SU1675343A1 - Lance - Google Patents

Abstract

The invention relates to metallurgy, mainly to steel-making units and after-furnace processing units. The goal is to increase the durability of the tuyere and the efficiency of purging by eliminating reverse hydraulic shocks. The lance consists of at least one pipe 1, forming a channel 2 for supplying non-circular, elongated process gas with a ratio of length in cross section to a width of at least 2: 1. A smooth narrowing of the cross section is made in the central part of the channel, with the minimum width of the channel at the narrowing point being no more than 0.25 of the maximum width of the tuyere channel. The ratio of the areas of the channel parts on both sides of the minimum width line at the site of the constriction is 0.5-2. 6 Il. 2 tab.

Description

(L

WITH

about VI ate with

 with

The invention relates to metallurgy, mainly to steel-making units and after-furnace processing units.

The aim of the invention is to improve the durability of the tuyere and the efficiency of the blow through the elimination of reverse hydraulic shocks.

FIG. 1-6 shows the proposed lance, a cross-section.

The lance consists of at least one coarse 1 (Fig. 1-3), forming a channel 2 for supplying the process gas. Channel 2 has a non-circular elongated shape with a ratio of length I in cross section to a width d of at least 2: 1 with a smooth narrowing of the cross section in the central part of the channel, and the minimum width of the channel at the site of the narrowing ds is not more than 0.25 of the maximum width of the lance channel d. The areas of the channel parts on both sides of the minimum width line at the narrowing point are 0.5 - 2. Channel 2 can be made in solid gas-tight refractory blocks and without a pipe. Single-channel tuyeres are used to blow the melt with a neutral or inert gas. In the case of purging with oxygen or other oxidizing gas, the lance in addition to the main oxidant supply channel 2 has an additional channel 3 (there may be several additional channels) for supplying protective gas, which is formed by the inner pipe 1 and the outer pipe 4 surrounding it (Fig. 4-6) . At the same time, the outer pipe 4, as well as other additional pipes, when there are several channels in the tuyere, concentrates around the inner pipe, repeating its outline so that the gap between the pipes (the width of the additional channel) remains constant along the entire perimeter of the tuyere. For this purpose, in the additional channel 3 of the lance there are special dividers 5.

The lance works as follows

A process gas stream is fed into the lance 2 channel, which flows from it into the melt in the form of a two-dimensional jet. With this over the entire range of gas pressure variations and the maximum width of the tuyere channels. used in metallurgical practice, the mode of jet outflow from the lance channel is unstressed, since at these geometric dimensions of the lance channel the eddies formed in the mixing layer of the vortices do not generate powerful large-scale vortex structures capable of causing local pinching of the jet

Hydrodynamic strokes. In the shock-free mode of jet outflow from the lance, the lance and underfurmening areas of the lining are highly resistant, since dynamic, thermal and chemical (aggressive attack of the peroxidized metal and its oxides of the reaction zone) are significantly reduced on the material of the Lining and tuyeres (compared to the mode of outflow accompanied by reverse hydraulic shocks). In addition, turbulent pulsations in the gas-liquid jet are reduced, the latter becoming more stable, which leads to a more relaxed flow, reduced emissions and metal carry-over, as well as reduced vibrations of the unit. Almost all of the kinetic energy of the jet is spent on creating

large-scale circulation flows of the melt throughout the bath. The purge efficiency is also increased due to the degree of gas dispersion in the melt, i.e. increasing the contact surface of the interacting phases.

The results of the study of the influence of the ratio of the areas of the flow sections of the parts of the lance channel on both sides of the narrow part of the narrowing and the ratio of the minimum width of the channel to the maximum width of the outflow are shown in Table. 1 and 2

In the indicated parameter ranges, the lance channel provides, unaccented

the mode of outflow of energy carrier into the liquid, a sharp increase in the stool of the lance and an increase in the efficiency of the purge (reducing the time of complete mixing of the liquid bath).

Claims (1)

Invention Formula A lance containing at least one channel for supplying non-circular elongated energy carriers with a ratio of length in cross section to a width of at least 2.1, characterized in that, in order to increase the durability of the lance and the efficiency of purging by eliminating reverse hydraulic pipelines, in the central part of the channel, a smooth narrowing of the cross section is performed, with the minimum channel width at the narrowing point not more than 0.25 of the maximum width of the lance channel. and the ratio of the areas of the parts of the channel on both sides of the minimum width line at the site of the constriction is 0.5-2 table 2 2 Rig.Z Fm.4 Fm.6