JP2008045667A - Rupture disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rupture disk in which an explosion is not generated even if alternating pressure exceeding a fatigue limit acts on the rupture disk. <P>SOLUTION: In the rupture disk, an outer shell is mounted on one surface of a circular spacer 2, an inner shell 4 as a pressure receiver is arranged on the other surface of the circular spacer 2, a filling material 5 for relieving pressure changes is also arranged on a spacer between both shells, and the inner shell 4 is supported by a circular support ring 6 mounted on the circular spacer 2. An outer periphery of the inner shell is supported by the circular support ring, and a damping mechanism 7 for damping transmission of pressure waves caused by pressure changes is provided on a circular gap between both opposite surfaces. The damping mechanism is provided with a plurality of circular projections 11 and 12 concentrically formed on the circular support ring and inner shell, respectively, and the circular projections are arranged with each other in a comb-shaped state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rupture disk.

  2. Description of the Related Art In recent years, gas engine cogeneration facilities that use a gas engine to generate power and recover thermal energy (exhaust heat from exhaust gas or cooling water) generated at that time have been adopted.

  In the exhaust system of the exhaust gas of the gas engine in the gas engine / cogeneration facility, as shown in FIG. 7, a silencer 53 is provided in the exhaust duct 52 that leads to the exhaust gas having a large pressure fluctuation discharged from the gas engine 51 and high-temperature exhaust gas. In addition, when an abnormal pressure, for example, a high pressure occurs, a gas discharge pipe 54 for discharging to the atmosphere is connected to the branch duct portion 52a, and further to the branch duct portion 52a in the gas discharge pipe 54 The connection part is provided with a rupture disk 55 (see, for example, Patent Document 1).

By the way, since the exhaust gas discharged from the gas engine 51 has a high temperature, a rupture disk 55 having a double structure in which a heat insulating material is inserted is employed.
For example, in this rupture disk, an outer shell as a pressure-resistant portion is attached to one surface of an annular spacer having a predetermined thickness, and an inner shell as a pressure-receiving portion is disposed on the other surface, and formed between the two shells. The space can be relieved of pressure fluctuations, and a filler (also a heat insulating material) such as glass wool is arranged for heat insulation, and the inner shell is attached by an annular support ring attached to the other surface of the annular spacer. It was what was supported. Of course, the outer shell is formed with a stress concentration portion that breaks when the pressure of the exhaust gas exceeds a predetermined value (so-called set pressure).
Japanese Patent Publication No. 06-104191

  According to the structure of the rupture disk, since the inner shell is placed on the annular support ring, the pressure fluctuation of the exhaust gas is mostly caused by the space between the two shells, that is, the outer shell through the filler. It will be transmitted to.

  For this reason, when the pressure fluctuation, so-called alternating pressure, does not exceed the set pressure of the rupture disk (also referred to as burst pressure) and is close to or exceeds the fatigue limit of the rupture disk, the outer shell There is a problem that the stress concentration portion provided in advance causes metal fatigue and the rupture disk bursts.

  Accordingly, an object of the present invention is to provide a rupture disk capable of preventing a stress concentration portion from being damaged by fatigue even when an alternating pressure such as a value close to or exceeding the fatigue limit is applied.

In order to solve the above problems, the rupture disk according to the present invention has an outer shell that is a pressure-resistant portion attached to one surface of an annular spacer having a predetermined thickness, and an inner shell that is a pressure-receiving portion is arranged on the other surface, In addition, a filler that can relieve pressure fluctuation is disposed in the space between the two shells, and the inner shell is a rupture disk that is supported by an annular support ring attached to the other surface of the annular spacer. And
The outer peripheral portion of the inner shell is supported by the annular support ring, and a mitigation mechanism that can reduce the propagation of pressure waves due to pressure fluctuations is provided in the annular gap between the opposing surfaces.

