JP2003034811A - Method for cutting hot-air main pipe when diverting hot blast stove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cutting a hot-air main pipe when diverting a hot blast stove, which enables cutting in a short time of the high-temperature existing hot-air main pipe, while maintaining a hot state of an accumulation brick, and thereby enables shortening of a work period for switching. SOLUTION: This method of cutting the hot-air main pipe 13 in high temperature, which is connected to the high-temperature hot blast stove 12 just after operation, and is provided with a steel shell 21 and a lining refractory 23 for lining the inner face 22 of the steel shell 21, comprises cutting a perimeter of the steel shell 21 by predetermined width W, and cutting the lining refractory 23, while pressing and pulling a wire saw 26 set up to rotate with no end, onto the exposed surface 25 of the refractory 23 which lines the inner face of the cut steel shell 21, along a perpendicular direction to the axial 29 of the main pipe 13 for the hot blast, and while cooling the wire saw 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention cuts an existing hot-air main pipe and newly installs it when the hot-blast stove and hot-air main pipe for other blast furnaces that have been operating until just before are partially diverted according to the burning of the repaired blast furnace. The present invention relates to a method of cutting a hot-air main when using a hot-blast stove for switching and connecting to the hot-air main.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 1, four hot blast stoves 12 and hot blast main pipes 13 for a blast furnace 11 which has been in operation until just before are partially diverted according to the burning of a renovated blast furnace 10. In the blast furnace refurbishment work to be performed, a short cutting pipe 14 (indicated by diagonal lines in the figure) that is part of the existing hot air main that was in operation
It is necessary to perform a switching work in which the pipe is cut midway and is joined to the newly installed hot-air main pipe 15 whose route has been changed through the joining short pipe 16 (elbow). That is, by cutting the iron shells at both ends of the cut short tube 14 of the hot-air main pipe 13 to be diverted, the lining refractory (castable, heat-insulating bricks and fire-resistant bricks) lined on the inner surface of the iron shell is hot-heated for a short time. It is necessary to perform the furnace construction work after efficiently cutting and connecting the newly joined short pipe 16 to the hot air main pipe 15 by welding. In the method for cutting the hot air main pipe when the hot air stove is diverted, the hot air stove upper brick is 800 ° C. in order to prevent material deterioration due to temperature transformation of the hot air stove upper brick (silica brick) used in the hot air stove 12 to be diverted. For a short period of time during the above heat (as an example, the switching work period is about 10 days, the cutting short pipe 14 of the existing hot air main 13 is cut, and the joining period of the joining short pipe 16 to the new hot air main 15 is 4 days).

[0003]

However, the above-mentioned conventional method for cutting the hot-air main pipe when the hot-air stove is used still has the following problems to be solved. Since there is no way to cut the lining refractory after cutting the iron skin at once, because it is done by a brick dismantling method with a manual call pick hammer etc.
It was impossible to implement it because it could not be adapted to the above short-term process at all, and it was a disassembling work at a high temperature, which was a dangerous work.

The present invention has been made in view of such circumstances, and in a short period of time, a route changing work and a hot air furnace upper brick maintenance measure (a measure for preventing air intrusion at a hot air main cutting section carried out by a furnace building contractor) And additional burning work)
By maintaining the hot temperature of the bricks in the hot stove, the existing hot air main can be cut in a short period of time, which makes it possible to shorten the switching work period. The purpose is to provide.

[0005]

According to the present invention, there is provided a method for cutting a hot blast main pipe for use in a hot blast stove according to the present invention, which is connected to a high temperature hot blast stove immediately after operation and is lined with an inner skin and an inner skin. A method for cutting a high-temperature hot-air main with a lined refractory material, the method comprising: cutting the entire circumference of the iron shell with a predetermined width, and then exposing the exposed surface of the lined refractory material inside the cut iron shell. In addition, the lining refractory is cut while pressing the endless rotatably formed wire saw in a direction orthogonal to the axial direction of the hot air main pipe and pulling the wire saw while cooling the wire saw. by this,
The steel skin and the lining refractory can be cut separately, and the hot lining refractory can be cut while cooling the wire saw. When the iron skin is cut by the wire saw, the wire saw slides on the surface of the iron skin, which makes it difficult to cut the wire. Therefore, another cutting method that facilitates cutting is used. In the method of cutting the hot air main when using the hot air stove according to the present invention,
It is also possible to mount the drive pulley of the wire saw on the tow truck, and to pull the tow truck by the tow means along the truck guide that can prevent the tow from rising. As a result, the tension necessary for cutting the lining refractory can be reliably applied to the wire saw, and the cutting direction can be made constant.

