JPS61205704A - Expansion bellows for skin casing of boiler, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an expansion bellows installed in a skin casing of a boiler or the like. The present invention, however,
In addition to such skin casings, the present invention can also be applied to devices that generate movement due to thermal expansion and which require connecting objects that move differently.

Conventional boilers are equipped with a skin casing to prevent combustion gas inside the furnace from leaking out of the furnace, and various communication pipes often pass through this skin casing.

Expansion bellows are usually attached to this penetration part to absorb the amount of thermal expansion in the axial direction and perpendicular direction of the various connecting pipes, and one end of the expansion bellows is welded to the skin casing and the other end to the connecting pipe. It is installed to prevent combustion gas leaks.

FIG. 2 shows the equipment state of a conventional general expansion bellows, and its structure and function will be explained below.

A skin casing 2 provided in contact with the boiler wall surface (evaporation pipe, etc.) 1 is provided for the purpose of preventing combustion gas inside the furnace from leaking out of the furnace, and various communication pipes 3 are installed in this part. often penetrates. These various communication pipes 3 move in the pipe axial direction and in the pipe perpendicular direction due to thermal expansion. At this time, the boiler wall (evaporation tube, etc.) 1, skin casing 2
A difference in the amount of movement occurs between the connecting pipe 3 and the various communication pipes 3 due to the temperature difference. Because of this difference, the skin casing 2 and various communication pipes 3 cannot be fixed. Therefore, an expansion bellows 4 is provided to absorb this difference in movement amount.

Problems to be Solved by the Invention In the conventional example described above, however, the number of expansion bellows (40) and the distance between the mounting surfaces are determined by the expansion bellows used to absorb the amount of movement of the various connections V3 in the tube axis direction and in the tube perpendicular direction. It is calculated from the allowable expansion/contraction amount of bellows 4, but depending on the surrounding conditions where it is installed, there may be cases where it is not possible to secure the distance between the surfaces to install the necessary number of ridges to absorb the movement, and the required number of ridges cannot be obtained. There are cases. For this reason, the amount of movement of the various communication pipes 3 cannot be completely absorbed, which may lead to damage to the expansion bellows 4.

Therefore, the present invention was made to solve these conventional problems, and when attempting to install a single expansion bellows for the amount of movement of various connecting pipes, etc., it is difficult to In order to completely absorb the amount of movement in places where the necessary distance between surfaces cannot be secured, a dual type expansion bellows is installed, and the synergistic effect of the inner expansion and outer expansion of this dual type expansion bellows allows for a short distance between surfaces. The purpose is to make it possible to increase the effect of absorbing the amount of movement.

Means for Solving the Problems The present invention provides a Salel expansion bellows installed in a skin casing of a boiler, etc., which has a double (r)

Attach one end of the pansion to the skin casing cylinder and the other end to the first seal plate, and attach the skin casing side end of the expanded inner expansion to the second seal plate fixed to the pipe and the other end. part is attached to the first seal plate.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In Figure 1, 1 is the boiler wall surface (evaporation tube, etc.), 2 is the skin casing, 3 is various communication pipes, and these are the second
This is similar to the conventional example shown in the figure.

According to this embodiment, the boiler wall surface (evaporation tube, etc.)
Various communication pipes 3 passing through the skin casing 2 in contact with the skin casing 1
A dual type expansion bellows 14 is installed at a short distance between two surfaces with a predetermined amount of movement in the tube axis direction and in the tube perpendicular direction.

That is, specifically, the outer expansion 14
a is attached to the skin casing 2 at one end and to the seal plate 5 at the other end. On the other hand, the inner expansion 14b is connected to the other seal plate 6 at one end of the sleeve (end on the skin casing side).
The other end of the outer expansion 14a is attached to the seal plate 5 to which the other end of the outer expansion 14a is attached. This seal plate 5 is
.

It is loosely fitted around the seed communication pipe 3 and is movable, and the other seal plate 6 is fixed to the various communication pipes 3.

In this way, in places where it is not possible to provide a sufficient distance between the surfaces required to install a single expansion bellows to absorb the amount of movement of the various communication pipes 3, a dual type expansion bellows 14 can be used to provide a predetermined short distance. This effect can be achieved by changing the distance between the surfaces.

That is, as the various communication pipes 3 move, the inner expansion 14b operates first, and when the movement exceeds the allowable expansion/contraction amount of the inner expansion, the outer expansion 14a operates and completely absorbs the amount of movement. There is an effect due to the synergistic effect of the inner expansion and outer expansion.

This structure is especially effective when absorbing the amount of movement of the various communication pipes 3 in the direction perpendicular to the pipes. Although the expansion bellows have a considerable amount of allowable expansion/contraction in the axial direction, the allowable expansion/contraction in the direction perpendicular to the axis is drastically reduced. The only way to do that is to increase the number of bellows, but this dual type expansion bellows 1
4 can have the effect of at least twice the number of peaks as a single bellows at the same distance between surfaces.

Effects of the Invention As detailed above, according to the present invention, short distances between surfaces determined to absorb the difference in the amount of movement that occurs between the boiler wall (evaporation pipe, etc.), skin casing, and various communication pipes are provided. By installing a dual-type expansion bellows in the cylinder, it is possible to completely absorb the amount of movement, which was insufficient with a single expansion.

[Brief explanation of the drawing]

FIG. 1 shows an example of an expansion bellows for a skin casing of a boiler or the like according to the present invention, and FIG. 2 shows a conventional example. 1. Boiler wall surface (evaporation tube, etc.), 2. Skin casing, 3. Various communication pipes, 5, 6. Seal plate, 1
4... Expansion bellows, 14a... Outer expansion, 14b... Inner expansion.

Claims (1)

[Claims] Expansion bellows installed in the skin casing of boilers, etc. have a double expansion structure, with one end of the outer expansion attached to the skin casing, the other end attached to the first seal plate, and the inner expansion bellows attached to the skin casing. An expansion bellows comprising: an end of the expansion on the skin casing side attached to a second seal plate fixed to a pipe, and the other end attached to the first seal plate.