JPH01104713A - Method for repairing damaged part of bottom brick of bottom blown furnace - Google Patents

Abstract

PURPOSE:To easily and rapidly repair the entire part of the damaged part of the bottom bricks of a bottom blown furnace by charging brick scrap to the damaged peripheral brick part of a bottom blowing furnace and opening a force-feed hole of the press-feed hole bricks stacked in the central part of the furnace bottom, then force-feeding castable refractories through this hole. CONSTITUTION:A pipe 6 which is made of steel such as stainless steel and into which refractories 7 are previously packed is embedded into the bricks to form the force-feed hole bricks 5. The force-feed hole bricks 5 are previously stacked in the central part of the bottom of a converter, which consists of a shell 1, permanent bricks 2 and wear bricks 3 and is provided with bottom blowing tuyeres 4 penetrating the tuyere bricks 3a, in such a manner that the above-mentioned steel pipe 6 penetrates the furnace to the inside and outside thereof. The tuyeres 4 are replaced and the press-feed hole is opened by boring in the above-mentioned refractories 7. The brick scope 8 is further charged as aggregate from the upper part of the converter to the damaged peripheral brick part of the tuyeres 4. The castable refractories 9 are then force-fed from the force-feed hole to pack the spacing of the brick scrap 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for repairing a bottom blowing tuyere in a converter and a damaged part of the surrounding bricks.

(Prior Art) The bottom blowing tuyere and surrounding bricks in a converter are more severely damaged than other parts. The repair methods include spraying,
Baking, slag coating, or brick scrap coating, which leaves slag in the furnace and mixes brick scraps into it, are commonly practiced, but these have low durability. Recently, a repair method has been adopted in which a slurry-like monolithic refractory is injected into the damaged area, but sufficient durability has not been achieved.

On the other hand, Japanese Patent Application Laid-open No. 59-93819 discloses a method for constructing a refractory wall around a tuyere, in which a coarse-grained refractory material and a fluid (amorphous) refractory material are used in combination to suppress the wear rate. I suggest that. That is, when constructing a refractory wall around a gas injection tuyere that is installed to penetrate the refractory wall of a refining vessel that accommodates molten iron, when setting a new tuyere, First, a particle size of 1■
Coarse-grained refractory material of the above size is filled, then fine-grained fluidized refractory material is press-fitted and filled into the above-mentioned construction area after filling the coarse-grained refractory material, and after solidification, drying and sintering are carried out as usual. This is a method of constructing a refractory wall around the tuyere of a refining vessel, which is characterized by:

(Problems to be Solved by the Invention) When comparing the durability of bricks and irregular shaped materials, it is generally known that irregular shaped materials are significantly inferior to bricks. Therefore, the method proposed in the above-mentioned publication is also effective in suppressing the damage rate of the refractories around the tuyere and extending the life of the furnace.

However, in the method disclosed in this publication, the irregularly shaped material is press-fitted through the gap between the tuyere and the remaining refractory wall, which causes the following problems.

Since the gap between the tuyere and the remaining refractory is narrow, less than 1h+w,
If the flow rate of the irregular shaped material to be press-fitted is low, press-fitting becomes difficult. Therefore, the particle size of the aggregate (magnesia grains, etc.) mixed into the irregularly shaped material is limited, which prevents further improvement of its durability.

■Repair areas are limited to the immediate vicinity of the tuyere.

Therefore, it is an object of the present invention to easily repair the entire hearth damage area including the siding by using a wide range of irregularly shaped materials, including highly durable irregularly shaped materials using aggregate with relatively large grain size. and to provide a method for quick repair.

(Means for Solving the Problems) Thus, the gist of the present invention is to install a press-fit hole brick in which an iron pipe filled with refractories is embedded in the center of the furnace bottom, and the iron pipe is continuously inserted into the furnace. The holes were stacked so that they penetrated inside and outside, brick scraps were put into the damaged bottom blowing tuyeres and surrounding bricks, and the refractories filled in the press-in hole bricks were removed to form iron pipes. This is a method for repairing a damaged part of a bottom blowing furnace bottom brick of a converter, which is characterized by: drilling a press-fit hole in the brick waste, and press-filling a monolithic refractory through the press-fit hole into a gap between brick scraps.

(Function) In the present invention, at a stage when damage has progressed due to agitation of bottom-blown gas, holes are made in the refractories in the iron pipes embedded in the bricks by drilling, poling, etc., and brick scraps are thrown into the damaged parts. By press-fitting an unshaped material (unshaped refractory) from the outside into the gap between brick scraps through the press-fitting hole, the filling density is improved and the durability is improved.

The press-in hole brick is located in the center of the hearth bottom, but the brick quality and shape may be the same as the brick used for the hearth bottom. Since the iron pipe embedded in the press-fit hole brick is exposed to high heat, it is preferably made of stainless steel and has an inner diameter of about 15 to 301 m.

The refractory to be filled into the iron pipe is a basic, coarse-grained, monolithic refractory. However, instead of the monolithic refractory, bricks made of magnesia carbon or the like may be processed and embedded in the iron pipe.

