JPH01316411A - Tuyere for blowing gas in converter - Google Patents

Abstract

PURPOSE:To facilitate pull-out and change of a tuyere under heat state at the time of repairing the tuyere by supporting double tubes in a tuyere for blowing gas in a converter with a holding metal fitting, surrounding the outside thereof with top-cutting conical shaped tapered sleeve brick upward and inserting into a tuyere brick. CONSTITUTION:The gas blowing tube 4 in the converter is constituted with the double tubes composing of all inner tube 4a and an outer tube 4b and supported with the holding metal fitting 6 fitted to iron shell 9 at the furnace bottom and inserted into the truncated conical shaped tapered sleeve brick 3, which the diameter at outside of the furnace is larger than the diameter at inside of the furnace, and the lower part of the sleeve brick 3 is closely coated with a metal-made cylindrical body 1 without any gap. At the time of changing the tuyere at repairing time, by pilling out the holding metal fitting 6, as the sleeve brick 3 and the double tubes 4 for blowing gas are simply and easily pulled out together with the holding metal fitting 6, the repair by changing the tuyere can de executed for short time.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a tuyere for blowing gas into a refining furnace, particularly a converter.

<Prior Art> In a converter, there is significant local melting tJ1 of the bottom refractory material around the bottom blowing gas injection part, which shortens the life of the furnace. In the bottom-blowing converter method and top-bottom blowing converter method, when the area around the tuyeres melts, the furnace bottom in the area that includes all the tuyeres is replaced with a replacement furnace bottom prepared separately. The replacement method is used to extend the life of the converter, but this method requires high equipment costs, requires a large amount of bricks to be disposed of, and is difficult to replace. There is a drawback that the steel manufacturing cost increases due to the long downtime of the converter required.

In contrast to the above means, as shown in Fig. 4, frustoconical sleeve bricks 10a to 10d, each having a tapered outer periphery such that the inside of the furnace has a small diameter and the outside of the furnace has a large diameter, are joined and held in multiple stages. A tuyere inner pipe 4 is held in a metal fitting 6 and inserted into a center hole 2 that vertically passes through the center of the multi-stage sleeve brick unit 10.
It has a structure in which a gas blowing pipe 4 consisting of a and a tuyere outer pipe 4b is inserted, and means for setting it inside the tuyere brick 12 (see Japanese Utility Model Publication No. 59-29946) is provided.

In addition, as shown in FIG. 5, the sleeve bricks 10a-10c each have a truncated conical shape with a tapered outer periphery so that the inside of the furnace has a small diameter and the outside of the furnace has a large diameter. are screwed together at a retaining part 11, and a gas blowing pipe 4 consisting of a tuyere inner pipe 4a and a tuyere outer pipe 4b is inserted into a center hole 2 that vertically passes through the center of the multi-stage sleeve brick unit 10. Toshi, tuyere brick 1
2 (see Japanese Unexamined Patent Publication No. 129710/1983).

Both of the systems shown in FIGS. 3 and 4 are intended for hot replacement of the double pipe for blowing gas and the sleeve brick.

In addition, in FIGS. 4 and 5, 7 indicates a work brick, 8 a permanent brick, and 9 a hearth bottom shell.

<Problems to be Solved by the Invention> However, none of the gas injection tuyeres of the above-mentioned conventional structure do not take into account the refractory property of the sleeve brick, which is weak against tension. There are the following problems when replacing.

That is, the method shown in FIG. 4 disclosed in the above-mentioned Japanese Utility Model Publication No. 59-29946 only applies a pulling force in the direction outside the furnace to the double gas blowing pipe 4 or the holding metal fitting 6.
The structure is not such that the multi-tiered sleeve brick unit 10 can be pulled out, and although we conducted a trial experiment, the sleeve brick unit 10 was separated from the joint and a portion remained in the furnace. I couldn't pull it out properly.

Furthermore, regarding the device shown in FIG. 5 disclosed in the above-mentioned Japanese Patent Application Laid-open No. 59-129710, a pulling force was applied to the holding hardware 6 on a trial basis to remove the sleeve unit 10 and the gas blowing 2.
An attempt was made to pull out the heavy pipes in one piece at the same time, but as shown in Figure 6, the sleeve bricks broke halfway at the screw-like retaining part 11 between the sleeve bricks where stress was concentrated, and the upper sleeve bricks were removed from the furnace. As a result, it remained in the interior.

As mentioned above, in the conventional tuyere structure, a pulling force is applied to the gas blowing pipe or the holding metal from outside the furnace, and the gas blowing pipe and the sleeve brick are removed simultaneously and integrally, or the holding metal and the gas blowing Since it is difficult to pull out the pipe and the sleeve brick simultaneously and as one unit, it takes considerable time and labor to dismantle and remove the sleeve brick remaining in the furnace, and the downtime of the furnace becomes longer. for that,
0) Increase in the amount of falling bricks due to a decrease in brick temperature in the furnace,
A number of problems cannot be avoided, such as (2) an increase in high-temperature work and (3) a decrease in productivity.

