JPS5985814A - Method for attaching bottom blowing tuyere to converter - Google Patents

Abstract

PURPOSE:To extend considerably the life of a tuyere of a converter and to save expenses required to exchange the tuyere by charging molten slag into the burnt- out parts of bottom brick and a sleeve around the tuyere to repair the parts in the interim repairing of the converter. CONSTITUTION:When the wall brick of a converter is subjected to interim repairing after discharging molten metal, a protective cap 21 is put on a tuyere 1a, and molten slag 9 is charged into the burnt-out parts 8. The slag 9 is uniformly filled by shaking the body of the converter, and it is allowed to stand and solidified. After solidifying the slag 9, the cap 21 is removed. The repairing can be carried out repeatedly until the wall brick of the converter is exchanged, so the life of the tuyere 1a is considerably extended.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing bottom blowing tuyeres in a top and bottom blowing converter.

In order to strengthen the stirring of the steel bath and improve the refining efficiency, oxygen is blown in from the earth blowing lance and stirring gas is blown in from the bottom blowing tuyere.
It is well known that top-bottom blowing converter operation for refining has been actively adopted in recent years. The bottom blowing tuyeres (hereinafter referred to as tuyeres) for blowing the agitated gas into the furnace are generally installed by providing mounting holes in the iron shell and lining brick wall of the bottom of the converter furnace.

By the way, the brick wall in the vicinity of the tuyere and its mounting portion is subjected to severe erosion due to direct contact with the strong stirring flow of molten steel generated by gas injection. Therefore, it is extremely important to improve the durability of the tuyere and the brick wall in its vicinity against the above-mentioned melting damage effect in order to carry out stable operation of the top-bottom blowing converter.

The present invention provides a tuyere installation method that has sufficient resistance to the erosion effects and allows for efficient replacement. Hereinafter, the present invention will be explained in detail based on Examples.

Now, FIG. 1 is a cross-sectional structural diagram showing one embodiment of the mounting state of the tuyere. In the figure, 1 is a tuyere, and the tuyere 1 is attached to a sleeve brick 2 buried in a hearth bottom brick 3 and fixed by a tuyere holding brick 4.5. In this embodiment, the tuyere 1 incorporates a plurality of small-diameter blowing pipes I2, and the stirring gas supplied from the gas supply pipe 6 is blown into the furnace from the blowing pipe 12 via the header 11.

By the way, the tuyeres 1 are subject to the erosion effect as described above, and are gradually eroded and damaged as the usage time progresses.

Moreover, since the well-known pine mushroom 7 is formed above the tuyere 1, the tuyere stirring gas is also ejected to the side of the sea, that is, in the direction of the sleeve brick 2, as indicated by the arrow y, and as shown by the broken line X.
As shown, the sleeve bricks 2 and the surrounding hearth bricks 3 are also sequentially melted away.

When the tuyere 1 reaches a predetermined amount of erosion, it is replaced with a new tuyere 1, but the sleeve brick 2 is generally used until the hearth brick 3 is repaired. Therefore, after the tuyere is replaced, the tip of the tuyere 1 is in a protruding state as shown in Figure 2 (=), and if it is used in this state, the rate of erosion of the protruding part of the tuyere 1 will be reduced. noticeably faster.

The present invention aims to effectively solve the above-mentioned problems, and its gist is that when replacing the tuyere, molten slag is injected and solidified around the bottom of the furnace centering on the top of the new tuyere. It is.

FIG. 3 shows an embodiment of the tuyere installation method based on the present invention, in which after installing the new tuyere la,
The lining layer 9 is formed by injecting molten slag into the melted portion 8 formed around the top of the slag and solidifying it.

As the molten slag, converter slag produced as a by-product in a converter, or dolomite added to the converter slag may be used in a molten state.

In particular, converter slag can be easily obtained from an operating converter installed adjacent to the converter whose siding is being replaced, so it is extremely easy to work with and is effective.

As a method for injecting and solidifying molten slag, for example, a new tuyere 1
After injecting a predetermined amount of molten slag into the furnace after replacing with A, the converter bodies are swung to inject it into the entire area of the melted part 8, and after that, the furnace body is left still. Just let it solidify.

In addition, when injecting the molten slag, the blowing pipe 1 of the tuyere 1a
In order to prevent molten slag from entering the tuyere, for example, stirring gas may be jetted out at a predetermined pressure, or as shown in FIG. It is effective to place it above.

As described above, the present invention enables molten slag to be injected and solidified around the bottom of the furnace centering around the top of the new tuyere when replacing the tuyere, thereby making it possible to maintain the area around the tuyere when only the tuyere is replaced. Furnace wall repair can be done easily, quickly, and reliably, making it possible to significantly extend the lifespan of new siding after replacement.

According to the experience of the present inventors, when the melted portion 8 is repaired by filling the monolithic refractory, the melting speed of the tuyere 1a is 2 to 3 r.
a/ch, but by implementing the present invention, the erosion rate was drastically reduced to 0.8 to 1.5 mm/ch.

As described above, the present invention has a simple configuration and has extremely great practical effects.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional structural diagram showing one embodiment of the tuyere, Fig. 2 is a cross-sectional structural diagram showing the state after replacement of the tuyeres, and Fig. 3 is a cross-sectional diagram near the tuyeres showing an embodiment of the present invention. It is a diagram. 1, la: tuyere 2; sleeve brick 3; hearth brick 4.5; tuyere holding brick 6; gas supply pipe 7; pine mushroom 8; melted part 9; lining layer 21; protective cap

Claims (1)

[Claims] When replacing the bottom blowing tuyere of a top and bottom blowing converter, a method for installing a bottom blowing tuyere in a converter is characterized by injecting and solidifying molten slag around the bottom of the furnace centering on the top of the new slag.