JP2001011511A - Method for setting inner cylinder of dust collector for blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a setting method of an inner cylinder of a dust collector for blast furnace, by which the inner cylinder can quickly and easily be set into an outer cylinder of the dust collector in either case of building time or repairing time of the dust collector for blast furnace. SOLUTION: In the setting method of the conical inner cylinder which is hung by penetrating a roof of the outer cylinder of the dust collector for blast furnace and has wide inner diameter at the lower end for executing the deceleration of passing exhaust gas and the change in the direction thereof, plural truncated conical annular members 11 each mutually different between the upper end diameter and the lower end diameter, are prepared in the inserting state by telescopically assembling the member having larger upper end diameter above the member having the min. upper end diameter in order. After carrying these into the inner part from an opening part 12 arranged at the side wall of the outer cylinder 4 of the dust collector, the member having the min. upper diameter is drawn upward and assembled as the conical state under the condition in which the upper end inner wall of the successively drawing-up member is brought into contact with the lower end outer wall of the foregoing member, and also, the respective contacting positions are welded and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for installing an inner cylinder for a blast furnace dust remover, and more particularly, to a technique for quickly installing an inner cylinder inside an outer cylinder of a blast furnace dust remover when newly installing or repairing the blast furnace dust remover. It is.

[0002]

2. Description of the Related Art Generally, exhaust gas generated from a blast furnace is used as a fuel for a hot blast stove, a coke oven, a heating oven, a boiler and the like. This exhaust gas contains about 10 to ³⁰ g / Nm ³ of dust when discharged from the blast furnace.
It is necessary to remove and wash to a dust content of about 10 mg / Nm ³ which does not interfere with use. Various types of dust removing and cleaning devices are employed. However, in order to remove relatively coarse dust in the exhaust gas, the dust removing and forming devices formed by the outer cylinder 4 and the inner cylinder 5 as shown in FIG. The vessel 1 is often used. According to this, deceleration and direction change of the blast furnace gas 2 (exhaust gas) passing through the inner cylinder 5 occur, and relatively coarse dust 3 in the exhaust gas 2 falls and separates. as a result,
The dust content of the exhaust gas 2 is reduced to about 5 to 10 Nm ³ ,
The load of another dust collecting device 6 arranged on the downstream side is reduced.

When newly constructing the dust remover 1, the inner cylinder 5
Can be assembled by carrying a large number of petal-shaped members obtained by dividing the inner cylinder into a plurality of parts in the height direction and the circumferential direction to the installation position of the dust remover 1 and sequentially welding from a lower part on a scaffold assembled therearound. . In the method of installing the inner cylinder 5 during this construction, the dust remover 1
Because the petal-shaped members are welded and assembled at the installation position, it is necessary to weld the members hung on a crane on a high altitude scaffold. There is a problem that evacuation occurs and the construction period of the on-site construction becomes longer.

[0004] The temperature of the blast furnace exhaust gas 2 is about 200 ° C in normal blast furnace operation, but may be as high as 1000 ° C if a trouble occurs in the operation. for that reason,
The inner cylinder 5 may be deformed or a hole may be partially formed. In such a situation, there is a problem that the gas flow in the dust remover 1 is disturbed, and the dust removing efficiency of the dust remover 1 is reduced. In this case, the inner cylinder needs to be replaced.

However, in order to replace the inner cylinder 5 of the dust remover 1 used for operation for repair, it is necessary to completely remove the blast furnace gas 2 in the dust remover 1. Limited during the wind. Furthermore, this dust remover 1
Is an important device for removing most of the coarse-grain dust in the blast furnace gas 2, so once the operation for replacing the inner cylinder 5 is started, air cannot be blown until the operation is completed. At present, the longest downtime that can be tolerated to keep the furnace conditions from deteriorating is 7
Since it is about 0 to 100 hours, in the installation method at the time of construction, the number of handling steps and the number of welding steps are large, and it takes too much work time, and it is impossible to complete the replacement work of the inner cylinder within a predetermined shutoff time. there were. Therefore, if the inner tube of the dust remover is damaged or damaged during the operation of the blast furnace, the dust remover 6 is forced to operate in a state where the dust removal efficiency is reduced, and is disposed downstream of the dust remover. The load on the system increases. If the degree of damage is large, decrease the production,
There is a possibility that problems such as early renovation of the blast furnace may occur.

