JP6364785B2 - Piston support support tube - Google Patents

Description

  The present invention relates to a structure of a piston support support tube that supports a piston support of a gas holder.

  The gas holder is a device that stores gas in the inside thereof, and is capable of absorbing time-dependent fluctuation (unbalance) amount of gas demand and supply by the vertical movement of the piston. As a gas holder, for example, a gas holder in which the piston and the bottom plate have the same shape and the piston and the bottom plate come into contact with each other with almost no gap when the piston is bottomed (for example, “Wiggins gas holder”) is known. ing. In this gas holder, the piston can move up and down in a space surrounded by the side plate and the roof according to the amount of gas stored.

  In this type of gas holder, there is no gap between the piston and the bottom plate when the piston is bottomed. For this reason, when carrying out inspection and repair inside the gas holder, each time a plurality of piston supports are attached between the piston and the bottom plate, and the piston load is supported by the bottom plate via the piston support. Work space needs to be secured. The piston support is attached by a procedure in which, after an operator gets on the top of the piston and removes the partition flange, the piston support is inserted between the upper side of the piston and the bottom plate, and the piston support is attached to the piston.

  Here, among a plurality of piston supports installed at the time of inspection / repair inside the gas holder, a piston support (hereinafter referred to as “outer piston support”) disposed along the side plate on the outer edge of the bottom of the holder is a piston. Installed on a support that is supported by the outer edge of the bottom of the holder. An outer piston support is inserted into the support, and a piston support support tube that supports the outer piston support is installed in advance.

Since the piston support support pipe is always placed inside the gas holder, it is exposed to a gas containing moisture and CO ₂ for a long time. In particular, gas (by-product gas) generated from ironmaking processes such as converter gas (LDG), blast furnace gas (BFG), coke oven gas (COG), etc. is caused by CO2 and water treatment for the purpose of dust removal. It contains a lot of moisture, and rust is likely to occur on the piston support support tube. For this reason, corrosion progresses on the inner peripheral surface of the piston support support tube, and the inner peripheral surface of the piston support support tube is deformed by the rust generated by the corrosion, resulting in unevenness and swelling. Such deformation of the piston support support tube makes it impossible to insert the piston support, or increases resistance when the piston support is inserted, making it difficult to install the piston support.

  Further, since the strength of the piston support support tube is reduced due to corrosion, it is necessary to replace the piston support support tube that has been corroded. However, since the piston support support pipe is embedded in the concrete dam of the support tool, it is necessary to destroy all the concrete parts at the time of replacement. In addition, it is necessary to replace the piston support supporting pipe which is not corroded and does not need to be replaced.

  For such a problem, for example, in Patent Document 1, a piston support that can be tilted is permanently installed on the piston, thereby making it unnecessary to attach and detach the complicated piston support and simplifying the inspection and repair work inside the gas holder. A gas holder is disclosed. In the gas holder described in Patent Document 1, since the piston support is permanently installed on the piston, the piston support support tube is not necessary, so that there is no concern about the corrosion of the piston support support tube and its maintainability.

JP 2008-232345 A

However, in the gas holder described in Patent Document 1, the permanent piston support is exposed to a gas containing moisture and CO ₂ for a long time, and there is a concern about the durability of the piston support. Moreover, since the outer piston support is installed in the concrete dam of the support tool, when the outer piston support needs to be replaced, it is necessary to destroy the concrete part of the concrete dam of the support tool as before. .

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to ensure that the outer piston support can be installed without a load on the operator, and the piston support. It is an object of the present invention to provide a piston support support pipe that supports a new and improved gas holder piston support with high maintainability, in which the frequency of support pipe renewal work is reduced.

In a gas holder that stores gas, a piston support support that supports a piston support that is disposed between the piston and the bottom plate of the gas holder and that is disposed on the outer edge of the bottom plate among piston supports that support the piston at a position separated from the bottom plate. a tube, a hollow outer tube, Ri Do and a hollow inner tube disposed in the hollow portion of the outer tube, characterized that you form a space by the outer surface of the inner and the inner surface of the outer tube pipe.

