JPH05321482A - Method for reinforcing existent steel chimney - Google Patents

Abstract

PURPOSE:To strongly repair a cylindrical part of an existent steel chimney, which has a danger of buckling due to the secular change and corrosion or the like. CONSTITUTION:Vertical ribs 2 at a predetermined length are arranged with a space on the inner peripheral surface 1a of a cylindrical part 1, and are welded to the inner peripheral surface 1a of the cylindrical part 1. Next, horizontal ribs 3 are arranged with a space on the inner peripheral surface 1a, and are welded to the inner peripheral surface 1a and the welded vertical ribs 2. Next, ring-like reinforcements 4 are arranged with a space, and are welded to the vertical ribs 2. Thereafter, mortar 7 is blown to clearance parts partitioned by the vertical ribs 2 and the horizontal ribs 3 so as to be blown toward the inner peripheral surface 1a of the cylindrical part 1. Next, a mesh reinforcement 5 is welded to the reinforcements 4 so as to cover the parts filled with the mortar 7. Thereafter, the reinforcement 4 and the mesh reinforcement 5 are coated with mortar 7 more at a predetermined thickness. On the other hand, in the outer peripheral surface 1b side of the cylindrical part 1, a carbon fiber wire rod 8 is wound around the outer peripheral surface 1b of the cylindrical part 1 by a winding machine to construct the reinforcing structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing an existing steel chimney used for smoke exhaust in a thermal power plant or the like.

[0002]

2. Description of the Related Art FIG. 3 (a) shows a part of an existing steel chimney, which is used for flue gas emission in a thermal power plant or the like, which is sliced. A steel chimney as shown in FIG. 3 (a) has, for example, a height of 2
It has a cylindrical body 1 having a thickness of 7 mm with respect to 00 m. In such a steel chimney, due to aging, corrosion, etc.
As shown in (b), the wall thickness may become thin in a part A1 of the barrel.

If the wall thickness is partially reduced, buckling A2 may occur as shown in FIGS. 4 (a) and 4 (b). This buckling also renders the chimney unusable and causes a decrease in its power generation capacity, for example, at a thermal power plant.

[0004]

Such buckling of the chimney is a serious problem because it reduces the power generation capacity of the thermal power plant.

However, conventionally, there is no method for preventing the buckling of the existing steel chimney as shown in FIG. 4, and there has been a demand for a method of reinforcing the chimney.

The present invention has been made in order to meet the above-mentioned demand, and its purpose is to change with time,
An object of the present invention is to provide a method of reinforcing an existing steel chimney that can firmly repair the barrel of an existing steel chimney that may be buckled due to corrosion or the like.

[0007]

In order to achieve the above object, the present invention is a process of joining longitudinal ribs to an inner peripheral surface of a tubular body of an existing steel chimney at intervals along the circumferential direction. A step of joining the lateral ribs to the inner peripheral surface of the tubular body so as to form a cross with the vertical ribs at intervals along the height direction, and to the outer peripheral surface of the tubular body. And a step of winding a carbon fiber wire rod.

In the reinforcing method according to the present invention, a step of joining reinforcing bars to the longitudinal ribs at intervals in the height direction of the cylindrical body in the circumferential direction, and the longitudinal ribs and the lateral direction. A step of filling the mortar between the ribs, a step of covering the rebar and joining the mesh rebar,
Further covering the mortar from the upper surface of the mesh line.

[0009]

In the method of reinforcing an existing steel chimney according to the present invention, the tubular body is formed from the inner peripheral surface side by vertical ribs and lateral ribs joined in a cross pattern to the inner peripheral surface of the tubular body of the existing steel chimney. Reinforce the cylinder body from the outer peripheral surface side with a wire of carbon fiber wound around the outer peripheral surface of the cylinder body, and firmly prevent the cylinder body from falling toward the inside or the outside due to the weakening of the cylinder body. And it can be appropriately reinforced.

