JP3783126B2 - Bellow structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bellows structure, and relates to a bellows structure that prevents unnecessary bending of a bellows caused by thermal expansion between ducts during boiler operation or relative deformation during an earthquake.
[0002]
[Prior art]
FIG. 11 shows a configuration diagram of the power plant. The power plant includes a boiler 14, a duct 15, an air heater 16, a fan 17, and a chimney 18. Non-metal to block the expansion and contraction due to thermal expansion in the axial direction and shear direction between the two ducts 15 or between the duct 15 and the equipment such as the fan 17, absorption of relative deformation during an earthquake, and vibration from various fans A bellows consisting of A conventional structure of a non-metallic bellows is shown in FIGS. Consists of duct side coupling flange 1, bellow side coupling flange 2, rising flange 3, holding plate 4, non-metallic bellows 5, mounting bolt 6, inside sleeve 7, heat insulating material 8 and stud bolt 9, and bellow side coupling The duct flange 2 and the rising flange 3 are fixed by welding.
[0003]
A hole is made in the flange portion of the rising flange 3, the holding plate 4 and the non-metallic bellows 5, and a mounting bolt 6 is attached and fixed to the hole. In general, the bellows 5 uses a non-metallic material in which a fluororesin and a glass cloth are combined, and the heat resistant temperature is 200 ° C. The attachment of the bellows 5 has a slight bulge. In the case of a plant using a coal fired boiler, the inside sleeve 7 must be attached. Further, when the use site is at a high temperature, the heat insulating material 8 is required. Since the non-metallic bellows 5 is mounted between a duct and a fan that thermally expands, the bellows 5 is slackened due to thermal expansion during operation of the boiler 14, and when the bellows 5 is deformed in the shearing direction due to an earthquake or the like, the bellows 5 is bent several times. Arise. In addition, the boiler 14 is repeatedly started and stopped, and suddenly fluctuates due to a sudden pressure fluctuation in the duct 15 due to a load change. If it repeats, fatigue damage due to repeated fluttering occurs and the bellows 5 is locally damaged.
[0004]
[Problems to be solved by the invention]
In the above-described prior art, no consideration is given to bending or fluttering of the bellows 5, and the bellows 5 are locally damaged due to fluttering of the bellows 5 due to the start and stop of the boiler 14 and pressure fluctuation in the duct 15, resulting in a lifetime. There was a problem that speeded up. As one countermeasure for solving such a problem, an invention described in Japanese Patent Laid-Open No. 10-185071 has been made. Although the bellows structure of the present invention can be said to be able to cope with the flutter caused by pressure fluctuation due to a sudden bulge, it is ineffective against the flutter itself having a large amplitude such as folding back to the back surface.
[0005]
The subject of this invention is providing the bellows structure which suppresses the amount of bending of a bellows, and flutter itself, and improves a bellows lifetime suitably.
[0006]
[Means for Solving the Problems]
In the bellows installed between the duct coupling flanges for the purpose of absorbing the thermal expansion of the ventilation equipment (duct) through which high-temperature gas or air flows, or the relative deformation at the time of an earthquake, One end of a bellows-side coupling flange that is fixed to the coupling flange, a rising flange that is joined to the bellow-side coupling flange, a bellows that is fixed to the rising flange, and a pressing metal fitting that contacts the back surface of the bellows And a bellows structure comprising a protruding support joined to the rising flange at the other end.
[0007]
By supporting the bellows from the inside by giving the strength of the protruding support a rigidity that resists the resistance force caused by the change in internal pressure, the movement of the bellows can be suppressed so that the bellows cannot move inward.
[0008]
If link members attached via hinges are provided on the support bracket mounting part of the protrusion support and the web part of the rising flange on both sides or the base part of the protrusion support on the rising flange side, the protrusion support will expand and contract to act on the bellows part. The amount of bending of the bellows can be automatically adjusted according to the amount.
[0009]
[Action]
The bellows mainly made of a non-metallic material absorbs the deformation between the ducts when the duct is thermally expanded or deformed by an earthquake or the like, and the attachment portions at both ends of the bellows approach and the bellows itself bends. At this time, the bellows is in a sagging state and moves in the out-of-plane direction with a slight force. Further, by installing the protrusion support inside the bellows, the inward movement of the bellows is stopped by the support force of the protrusion support, and the amount of movement of the bellows in the out-of-plane direction is suppressed. In addition, it is possible to prevent a large-amplitude flutter that causes the bellows to be folded back on the back surface due to the start / stop of the boiler, the pressure fluctuation in the duct, or the like. Thus, fatigue damage due to repeated bending of the bellows can be prevented. Further, by attaching a bellows holding metal fitting to the tip of the protrusion support, it works to avoid stress concentration on the bellows in contact with the protrusion support tip.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the bellows structure of the present invention will be described with reference to the drawings.
The embodiment shown in FIGS. 1 to 3 will be described first.
1 is a side view of the bellows structure when used at a high temperature, FIG. 2 is a perspective view of the example of FIG. The bellows structure includes a duct side coupling flange 1, a bellows side coupling flange 2, a rising flange 3, a retainer plate 4, a non-metallic bellows 5, a mounting bolt 6, an inside sleeve 7, a heat insulating material 8, a stud bolt 9, a protruding support 10, and It consists of bellows holding metal fittings 11.
[0011]
The bellows structure is attached as follows.
