JP3272923B2 - Repair method of blast furnace wall - Google Patents

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.
During the hot wind breaks, the furnace walls of blast furnaces, especially small blast furnaces, can be repaired in a short period of time and at a low cost, that is, the damaged cooling plates can be removed and a new stave cooler (hereinafter sometimes referred to as a stave) can be installed. The present invention relates to a method for repairing 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 portion of a furnace wall refractory which is worn or dropped is conspicuous. A large heat load is applied to the steel skin of that part and the cooling board inserted from the outside into the furnace wall refractory, which causes cracks in the steel skin and the cooling board,
A situation in which gas in the furnace leaks from the cracked portion of the steel shell has occurred, and the operation of the blast furnace has been significantly reduced. Therefore, as a countermeasure, blast furnace furnace walls are being repaired. Conventionally, as a method of repairing a furnace wall of a large blast furnace, for example, a "method of repairing a blast furnace wall" disclosed in Japanese Patent Publication No. 58-50287 filed by the present applicant has been known. In addition, after the blast furnace is shut down, the charge in the blast furnace is lowered below the damaged part of the furnace wall, the cooling plate is removed from the furnace wall, and debris is collected on the vicinity of the charge in the furnace. And place
Then, the furnace wall refractory is blasted, the fragments are captured by a fragment receiver, then the fragment receiver is raised to remove the fragments, and then the stave is brought into the furnace from the furnace top and attached to the furnace wall. .

[0003]

According to the conventional method for repairing the furnace wall of a blast furnace, when a furnace wall refractory is blown up, a debris receiver is installed below the furnace wall, but it is lowered below the damaged part of the furnace wall. Some pieces of the furnace wall refractories fall on the blast furnace charge. In the case of a large blast furnace, even if some debris as impurities remain in the furnace, it is necessary to restart the operation because the total amount of ore and coke charged from the furnace top is large. It has little effect on the startup of the blast furnace. However, when the blast furnace is small, the total amount of charge is small, so if debris remains in the furnace as in the above-described method for repairing the furnace wall of a large blast furnace, if the debris remains in the furnace, it will Occupy a relatively large proportion of the charge,
Operation at the start-up is hindered, it takes time to start the operation, and the stall time is extended, and there is a risk that the small blast furnace where the inside of the furnace is severely cooled during this stall may not be able to start. there were.

Therefore, in order to avoid such inconveniences, when repairing the furnace wall of a conventional small blast furnace, the repair of the furnace wall has been performed as an emergency measure by spraying an irregular-shaped refractory. If the damage is severe, the operation of the blast furnace is completely stopped, and after the furnace body is cooled, the furnace wall refractory is broken and dropped, and the worker entering the furnace collects the dismantled debris and removes the furnace. It was carried out outside and then repaired, a so-called "renovation" cold repair method. The present invention has been made in view of such circumstances, without stopping the blast furnace,
A method for repairing the walls of blast furnaces, especially small blast furnaces, in a short period of time and at low cost during hot cold winds, that is, removing the damaged cooling plate and installing a new stave cooler, 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 wall according to the above includes, after the blast furnace is shut off, a step of lowering the blast furnace charge to below the damaged wall portion and after lowering the blast furnace charge below the damaged wall portion. Filling the ore ballast onto the blast furnace charge to a predetermined height and removing a cooling plate from the peripheral surface of the furnace wall; and slightly above the ore ballast filled portion of the furnace wall, the furnace wall refractory An upper opening where a scraping device of
Forming a lower opening for discharging the debris scraped by the scraping device to the outside of the furnace; and forming a core on the ore ballast-filled portion of the furnace wall along the inner peripheral surface of the furnace wall. 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, blasting the furnace wall refractories and debris of the fragments on the ore ballast. Dropping, using the scraping device, discharging the debris out of the furnace from the lower opening, and after scraping the debris, transporting a stave into the furnace from the upper opening, the furnace The method further comprises 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 debris.

[0006] The ore ballas referred to herein is made of a constituent material of a blast furnace charge, and refers to, for example, ore, coke, limestone, or a mixture thereof. A method for repairing a blast furnace furnace wall according to claim 2 is the method for repairing a blast furnace furnace wall according to claim 1, wherein another upper opening for a breaker excavator is formed in the furnace wall, and When scraping out pieces of the furnace wall refractory outside the furnace, a breaker shovel arranged near the other upper opening was used to crush the large pieces to a size that could be easily scraped out.