Further, on the inner peripheral surface side of the tubular body, mortar is filled and covered so as to cover the tubular body while burying the reinforcing bars and the mesh reinforcements to protect the tubular body and the reinforcing ribs from smoke emission. can do.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory view of an embodiment of a method for reinforcing an existing steel chimney according to the present invention. FIG. 2 shows a case where the longitudinal ribs 2 and the transverse ribs 3 are welded to the inner peripheral surface of the barrel 1 to reinforce the existing steel chimney, and further the ring-shaped reinforcing bars 4 are welded to the longitudinal ribs 2. FIG. 3 is a partial perspective view of a part of an existing steel chimney viewed from the inside of the chimney.

In this embodiment, basically, a step of joining longitudinal ribs 2 to the inner peripheral surface 1a of a tubular body 1 of an existing steel chimney at intervals along the circumferential direction, and the tubular body 1 Inner peripheral surface 1a
Then, a step of joining the lateral ribs 3 at intervals along the height direction so as to form a cross with the longitudinal ribs 2, and winding the carbon fiber wire 8 around the outer peripheral surface 1b of the barrel 1. And the process. Further, with respect to the inner peripheral surface 1a of the tubular body 1, a step of joining ring-shaped reinforcing bars 4 to the longitudinal ribs 2 at intervals in the height direction of the tubular body 1, and the longitudinal ribs 2 and the lateral ribs The steps of filling the mortar 7 between the directional ribs 3, the step of joining the ring-shaped reinforcing bar 4 with the mesh rebar 5 and the step of further covering the mortar 7 from the upper surface of the mesh rebar 5 are carried out. To be done.

As shown in FIG. 1A, first, for example, 10
Vertical ribs 2 having a length of about m are arranged at intervals of 1 m, for example, and are welded to the inner peripheral surface 1a of the barrel 1. Next, the horizontal ribs 3 are arranged at intervals of 1 m, for example, and welded to the inner peripheral surface 1a and the welded vertical ribs 2. Subsequently, the ring-shaped reinforcing bars 4 are arranged at intervals of 1 m, for example, and welded to the longitudinal ribs 2. In addition, 1b shows the outer peripheral surface of the barrel 1 in FIG.

When the reinforcing member is joined to the inner peripheral surface 1a of the cylindrical body 1 in this way, as shown in FIG. 1 (b),
After that, the mortar 7 is sprayed toward the inner peripheral surface 1a of the tubular body 1 in the space defined by the vertical ribs 2 and the horizontal ribs 3. This mortar spraying work is performed until the spray surface almost reaches the position of the ring-shaped reinforcing bar 4. next,
As shown in FIG. 1 (c), the mesh reinforcement 5 is welded to the ring-shaped reinforcement 4 so as to cover the portion filled with the mortar 7. Thereafter, as shown in FIG. 1D, the mortar 7 is further covered with a required thickness while covering the ring-shaped reinforcing bars 4 and mesh reinforcing bars 5.

On the other hand, on the outer peripheral surface 1b side of the barrel 1,
A carbon fiber wire rod 8 is wound around the outer peripheral surface 1b of the barrel 1 by a winding machine to construct a reinforcing structure.

The above-mentioned welding process, the spraying / covering process of the mortar 7 and the winding process of the carbon fiber wire 8 are repeated a required number of times in the height direction of the barrel 1. The repetition is
The required height of the above-mentioned reinforcement structure, for example, 1 / of the existing steel chimney
It is performed until the height of 10 is reached. Required height is 200
When the length of the vertical rib 2 is 2 m and the length is 2 m, the predetermined number of times is 10 times. The required height is determined in consideration of the site where buckling may occur.

In the embodiment described above, the inner circumference of the barrel 1 is formed by the vertical ribs 2 and the horizontal ribs 3 which are joined to the inner circumferential surface 1a of the existing steel chimney 1 in a cross beam shape. The carbon fiber wire 8 wound around the outer peripheral surface 1b of the tubular body 1 reinforces the tubular body 1 from the outer peripheral surface 1b side, and the tubular body 1 is fragile so that the tubular body 1 becomes inward or outward. It is possible to firmly and appropriately reinforce the tendency to fall.

