JPS5941414A - Method for repairing tuyere part of refining vessel - Google Patents

Abstract

PURPOSE:To shorten a time required for repairing for the enhancement of the working ratio, by packing the damaged part of the tuyere part of a spalled refining vessel with a powdery refractory material by spraying, and boring a new hole for the insertion of a tuyere in the packed part. CONSTITUTION:After melt and slag are discharged from a refining vessel equipped with a tuyere for injecting gas into the melt, the tuyere spalled with the progress of gas-injection refining is pulled out. The end part of a hole 6, formed by said pulling out, at the side of an outer wall is plugged with a refractory material 7. Thereafter, a worn-out area 2 is packed with another refractory material 8 under a molten or semimolten condition by flame spray. A hole for inserting a tuyere through it is re-bored in said packed refractory, and then a new injection tuyere 11 is inserted therein. Thus, a time required for the repair is shortened, and the working ratio is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention easily and conveniently repairs damage caused to the surface of a scouring container, that is, the tuyeres for blowing scouring gas into the molten metal contained in the container, and the surrounding refractories. This relates to possible repair methods.

Recently, in the steel manufacturing process, the provision of stirring action to molten metal has become particularly important. For example, in an oxygen bottom-blown converter, a top-bottom-blown converter, or an AOD furnace, scouring gas injection holes are mainly provided at the bottom of the furnace, and oxygen, hydrocarbons, or inert gases are injected through the tuyeres. The scouring efficiency is improved by stirring the molten metal.

By the way, when such scouring gas is injected, the first
As shown in Figures 1 and 2 at the bottom of the old blowing converter, the tuyere 1 and its surrounding refractories 2 are locally subject to significant wear due to the strong stirring of molten steel and slag that accompany the steelmaking reaction. . Conventionally, therefore, in order to maintain the balance of the entire converter refractory lining in the container, measures have been taken such as making the hearth bottom part, which is subject to a lot of wear, replaceable.

However, the wear rate of the siding and surrounding refractories is
It is generally 2 to 6 times larger than other parts of the hearth bottom, and therefore it is not only economically disadvantageous to replace the hearth bottom every time the tuyeres become locally worn out, but also reduces operational efficiency. This resulted in a significant drop in the rate.

In this regard, if only the tuyere part can be repaired, the above problem can be alleviated considerably.As a method of repairing only the tuyere part, it is necessary to replace the melted tuyere part with a new one, and then replace it with a new one. A method is known in which a powdered refractory mixed with a binder and made into a slurry is poured into the surrounding refractory melted area and then heated and fired.

However, in the conventional method as described above, the adhesion between the repair layer and the original brick layer is poor, and it is also difficult to obtain a sufficient firing temperature, so that satisfactory fire resistance cannot be obtained.
Since the time required for each batch is relatively long, there remained a problem in terms of the operating rate of the scouring vessel.

The present invention advantageously solves the above-mentioned problems, and uses flame spraying to prevent wear and tear on the scouring section of the scouring vessel equipped with the tuyeres 2 for blowing scouring gas, even under high temperatures immediately after tapping. This paper proposes a method of repairing the tuyere of a scouring vessel that can be repaired very effectively.

Here, the flame spraying method is a method in which powdery granular refractories and solid fuel such as coke are injected together with combustion-supporting gas such as oxygen, and the resulting high-temperature flame melts or semi-molten the powdery granular refractories. This is a thermal spray repair method in which refractories are sprayed onto damaged areas to repair them.

That is, this invention provides a method for repairing all of the tuyeres and surrounding refractories that have been melted and damaged due to the injection of the gas into a scouring vessel equipped with a tuyere for blowing scouring gas into a molten metal bath. After draining the tap water from the scouring vessel, the melted and damaged tuyere is extracted, and at least the outer wall side end of the pores created by this extraction is plugged with refractory material, and then the damage of the refractory around the siding including the remainder of the pores is removed. The above-mentioned problem can be solved by filling the area with molten or semi-molten refractory material by flame spraying, then drilling a siding insertion hole again in this filled part, and then inserting a new blowing tuyere. It is something to do.

Hereinafter, a case in which the present invention is applied to the repair of the bottom tuyere portion of a pure oxygen bottom-blowing converter will be specifically explained based on the drawings.

8 to 8 illustrate the repair procedure according to the present invention according to the operating procedure, and in the figures, number 1 is the melted tuyere, and 2 is the tuyere 1.
In the peripheral refractory wear area, 8 is the furnace bottom brick, 4 is the iron skin, and 5 is the attachment part of the tuyere 1.

Now, as shown in Fig. 3, in the bottom of the bottom-blowing converter that has undergone scouring of a predetermined charge, not only the tuyere 1 but also the surrounding refractories are locally greatly worn out, centering on the tuyere 1. .

Therefore, in this invention, the melted tuyere 1 is first extracted from the furnace bottom as shown in FIG. 4, and then at least the outer wall side end of the pore 6 created by this extraction is After closing with the refractory 7, the worn area 2 of the refractory around the tuyere, including the remainder of the hole v6, is filled with a molten or semi-molten refractory 8 by flame spraying, as shown in FIG. , to repair the heavy-duty layer at the bottom of the hearth. Note that as the refractory material 7 that closes the outer wall side end portion, any one of an amorphous refractory material, a brick cut into a predetermined shape, etc. may be used.

Next, as shown in FIG. 7, the siding insertion hole I is drilled again at the predetermined siding position using, for example, the illustrated drill 9.
After drilling and cutting O, as shown in Fig. 8, apply mortar to the outer periphery of the new tuyere 11, insert it, and fix it to the tuyere mounting part 5 to complete the repair. It is. In this way, the siding that was locally damaged due to blowing and scouring is completely restored.

As described above, according to the method of the present invention, the damaged refractory layer is repaired by spraying the powdered refractory in a molten or semi-molten state using a flame spraying method that produces a high-temperature flame of 2000°C or more. As a result, a strong repair layer can be obtained and its fireproof properties can be significantly improved, so the life of the refractory in the siding can be extended by 2.5 to 3 times compared to conventional methods. It is also possible to shorten the time required for refining, thereby significantly improving the operating rate of the refining vessel in the steelmaking process.

[Brief explanation of drawings]

Fig. 1 is a plan view of the bottom of a bottom blowing converter, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Figs. It is a sectional view of an illustrated panel part. Patent applicant Kawasaki Steel Corporation Figure 15 Figure 2

Claims (1)

[Claims] L In a scouring vessel equipped with a scouring gas blowing into the molten metal bath, when repairing the siding and surrounding refractories that have been melted and damaged as the gas injection progresses,
After draining the tap water from the scouring vessel, the melted and damaged slats are removed, at least the outer wall side ends of the pores created by this extraction are closed with refractory material, and then the refractory surrounding the tuyere containing the remainder of the pores is closed. A scouring condition characterized by filling the damaged area with molten or semi-molten refractory material by flame spraying, then drilling tuyere insertion holes in the filled area, and inserting new blowing holes. How to repair the mouth.