The rising flange 3 is fixed to the bellows side coupling flange 2 by welding, the stud bolt 9 having the heat insulating material 8 previously attached to the bellows side coupling flange 2 is fixed, and the bellows holding metal fitting 11 is attached to the end of the non-metallic bellows 5 side. The projecting support 10 attached to is joined to the web portion of one rising flange 3. Holes are made in the flange portion of the rising flange 3, the non-metallic bellows 5, and the holding plate 4, and each is fixed by the mounting bolt 6. At this time, it is attached so that the inner side of the non-metallic bellows 5 and the bellows holding metal fitting 11 are in contact with each other. This bellows structure is disposed between the two duct side coupling flanges 1 and the bellows side coupling flange 2 is fixed to the duct side coupling flange 1 using mounting bolts 6.
[0012]
Further, at this time, the shape of the bellows holding metal fitting 11 can be an arbitrary shape such as a round shape or an oval shape as shown in FIGS.
[0013]
When the boiler 14 (FIG. 11) repeatedly starts and stops, or when pressure fluctuation occurs in the duct 15 (FIG. 11) due to a load change of the boiler 14, the non-metallic bellows 5 moves to the inside of the duct 15 and flutters. Produce. In contrast to the fluttering of the non-metallic bellows 5, the bellows structure has the protrusion support 10 and the bellows holding metal fitting 11 attached thereto, so that the non-metallic bellows 5 can be prevented from moving inward and the swelling can be kept constant. is there.
[0014]
Another embodiment of the present invention is shown in FIGS. The bellows structure of the present embodiment is characterized in that the link type parts 12 and 13 are attached to the protrusion support 10 so that the amount of bending of the bellows 5 can be automatically adjusted according to the amount of expansion and contraction acting on the bellows 5. Non-metallic bellows structure.
[0015]
The bellows structure of the present embodiment is linked to the protrusion support 10 in the vicinity of the bellows pressing metal fitting 11 in addition to the protrusion support 10 connected to the web portion of one rising flange 3 in the example shown in FIGS. A hinged support stay 12 attached by joining is provided.
[0016]
One of the hinges 13 attached to the end of the support stay 12 is attached to the protruding support 10 in the vicinity of the bellows presser fitting 11. The other of the hinges 13 attached to the support stay 12 is provided at the web portion of the flange 3 or the base portion of the protruding support 10.
[0017]
When the bellows structure is displaced in the contracting direction due to the pressure fluctuation in the duct 15 (FIG. 11) (FIG. 7), the protrusion support 10 is deformed in FIG. It is bent clockwise and approaches the non-metallic bellows 5 to keep the gap between the non-metallic bellows 5 and the protruding support 10 to a minimum. Further, when the displacement in the direction in which the bellows structure extends due to the pressure fluctuation in the duct 15 (FIG. 8), the protrusion support 10 is bent in the clockwise direction in FIG. In this case, the gap between the non-metallic bellows 5 and the protrusion support 10 is kept to a minimum.
[0018]
Thus, the effect of the present embodiment is that the gap between the non-metallic bellows 5 and the add-on support 10 is suitably reduced by utilizing the thermal elongation and relative deformation of the duct 15.
[0019]
【The invention's effect】
According to the present invention, by providing a protrusion support or a protrusion support and a hinged support, unnecessary deformation of the bellows can be suppressed against the fluttering caused by pressure fluctuations generated in the duct and the deformation in the expansion and contraction, and the bellows life can be extended. There is an effect that can be achieved.
[Brief description of the drawings]
FIG. 1 is a side view showing an example of use of a bellows structure according to an embodiment of the present invention in a high-temperature duct portion.
2 is a side view showing an example of use in the low-temperature duct portion of the bellows structure of FIG.
FIG. 3 is a perspective view of the bellows structure of FIG. 1;
4 is a side view of the bellows holding metal fitting (round shape) having the bellows structure shown in FIG. 1. FIG. 5 is a side view of the bellows holding metal fitting (elliptical type) having the bellows structure shown in FIG.
FIG. 6 is a side view of the bellows structure according to the embodiment of the present invention.
7 is a side view of the bellows structure of FIG. 6 when inflated.
FIG. 8 is a side view of the bellows structure of FIG. 6 when contracted.
FIG. 9 is a side view showing an example of use in a high-temperature duct portion of a conventional bellows structure.
FIG. 10 is a side view showing an example of use in a low-temperature duct portion of a conventional bellows structure.
FIG. 11 is a configuration diagram of a power plant.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Duct side coupling flange 2 Bellow side coupling flange 3 Standing flange 4 Holding plate 5 Non-metallic bellows 6 Mounting bolt 7 Inside sleeve 8 Heat insulating material 9 Stud bolt 10 Protruding support 11 Bellow pressing metal 12 Support stay 13 with hinge 13 Hinge 14 Boiler 15 Duct 16 Air heater 17 Fan 18 Chimney

Claims (3)

In the bellows structure installed between the duct coupling flanges for the purpose of absorbing the thermal expansion of the duct through which hot gas or air flows inside or the relative deformation during an earthquake,
Bellow side coupling flanges fixed to the duct side coupling flanges on both sides, a rising flange joined to the bellow side coupling flange, a bellows fixed to the rising flange, and a presser that contacts the back surface of the bellows A bellows structure comprising a metal fitting provided at one end and a protruding support joined to the rising flange at the other end. 2. The bellows structure according to claim 1, wherein the strength of the protruding support is provided with a rigidity that resists a resistance force caused by a change in internal pressure. The link member attached via the hinge to the holding | fitting bracket attachment part of the protrusion support and the web part of the rising flange of both sides, or the base part of the protrusion support of the said rising flange side, respectively is provided. Bellow structure.

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