In addition, another rupture disk of the present invention has a mitigation mechanism in the rupture disk,
A plurality of concentric annular protrusions are formed on each of the annular support ring and the inner shell, and the annular protrusion formed on one of the annular support ring and the inner shell is an annular formed on the other. It is arranged to be positioned between the protrusions,
Also, a plurality of concentric annular protrusions formed on one of the annular support ring and the inner shell, a filler disposed between the annular protrusions, and the other of the inner shell and the annular support ring. And is configured with an annular protrusion pressed against the filler,
An annular protrusion formed on one of the annular support ring and the inner shell, and an engagement member having an annular recess formed on the other of the annular support ring and the inner shell and capable of guiding the annular protrusion. It is composed.

Furthermore, the other rupture disc of the present invention is one in which a weight member is attached to the pressure-receiving surface side of the inner shell in each rupture disc,
In addition, an accumulator is connected to a space formed between the outer shell and the inner shell in each of the rupture disks.

  According to the configuration of each of the rupture discs described above, due to pressure fluctuations in which annular protrusions are provided in a comb-teeth shape on the opposing surface of the inner shell of the rupture disk provided in the exhaust gas exhaust system having a large pressure fluctuation and the annular support ring. Pressure wave mitigation mechanism, or pressure wave mitigation mechanism due to pressure fluctuation caused by pressure applied to the filler disposed between the annular projections provided on one side, or provided on one side A pressure wave mitigation mechanism is provided due to pressure fluctuations consisting of an annular protrusion and an engaging member having an annular recess provided on the other side that can guide the annular protrusion, reducing pressure fluctuation transmitted from the inner shell side to the outer shell. For example, even when an alternating pressure close to or exceeds the fatigue limit is applied, the rupture disc itself There can be prevented from rupturing.

In addition, by attaching a weight member to the inner shell of the rupture disk, the pressure wave transmitted to the outer shell can be further reduced,
Furthermore, by connecting the accumulator to the space formed between the outer shell and the inner shell of the rupture disk, the pressure fluctuation transmitted to the space can be absorbed by the accumulator, so that it is also transmitted to the outer shell. The pressure wave can be further reduced.

[Embodiment]
Hereinafter, a rupture disk according to an embodiment of the present invention will be described.
The rupture disk here is described as being provided in the exhaust system for exhaust gas from a gas engine having a large exhaust gas pressure fluctuation and high temperature, as described in the background section. In addition, since the description about the gas discharge system of a gas engine is the same as what was demonstrated in the column of background art, it abbreviate | omits.

  As shown in FIG. 1, a rupture disk 1 attached to a base end portion of a gas discharge pipe connected to an exhaust duct that constitutes an exhaust system for exhaust gas discharged from a gas engine has a predetermined thickness. An outer shell 3 that is a pressure-resistant portion is attached to one surface of the annular spacer 2 via a flange portion (outer peripheral edge portion) 3a, and an inner shell 4 that is a pressure-receiving portion is disposed on the other surface. In the space S formed between the shells 3 and 4, a filler 5 such as glass wool as a heat insulating material capable of reducing (relaxing) pressure waves due to pressure fluctuations is disposed, and the inner shell 4 is an annular spacer. 2 is supported by an annular support ring 6 attached to the other surface, and the outer peripheral portion 4a of the inner shell 4 is further supported by the inner peripheral portion 6a of the annular support ring 6. And a reduction mechanism (attenuation mechanism) capable of reducing (attenuating) the propagation of pressure waves due to pressure fluctuations in the annular gap formed between the opposed surfaces of the annular support ring 6 and the outer peripheral portion 4a of the inner shell 4 7). In addition, the ring shown here is exactly an annular ring.

  By the way, the central body 3b and the inner shell 4 other than the flange portion 3a of the outer shell 3 are formed in a bowl shape (also referred to as a split spherical surface) so as to bulge outward. Although not shown, a stress concentration part (also a fracture part) such as a notch or a slit is formed in advance so as to rupture when an abnormal pressure, for example, a high pressure is applied (when the set pressure is exceeded). ing. In addition, this stress concentration part is subjected to an alternating pressure close to the fatigue limit (including an alternating pressure corresponding to the fatigue limit) or an alternating pressure exceeding the fatigue limit when vibrated by a pressure wave due to pressure fluctuation. In such a case, fatigue breakage or the like is likely to occur. For example, the outer shell 3 is usually formed at the boundary between the main body central portion 3b and the flange portion 3a.

