JPH09118905A - Method for repairing furnace wall of blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repairing method for furnace wall of a blast furnace which can repair the furnace wall of particularly a small size blast furnace in a short period and at a low cost during stopping blasting without stopping the blast furnace operation. SOLUTION: After stopping the blasting, charged material 12 of the blast furnace is descended from the damaged part A in the blast furnace and ore ballast 13 is packed on the charged material 12 in the blast furnace and cooling panels 14 are removed. An upper opening part 17 and a lower opening part 19 of the furnace wall 10a are formed at the little upper part from the ore ballast 13 packed part. Furnace wall protectors 20, 21 inclined downward on the surfaces 20a, 21a at the furnace core side are arranged along the inner peripheral surface of the furnace wall 10a on the ore ballast 13 packed part. Successively, furnace wall refractory 15 is exploded and broken pieces 15a are dropped and discharged from the lower opening part 19 with a scraping device 16. After scraping, staves are carried in the furnace from the upper opening part 17 and fitted to the furnace wall 10a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a furnace wall of a blast furnace, and more particularly, to a method for repairing a blast furnace without stopping the blast furnace.
Repairing the furnace wall of a blast furnace, especially a small blast furnace, that is, removing a damaged cooling plate, and installing a new stave cooler (hereinafter sometimes referred to as stave) during a hot blast, at low cost The present invention relates to a repair method for a blast furnace wall that can be attached.

[0002]

2. Description of the Related Art In a blast furnace at the end of its life, a part of a furnace wall refractory that is worn or dropped is noticeable. A large heat load is applied to the iron shell of that part and the cooling board inserted into the furnace wall refractory from the outside, which causes cracks in the iron shell and cooling board,
A situation occurs in which the gas in the furnace leaks from the cracked portion of the steel shell, which significantly reduces the operating rate of the blast furnace. Therefore, the blast furnace wall is repaired as a countermeasure. Conventionally, as a method for repairing a furnace wall of a large blast furnace, for example, a “method for repairing a blast furnace wall” disclosed in Japanese Patent Publication No. 58-50287 filed by the applicant of the present application is known. In addition, after the blast furnace is blown off, the blast furnace charge is lowered below the damaged part of the furnace wall, then the cooling board is removed from the furnace wall, and debris is received near the blast furnace charge in the furnace. Place
Then, there is a method in which the furnace wall refractory is blasted and the fragments are captured by the fragment receiver, then the fragment receiver is raised to remove the fragments, and then the stave is carried into the furnace from the top of the furnace and attached to the furnace wall. .

[0003]

By the way, in the conventional method for repairing the furnace wall of the blast furnace, when the furnace wall refractory is blasted, the debris receiver is installed downward, but it is lowered below the damaged portion of the furnace wall. Some debris from the furnace wall refractory drops onto the blast furnace charge. In the case of a large blast furnace, even if some impurities debris remain in the furnace, the total amount of ore and coke charged from the top of the furnace is large, so when the operation is restarted. It has little effect on the launch of the blast furnace. However, when the blast furnace is small, the total amount of the charge is small, so if debris remains in the furnace as in the method for repairing the furnace wall of the large blast furnace described above, it will be A relatively large proportion of the charge,
There is a risk that the operation at startup will be hindered, it will take time to start up, and the blast time will be long, and the small blast furnace, which is extremely cold in the furnace during this blast, will not be able to start up. there were.

In order to avoid such an inconvenience, therefore, when repairing the furnace wall of the conventional small blast furnace, the repair of the furnace wall is made as an emergency measure by spraying an amorphous refractory material. When the damage is severe, the blast furnace operation is completely stopped, the furnace wall refractory is destroyed after the furnace body is cooled and dropped, and the worker who enters the furnace scrapes up the dismantled fragments and collects them in the furnace. The cold repair method called so-called "repair" was carried out, in which it was carried out to the outside and then repaired. The present invention has been made in view of such circumstances, without stopping the blast furnace,
A method for repairing blast furnace walls, especially small blast furnace walls, that is, removing damaged cooling plates and installing new staves / coolers, in a short period of time and at low cost during hot hot blasts. The purpose is to provide.