[0007]

The method for repairing the blast furnace wall according to the first and second aspects of the present invention provides a method of repairing a blast furnace wall, for example, after the blast furnace is shut down, the blast furnace charge is lowered to below the damaged wall of the blast furnace during the hot period. After filling the ore ball of the furnace wall, the cooling wall of the furnace wall was removed, and then, for example, a plurality of furnace wall protectors were carried from the upper opening formed slightly above the ore ballast filling portion of the furnace wall, and they were removed from the furnace wall. Are placed in a substantially annular shape on the ore ballast filling part, so that when the furnace wall refractory is subsequently blasted, the fragments gather toward the furnace center along the downwardly inclined core side surface of each furnace wall protector. While falling on the ore ballas. Thereby, when scraping out the debris from the lower opening portion by using the scraping device thereafter, the scraping operation is facilitated and the possibility of damaging the inner peripheral surface of the furnace wall is reduced. Next, from the upper opening where the scraping device was retracted,
Carrying a large number of staves into the furnace and performing repair work by attaching them to the inner peripheral surface of the furnace wall, so without stopping the blast furnace, during hot cold winds, in a short time and at low cost, Repair the walls of blast furnaces, especially small blast furnaces, that is, remove the damaged cooling plate, and then add a new stave
A cooler can be attached. Since the ore ballas is made of the constituent material of the blast furnace charge, it does not affect the startup of the blast furnace after the repair. In the method for repairing a blast furnace furnace wall according to claim 2, a large furnace wall refractory is crushed into small pieces by using a breaker shovel in this manner, and then the fragments are scraped out of the furnace by a scraping device. The risk of leaving the lump in the furnace and hindering the startup of the blast furnace is reduced, and the scraping out of the fragments becomes smooth.

[0008]

According to the method for repairing a blast furnace wall according to the first and second aspects of the present invention, the fragments dropped onto the ore ballast by blasting the refractory of the furnace wall are removed from the ore ballast filling portion of the furnace wall. Using a scraping device near the upper opening formed slightly above, the scraper was scraped out of the furnace from the lower opening, and the stave was brought into the furnace from the upper opening and attached to the furnace wall, so the blast furnace was stopped. Without the need for repair, the blast furnace wall can be repaired, that is, the damaged cooling plate can be removed and a new stave cooler can be installed in a short period of time and at a low cost during the hot outage. In particular, the effect of this repair method increases in the case of repairing a small blast furnace. In addition, each furnace wall protector is arranged along the inner peripheral surface of the furnace wall, and debris at the time of blasting of the furnace wall refractory is guided by the downwardly inclined core side surface of each furnace wall protector, and the center of the furnace is protected. Since the pieces are gathered to the side, when the pieces are scraped out from the lower opening using the scraping device, the scraping operation of the pieces becomes easy. Moreover, at the time of the scraping, the furnace wall protector can protect the inner peripheral surface of the remaining cooling board and the remaining refractory. In the method for repairing a blast furnace wall according to the second aspect of the present invention, the lump of the large refractory of the furnace wall is crushed into small pieces by a breaker shovel, so that 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 a main part showing a scraping operation of fragments of a furnace wall refractory in a small blast furnace to which a method for repairing a blast furnace wall according to an embodiment of the present invention is applied, and FIG. FIG. 3 is an enlarged longitudinal sectional view of a main part showing a scraping operation state of fragments of the furnace wall refractory, FIG. 3 is an enlarged vertical sectional view of a main part showing a starting state of crushing of fragments using the breaker shovel, and FIG. FIG. 4 (b) is a vertical sectional view showing an operation state in which the ore ballast is filled on the lowered blast furnace charge and the cooling plate is removed from the furnace wall, and FIG. FIG. 5 (a) is a longitudinal sectional view showing a work state in which a furnace wall protector is laid on an ore ballast in the furnace, and FIG. 5 (b) is a furnace wall refractory. FIG. 6 (a) is a vertical cross-sectional view showing a scraping operation state of a blasted piece.
Fig. 6 is a longitudinal sectional view showing an operation state in which the furnace wall protector is removed from the furnace and the lower opening is closed, and Fig. 6 (b) shows an operation state in which a stave is loaded into the furnace from the upper opening. FIG. 7A is a longitudinal sectional view showing a state in which an amorphous refractory is sprayed to the vicinity of the lower opening forming portion, and FIG.
(B) is a longitudinal sectional view showing a work state of filling the gap between the stave and the furnace wall with an irregular refractory, FIG. 8 is a longitudinal sectional view showing a startup state of the blast furnace, and FIG. It is a principal part expanded sectional view which shows the working state which fills the gap with a wall with an irregular-shaped refractory. 1 and 4 to 8 are cross-sectional views taken along the line SS 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 a small blast furnace having a capacity of 1000 m ³ . Hereinafter, a method for repairing the blast furnace wall will be described in detail in accordance with each operation process of FIGS. As shown in FIG. 4A, first, the supply of hot air from the tuyere 11 provided on the lower peripheral surface of the blast furnace 10 is stopped, and the blast furnace 10 is shut off. Next, the blast furnace charge 12 is replaced with the furnace wall damaged portion A.
Down to below, then onto the blast furnace charge 12,
For example, an ore ballast 13 such as iron ore or coke is used for about 1.
Fill to a height of 5 m. Outside the furnace, a plurality of cooling boards 14 provided around the steel shell of the furnace wall 10a are removed.