[0006]

As described above, according to the conventional method of installing the inner cylinder for the blast furnace dust remover, it takes time to install the inner cylinder 5 either at the time of new installation or at the time of repair. As a result, not only is it disadvantageous in terms of ensuring safety, but in the case of replacement and repair while the blast furnace is shut down, repair itself cannot be performed temporally.

The present invention has been made in view of the above circumstances, and provides a method of installing an inner cylinder for a blast furnace dust remover that enables the inner cylinder to be quickly and easily attached to the outer cylinder of the dust remover either when constructing or repairing the blast furnace dust remover. It is intended to provide.

[0008]

Means for Solving the Problems The inventor has conducted intensive studies in order to achieve the above object, and has embodied the results in the present invention.

That is, according to the present invention, a blast furnace exhaust gas inlet located at an upper end of a blast furnace dust remover outer cylinder is connected inside the outer cylinder,
A method of installing a cone-shaped inner cylinder in which an inner diameter is widened downward, wherein a plurality of frustoconical ring members having different upper end diameters and lower end diameters are different from each other in advance, and an upper end diameter is set outside a ring member having a minimum upper end diameter. The larger ring members are sequentially combined in a telescopic manner, prepared in a nested state, and after carrying them into the inside from the opening provided on the side wall of the dust remover outer cylinder, the ring member having the minimum upper end diameter is lifted upward, The lower end outer wall of the ring member located above is assembled in a cone shape with the upper end inner wall of the ring member to be lifted next being in contact with each other, each contact point is fixed, and the upper end of the ring member having the minimum upper end diameter is further fixed. A method for installing an inner cylinder for a blast furnace dust remover, wherein the inner cylinder is connected to the blast furnace exhaust gas inlet at an upper end of an outer cylinder.

In the present invention, the plurality of frusto-conical ring members are prepared on a trolley, and the trolley is carried into the dust remover outer cylinder, so that the operation can be performed easily. Alternatively, by providing a work floor at the same level inside and outside the opening, it is convenient to carry the ring member in a nested state into the inside of the outer cylinder of the dust remover.

In the practice of the present invention, when a blast furnace dust remover is newly installed or repaired, an opening is previously opened in the side wall of the outer cylinder of the dust remover, and a plurality of working beams are provided inside, It is necessary to provide a work floor at the same height as the beam and a suspending tool for suspending the inner cylinder on the inner ceiling. In particular, at the time of repair, the existing inner cylinder is disassembled into a plurality of rings using these hanging tools and the like, and is sequentially carried out of the outer cylinder, and then a new inner cylinder is installed.

In the present invention, a plurality of truncated cone-shaped members are carried into a so-called "telescopic" state as will be described later, and are carried into the outer casing of the dust remover, and only the uppermost member is lifted. The work of carrying in the parts for
And welding of each member also becomes easy. As a result, when a new dust remover is installed, not only can the inner cylinder be installed in a much shorter time than in the past, but it is also possible to easily replace and repair the existing inner cylinder even during the blast furnace shut down time of only about 100 hours. become.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

The most important point of the present invention is that, as shown in FIG. 1, the member used as the inner cylinder 5 of the dust remover 1 has a ring shape to facilitate handling. In other words, a plurality of ring-shaped inner cylinder members 11 (hereinafter, referred to as ring members) having different upper end diameters and lower end diameters are formed by placing a ring member 20 having a larger upper end on a ring member 19 having a minimum upper end. And nested by combining them sequentially. At that time, the adjacent ring members, when lifting the inner ring member, contact the lower end outer wall of the inner ring member, the upper end inner wall of the outer ring member, and do not come off from each other due to external force. It is important to have a size relationship. This state is called telescopic. Thereby, all the members to be the inner cylinder can be put together in a small volume, and handling can be performed at once. If necessary, if only the member 19 having the minimum upper diameter is lifted upward, the other members 20 are also brought into contact with each other and lifted up, and assembled to the target size of the inner cylinder 5.

Therefore, the inventor of the present invention has conceived that the member 11 to be used as the inner cylinder for the dust remover is made in a truncated cone shape from a steel plate in advance, and the above-described telescopic state is combined with the operation described below. The present invention has been completed.