The purpose of the present invention is to solve the above-mentioned conventional problems, and to make it possible to easily pull out the sleeve bricks out of the furnace during hot operation, or to remove the sleeve bricks from the furnace by simply applying a pulling force to the holding metal fittings. It is an object of the present invention to provide a bottom blowing tuyere from which a plunger pipe and a sleeve brick can be pulled out simultaneously and integrally.

Means for Solving the Problems To achieve the above object, the gas blowing tuyere of the converter of the present invention comprises a gas blowing pipe supported by a holding metal fitting attached to the tuyere opening at the bottom of the converter. The sleeve brick is inserted into a sleeve brick and set in the hearth bottom tuyere brick.The sleeve brick is integrated into the tuyere for blowing gas into the converter, and the sleeve brick is integrated with the sleeve brick from the inside end to the outside end of the furnace. The sleeve brick is tapered so that the inside of the furnace is small and the outside of the furnace is large, and a metal cylinder is tightly covered along the outer periphery of the sleeve brick outside the furnace.

Instead of tapering the outer periphery of the sleeve brick from the inner end of the furnace to the outer end of the furnace so that the inside of the furnace is small and the outside of the furnace is large, the outer periphery of the sleeve brick is not tapered. The metal tube may be tightly covered along the outer periphery.

Furthermore, although the metal cylinder covering the sleeve brick and the holding hardware may be constructed as separate structures, it is preferable that they be integrally constructed.

<Function> As described above, the present invention uses a sleeve brick as an integral body, and the outer circumference of the sleeve brick extends from the furnace inner end to the furnace outer end, or the outer periphery of the sleeve brick inside the furnace excluding the furnace outer side has a small furnace inner side. The outer side of the furnace is tapered so that it becomes larger, and the outer circumference of the furnace is tightly covered with a metal tube, so when replacing the tuyeres, the pulling force applied to the metal tube is absorbed by the sleeve. It is effectively transmitted to the brick and can be easily pulled out.

In addition, by making the metal tube that covers the sleeve brick and the holding hardware that supports the gas blowing pipe into an integral structure, the gas blowing pipe and the sleeve brick can be securely held together by simply applying a pulling force to the holding hardware. It can be pulled out.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment of a gas injection tuyere for a converter according to the present invention.

In FIG. 1, 9 is the bottom shell of the converter, 5 is a tuyere opening provided in the bottom shell 9, and 6 is a holding hardware attached to the tuyere opening 5. An integral sleeve brick 3 is supported on the holding hardware 6, and the gas blowing double pipe 4, which is supported by penetrating the center of the holding hardware 6, is inserted into a central hole bored in the center of the sleeve brick 3. It is installed on 2.

The double pipe 4 for gas blowing includes an inner tuyere pipe 4a and an outer tuyere pipe 4b.
Oxygen gas is injected from the inner tuyere pipe 4a, and cooling gas such as propane gas is blown from the outer tuyere pipe 4b.

The outer periphery of the sleeve brick 3 is tapered from the inner end of the furnace to the outer end of the furnace so that the inside of the furnace has a small diameter and the outside of the furnace has a large diameter. The metal tube l is tightly covered with no gaps.

The lower end of the metal tube 1 extends to the space formed between the opening 5 of the hearth bottom shell 9 and the holding hardware 6, and is provided with a flange 1a to facilitate the pulling operation. It has a built-in structure.

The sleeve brick 3 is set in a bore provided in the center of the tuyere brick 12 and the tuyere permanent brick 8, which have the same taper as the outer periphery of the sleeve brick 3. The height of the metal cylinder covering the outside of the furnace of the sleeve brick 3 is approximately the same as the thickness of the permanent brick 8. 7 are work bricks laid on the bottom of the hearth.

FIG. 2 shows another embodiment of the tuyere for blowing gas in a converter according to the present invention. In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals to simplify the explanation.

In FIG. 2, the outer periphery of the sleeve brick 3 is tapered from the inner end of the furnace to the outer end of the furnace so that the inner side of the furnace has a small diameter and the outside of the furnace has a large diameter. This is the same as in FIG. 1 in that the metal tube 1 is tightly covered along the taper of the tube.

In FIG. 2, the lower end of the metal cylinder 1 is welded to the upper end of the holding metal fitting 6 by a welding part 14 to form an integral structure, and by applying a tensile force to the holding metal fitting 6, the double gas injection pipe 4 and the sleeve brick 3 can be pulled out integrally through the metal tube 1.

FIG. 3 shows still another embodiment of the tuyeres for blowing gas in a converter according to the present invention.

In Fig. 3, instead of tapering the outer periphery of the sleeve brick 3 from the inner end of the furnace to the outer end of the furnace so that the inner side of the furnace has a small diameter and the outside of the furnace has a large diameter, only the outer periphery of the sleeve brick outside the furnace is tapered. The metal tube 1 is tightly covered along the outer periphery of the untapered furnace outside of the sleeve brick 3 without adding any tapering, and the metal tube 1 and the holding hardware 6 are welded together at the welding part 14. It has an integrated structure.

