JPH0426652Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an expansion joint, and in particular, this invention is provided with an accordion-shaped metal bellows and an inner cylinder disposed inside the metal bellows, and the internal space of the inner cylinder is This relates to an expansion joint that allows fluid to pass through it.

[Prior art and problems to be solved]

Generally, this type of expansion joint is constructed as shown in FIG.

That is, a pair of flanges 2 facing each other
A telescopic metal bellows 23 is disposed between the flanges 21 and 22 with both ends fixed to the flanges 21 and 22, respectively.
One end of an inner tube 26 extending toward the center hole 25 of the other flange 22 is fitted into the center hole 24 of the other flange 22, and the other end of the inner tube 26 is fitted into the center hole 24 of the other flange 22. It is in a state adjacent to the central hole 25 of.

In the conventional expansion joint configured as described above, both flanges 21 and 22 are connected to bolts 27 and 27 to piping, tanks, equipment, etc. (not shown).
28 etc., and is designed to be used as a part of piping.

In the pipe expansion joint, when the distance between the flanges 21 and 22 changes due to thermal expansion or vibration in the piping, equipment, etc., the metal bellows 23 It is designed to absorb displacement by expanding and contracting, and at this time, the inner cylinder 26 is not fixed to both flanges 21 and 22, but only to one flange 21, so there is no risk of damage. It is something.

However, in the conventional expansion joint configured as described above, a part of the gas, gas, powder, etc. passing through the inside of the inner cylinder 26 and the combustion gas contained therein, for example, Inclusions such as soot, corrosive gas, foreign matter, solid matter, etc. inside the inner tube 26 and the metal bellows 23 as shown by arrow A through the gap created between the other flange 22 and the other end of the inner tube 26. The metal bellows 23 has a problem in that it flows between the metal bellows 23, adheres to or accumulates on the inner surface of the metal bellows 23, or enters the valleys of the metal bellows 23, corroding or damaging the metal bellows 23.

Furthermore, since the space between the metal bellows 23 and the inner cylinder 26 is just a space, the heat insulation effect is not sufficient. This causes the problem of repeated expansion and contraction while being exposed to high temperatures, resulting in a shortened lifespan due to the corrosion problem mentioned above.

This invention solves the problems of the conventional ones as described above, and prevents the fluid passing through the inner cylinder and the inclusions contained in this fluid from coming into contact with the metal bellows. With,
To provide an expansion joint that can prevent the metal bellows from becoming high temperature and prolong the life of the metal bellows, thereby allowing the metal bellows to be used for a long period of time.

[Means to solve the problem]

In order to achieve the above object, this invention also includes a first inner cylinder inside the metal bellows.
a second inner cylinder is located inside each of the inner cylinders, one end of the metal bellows is fixed to one flange, and one end of the first inner cylinder is fixed to a central hole of the flange, and The other end of the metal bellows is fixed to the other flange, and one end of the second inner cylinder is fixed to the center hole of this flange, and further, between the first inner cylinder and the second inner cylinder, A heat insulating material is disposed in an annular cavity formed by the above, and the heat insulating material is placed in either the first inner cylinder or the second inner cylinder, and the heat insulating material is applied only to the other inner cylinder. The expansion joint is characterized in that a holding means is provided to enable the second inner cylinder to slide, and a fluid is allowed to pass through the inside of the second inner cylinder. The holding means includes a small diameter portion bent inward and provided at one end of the first inner cylinder adjacent to an outer circumferential surface of the second inner cylinder;
and a metal fitting provided on the inner peripheral surface of the other end of the inner cylinder and adjacent to the outer peripheral surface of the second inner cylinder.

[Effect]

By adopting the above-mentioned means, this idea
The metal bellows comes into contact with the high-temperature fluid through an insulating material, so there is no risk of direct exposure to high temperatures.Moreover, this insulating material is always maintained, and the fluid does not come into contact with the metal bellows. Therefore, there is no fear that the metal bellows will be corroded by inclusions contained in the fluid.

〔Example〕

Embodiments of this invention shown in the drawings will be described below.

FIG. 1 shows an expansion joint according to this invention, which has a pair of flanges 1 and 2 facing each other, and both flanges 1 and 2.
The center holes 3 and 4 of one flange 1 are smaller than the center hole 4 of the other flange 2.

Then, in the central hole 3 of the one flange 1,
The second flange 2 extends in the direction of the other flange 2 and has a tip bent inward to form a small diameter portion 5, the small diameter portion 5 having a slightly larger diameter than the central hole 4 of the other flange 2. The rear end of one inner cylinder 6 is fixed, and a second inner cylinder 7 extending toward the one flange 1 is disposed in the center hole 4 of the other flange 2. An annular space 8 is formed between the inner cylinder 6 and the second inner cylinder 7.