[0005]

According to the present invention, there is provided a semiconductor device comprising:
The method for repairing the blast furnace furnace wall described is, after the blast furnace is blown off, a step of lowering the blast furnace charge below the damaged portion of the furnace wall, and a step of lowering the blast furnace charge below the damaged portion of the furnace wall. , Filling the blast furnace charge to a predetermined height with ore ballast, and removing the cooling plate from the peripheral surface of the furnace wall, and slightly above the ore ballast filling portion of the furnace wall, the furnace wall refractory An upper opening in which the scraping device for the debris of
A step of forming a lower opening for discharging the fragments scraped off by the scraping device to the outside of the furnace, and on the ore ballast-filled portion of the furnace wall, along the inner peripheral surface of the furnace wall, respectively, A step of arranging a plurality of furnace wall protectors whose side surfaces are inclined downward in a substantially annular shape, and after arranging the furnace wall protectors in the furnace, blast the furnace wall refractory, and debris thereof on the ore ballast. A step of dropping, a step of discharging the fragments from the lower opening to the outside of the furnace by using the scraping device, and a step of scraping the fragments, and then carrying the stave into the furnace from the upper opening, A step of attaching to the inner peripheral surface of the wall and a step of closing the upper and lower openings after scraping out the fragments are provided.

The ore ballast as used herein is made of a constituent material of a blast furnace charge, and is, for example, ore, coke, limestone, or a mixture thereof. The method for repairing the blast furnace wall according to claim 2 is the method for repairing the blast furnace wall according to claim 1, wherein another upper opening for a breaker excavator is formed in the furnace wall, and the scraping device is used to remove the upper opening. When the fragments of the furnace wall refractory were scratched out of the furnace, the breaker shovel arranged near the other upper opening was used to crush the large fragments to a size that facilitates scratching.

[0007]

According to the method of repairing the blast furnace furnace wall according to the first or second aspect, the blast furnace charge is transferred onto the blast furnace charge while the blast furnace charge is lowered below the damaged portion of the blast furnace wall after the blast furnace is blown off. After filling the ore ballast of the furnace wall, remove the cooling plate of the furnace wall, and then carry in several furnace wall protectors from the upper opening formed slightly above the ore ballast filling part of the furnace wall and bring them into the furnace wall. Since it is placed in a substantially annular shape on the ore ballast filling part of the ore, when the furnace wall refractory is subsequently blasted, the fragments gather along the surface of the core wall side inclined downward of each furnace wall protector toward the furnace center side. While falling on the ore ballas. As a result, when the scraping device is used to scrape the debris from the lower opening thereafter, the scraping operation is facilitated and the risk of damaging the inner peripheral surface of the furnace wall is reduced. Next, from the upper opening where the scraping device is retracted,
Since a large number of staves are carried into the furnace and repair work is performed by attaching them to the inner peripheral surface of the furnace wall, without stopping the blast furnace, during a hot blast, at a short time and at low cost, Repairing the furnace wall of a blast furnace, especially a small blast furnace, i.e. removing a damaged cooling plate, and then adding a new stave
A cooler can be installed. Since the ore ballast is made of the constituent material of the blast furnace charge, it does not affect the start-up of the blast furnace after repair. Further, in the method for repairing the blast furnace furnace wall according to claim 2, since the large furnace wall refractory material is crushed into small pieces by using the breaker shovel in this way, the fragments are scraped out of the furnace by the scraping device, The risk of leaving the lump in the furnace and hindering the start-up of the blast furnace is reduced, and scrapes can be scraped out smoothly.

[0008]