On the inner peripheral surface 1a side of the barrel 1,
It is possible to protect the cylinder body 1 and the ribs 2 and 3 for reinforcement from smoke emission by filling and covering the cylinder body 1 so as to cover the cylinder body 1 while burying the reinforcing bars 4 and the mesh bars 5.

[0019]

As described above, according to the method of reinforcing an existing steel chimney according to the present invention, the longitudinal ribs are formed on the inner peripheral surface of the tubular body of the existing steel chimney at intervals along the circumferential direction. And the step of joining the horizontal ribs to the inner circumferential surface of the barrel so as to form a cross with the vertical ribs at intervals in the height direction, and the outer circumferential surface of the barrel. The process consists of winding a carbon fiber wire, and reinforced the tubular body from its inner peripheral side with vertical ribs and horizontal ribs that are joined in a girder pattern on the inner peripheral surface of the existing steel chimney. In addition to being able to do it, it is possible to reinforce the barrel from the outer peripheral surface side with a carbon fiber wire wound around the outer peripheral surface of the barrel, and to firmly prevent the barrel from weakening toward the inside or the outside due to weakening of the barrel. Can be appropriately reinforced. Therefore, the existing barrel of the steel chimney, which may be buckled due to aging, corrosion, etc., can be firmly repaired.

In the above reinforcement, a step of joining reinforcing bars to the longitudinal ribs at intervals in the height direction of the cylindrical body in the circumferential direction, and a step of filling mortar between the longitudinal ribs and the lateral ribs. On the inner peripheral surface side of the tubular body, the reinforcing bar and the mesh bar are connected to the reinforcing bar and the step of joining the mesh bar to the reinforcing bar, and the step of further covering the mortar from the upper surface of the mesh bar. The mortar can be filled and covered so as to cover the tube body while burying the tube, and the tube body and the reinforcing ribs can be protected from smoke emission.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of a method for reinforcing an existing steel chimney according to the present invention.

FIG. 2 is a partial perspective view of a part of an existing steel chimney when a rib or the like is welded to the inner peripheral surface of the existing steel chimney, as viewed from the inside of the chimney.

FIG. 3 is a partial perspective view and a vertical cross-sectional view showing a part of an existing steel chimney that has been sliced.

FIG. 4 is a partial perspective view showing a buckling generated in an existing steel chimney and a vertical sectional view thereof.

[Explanation of symbols]

 1 Tube Body 1a Inner Surface 1b Outer Surface 2 Longitudinal Rib 3 Lateral Rib 4 Reinforcing Bar 5 Mesh Rein 7 Mortar 8 Carbon Fiber Wire Rod

[Procedure amendment]

[Submission date] May 28, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

The above-mentioned welding process, the spraying / covering process of the mortar 7 and the winding process of the carbon fiber wire 8 are repeated a required number of times in the height direction of the barrel 1. The repetition is
The required height of the above-mentioned reinforcement structure, for example, 1 / of the existing steel chimney
It is performed until the height of 10 is reached. Required height is 20m
If the length of the longitudinal rib 2 is 2 m, the predetermined number of times is 1
0 times. The required height is determined in consideration of the site where buckling may occur.

Claims (2)

[Claims] 1. A step of joining longitudinal ribs to an inner peripheral surface of a tubular body of an existing steel chimney at intervals along the circumferential direction, and a height direction to the inner peripheral surface of the tubular body. A step of joining the lateral ribs so as to form a girder with the longitudinal ribs at intervals along with, and a step of winding a carbon fiber wire around the outer peripheral surface of the tubular body. Reinforcement method for existing steel chimneys. 2. A step of joining reinforcing bars to the longitudinal ribs at intervals in the height direction of the cylindrical body and in the circumferential direction thereof, and filling mortar between the longitudinal ribs and the lateral ribs. The existing steel according to claim 1, further comprising: a step of covering the rebar with a mesh rebar, and a step of further covering the mortar from an upper surface of the rebar. How to reinforce the chimney.