Next, as shown in FIG.
In the vicinity of the bottom of the furnace slightly above the portion filled with the ore ballast 13 of 0a, an operator outside the furnace melts the steel shell and removes the furnace wall refractory 15 in that portion outside the furnace, so that a total of 6 Opening is formed. Specifically, a pair of upper openings 17 for a device 16 for scraping out pieces of the furnace wall refractory 15 (see FIGS. 1 and 2) is formed at a position opposed to the furnace wall 10a, and in the circumferential direction of the furnace wall 10a. 9 for upper opening 17
A pair of the breaker excavator 18 and the other upper opening 17a (see FIGS. 2 and 3) into which only the stave 23 is carried into the furnace are formed at a position of 0 degree. , Lower openings 19 are respectively formed. Here, a backhoe is employed as the scraping device 16. Then, see Figs.
As shown in (a), on the ore ballast 13 filling portion of the furnace wall 10a, along the inner peripheral surface of the furnace wall 10a, in a shape along the scraping locus k of the scraping device 16 in plan view, respectively. And eight trapezoidal furnace wall protectors 20 whose core side surfaces 20a are inclined downward, and two triangular furnace wall protectors arranged immediately below each lower opening 19 and whose core side surfaces 21a are inclined downward. And 21 are arranged in an annular shape.

Subsequently, as shown in FIGS. 1 and 5 (b), an appropriate amount of dynamite is disposed at a required portion of a furnace wall refractory 15 provided around the furnace of the blast furnace 10, and the dynamite is exploded. The furnace wall refractory 15 is broken into pieces and dropped into the furnace bottom. On this occasion,
In the furnace, trapezoidal and triangular furnace wall protectors 20, 21 are arranged in a substantially annular shape on the ore ballast 13 filling portion along the inner peripheral surface of the furnace wall 10a, so that the furnace wall refractory 15 is blasted. Occasionally, the fragments 15a are guided by the downwardly inclined core side surfaces 20a, 21a of the furnace wall protectors 20, 21, and
It falls on the ore ballast 13 while gathering toward the furnace center. Thereafter, 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 via the furnace wall protectors 20 and 21, the scraping work becomes easy, and the furnace wall refractory laid on the inner peripheral surface of the furnace wall 10a. 15 is less likely to be damaged.

Further, the arm 18a of the excavator 18 shown in FIGS. 2 and 3 is moved to vibrate the breaker 18b at the tip of the arm 18a, and the large furnace wall refractory 15 is crushed into small pieces. Its fragment 1
5a is scraped out of the furnace, leaving a large lump inside the furnace.
The risk of hindering the startup of the blast furnace 10 is reduced, and the scraping of the fragments 15a becomes smooth. The scraped-out fragments 15a are discharged from the vicinity of each lower opening 19 (see FIG. 1) through a discharge duct 22 extending downward 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 are moved up and down in the furnace using a pair of cranes 24 arranged on the furnace top. The stave 23 is attached to a predetermined position of the furnace wall 10a. As shown in FIG. 9, the stave 23 has a refractory 23b embedded in a cast iron plate 23a.
A cooling pipe 23c protruding from the back surface of the cast iron plate 23a is inserted into and attached to the steel shell of the furnace wall 10a. Finally,
As shown in FIG. 7 (a), the upper opening 17 is closed with an iron cover and welded to the furnace wall 10a, and then a stave 23 waiting in the furnace is attached to the furnace inner surface of the iron cover.

Next, as shown in FIG. 7 (a), a crane 24 is used to hang an irregular-shaped refractory spraying device 25 into the furnace bottom, and then scrape off fragments 15a to remove the furnace wall refractory. 15 furnace wall protectors 20, 2
1 from the injection nozzle of the spraying device 25,
An irregular-shaped refractory 28 is sprayed to repair. The irregular-shaped refractory 28 is pressure-fed at a predetermined pressure by a kneader 26 arranged outside. In order to prevent thermal damage to the stave 23 during operation, the spray wall 25 is used to
An irregular-shaped refractory 28 is sprayed on the inner surface of the stave 23 attached to the stove 0a. Subsequently, as shown in FIG. 7B, the cast iron plate 23a and the furnace wall 1 of each stave 23 are formed.
A kneader 26 presses in an amorphous refractory 28 having a predetermined viscosity at a predetermined pressure into a space 27 formed between the iron skins 0a, and then dry-solidifies. Then, as shown in FIG. 8, hot air was blown from tuyeres 11 at the bottom of the furnace to
Resume operations. At this time, since the ore ballast 13 is made of the constituent material of the blast furnace charge 12, even if it is not collected outside the furnace, it does not affect the startup of the blast furnace 10 after the repair.