[0006] In the method for cutting a hot-air main pipe when using a hot-blast stove according to the present invention, the iron shell can be cut by an arc cutter or a gas cutting machine. Thereby, the iron shell can be cut in a short time with sufficient cutting accuracy. In the method for cutting a hot air main pipe when using the hot air stove according to the present invention, the wire saw may be cooled by water spray. This reduces running costs and equipment costs for cooling. In the method for cutting a hot-air main when using a hot-blast stove according to the present invention, all operations can be performed remotely. As a result, the safety of the worker can be ensured from the high temperature working environment. In the method for cutting a hot-air main pipe when using a hot-blast stove according to the present invention, diamond may be attached to the cutting edge of the wire saw. This improves the cuttability of the refractory lining.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is an overall layout diagram for explaining a method of cutting a hot-air main when using a hot-blast stove according to an embodiment of the present invention, and FIG. 2 is an iron in a method of cutting a hot-air main when using the hot-blast stove. FIG. 3 is an explanatory view showing a cut state of the skin, and FIG. 3 is an explanatory view showing a cutting procedure of the lining refractory material in the method of cutting the hot air main when the hot air stove is used.

As shown in FIG. 1, a refractory cutting device 20 used in a method for cutting a hot-air main pipe when using a hot-blast stove according to an embodiment of the present invention is placed immediately before the blast furnace 10 is refurbished. The short cutting tubes 14 (indicated by diagonal lines in FIG. 1) that are part of the high-temperature hot-air mains 13 connected to the high-temperature hot-air stoves 12 (four in the embodiment) for the other blast furnaces 11 that have been operating up to It is a device used for cutting the (shown portion) and connecting it to the newly installed hot air main pipe 15 for the blast furnace 10 through the joining short pipe 16 (elbow). In addition, hot-air annular pipes 17 and 18 connected to the hot-air main pipes 15 and 13 are arranged near the furnace abdomen of the blast furnaces 10 and 11, respectively. These will be described in detail below. The axial direction of the hot air main pipe 13 or the cut short pipe 14 is the Y direction, and the direction orthogonal to the Y direction is the X direction.
The direction and the height direction are defined as the Z direction.

As shown in FIGS. 2 and 3, the hot air main 13
Is equipped with an iron lining 21 and an inner refractory 23 lined on the inner surface 22 of the iron ridge 21, and has a high temperature immediately after operation (for example,
It is connected to four hot blast stoves 12 having a hot blast stove upper brick temperature of 800 ° C. or higher) via hot blast stove outlet pipes 24. The refractory lining 23 is castable in order from the iron skin 21 side.
It is constructed by stacking heat insulating bricks and refractory bricks. As shown in FIG. 1 and FIG. 2, the cutting portions a and b at both ends of the cutting short pipe 14 of the hot air main pipe 13 are the refractory cutting device 2
Before using 0, the entire circumference of the iron shell 21 is cut with a predetermined width W by an arc cutter which is an example of the iron shell cutting means. The structures of the hot air main pipe 15 and the joining short pipe 16 are the same as the structure of the hot air main pipe 13. As shown in FIG. 3, the hot-air main pipe 13 including the cut short pipe 14 is attached to a plurality of pipe stubs 19 a arranged on the pedestal 19 at predetermined intervals. The hot air main 15 and the joining short pipe 16 are also the hot air main 13.
In the same manner as above, it is attached to a plurality of nozzles arranged on the pedestal 19 at predetermined intervals.

As shown in FIGS. 1 to 3, a refractory cutting device 20 includes a refractory lining 23 inside a cut iron shell 21.
An endless wire saw 26 wound around the exposed surface 25 (at a temperature of 800 to 900 ° C.), a drive pulley 27 that rotationally drives the wire saw 26, a tow truck 28 equipped with the drive pulley 27, and a tow truck 28 And a chain block 30 which is an example of a pulling means capable of pulling and moving while pressing in a direction orthogonal to the axial direction 29 of the hot air main pipe 13.

