JPH09229307A - Structure for corner part of boiler casing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mitigate the generation of a stress accompanied by the difference of thermal expansions generated between the main body of a boiler and the corner part of a casing, covering a part of the outside of the main body. SOLUTION: The corner part 15 of a boiler casing 3, having an outer peripheral wall 7b extended from a leg unit 12, fixed to the outer periphery of the furnace wall 6 of the rectangular main body 1 of boiler, to the outside of the furnace wall 6 and bent thereafter into up-and-down direction so as to cover a part of the boiler main body 1, is structured so that a fan type horizontally inflated part 16 is formed at the corner part 15 of the boiler easing 3 and a plurality of projected threads 17, extending radially substantially from the side of the boiler main body 1, are formed on the fan type horizontally inflated part 16 while the horizontally inflated part 7a, continued to the leg unit 12 at the vicinity of the corner unit 15, and the outer peripheral wall 7b, continued to the fan type horizontally inflated part 16, are constituted of corrugate plates 19 respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corner structure of a boiler casing which covers a boiler body.

[0002]

2. Description of the Related Art When a boiler is in operation, the inside of the boiler is under a positive pressure, and in order to prevent high temperature combustion gas from being directly ejected to the outside from a ceiling or the like where there are many penetrations such as heat transfer tubes, it is shown in FIG. As described above, the boiler casing 3 is provided so as to cover the ceiling portion 2 of the boiler body 1, and the inside of the boiler casing 3 is kept at a positive pressure. Further, a boiler casing 3 for an ash removing device that covers the ash outlet 2a is provided at the bottom of the boiler body 1.

FIGS. 6 to 8 show a case of a boiler casing 3 covering the ceiling portion 2 as an example, which has a rectangular shape composed of a furnace wall tube 4 of a boiler body 1 and fins 5 connecting the same. The inner peripheral edge of the lower end of the leg portion 8 of the boiler casing 3 is fixed through the bracket 9 over the entire outer circumference of the furnace wall 6, and above the furnace wall 6 is horizontally positioned outside the furnace wall 6 as shown in FIGS. 6 and 8. A horizontal bulging portion 7a bulging is formed, and further constitutes an outer peripheral wall 7b which is erected upward.

In the boiler casing 3 as described above,
Due to the difference in thermal expansion between the furnace wall 6 and the boiler casing 3 at the time of starting the boiler, stress tends to concentrate particularly on the portion of the boiler casing 3 arranged at the corner portion 10 of the furnace wall 6, so that the furnace wall 6 As shown in FIGS. 6 and 8, a corrugated plate 11 is used for the horizontal bulging portion 7a of the boiler casing 3 arranged in the corner portion 10, and the corrugated plate 11 absorbs the deformation.

[0005]

However, FIG.
As shown in FIG. 8, the horizontal bulging portion 7a corresponding to the corner portion
In the boiler casing 3 using the corrugated plate 11 in the above, when the corner portion 10 of the furnace wall 6 is deformed as shown by an imaginary line in FIG. 7 when the boiler is started, the boiler casing 3 can follow the deformation. However, stress is likely to occur at the corners of the boiler casing 3, and there is a problem that cracks occur in the boiler casing 3.

The present invention solves such a problem, and at the time of starting the boiler, the stress caused by the difference in thermal expansion generated between the corner portion of the boiler main body and the corner portion of the boiler casing covering the outside thereof is prevented from occurring. An object of the present invention is to provide a corner portion structure of a boiler casing that can be relaxed.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a leg portion is fixed to the outer periphery of a furnace wall of a rectangular boiler body, and an outer peripheral wall is formed by projecting from the leg portion to the outside of the furnace wall and then bending in the vertical direction. In the corner structure of the boiler casing that covers a part of the boiler main body, a fan-shaped horizontal bulge is formed in the corner of the boiler casing, and the fan-shaped horizontal bulge is formed from the boiler main body side. A corrugated gate which forms a plurality of substantially linearly extending projections and which is continuous with the leg portion in the vicinity of the corner portion and the outer peripheral wall, and the outer peripheral wall which is continuous with the fan-shaped horizontal bulge portion. According to the structure of the corner portion of the boiler casing, which is characterized by being configured by a plate, the fan-shaped horizontal bulge portion in the corner portion of the boiler casing, in which the difference in thermal expansion between the boiler body and the boiler casing is the largest, is A plurality of ridges extending substantially radially from the main body of the body absorb the difference in thermal expansion, and in the vicinity of the corner, the horizontal bulging portion and the outer peripheral wall that are continuous with the leg portion and the fan-shaped horizontal bulging portion are continuous. The difference in thermal expansion between the outer peripheral wall and the boiler body is absorbed by the corrugated plate, and a large stress due to the difference in thermal expansion does not occur in the boiler casing.