Next, the mitigation mechanism 7 that can reduce the propagation of pressure waves due to pressure fluctuations will be described.
As shown in FIG. 2, the mitigation mechanism 7 has a plate-like shape, for example, a plurality of concentric surfaces on the opposed surfaces of the inner peripheral portion 6a of the annular support ring 6 and the outer peripheral portion 4a of the inner shell 4. The annular projections 11 and 12 are formed, and the annular projections 11 and 12 are arranged so as to enter into the annular groove portions 13 and 14 formed between the other projections.

In other words, the labyrinth structure is formed by fitting the annular projections 11 and 12 formed in a comb-teeth shape to each other.
Thus, since the annular protrusions 11 and 12 are fitted to each other, when the pressure wave due to the pressure fluctuation of the exhaust gas from the exhaust duct passes between the annular protrusions 11 and 12, that is, the pressure loss due to the labyrinth structure. Is generated, and the pressure wave transmitted to the outer shell 3 is reduced. In the drawings, for the sake of clarity, the annular spacer 2 is illustrated as having a gap between each of the shells 3 and 4 and the annular support ring 6.

Here, the overall operation of the rupture disk 1 will be described.
That is, the exhaust gas from the gas engine enters the exhaust duct, and part of the exhaust gas passes through the silencer and is guided to the exhaust heat recovery boiler.

  By the way, when the pressure on the exhaust duct inlet side increases, a pressure difference is generated between the exhaust duct inlet and the vicinity of the rupture disk 1, and a pressure wave from the exhaust duct inlet to the vicinity of the rupture disk 1 is generated. That is, the pressure fluctuation is transmitted to the inner shell 4.

  When the pressure fluctuation is an abnormal pressure exceeding the set pressure of the rupture disk 1, a pressure wave is generated from the inner shell 4 to the outer shell 3 through the space S between the shells 3 and 4. The stress concentration portion formed on the outer shell 3 is broken and the high-pressure exhaust gas is released to the atmosphere.

  On the other hand, when the pressure fluctuation is such that the alternating pressure does not exceed the set pressure and is close to the fatigue limit of the rupture disk 1 or exceeds the fatigue limit, the pressure wave Is entered into the space S from the annular gap between the shells 3 and 4 and is transmitted to the outer shell 4, but in the labyrinth structure by the annular projections 11 and 12 that are the reduction mechanisms 7 provided in the annular gap, Since the pressure wave is reduced (damped), fatigue failure of the stress concentration portion formed in the outer shell 3 is suppressed, and the rupture disk 1 itself is prevented from bursting. Needless to say, the pressure wave is attenuated by the deformation of the filler 5 disposed in the space S and by spreading into the space S through the annular gap. Although the case where the alternating pressure is close to or exceeds the fatigue limit has been described, of course, the pressure wave is attenuated even when the alternating pressure is less than the fatigue limit.

  In this way, the plate-like annular projections are provided so as to enter the annular gap between the opposed surfaces of the inner shell of the rupture disk and the annular support ring provided in the exhaust gas exhaust system having a large pressure fluctuation. Since the labyrinth structure reducing mechanism is provided, it is possible to suppress the pressure wave due to the pressure fluctuation from being transmitted to the outer shell, and thus it is possible to extend the life of the rupture disk.

  By the way, in the above description, the annular protrusions are arranged in a comb-teeth shape as the reducing mechanism 7, but as shown in FIG. 3, for example, as an annular protrusion on the lower surface of the outer peripheral portion 4a of the inner shell 4, 21 is attached via an annular mounting member 22, and an engagement member 23 having a V-shaped cross section having an annular recess 23a capable of guiding and supporting the ring body 21 from below on the upper surface of the inner peripheral portion 6a of the annular support ring 6. You may comprise. Of course, the ring body 21 and the engaging member 23 can reduce (suppress) the transmission of pressure waves to the outer shell 3.