The wire saw 26 has diamonds attached to its cutting edges, and has a connecting structure using links and link pins, similar to the structure of a chain saw. Since the wire saw 26 becomes very hot because the high-temperature lining refractory 23 is cut, a sprinkling means (not shown) for sprinkling water on the wire saw 26 and cooling the wire saw 26 is provided on the tow truck 28. It is installed. An electric motor 31 with a speed reducer that rotates the drive pulley 27 is provided on the tow truck 28. The tow truck 28 is provided with four wheels (not shown) in the front-rear (X) and left-right (Y) directions of the bogie body. The four wheels can be prevented from rising and are detachably provided on the pedestal 19. It is configured so that it can be moved back and forth in the X direction by being guided by the guided cart guide 32.

Next, a construction procedure using the method of cutting the hot air main pipe when the hot air stove is used according to the embodiment of the present invention will be described with reference to the drawings. (1) As shown in FIG. 1, the weight of the newly installed hot-air main pipe 15, joining short pipe 16, cutting short pipe 14, the capacity of this lifting means (for example, an overhead crane), and the refractory cutting device 20.
The position and size (cutting portions a, b) of the cutting pipe end 14 of the existing hot-air main pipe 13 are determined in consideration of the installation location, the cutting stroke, and the like. (2) As shown in FIGS. 1 and 3, first, the carriage guide 32 is fixed on the pedestal 19 in accordance with the cut portion a, the towing carriage 28 is set on the carriage guide 32, and further, the chain is attached to the towing carriage 28. The blocks 30 are connected. (3) As shown in FIG. 2, a marking line having a cutting width W (100 mm) is marked at the cutting portions a and b.

(4) As shown in FIG. 2, cutting sites a and b
In order to prevent the hot-air main pipe 13 from being deformed due to cutting, a U-shaped temporary receiving jig 33 shown by a chain line is temporarily welded at a total of four places. (5) As shown in FIG. 2, an arc cutter is used to cut a portion of the iron shell 21 having a cutting width W. (6) As shown in FIG. 3, the link pin is detached and the endless wire saw 26 is wound around the exposed surface 25 of the lining refractory 23 lined on the inner surface 22 of the iron shell 21 and the drive pulley 27.

(7) While driving the electric motor 31 with a speed reducer to rotate the wire saw 26 via the drive pulley 27, water is sprayed onto the wire saw 26 by the water sprinkling means to cool the wire saw 26 and the chain block 30. Is pulled to gradually cut the lining refractory 23 at the cutting site a while applying a constant tension to the wire saw 26. (8) Next, regarding the cleavage site b, the above (2),
The same procedure as (5) to (7) is performed, and the lining refractory material 23 at the cutting portion b is gradually cut. (9) The short cut tube 14 is conveyed and removed by the lifting means. (10) The cut portion a on the hot air main 13 side of the cut portion a is cared for with a grinder, and the steel shell is welded to the hot air main 15 and the hot air main 13 on the hot stove 12 side via the joining short pipe 16. To do. (11) The lining refractory 23 of the joint short pipe 16 is constructed.

In the above-mentioned embodiment, it is considered that the cutting edge of the wire saw 26 is equipped with diamond, but it is considered to be the best, but the cutting edge is not limited to this, and other materials may be used. Although the operating method and operating position of the refractory cutting device 20 have not been described, it is also possible to configure the operator to perform all operations remotely if necessary. Although the water sprinkling means is provided on the tow truck 28, the water sprinkling means is not limited to this, and an operator can hold the water hose by hand to water the wire saw 26. Although the wire saw is cooled by sprinkling water, it is not limited to this and may be cooled by another cooling medium (including liquid and gas) depending on the situation. Although the arc cutter was used as the iron skin cutting means, the invention is not limited to this and other methods (for example, a gas cutting method) can also be used.

The width W for cutting the iron shell 21 is equal to that of the wire saw 2.
The size and material of No. 6, hot air main pipe diameter, main pipe thickness, etc. are taken into consideration. Although the wire saw 26 is pulled in a substantially horizontal direction via the tow truck 28 and the truck guide 32, the wire saw 26 is not limited to this and may be pulled vertically or diagonally depending on the situation. Although the chain block 30 is used as the pulling means, the invention is not limited to this, and a hydraulic or electric cylinder or the like may be used. Although one refractory cutting device 20 was used to cut the cutting parts a and b in two times, the refractory cutting device 20 is not limited to this.
It is also possible to cut the cutting portions a and b at the same time or separately using a table.