In general, the outer cylinder 4 of the blast furnace dust remover 1 has a shape as shown in FIG. 1 and is supported by a support beam 21 having a certain height for convenience of discharging the collected dust 3 downward. Further, the inner cylinder 5 is connected to an exhaust gas inlet provided on the ceiling of the outer cylinder 4 to be suspended and suspended in a suspended state, and has a length such that its lower end reaches the lower end of the straight body portion of the outer cylinder 4. . The present invention
When constructing or repairing the blast furnace dust remover 1, the inner cylinder 5 is installed on the outer cylinder 4 as described below.

First, an opening 12 is provided on a side wall of the outer casing 4 of the dust remover. The size of the opening 12 is such that the size of the conveying jig and the clearance are added to the maximum size of the member (ring shape) to be carried in and out. Further, the position of the opening 12 is desirably the straight body of the outer cylinder 4 in consideration of the convenience of all operations required for installation. Further, a plurality of work girders 14 are installed from the inside of the outer cylinder 4 to the outside so as to correspond to the height near the lower end of the straight body, and a work floor 15 is installed thereon. In this case, it is preferable to lay a carriage traveling rail 17 on the work girder 14 and the work floor 15 so that the horizontal pulling carriage 16 can travel. Inner cylinder member 1
This is because the loading / unloading of the device 1 is quick and smooth. In addition, hanging members 18 are provided on the ceiling of the outer cylinder 4 at a plurality of locations appropriately separated along the circumferential direction.

When the blast furnace dust remover 1 is constructed, since the inside of the outer cylinder 4 is hollow, the installation of the inner cylinder 5 is performed by using the frusto-conical member 11 previously prepared around the outer cylinder (a carriage on the work floor).
Is loaded into the outer cylinder 4 from the opening 12 and positioned. That is, when only the member 19 having the minimum upper diameter is pulled up by the hanging member 18, the other members 20 are also pulled up in a telescopic manner, and the inner cylinder 5 is assembled in a cone shape. Subsequently, when the parts where the members are in contact with each other (called welding lines) are welded, the installation of the new inner cylinder is completed, and thereafter, the carriage 16 is pulled out, the work girders 14 and the work floor 15 are removed, and the opening 12 is opened. All work is completed by the blockage of.

On the other hand, at the time of repair for replacing the existing inner cylinder 5 with a new one, it is necessary to remove the existing inner cylinder 5 before installing the inner cylinder 5. This removal is performed by cutting the inner cylinder 5 in a ring shape with a proper size from the lower part of the inner cylinder while suspending the uppermost part of the existing inner cylinder 5 and repeatedly carrying out and jacking down. When the removal is completed, the inner cylinder 5 may be installed in the same procedure as when the dust remover 1 is constructed. In addition, since all the work at the time of this repair is performed using the time when the blast furnace 7 is closed, degassing is indispensable in advance. Hereinafter, the inner cylinder installation work at the time of repair will be described in detail with reference to examples.

[0020]

EXAMPLE A method for installing an inner cylinder of a dust remover according to the present invention was carried out in a dust remover 1 provided in a blast furnace gas system of a large blast furnace (5000 m ³ class). The outer cylinder 4 of the dust remover 1 has a height of 40
m, a cylindrical body having an inner diameter of 18 m, and an upper inner diameter of 6 m inside.
A cone-shaped inner cylinder 5 having a lower end inner diameter of 12 m is incorporated.

First, the size of the inner cylinder 5 when newly installed and the size of each frusto-conical ring member 11 for telescopic formation were determined, and a new ring member was made in advance. After the venting of the outer cylinder 4 is completed two hours after the blast furnace is shut down, the inner cylinder is transported to the side wall of the outer cylinder 4 at a position lower than the lower end of the inner cylinder 5 as shown in FIG. Member 11 and cart 1
An opening 12 large enough to allow the passage of the nozzle 6 was provided. Continued
A work girder 14 capable of supporting the entire weight of the inner cylinder 5 from the inside to the outside of the outer cylinder 4 was installed, and a work floor 15 was installed.
A rail 17 for running the carriage and a carriage 16 for horizontal pulling are installed on the work floor 15 and the like, and hanging members 18 are provided at a plurality of places on the ceiling of the outer cylinder 4.