A heat insulating material 9 such as glass wool or ceramic wool is disposed in this annular space 8, and the first inner cylinder 6 is then placed in order to prevent the heat insulating material 9 from scattering or falling off. An annular metal fitting 10 is fixed inside the rear end side by welding or the like. Therefore,
The small diameter portion 5 of the first inner cylinder 6 and the metal fitting 10 form a holding means for the heat insulating material 9.

Further, on the outside of the first inner cylinder 6, a metal bellows 11 is positioned between the flanges 1 and 2, and is attached with both ends fixed.

In the expansion joint configured as described above, both the flanges 1 and 2 are fixed to the piping etc. with bolts 12 and 13, etc., and the inside of the second inner cylinder 7 is closed. The fluid is designed to flow as shown by the arrow.

When the piping, etc. is displaced due to thermal expansion, vibration, etc., and the distance between the flanges 1 and 2 is displaced, the first inner cylinder 6 and the second inner cylinder fixed to the flanges 1 and 2, respectively, are displaced. Since the inner cylinders 7 are not connected to each other, they can move freely and follow the displacement of the piping, etc., while the metal bellows 11 itself can be expanded and contracted, so they can move the piping etc. It is now possible to track displacements such as

In this case, the heat insulating material 9 disposed in the annular space 8 formed between the first inner cylinder 6 and the second inner cylinder 7 is held inside the first inner cylinder 6 by the holding means. By being held on the peripheral surface and sliding only against the second inner cylinder 7, it can easily follow displacement, and
Due to the holding means formed by the small diameter portion 5 at the tip of the first inner cylinder 6 and the metal fitting 10 on the inner surface of the rear end, the heat insulating material 9 is always held without fear of falling out of the annular space 8.
is disposed between the fluid and the metal bellows 11, thereby preventing fluids such as gas, powder, etc., and the soot contained therein, such as soot in combustion gas, corrosive There is no risk that inclusions such as gas, foreign matter, solid matter, etc. will come into contact with the metal bellows 11, and corrosion etc. can be prevented, and since the heat insulating material 9 is disposed between the fluid and the metal bellows 11, the metal There is no fear that the bellows 9 will be exposed to high temperatures.

In the above embodiment, the tip of the first inner cylinder 6 attached to the center hole 3 of one flange 1 is bent inward to form the small diameter part 5, and the rear end of the first inner cylinder 6 is bent inward. The metal fittings 10 are placed inside, and the small diameter portion 5 and the metal fittings 10 are used as holding means to hold both sides of the heat insulating material 9. The first
It may be configured to slide between the inner cylinder 6 and the inner side of the inner cylinder 6.

[Effect of idea]

By configuring this idea as described above,
Since there is no risk of the fluid flowing inside the second inner cylinder coming into direct contact with the metal bellows, there is no risk of corrosion or damage to the metal bellows due to the fluid and inclusions contained in this fluid. Since a heat insulating material is provided between the fluid and the metal bellows, there is no risk that the metal bellows will be directly exposed to high temperatures, and these can extend the life of the metal bellows, that is, the overall life. Moreover, even if the first inner cylinder and the second inner cylinder are displaced, the heat insulating material held by the holding means in one inner cylinder slides only against the other inner cylinder, so the heat insulating material remains secure. It can be held in a cavity and exhibit a heat insulating effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an expansion joint according to this invention, and FIG. 2 is a schematic diagram showing a conventional expansion joint. 1, 2, 21, 22...flange, 3, 4, 2
4, 25...Central hole, 5...Small diameter part, 6...First
inner cylinder, 7... second inner cylinder, 8... annular cavity,
9...Insulating material, 10...Metal fittings, 11, 23...Metal bellows, 12, 13, 27, 28...Bolts, 26...Inner cylinder.

Claims (1)

[Claims for Utility Model Registration] (1) Inside the metal bellows 11, the first inner cylinder 6
Further, a second inner cylinder 7 is located inside the first inner cylinder 6, and one end of the metal bellows 11 is fixed to one flange 1,
The first inner cylinder 6 is inserted into the center hole 3 of this flange 1.
One end of the metal bellows 11 is fixed, and the metal bellows 11
The other end is fixed to the other flange 2, and one end of the second inner cylinder 7 is fixed to the center hole 4 of this flange 2, and further, the first inner cylinder 6 and the second inner cylinder 7 are fixed. A heat insulating material 9 is disposed in an annular space formed between the first inner cylinder 6 and the second inner cylinder 7.
7 is provided with a holding means for making the heat insulating material 9 slidable only with respect to the other inner cylinder 6, 7, so that the fluid passes through the inside of the second inner cylinder 7. An expansion joint characterized by: (2) The holding means includes a small diameter portion 5 bent inward and provided at one end of the first inner cylinder 6 adjacent to the outer circumferential surface of the second inner cylinder 7; 2. The expansion joint according to claim 1, further comprising a metal fitting 10 provided on the inner circumferential surface of the other end of the tube 6 and adjacent to the outer circumferential surface of the second inner tube 7.