[0008]

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

FIG. 1 is a perspective view of an embodiment of the present invention seen from the direction I in FIG. 3, and FIG. 2 is a sectional view taken along line II-II in FIG.
2 is a sectional view taken along line III-III of FIG. 2, and FIG. 4 is taken along line IV-I of FIG.
It is a V cross-sectional view, and the boiler casing 3 is provided over the entire circumference on the upper outer periphery of the furnace wall 6 consisting of the furnace wall tube 4 of the boiler body 1 and the fins 5 connecting the same, and the boiler casing 3 3, the inner peripheral edge of the lower end of the leg portion 12 is fixed to the outer periphery of the furnace wall 6 via a bracket 14 so that a required gap 13 is formed from the furnace wall 6.

A little above this fixing point, the leg portion 12 of the boiler casing 3 has a furnace wall 6 as shown in FIG.
A horizontally bulged portion 7a that is horizontally bulged is formed on the outer side of, and an outer peripheral wall 7b that rises further upward is formed.

The corner portion 15 of the boiler casing 3
The fan-shaped horizontal bulging portion 16 having an arcuate outer periphery is formed in the horizontal bulging portion 7a of the above, and the outer peripheral wall 7b continuous to the upper side of the fan-shaped horizontal bulging portion 16 also follows the outer periphery of the fan-shaped horizontal bulging portion 16. It has a curved shape.

Since it is difficult to use a corrugated plate for the fan-shaped horizontal bulging portion 16, a plurality of ridges 17 are provided outside the furnace body 6 side of the boiler body 1 as shown in FIGS. Fan-shaped horizontal bulging portion 16 in a substantially radial shape extending in one direction
The ridge 17 is deformed in cross section to absorb the thermal deformation of the fan-shaped horizontal bulging portion 16.

As shown in FIGS. 2 to 4, a corrugated plate 19 is used for the horizontal bulging portion 7a (see FIG. 1) of a required range 18 near both sides of the fan-shaped horizontal bulging portion 16, and the corrugated plate is used. The plate 19 is provided continuously to the leg 12 and the outer peripheral wall 7b.

As shown in FIGS. 1 and 3, a flat plate 21 is connected to the right and left sides of the corrugated plate 19 and above the corrugated plate 19 via a corrugated expandable joint plate 20. Reference numeral 22 indicates a shape change portion.

In the corner portion structure of the boiler casing 3 shown in FIGS. 1 to 4 described above, when a difference in thermal expansion occurs between the corner portion 10 of the furnace wall 6 and the corner portion 15 of the boiler casing 3 when the boiler is started, the boiler expands. Casing 3
The fan-shaped horizontal bulging portion 16 of the corner portion 15 of the
Thermal deformation is absorbed by the deformation of the cross-sectional shape of 7.

The horizontal bulging portion 7a and the upper outer peripheral wall 7b connected to both sides of the fan-shaped horizontal bulging portion 16 absorb the thermal deformation due to the deformation of the corrugated plate 19, and the boiler casing 3 has Large stress due to the difference in thermal expansion does not occur.

In the above-mentioned embodiment, the case of the boiler casing 3 provided as the ceiling enclosure of the boiler has been described, but the present invention is not limited to this, and the boiler body 1 is not limited to this.
Of course, it can be applied to the boiler casing 3 and the like for the ash removing device that covers the lower ash outlet 2a.

[0018]

According to the present invention, when the corner portion of the furnace wall is deformed at the time of starting the boiler, the corner portion of the boiler casing follows the deformation of the furnace wall by the ridge and the corrugated plate, and an excessive stress is generated. It does not occur, and there is an effect that damage such as cracking of the boiler casing does not occur.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention viewed from the direction I in FIG.

FIG. 2 is a sectional view taken along line II-II of FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a vertical cross-sectional view showing an outline of an example of a boiler provided with a boiler casing.

6 is an enlarged view showing an example of a conventional VI section of FIG.

FIG. 7 is a vertical sectional view taken along the line VII-VII in FIG.

FIG. 8 is a perspective view seen from the direction VIII in FIG.

[Explanation of symbols]

 1 Boiler main body 3 Boiler casing 6 Furnace wall 7a Horizontal bulging part 7b Outer peripheral wall 12 Leg part 15 Corner part 16 Fan-shaped horizontal bulging part 17 Convex strip 19 Corrugated plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiharu Hirakawa Asahigaoka 2007, Asa-cho, Asakita-ku, Hiroshima City, Hiroshima Prefecture 2007

Claims (1)

[Claims] 1. A rectangular boiler main body is provided with a leg portion fixed to the outer periphery of the furnace wall, and an outer peripheral wall is formed by projecting from the leg portion to the outside of the furnace wall and then bent in the up-and-down direction. In the structure of a corner portion of a boiler casing that is covered, a fan-shaped horizontal bulging portion is formed in the corner portion of the boiler casing, and a plurality of ridges extending substantially radially from the boiler main body side are formed in the fan-shaped horizontal bulging portion. And each of the horizontal bulging portion and the outer peripheral wall continuous with the leg portion in the vicinity of the corner portion and the outer peripheral wall continuous with the fan-shaped horizontal bulging portion are constituted by corrugated plates. Boiler casing corner structure.