SU1548209A1 - Blast furnace lance - Google Patents

Abstract

The invention relates to the metallurgy of ferrous metals and can be used in blast furnace production for the supply of hot blowing into the forge. The aim of the invention is to save and increase the durability of the tuyere. The proposed design of an air tuyere makes it possible, without significant capital expenditures, to improve the mixing of carbon-containing additives with the flow of blowing. For this purpose, at least one protrusion smoothly mating with it is made on the inner beaker, at the apex of which the reagent tube is located. The distance between the center of the output section of the tube and the output section of the tuyere is determined from the expression L / D = 2.3- (0.5-H / D) / TGΑ + K _e , where L is the distance between the center of the output section of the reagent supply tube and output tuyere section, m

D is the diameter of the output section of the tuyere, m

H - height of the protrusion on the inner glass, m

α is the angle of inclination of the outlet section of the reagent supply pipe to the lance axis, hail

K _e - empirical coefficient, K _e = (1-2) ^. (-0.1 + 0.5 COSΑ). The angle of inclination of the reagent supply pipe to the axis of the tuyere is 30-90 °, and the height of the protrusion on the inner glass is 1 / 5-1 / 3D. them in one plane, perpendicular to the tuyere axis. The ratio of the through-section area of the tuyere in this plane to the output area of the tuyere channel is in the range of 0.6-0.8. 2 hp ff, 1 ill.

Description

The invention relates to the metallurgy of ferrous metals and can most effectively be used in blast furnace production for the supply of hot blowing and carbon-containing additives to the forge.

The aim of the invention is to save fuel and increase durability.

The drawing shows a lance, section.

The reagent supply pipe 1 is located in a protrusion 2 smoothly mated with the surface of the inner glass and directed in the direction opposite to the flow to blow. The cavity 2 begins directly

behind the flange and ends near the mouth of the tuyere.

Water circulates freely in the cavity, ensuring its intensive cooling, which contributes to an increase in the resistance of the tuyere. Optimal values without the length L / D of the height of the protrusion and the angle of inclination of the reagent supply tube are determined experimentally and calculated taking into account the influence of these values on the degree of mixing of the reagent with the blast and the distribution (direction and length) of the natural gas jet stream. Processing the experimental and calculated data shows that the optimal ratio of the distance between the center of the outlet section of the reagent supply pipe (L) and the output cross section of the tuyere channel to the diameter of the output section of the tuyere (D) is within the limits determined by the formula:

L / D 2,3 - (0,5 - H / D) tgei + Ke,

v

where H is the height of the protrusion on the inside

glass, m;

oi is the angle of inclination of the EXERCISE section of the reagent supply pipe to the axis of the tuyere, deg; empirical coefficient equal to

K (1 - 2) (0.5 costi -0.1).

The angle of inclination of the tube for feeding the regent to the axis of the tuyere while maintaining the rest of the claimed ratios ensures effective mixing of the reagent and blowing at values of 30-90 °.

The effective mixing of the blowing and reagents corresponds to the height of the protrusion within H / D (1/5 - 1/3).

If there is a reserve for the pressure of natural gas (it is fed into the furnace without pre-compression) or its consumption is large, it is advisable to perform several recesses in the inner tuyere glass. This arrangement of the feeds allows the EI to further displace the blast and the reagent, especially at high flow rates of the latter.

When the flow of CH4 is supplied by several jets, the possibility arises due to an increase in the specific surface

about

five

0

interactions of air flow and air improve mixing efficiency. , When submitting CH $ in several streams, i.e. when there is more than one protrusion on the inner cup, their placement in one plane (perpendicular to the tuyere axis) is most appropriate. This allows, in addition to the effects described, to provide an additional effect of local narrowing of the lance channel in the place of supplying CH4, resulting in an even more efficient mixing. This is due to the intensification (after local narrowing) of the ejecting and turbulising effect of the flow of air blowing on the flows of natural gas.

I

In this case, the optimal ratio

the areas of the tuyere bore in the reagent insertion plane to the outlet area of the tuyere channel is 0.6-0.8.

Two methods have been developed for the manufacture of these tuyeres: a method of welding a preformed protrusion with an internal glass of a tuyere, a method of stamping a protrusion on an inner glass of a tuyere.

The second method is more preferable because it increases the smoothness of the mating of the inner cup and the protrusion, reduces stress concentrations, and simplifies manufacture. All other tuyere assembly operations are performed in a standard pattern.

The use of the proposed blast tuyere structure allows reducing coke consumption for smelting pig iron by 5 kg / t of pig iron due to an increase in the rate of replacement of coke with natural gas.

five

50

Claims (3)

1. A blast tuyere of a blast furnace containing a water-cooled body consisting of a flange, a toe cap, an outer and an inner cup, supply and discharge tubes of a cooler and a supply of a reagent, characterized in that, in order to save fuel and increase the durability of the tuyere, in the flow section of the tuyere on the surface of the inner cup, at least one protrusion smoothly mating with the surface is expressed, at the top of which there is a PE-5 supply tube 51 , genta, moreover, the distance between the center of the outlet section of the tube and the outlet section of the tuyere is determined from the expression L / D - 2.3 - (0.5 - H / D) tgod, + K. de l D Н oi К - distance between the center of the outlet cross section of the reagent supply tube and the outlet cross section of the tuyere, m; diameter of the output section of the tuyere, m; height of protrusion, m; angle of inclination of the outlet section of the reagent supply tube to the lance axis, deg; empirical coefficient, K9 (I ... 2) (0t5cos about -0,1). 482096 2. A lance according to claim 1, characterized in that the reagent supply pipe is directed to the side, protissed opposite the mouth of the lance, and the angle of inclination of the tube to the lance axis is 30-90 °. 3.Furma on PP. 1 and 2, that is, the fact that the height of the protrusion is 1 / 5-1 / 3 of the diameter of the inlet section of the tuyere channel. The lance according to claim 1, wherein when the number of projections is more than one, the centers of the outlet openings of the reagent supply pipes are located in the same plane perpendicular to the axis of the lance, and the ratio of the area of the lance of the lance in this plane to the area of the outlet section of the channel tuyere is 20: s in the range of 0.6-0.8. Podboe natures whom gas