According to the method for repairing the furnace wall of the blast furnace according to the first and second aspects of the present invention, the debris dropped on the ore ballast by blasting the refractory material of the furnace wall in this way is removed from the ore ballast filling portion of the furnace wall. Using a scraping device near the upper opening, which was formed slightly above, scraped it out of the furnace from the lower opening, carried the stave from the upper opening into the furnace, and attached it to the furnace wall. Without doing so, it is possible to repair the blast furnace furnace wall, that is, remove the damaged cooling plate and install a new stave / cooler in a short period of time and at low cost during a hot blast. In particular, this repair method is more effective in repairing a small blast furnace. Also, by arranging each furnace wall protector along the inner peripheral surface of the furnace wall, the fragments at the time of blasting of the furnace wall refractory are guided by the surface of the core wall side inclined downward of each furnace wall protector, and Since they are gathered to the side, the scraping operation of the scraps becomes easy when the scraps are scraped from the lower opening by using the scraping device. Moreover, during the scraping, the furnace wall protector can protect the inner surface of the remaining cooling board and the remaining refractory. Further, in the method for repairing the blast furnace wall according to the second aspect of the present invention, since the large lumps of the refractory wall of the furnace wall are crushed into small pieces by the breaker shovel, the scraping device can smoothly scrape the fragments.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is an enlarged longitudinal sectional view of an essential part showing a scraping operation state of fragments of a furnace wall refractory in a small blast furnace to which a method for repairing a furnace wall of a blast furnace according to an embodiment of the present invention is applied, and FIG. FIG. 4 (a) is an enlarged horizontal cross-sectional view showing an operation state of scraping out fragments of the furnace wall refractory, FIG. 3 is an enlarged vertical sectional view showing an operation state of crushing fragments using the breaker shovel, and FIG. FIG. 4B is a vertical sectional view showing a working state in which ore ballast is filled on the lowered blast furnace charge and the cooling plate is removed from the furnace wall, and FIG. 5A is a vertical cross-sectional view showing a state in which a furnace wall protector is installed around an ore ballast in the furnace, and FIG. 5B is a furnace-wall refractory material. Fig. 6 (a) is a vertical cross-sectional view showing the state of work for scraping out the fragments that have exploded
Is a vertical cross-sectional view showing a working state in which the furnace wall protector is removed from the furnace and the lower opening is closed, and FIG. 6B shows a working state in which the stave is carried into the furnace from the upper opening. FIG. 7A is a vertical cross-sectional view showing a work state of spraying an irregular-shaped refractory near the lower opening forming portion.
(B) is a vertical cross-sectional view showing a working state of filling an irregular-shaped refractory in a gap between the stave and the furnace wall, FIG. 8 is a vertical cross-sectional view showing a startup state of the blast furnace, and FIG. 9 is the stave and the furnace. It is a principal part expanded sectional view which shows the working state which fills up an irregular-shaped refractory material in the clearance gap with a wall. 1, 4 to 8 are sectional views taken along the line S-S in FIG.

As shown in FIG. 1, a blast furnace 10 to which a method for repairing a blast furnace wall according to an embodiment of the present invention is applied is a small blast furnace having a capacity of 1000 m ³ . Hereinafter, the method for repairing the furnace wall of the blast furnace will be described in detail in accordance with the respective work steps of FIGS. As shown in FIG. 4A, first, the hot air supply from the tuyere 11 arranged on the lower peripheral surface of the blast furnace 10 is stopped to shut down the blast furnace 10. Next, the blast furnace charge 12 is placed on the damaged portion A of the furnace wall.
Down to the bottom and then onto the blast furnace charge 12,
For example, the ore ballast 13 such as iron ore and coke is about 1.
Fill to a height of 5 m. Further, outside the furnace, a large number of cooling boards 14 provided around the iron shell of the furnace wall 10a are removed.

Next, as shown in FIG. 4 (b), the furnace wall 1
In the vicinity of the bottom of the furnace, which is slightly above the portion where the ore ballast 13 of 0a is filled, an operator outside the furnace melts the iron shell and removes the furnace wall refractory material 15 from the furnace to the outside of the furnace. Is formed. Specifically, a pair of upper openings 17 for scraping-out device 16 (see FIGS. 1 and 2) for scraping off the furnace wall refractory material 15 are formed at opposite positions of the furnace wall 10a, and in the circumferential direction of the furnace wall 10a. 9 for upper opening 17
At a position of 0 degree, a pair of the breaker excavator 18 and another upper opening 17a (see FIGS. 2 and 3) into which only the stave 23 is carried in the furnace are formed in pairs, and both upper openings 17 are formed. Lower openings 19 are formed below the respective. A backhoe is used as the scraping device 16 here. Then, Figures 2, 5
As shown in (a), on the portion where the ore ballast 13 is filled in the furnace wall 10a, along the inner peripheral surface of the furnace wall 10a, in a plan view, along a scraping locus k of the scraping device 16, respectively. And eight trapezoidal furnace wall protectors 20 whose core-side surfaces 20a are inclined downward, and two triangular furnace wall protectors which are arranged immediately below each lower opening 19 and whose core-side surfaces 21a are inclined downward. 21 and 21 are annularly arranged.

