SU1650712A1 - Multiple-nozzle water-cooled lance head - Google Patents

Abstract

This invention relates to the steel industry. The goal is to reduce the consumption of liquid iron by increasing the degree of afterburning of CO to COs. The tip contains pairwise mounted radially and tangentially positioned nozzles whose axes intersect outside the tip in a plane perpendicular to its vertical axis. The ratio of the flow sections of the radial nozzles to the tangential nozzles is 0.15-0.25, which leads to an increase in the degree of afterburning. 2 Il.

Description

The invention relates to ferrous metallurgy, and more specifically to the design of devices for blowing liquid metal in oxygen converters upper blowing.

The aim of the invention is to increase the efficiency of the purge by increasing the degree of CO afterburning,

Placing the nozzles in this way provides additional oxygen from radial nozzles with a smaller cross section to CO streams that reach the bath surface in the zones of oxygen jets interacting with the metal flowing from tangential nozzles with large cross sections. This is most effective when the plane in which the intersection points of the axes of adjacent tangentially and radially located nozzles lie coincides with the surface of the bath. In this case, oxygen jets emanating from tangential nozzles are introduced into the liquid metal with the formation of primary reaction zones, in

the limits of which is mainly burning of iron. The formed iron oxides are mixed with the metal of the main volume of the bath and interact with it within the secondary reaction zones. Here intensive formation and release of CO takes place, and oxygen jets flowing from radial nozzles are introduced into the streams and provide CO after-burning to C02 with release of a significant amount heat

Due to the fact that during purging the position of the tuyere relative to the surface of the bath may vary, each pair of nozzles is placed so that the plane in which the points of intersection of their axes lie is separated from the tip by bf 30-35 calibres in terms of output diameter tangential nozzle. By ff is meant the distance from the end of the tip to the plane of intersection of the axes of the pair of installed nozzles, which takes place after

e

about ate oh

Yu

When bf 35, 25-30% of the duration of the blowdown is observed, since at the beginning of the blowdown the lance is usually held higher for the purpose of early setting of ferrous slag and melting the scrap metal. During this period, metal emissions are absent due to the low carbon oxidation rate.

At Pf 30, an enhanced removal of metal from the converter is observed and the likelihood of burnout of the tuyere tip sharply increases.

slag foaming, metal losses increase with emissions, heat transfer from the after-burning torch to the liquid metal deteriorates, which leads to a decrease in the proportion of scrap metal in the charge.

It has been experimentally established that the ratio of oxygen consumption through radial Qp and tangential QT nozzles should be 0.15-0.25.

QP From

The afterburning of CO from the secondary reaction zones to CO2 is caused by the lack of oxygen for the afterburning.

At a ratio of 0.25, oxygen jets emanating from radial nozzles shoot through the CO streams, mixing poorly with them, which reduces the thermal effect of the afterburning. In addition, with increased (35 calibers) height of the tuyere above the bath, these jets can reach the lining surface, causing its local wear.

Figure 1 shows the tip; figure 2 - view And figure 1.

The tip consists of an upper T and a lower 2 plates, between which tangential 3 and radial 4 nozzles are placed in pairs. The upper 1 and lower 2 plates are connected to pipes 5 and 6. Between which a separation pipe 7 is installed.

With respect

 0.15 non-despongate tubes form the paths for oxygen supply, supply and removal of cooling water.

The tip works as follows.

Oxygen is supplied through pipe 5 to the nozzles.

3 and 4, the critical diameters of which are calculated so that the oxygen consumption through the radial nozzles is 0.15-0.25 of the total oxygen consumption for the tuyere. After flowing out of the nozzles, oxygen jets propagate along their axes, which intersect outside the tip in a plane, perpendicular to the vertical, which coincides with the surface of the bath and is separated from

tip for 30-35 calibres, counting the output diameter of the tangential nozzle. Oxygen jets of tangential nozzles have sufficient kinetic energy and burn out the flow

CO to C02. This increases the heat transfer to the bath. The use of the proposed tip due to the rational organization of the supply of blowing will allow an increase in the proportion of scrap metal in the charge of converters and reduce the specific consumption of liquid iron oriented for 20 kg / t of steel.

Claims (1)

Invention A water cooled multi-nozzle tip of a tuyere containing radially and tangentially positioned nozzles, characterized in that, in order to increase the efficiency of purging due to an increase in the degree of afterburning of CO, the radial nozzles are installed in pairs d tangential, the points of intersection of the axes of the pairs of nozzles installed outside the tip plane, perpendicular to its vertical axis and located at a distance of 30-35 diameters of the output section of the tangential nozzle, with the ratio of flow sections adialnyh tangential nozzles and is 0.15-0.25. Н20 НгО