[0017]

According to the method for cutting a hot-air main when using a hot-blast stove according to claims 1 to 6, the iron shell and the lining refractory are cut separately, and at the same time, the wire saw is cooled to a high temperature. Since the lining refractory can be cut, the lining refractory can be hot-cut with high accuracy and in a short time, which can shorten the switching work period. In particular, claim 2
In the method for cutting the hot air mains when using the hot air stove described,
Since the tension necessary for cutting the refractory lining can be reliably applied to the wire saw and the cutting direction can be made constant, the cutting accuracy is improved and the cutting time is shortened.

In the method for cutting a hot-air main pipe when using a hot-blast stove according to claim 3, the iron shell can be cut in a short time and with sufficient cutting accuracy, so that the entire switching work period is shortened. Is planned. In the method for cutting a hot air main when using a hot air stove according to claim 4, the running cost for cooling and the equipment cost are reduced, which is economical. In the method for cutting a hot-air main pipe when using a hot-blast stove according to the fifth aspect, the safety of the worker can be ensured from a high-temperature working environment, so that the safety is improved. In the method of cutting a hot-air main when using a hot-blast stove according to claim 6, since the cutting property of the lining refractory material is improved, the lining refractory material can be hot-cut accurately and in a short time. By this, the switching work period can be further shortened.

[Brief description of drawings]

FIG. 1 is an overall layout diagram illustrating a method of cutting a hot air main pipe when using a hot air stove according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a cutting state of an iron shell in a method for cutting a hot air main pipe when the hot air stove is used.

FIG. 3 is an explanatory view showing a procedure for cutting a lining refractory in a method for cutting a hot air main when the same hot air stove is used.

[Explanation of symbols]

10, 11: Blast furnace, 12: Hot air furnace, 13: Hot air main, 1
4: Cut short pipe, 15: Hot air main pipe, 16: Joined short pipe (elbow), 17, 18: Hot air annular pipe, 19: Stand, 19a:
Pipe stand, 20: refractory cutting device, 21: iron skin, 22: inner surface, 23: lined refractory material, 24: hot-air stove outlet tube, 25: exposed surface, 26: wire saw, 27: drive pulley, 2
8: Towing cart, 29: Axial direction, 30: Chain block (towing means), 31: Motor with reduction gear, 32: Cart guide, 33: Temporary receiving jig

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomonori Sakamoto             Fukuoka Prefecture Kitakyushu City Kokurakita-ku Kintoricho 8-chome 3-             101

Claims (6)

[Claims] 1. A method for cutting a high-temperature hot-air main, which is connected to a high-temperature hot-air stove immediately after operation and comprises a steel shell and a lining refractory lined on the inner surface of the steel shell, the method comprising the steps of: After cutting the entire circumference of the inner wall of the refractory lining, the wire saw formed endlessly rotatable in the axial direction of the hot-air main pipe. A method for cutting a hot-air main pipe when a hot-blast stove is used, wherein the lining refractory material is cut while pressing and pulling in a direction orthogonal to each other and cooling the wire saw. 2. The method for cutting a hot-air main when diverting a hot-blast stove according to claim 1, wherein the drive pulley of the wire saw is mounted on a towing carriage, and the towing carriage is pulled along a carriage guide capable of preventing floating. A method for cutting a hot-air main when using a hot-air stove, characterized in that it is pulled by means. 3. The method for cutting a hot-air main pipe according to claim 1 or 2, wherein the iron shell is cut by an arc cutter or a gas cutting machine. How to cut the main pipe. 4. The method for cutting a hot-air main at the time of diversion of a hot-blast stove according to any one of claims 1 to 3, wherein the wire saw is cooled by water spray. How to cut the main pipe. 5. The method for cutting a hot-air main when using a hot-air stove according to any one of claims 1 to 4, wherein all operations are performed remotely. How to cut the pipe. 6. The method for cutting a hot-air main when using a hot-blast stove according to any one of claims 1 to 5, wherein a diamond is attached to a cutting edge of the wire saw. Method for cutting hot air mains when using hot air stoves.