The ring body 21 and the engaging member 23 may be made of metal, and may be made of synthetic resin or synthetic rubber when the temperature is low.
As shown in FIG. 4, as the mitigating mechanism 7, two plate-like annular protrusions 31, 31 are formed on the upper surface of the inner peripheral portion 6 a of the annular support ring 6, and the lower surface of the outer peripheral portion 4 a of the inner shell 4. A plate-like annular protrusion 33 that enters into the annular groove 32 between the annular protrusions 31, 31 is formed in the annular groove 32, and a filler 34 such as glass wool that is a porous material having heat resistance is formed in the annular groove 32. An arranged configuration may be used.

  Furthermore, in the above-described embodiment (including the variation of the mitigation mechanism), as shown in FIG. 5, a predetermined weight member 41 is attached to the inner shell 4 (in this case, the lower surface of the inner shell has a bowl shape) The pressure wave due to the pressure fluctuation transmitted to the outer shell 3 may be reduced (suppressed), and the connection pipe 42 inserted in the through hole 2a formed in the annular spacer 2 may be provided. The accumulator 43 may be connected to the accumulator 43 so that the pressure fluctuation transmitted in the space S is absorbed by the accumulator 43, thereby reducing (attenuating) the pressure wave caused by the pressure fluctuation transmitted to the outer shell 3.

It is sectional drawing of the rupture disk which concerns on embodiment of this invention. It is the A section expanded sectional view of FIG. 1 which shows the same rupture disk. It is an expanded sectional view equivalent to the A section of Drawing 1 concerning the modification of the same rupture disk. It is an expanded sectional view equivalent to the A section of Drawing 1 concerning the modification of the same rupture disk. It is an expanded sectional view equivalent to the A section of Drawing 1 concerning the modification of the same rupture disk. It is an expanded sectional view equivalent to the A section of Drawing 1 concerning the modification of the same rupture disk. It is a schematic block diagram explaining the exhaust system of the exhaust gas of the gas engine which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rupture disk 2 Annular spacer 3 Outer shell 3a Flange part 4 Inner shell 4a Outer part 5 Filler 6 Annular support ring 6a Inner part 7 Mitigation mechanism 11 Annular protrusion 12 Annular protrusion 13 Annular groove part 14 Annular groove part 21 Ring body 23 Engagement Member 23a Annular recess 31 Annular protrusion 32 Annular groove 33 Annular protrusion 34 Filler 41 Weight member 43 Accumulator

Claims (6)

An outer shell, which is a pressure-resistant portion, is attached to one surface of an annular spacer having a predetermined thickness, and an inner shell, which is a pressure-receiving portion, is disposed on the other surface, and pressure fluctuation can be reduced in the space portion between both shells. A rupture disk in which a filler is disposed and an inner shell is supported by an annular support ring attached to the other surface of the annular spacer,
A rupture disk characterized in that the outer circumferential portion of the inner shell is supported by the annular support ring and a mitigation mechanism capable of reducing the propagation of pressure waves due to pressure fluctuations is provided in the annular gap between the opposing surfaces. Mitigation mechanism
Consists of a plurality of concentric annular protrusions formed on the annular support ring and the inner shell, respectively,
The rupture disk according to claim 1, wherein the annular protrusion formed on one of the annular support ring and the inner shell is disposed so as to be positioned between the annular protrusions formed on the other. Mitigation mechanism
A plurality of concentric annular protrusions formed on one of the annular support ring and the inner shell, a filler disposed between the annular protrusions, and the other of the inner shell and the annular support ring. The rupture disk according to claim 1, further comprising an annular protrusion pressed against the filler. Mitigation mechanism
An annular protrusion formed on one of the annular support ring and the inner shell, and an engaging member having an annular recess formed on the other of the annular support ring and the inner shell and capable of guiding the annular protrusion. The rupture disk according to claim 1, wherein   The rupture disk according to any one of claims 1 to 4, wherein a weight member is attached to the pressure-receiving surface side of the inner shell. The rupture disk according to any one of claims 1 to 4, wherein an accumulator is connected to a space formed between the outer shell and the inner shell.

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