When the remaining thickness of the wing wear brick is 50 to 100 m+* and the damage is severe, first use a drill or boring machine to remove the refractory in the iron pipe embedded in the press-fit hole brick, and then drill the press-fit hole. Next, after brick scraps are thrown into the damaged area, an unshaped refractory (unshaped material) is press-filled into the gap between the brick scraps from the outside through the press-fit hole that has been opened.

For example, the following is used as the monolithic refractory to be press-fitted: Aggregate: Magnesia, maximum particle size 3 mm Binder:
By appropriately selecting the inner diameter of the resin press-fit hole, a highly durable monolithic refractory can be easily press-fitted.

(Example) Next, an example of the present invention will be described in detail with reference to the accompanying drawings.

Set of dung tiles FIG. 1 is a cross-sectional view of the bottom blowing furnace bottom of a converter 6 in which the press-in hole bricks according to the present invention are set in advance at the center of the furnace bottom.

The bottom of the furnace is made of 1 iron shell, 2 permanent bricks, and 3 wear bricks.
Consists of. A tuyere 4 provided at the bottom of the furnace penetrates the iron skin 1, the permanent bricks 2, and the tuyere bricks 3a.

The press-in hole bricks-5 according to the present invention are stacked at the center of the hearth bottom. FIG. 3 is a sketch of the press-fit hole brick 5 as shown in FIG. This press-fit hole brick 5 is made of a magnesia carbon brick 5a with an outer diameter of 22 o.
++m, an inner diameter of 18 IIIll was inserted into the stainless steel vibro, and the inside of the stainless steel vibro was filled with a non-aqueous magnesia carbon monolithic refractory (25
07 converter).

The press-in hole bricks 5 are stacked so that the stainless steel vibro of the upper and lower bricks are continuous and penetrate inside and outside the furnace. (Pre-drill a hole in the steel shell 1 to match the press-fit hole formed by the stainless steel vibro.) As shown in Figure 2, damage to the surrounding area progresses due to the 91L rainbow blowing process. The thickness 2 of the part of the tuyere brick 3a into which the tuyere 4 is inserted is 5
When the temperature reaches 0 to 100 a+m, repair is carried out as follows according to the method of the present invention.

First, the tuyere 4 is replaced, and the refractory 7 inside the stainless steel vibro of the press-fit hole brick 5 and the following inside the opening of the iron skin 1 is removed using a boring machine to form a press-fit hole formed by the stainless steel vibro.

Open a hole.

Next, brick scraps 8 are introduced from the upper part of the converter to fill the melted portion, and then an irregularly shaped member 9 is press-fitted through a press-fit hole formed by stainless steel vibro to fill the gap between the brick scraps. The following was used as the brick waste 8: Particle size: 30 to 100 mm Material: Magnesia carbon (MgO-C) The following was used as the irregularly shaped material: Aggregate: Magnesia, maximum particle size 31 Binder : Resin system (effects of the invention) A slag erosion test was carried out in an experimental furnace to compare the durability of irregularly shaped materials alone and when brick scraps were mixed. FIG. 4 is a graph comparing the amount of erosion in the case of repair according to the present invention (using irregularly shaped materials and brick scraps) and in the conventional case (using only irregularly shaped materials). In this experiment, the following materials were used as irregular shaped materials and brick scraps: irregular shaped materials: magnesia aggregate, resin binder brick scraps
: Magnesia carbon, particle size 20 to 30 mm The amount of erosion loss (arm) in the figure is the value per 2 hours of heating time at 1650°C.

From the results shown in FIG. 4, it was confirmed that the repair material made of irregularly shaped material mixed with brick scraps had about four times the durability of the irregularly shaped material alone.

In addition, in the present invention, a press-fit hole brick is placed in the bottom of the furnace in advance, and the hole is opened during repair to press-fit the irregularly shaped material. Therefore, compared to the method of the above-mentioned publication (JP-A-59-931319), the particle size range of the irregularly shaped aggregate can be selected more freely, and the durability can be further improved compared to the method of the publication. Furthermore, there is no particular need to limit the particle size of the brick scraps that are thrown in before the irregular shaped material is poured.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the bottom of a converter furnace in which press-in hole bricks are set in the bottom of the furnace according to the present invention; Fig. 2 is a sectional view similar to Fig. 1; Fig. 3 is a sketch of the single press-in hole brick inserted into the bottom of the furnace in Fig. 1; and Fig. 4 shows the state in which the repair was completed according to the method of the present invention and the conventional method. It is a graph comparing the amount of erosion when parts are repaired. l; Steel shell 2: Permanent brick 3: Wear brick 4: Tuyere 5; Press-in hole brick 6: Stainless steel pipe (I-type pipe) 7: Refractory 8; Brick scrap 9: Irregular material (irregular refractory)

Claims (1)

[Scope of Claims] Press-in hole bricks in which iron pipes filled with refractories are embedded are stacked in the center of the furnace bottom so that the iron pipes continuously pass through the inside and outside of the furnace, and damage. Injecting brick waste into the bottom blowing tuyere and surrounding brick area, removing the refractory filled in the press-in hole bricks and opening a press-in hole formed by an iron pipe, and removing the brick waste. A method for repairing a damaged part of a bottom blowing furnace bottom brick of a converter, comprising: press-filling a monolithic refractory into a gap through a press-fit hole;