In FIG. 3, a case has been described in which the metal tube l and the holding hardware 6 are integrated, but a structure in which they are separated may also be used as in FIG. 1.

In the above embodiment, the sleeve brick has a circular horizontal cross section with a taper on the outer periphery such that the inside of the furnace has a small diameter and the outside of the furnace has a large diameter, but the sleeve brick is not limited to a circular shape and may have a square or other shape. be able to. In this case, it goes without saying that the metal tube that covers the outer periphery of the sleeve brick is shaped like a pyramidal cylinder or the like and tightly covers the outer periphery of the sleeve brick.

When constructing the gas blowing tuyeres for the converter according to the present invention, it is important to ensure that the metal tube 1 and the sleeve bricks 3 are closely covered with the outer periphery without any gaps. If it is coated without any gaps, the surface of the metal cylinder 1 (mainly made of steel plate 3) will oxidize to a considerable extent in a high temperature oxidizing atmosphere of 300 to 400°C, and the frictional force with the sleeve brick 3 will be greater than that of the sleeve in normal cases. It is larger than the tensile breaking force of the mortar between the brick 3 and the tuyere brick 12, and of course the breaking force of the mortar is smaller than the tensile breaking force of the sleeve brick 3 (furthermore, the furnace side of the sleeve brick 3 has a small diameter. Since it is tapered so that when the outer tuyere tube 3 is pulled out to the outside of the furnace, the mortar breaks and the gas blowing tube 4 and the sleeve brick 3 are pulled out as one through the metal cylinder l. becomes possible.

When we fabricated a bottom blowing tuyere in which a sleeve brick and holding hardware were integrated through a steel cylinder as shown in Figure 2, we conducted a hot pull-out experiment of the bottom blowing tuyere. Gas injection pipes and sleeve bricks can be easily removed by simply applying a pulling force to the holding hardware.

The holding hardware could be pulled out in one piece, and the time required for this pulling out operation was only 10 minutes.

The conventional bottom-blown tuyeres mentioned above (Japanese Patent Application Laid-Open No. 59-12971
0 (disclosed in Utility Model Publication No. 59-29946) on a trial basis and similar work was performed, the sleeve bricks could not be easily pulled out, so the sleeve bricks in the furnace were removed from the start of pulling out the tuyeres. It took 60 to 80 minutes to completely disassemble and remove the tuyere, proving that the present invention is highly effective in shortening the time required to pull out the tuyere.

<Effects of the Invention> Since the present invention has the above-mentioned configuration, the gas blowing pipe and the sleeve brick can be pulled out as a unit, and the time required for hot tuyere replacement is reduced compared to the conventional one. can be significantly shortened.

As a result, significant effects such as improved converter productivity, reduced temperature drop inside the furnace, and reduction of Ti scratches on converter bricks, which are prone to splintering, as well as a reduction in high-temperature work, have been achieved, resulting in improvements in steel manufacturing. The usefulness is huge.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view showing another embodiment of the invention, and Fig. 3 is a longitudinal sectional view showing yet another embodiment of the invention. , FIG. 4 is a vertical cross-sectional view showing a conventional example, FIG. 5 is a vertical cross-sectional view showing another conventional example, and FIG. 6 is an explanatory diagram showing the results of tuyere extraction in the conventional example. l...metal cylinder, 2...center hole, 3...
... Sleeve brick, 4... Gas blowing pipe, 5...
- Tuyere opening, 6... Holding hardware, 7... Work brick, 8... Permanent brick, 9... Hearth shell, 12... Tuyere brick, 14...
welded part. Patent applicant: Kawasaki Steel Corporation Figure 1 Figure 3

Claims (1)

[Claims] 1. A converter in which a gas blowing pipe supported by a holding metal fitting attached to a tuyere opening at the bottom of a converter furnace is inserted into a sleeve brick and set in the tuyere brick at the bottom of the converter. In the gas blowing tuyere of a furnace, the sleeve brick is integrally formed, and the outer periphery of the sleeve brick is tapered from the inside end of the furnace to the outside end of the furnace so that the inside of the furnace is small and the outside of the furnace is large. A tuyere for blowing gas into a converter, characterized in that it is formed by tightly covering a metal cylinder along the outer periphery of the furnace. 2. Instead of applying a taper to the outer periphery of the sleeve brick from the inner end of the furnace to the outer end of the furnace so that the inside of the furnace is small and the outside of the furnace is large, the outer periphery of the sleeve brick is not tapered only to the outside of the furnace. The tuyere for blowing gas in a converter according to claim 1, wherein the outer periphery of the tuyere is tightly covered with a metal tube. 3. The gas blowing tuyere for a converter according to claim 1 or claim 2, wherein the metal cylinder covering the sleeve brick and the holding hardware supporting the gas blowing pipe are integrally constructed.