pool, the iron oxide content in the slag and other important process factors, so it plays an important role in slag, splashing, removal of impurities, converter steelmaking endpoint control and various steelmaking technical and economic indicators. The oxygen gun consists of three parts: the nozzle, the body and the tail (Figure 1). The nozzle is made of industrial pure copper and is the most important part of the oxygen gun.
According to the structural form,
Oxygen guns can be divided into single-channel oxygen guns, multi-channel oxygen guns, cone oxygen guns, split oxygen guns and other forms.
Main parameters
According to the requirements of the converter blowing process, the oxygen gun should be able to ensure the required oxygen supply strength, and the oxygen jet has a suitable impact depth and impact radius for the metallurgical melting pool. It is necessary to have a certain stirring ability to the molten pool, and to prevent impact on the furnace lining and damage to the refractory material of the furnace lining. For this purpose, the oxygen gun nozzle should be able to produce a stable supersonic jet, the number, speed and spread of which need to be coordinated with the size of the converter melting pool. Therefore, the main design parameters of the nozzle are: the number of nozzles (n), the number of nozzle outlet Mach (M), the diameter of the nozzle throat (d), the nozzle expansion angle, the nozzle outlet diameter (dt) and the nozzle angle (α).
There are two layers of concentric seamless steel pipes outside the oxygen supply pipeline in the center of the oxygen gun, and the oxygen gun is protected by cooling water. The minimum flow rate of cooling water Q-H2O(m/h) = 6.45×10-D×L, D is the diameter of the outer tube of the oxygen gun, mm; L is the heating length of the oxygen gun, m. The water inlet speed of the gun body is 3~4m/s, the water outlet speed is 5~7m/s, the water speed at the end of the nozzle is 10m/s, and the specifications of the inner and outer steel pipes and the spacing between the nozzle and the steel pipe head are determined according to the above data.