Next, the existing inner cylinder was dismantled. In the dismantling, first, the inner cylinder 5 was cut off from the exhaust gas inlet 23 in a state where the uppermost part of the existing inner cylinder was hung by the hanging member 18. Thereafter, the inner cylinder 5 was lowered onto the carriage 16 by using a hanging tool, and was blown from the lower end of the inner cylinder 5 into a ring of a predetermined size. The ring-shaped dismantled product was moved to the outside of the outer cylinder by the carriage 16 and was carried out by a crane. After returning the carriage 16 to the inside of the outer cylinder, the work from suspending and lowering the inner cylinder was sequentially repeated, and the disassembly of the existing inner cylinder 5 was completed.

Thereafter, a new inner cylinder was installed.
A ring member 1 having a minimum upper end diameter is set on a carriage 16 on which a new and prepared ring member is placed outside the outer cylinder of the working floor.
9 and were prepared sequentially. Truck 1 for all ring members
After the preparation on 6, the carriage 16 was moved into the outer cylinder.
After the movement, the ring member 19 having the minimum upper end diameter was lifted by the lifting tool 18. When lifting, when the outside of the lower end of each ring member and the inside of the upper end of the ring member adjacent to the outside contact, the welding line between the members was welded.
After welding all the ring members and assembling the inner cylinder 5 telescopically, the inner cylinder 5 is further lifted by the suspending tool 18 so that the upper end of the inner cylinder 5 is aligned with the exhaust gas inlet 23 of the outer cylinder 4 and welded. did. After welding, the temporary work girder 1
4. The work floor 15, the trolley rail 17, the trolley 16, and the hanger 18 were removed, the opening 12 provided in the outer cylinder 4 was closed by welding, and all inner cylinder replacement work was completed.

In the present embodiment, the inner cylinder 4 is divided into seven parts and disassembled, and a new ring member 11 is assembled with seven pieces.
Fusing and unloading time of the dismantled inner cylinder 5 is 4 ~ per ring.
5 hours. The loading and welding time of all the truncated conical members 11 stacked on the concentric circle was 30 hours. Furthermore, the time required for degassing, opening, erection of work girders, work floors and the like was 30 hours. Therefore, all the inner cylinder installation work was 100 hours, and the replacement of the inner cylinder was completed within the blast furnace downtime.

From these results, it is expected that when a blast furnace dust collector is newly constructed, the installation work of the inner cylinder 5 can be performed in about 50 hours. This is a significant reduction in the working time of the conventional construction.

[0026]

As described above, according to the present invention, it is possible to quickly and easily install the inner cylinder of the blast furnace dust remover at any time of repair at the time of new installation. In consideration of the fact that the inner cylinder could not be replaced while the blast furnace was closed before, the present invention is expected to ultimately contribute significantly to extending the life of the blast furnace.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing a replacement operation state of a dust remover inner cylinder according to the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a diagram illustrating a gas cleaning system of a general blast furnace.

[Explanation of symbols]

 Reference Signs List 1 blast furnace dust remover (dust remover) 2 blast furnace gas (exhaust gas) 3 dust 4 outer cylinder 5 inner cylinder 6 another dust collector 7 blast furnace 8 raw material charging bell 9 blast furnace gas flow path 10 thickener 11 ring-shaped inner cylinder member (cone 12 Opening 14 Work girder 15 Work floor 16 Dolly 17 Rail 18 Hanging tool 19 Member having minimum top diameter 20 Other members 21 Support beam 22 Duct 23 Exhaust gas inlet 24 Exhaust gas outlet

Claims (1)

[Claims] 1. A method for installing a cone-shaped inner cylinder connected inside the outer cylinder to a blast furnace exhaust gas inlet located at the upper end of the outer cylinder of the blast furnace dust remover and expanding the inner diameter downward. A plurality of frusto-conical ring members having different lower end diameters are sequentially telescopically combined with a ring member having a larger upper end outside the ring member having the minimum upper end diameter, and prepared in a nested state, and these are removed from the dust remover. After being carried into the inside from the opening provided in the side wall of the cylinder, the ring member having the minimum upper end diameter is lifted upward, and the lower end outer wall of the ring member located above is brought into contact with the upper end inner wall of the ring member to be lifted next. In this state, each contact point is fixed, and the upper end of the ring member having the minimum upper end diameter is connected to the blast furnace exhaust gas inlet at the upper end of the outer cylinder. Installation method for a blast furnace dust dexterity inner cylinder to.