Subsequently, as shown in FIGS. 1 and 5 (b), an appropriate amount of dynamite is provided at a required position of the furnace wall refractory material 15 provided around the furnace of the blast furnace 10 and the dynamite is exploded. The furnace wall refractory material 15 is shattered and dropped into the furnace bottom. On this occasion,
In the furnace, trapezoidal and triangular furnace wall protectors 20 and 21 are arranged in a substantially annular shape on the filled portion of the ore ballast 13 along the inner peripheral surface of the furnace wall 10a, so that the furnace wall refractory material 15 is blasted. At times, the fragments 15a are guided by the core-side surfaces 20a, 21a of the respective furnace wall protectors 20, 21 which are inclined downward,
While gathering toward the center of the furnace, it falls onto the ore ballast 13. After that, the arm 16a of the scraping device 16 is moved to scrape the fragments 15a out of the furnace through the lower opening 19. At this time, since the fragments 15a are gathered toward the furnace center side via the respective furnace wall protectors 20 and 21, the scraping work is facilitated and the furnace wall refractory laid on the inner peripheral surface of the furnace wall 10a is facilitated. The risk of damaging 15 is reduced.

Moreover, the arm 18a of the breaker shovel 18 shown in FIGS. 2 and 3 is moved to vibrate the breaker 18b at the tip of the arm 18a to crush the large furnace wall refractory material 15 into small pieces, and then the scraping device 16 is used. The fragment 1
Since 5a is scraped out of the furnace, leave a large lump inside the furnace,
The risk of hindering the startup of the blast furnace 10 is reduced, and the scraps 15a can be scraped out smoothly. The scraped out fragments 15a are discharged to the outside through a discharge duct 22 extending downward from the vicinity of each lower opening 19 (see FIG. 1) along the outer peripheral surface of the furnace bottom. Then, as shown in FIG. 6A, each lower opening 19 is closed, and each furnace wall protector 20, 21 is carried out from the upper opening 17. next,
As shown in FIG. 6 (b), the staves 23 are sequentially carried into the furnace from the upper opening 17, and they are moved up and down in the furnace using a pair of cranes 24 arranged at the top of the furnace. The stave 23 is attached to a predetermined position of the furnace wall 10a. As shown in FIG. 9, the stave 23 is a cast iron plate 23a in which a refractory material 23b is embedded,
The cooling pipe 23c protruding from the back surface of the cast iron plate 23a is inserted and attached to the iron skin of the furnace wall 10a. Finally,
As shown in FIG. 7 (a), the upper opening 17 is closed by the iron skin cover and welded to the furnace wall 10a, and then the stave 23 waiting in the furnace is attached to the inner surface of the iron skin cover.

Next, as shown in FIG. 7 (a), similarly, a crane 24 is also used to suspend a spraying device 25 for indeterminate refractory material in the bottom of the furnace, and then scrape off the fragments 15a to blast the refractory material on the furnace wall. 15 wall protectors 20, 2
From the injection nozzle of the spraying device 25 to the disposition part of 1,
Irregular refractories 28 are sprayed and repaired. The amorphous refractory 28 is pressure-fed at a predetermined pressure by the kneader 26 arranged outside. In addition, in order to prevent heat damage to the stave 23 during operation, the blowing device 25 is used to
The amorphous refractory material 28 is sprayed on the inner surface of the stave 23 attached to 0a. Subsequently, as shown in FIG. 7B, the cast iron plate 23 a of each stave 23 and the furnace wall 1
The amorphous refractory 28 having a predetermined viscosity is pressed into the void 27 formed between the iron shells 0a at a predetermined pressure by the kneading machine 26, and then dried and solidified. Then, as shown in FIG. 8, hot air was blown into the blast furnace 10 from the tuyere 11 at the bottom of the furnace.
Resume operations. At this time, since the ore ballast 13 is made of the constituent material of the blast furnace charge 12, the startup of the blast furnace 10 after repair is not affected even if it is not recovered outside the furnace.

As described above, the fragments 15a dropped on the ore ballast 13 by blasting the furnace wall refractory material 15 are transferred to the furnace wall 1
Using the scraping device 16 near the upper opening 17 formed slightly above the filled portion of the ore ballast 13 of 0a, the stave 23 is carried into the furnace from the lower opening 19 by scraping it out of the furnace. Since the blast furnace 10 is attached to the furnace wall 10a at a low temperature, the furnace wall 10a of the blast furnace 10 can be repaired, that is, a damaged cooling plate can be performed in a short period of time and at low cost during a hot blast without stopping the blast furnace 10. Get rid of,
You can install a new stave cooler. In particular, this repairing method has a great effect in repairing a small blast furnace, which causes a great hindrance to start-up when the operation is restarted if the air is blown for a long time.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional view of an essential part showing a scraping operation state of fragments of a furnace wall refractory in a small blast furnace to which a method for repairing a furnace wall of a blast furnace according to an embodiment of the present invention is applied.