As described above, the fragments 15a that fall on the ore ballast 13 by blasting the furnace wall refractory 15 are converted into the furnace wall 1
Using the scraping device 16 near the upper opening 17 formed slightly above the ore ballast 13 filled portion of 0a, the scraping device 16 is scraped out of the furnace from the lower opening 19, and the stave 23 is carried into the furnace from the upper opening 17. Since the blast furnace 10 is attached to the furnace wall 10a at a time, the blast furnace 10 can be repaired, that is, the damaged cooling plate can be repaired without stopping the blast furnace 10 at a short period of time and at low cost during the hot wind break. Remove
A new stave cooler can be installed. In particular, the effect of this repair method is increased in the case of repair of a small blast furnace, which causes a great hindrance to start-up at the time of restarting the operation if the wind is shut down for a long time.

[Brief description of the drawings]

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

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

FIG. 3 is an enlarged longitudinal sectional view of a main part 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 an operation state in which an ore ballast is filled on the lowered blast furnace charge and a cooling board is removed from a furnace wall. (B) It is a longitudinal cross-sectional view showing the state where the upper and lower openings were formed in the furnace wall.

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

FIG. 6 (a) is a longitudinal sectional view showing an operation state in which a furnace wall protector is removed from the furnace and a lower opening is closed. (B) It is a longitudinal cross-sectional view which shows the working state which carries in a stave from the upper opening part in the same furnace.

FIG. 7A is a vertical cross-sectional view showing a state in which an irregular-shaped refractory is sprayed around the lower opening forming portion. (B) It is a longitudinal cross-sectional view which shows the working state which fills the gap of the same stave with the furnace wall with an irregular-shaped refractory.

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

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Blast furnace 10a Furnace wall 11 Tuyere 12 Blast furnace charge 13 Ore ballast 14 Cooling board 15 Furnace wall refractory 15a Fragments 16 Scavenging device 16a Arm 17 Upper opening 17a Upper opening 18 Breaker shovel 18a Arm 18b Breaker 19 Lower opening Part 20 Trapezoidal furnace wall protector 20a Core side surface 21 Triangular furnace wall protector 21a Core side surface 22 Discharge duct 23 Stave 23a Cast iron plate 23b Refractory 23c Cooling pipe 24 Crane 25 Spraying device 26 Kneader 27 Air gap 28 Irregular refractory A Damaged furnace wall

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yukio Kowaki 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Machinery & Plant Business Department (72) Inventor Tsunemi Fukami Tobata-ku, Kitakyushu-shi, Fukuoka 46-59, Oaza Nakahara Nippon Steel Corporation Machinery & Plant Division (56) References JP-A-57-2809 (JP, A) JP-A-58-9903 (JP, A) JP-A-1-201405 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C21B ⁷ /00-7/06 F27D 1/16

Claims (2)

(57) [Claims] A step of lowering the blast furnace charge to below the damaged wall portion after the blast furnace is shut down; and lowering the blast furnace charge to below the damaged wall portion.
A step of filling the ore ballast on the blast furnace charge to a predetermined height, and removing a cooling plate from the peripheral surface of the furnace wall; and slightly above the ore ballast filled portion of the furnace wall, the furnace wall refractory Forming an upper opening where the scraping device is disposed, and a lower opening for discharging the fragments scraped out by the scraping device to the outside of the furnace, on the ore ballast filling portion of the furnace wall, Arranging a plurality of furnace wall protectors whose surfaces on the core side are inclined downward in a substantially annular shape along the inner peripheral surface of the furnace wall; and, after disposing the furnace wall protector in the furnace, the furnace wall refractory. Blasting the shards onto the ore ballast; discharging the shards out of the furnace through the lower opening using the scraping device; and Stave into furnace through opening 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. A further upper opening for a breaker excavator is formed in the furnace wall, and is disposed near the other upper opening when the scraping device scrapes out pieces of the furnace wall refractory outside the furnace. The blast furnace wall repair method according to claim 1, wherein the broken pieces are crushed to a size that can be easily scraped out by the breaker shovel.