FIG. 2 is an enlarged transverse cross-sectional view of a main part showing a scraping operation state of fragments of the furnace wall refractory material.

FIG. 3 is an enlarged longitudinal cross-sectional view of essential parts showing a state in which a crushing operation of fragments using the breaker shovel is started.

FIG. 4 (a) is a vertical cross-sectional view showing a working state in which ore ballast is charged on the lowered blast furnace charge and the cooling board is removed from the furnace wall. (B) It is a longitudinal cross-sectional view showing a state in which upper and lower openings are formed in the furnace wall.

FIG. 5 (a) is a vertical cross-sectional view showing a working state in which a furnace wall protector is provided around an ore ballast in the furnace. (B) It is a longitudinal cross-sectional view showing a scraping operation state of a fragment of the furnace wall refractory blasted.

FIG. 6 (a) is a vertical cross-sectional view showing a working state in which the furnace wall protector is removed from the furnace and the lower opening is closed. (B) It is a longitudinal cross-sectional view showing a working state in which the stave is loaded into the furnace from the upper opening.

FIG. 7 (a) is a vertical cross-sectional view showing a work state of spraying an irregular-shaped refractory near the lower opening forming portion. (B) It is a longitudinal cross-sectional view showing a working state in which the irregular-shaped refractory is filled in the gap between the stave and the furnace wall.

FIG. 8 is a vertical sectional view showing a startup state of the blast furnace.

FIG. 9 is an enlarged cross-sectional view of a main part showing a working state of filling an irregular-shaped refractory material in a gap between the stave and the furnace wall.

[Explanation of symbols]

10 Blast Furnace 10a Furnace Wall 11 Tuyere 12 Blast Furnace Charge 13 Ore Ballast 14 Cooling Plate 15 Refractory Wall Refractory 15a Fragment 16 Scraping Device 16a Arm 17 Upper Opening 17a Upper Opening 18 Breaker Excavator 18a Arm 18b Breaker 19 Lower Opening 20 trapezoidal wall protector 20a core-side surface 21 triangular furnace wall protector 21a core-side surface 22 exhaust duct 23 stave 23a cast iron plate 23b refractory 23c cooling pipe 24 crane 25 sprayer 26 kneader 27 void 28 irregular refractory A Furnace wall damaged part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutsumi Fumimizu 46-59 Nakahara, Tobata-ku, Kitakyushu City, Fukuoka Prefecture Nippon Steel Corporation Machinery & Plant Division

Claims (2)

[Claims] 1. A step of lowering a blast furnace charge below a damaged portion of a furnace wall after the blast furnace is blown off; and a step of lowering the blast furnace charge below a damaged portion of the furnace wall,
Filling the ore ballast on the blast furnace charge to a predetermined height, and removing the cooling plate from the peripheral surface of the furnace wall, and slightly above the ore ballast filling portion of the furnace wall, the furnace wall refractory An upper opening where a scraping device for scraps is arranged, and a step of forming a lower opening for discharging scraps scraped off by the scraping device to the outside of the furnace, and on the ore ballast filling portion of the furnace wall, Along the inner peripheral surface of the furnace wall, a step of arranging a plurality of furnace wall protectors, each of which has a core-side surface inclined downward, in a substantially annular shape, and after arranging the furnace wall protector in the furnace, the furnace wall refractory And dropping the fragments onto the ore ballast; discharging the fragments from the lower opening to the outside of the furnace by using the scraping device; and after scraping the fragments, the upper part Stave from opening to furnace Crowded beauty, and attaching the inner peripheral surface of the furnace wall, after scraping the debris, the upper, method of repairing a blast furnace wall, characterized in that a step of closing the lower opening. 2. An upper opening for a breaker excavator is formed in the furnace wall, and is arranged near the other upper opening when scraping out the fragments of the refractory from the furnace wall by the scraping device to the outside of the furnace. The blast furnace wall repair method according to claim 1, wherein the breaker shovel is used to crush the large pieces to a size that facilitates scraping.