  According to the present invention, the piston support support pipe has a double pipe structure including an outer pipe and an inner pipe, and a space is provided between them. Thereby, even if unevenness and swelling are generated on the inner surface due to rust caused by corrosion of the inner surface of the inner tube, the inner tube is mainly elastically deformed when the piston support is inserted, and the thickness of the rust portion is absorbed. Therefore, the resistance when the piston support is inserted is reduced.

  The wall thickness of the inner tube is preferably 6.15 mm or less. Thereby, an inner pipe | tube becomes easy to deform | transform at the time of piston support insertion, and the thickness of a rust part can be absorbed.

  Further, an interval larger than the maximum deformation of the inner tube may be provided between the inner surface of the outer tube and the outer surface of the inner tube. As a result, even when the inner tube is deformed to the maximum extent, the inner tube does not push the outer tube outward due to the deformation, so that the thickness of the rust portion can be reliably absorbed.

  Furthermore, the outer tube may be fixed to a support that supports the outer edge of the piston of the gas holder, and the outer tube and the inner tube may be fixed by welding. As a result, even when the inner pipe is corroded and needs to be replaced, it is not necessary to destroy the support in which the piston support support pipe is embedded, and the repair can be performed only by replacing the inner pipe.

  As described above, according to the present invention, the outer piston support can be reliably installed without a load on the operator, and the frequency of construction of the piston support support pipe is reduced and the maintainability is improved. Can do.

It is a schematic diagram which shows the structure at the time of the normal driving | operation of the gas holder which concerns on embodiment of this invention. It is a schematic diagram which shows the structure at the time of the internal inspection of the gas holder which concerns on the same embodiment. It is a top view which shows an example of the arrangement | sequence of the piston support in the piston which concerns on the same embodiment. It is a schematic explanatory drawing which shows the state of the piston support support pipe at the time of the normal driving | operation of the gas holder which concerns on the embodiment. It is a schematic explanatory drawing which shows the state of the piston support support pipe at the time of the internal inspection of the gas holder which concerns on the embodiment. It is a fragmentary sectional view which shows the state of a piston support support pipe when the outer piston support shown in FIG. 5 is inserted. It is a partial expanded sectional view explaining the arrangement relation of the outer pipe of the piston support support pipe concerning the embodiment, an inner pipe, and an outer piston support.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. General configuration of gas holder>
[Appearance example of automatic imaging device]
First, with reference to FIGS. 1-3, schematic structure of the gas holder 10 which concerns on embodiment of this invention is demonstrated. FIG. 1 and FIG. 2 are schematic views showing the entire configuration of the gas holder 10 according to the present embodiment for each operation and each internal inspection. FIG. 3 is a plan view showing an example of an arrangement of piston supports in the piston 1.

  As shown in FIG. 1, the gas holder 10 according to the present embodiment includes a circular dome-shaped piston 11 that is disposed so as to be movable up and down in the holder, a circular dome-shaped bottom plate 12 that is installed at the bottom of the holder, and a holder. It mainly includes a cylindrical side plate 13 erected so as to surround the side surface, and a circular dome-shaped roof 14 covering the upper part of the holder.

  The gas holder 10 is a dry gas holder having a substantially cylindrical shape as a whole, and the piston 11 and the bottom plate 12 have substantially the same shape, and the piston 11 is connected to the side plate 13 via a rubber seal mechanism 16. It is a gas holder. The gas holder 10 is, for example, a storage facility having a height of several tens of meters and a diameter of several tens of meters, and includes, for example, converter gas (LDG), blast furnace gas (BFG), coke oven gas (COG), natural Various gases such as gas and coal gas can be stored.

  The piston 11 has a substantially circular shape whose outer periphery is slightly smaller than the diameter of the holder, and has a circular dome shape in which the center portion is located at the highest point. The piston 11 is made of a relatively thin steel plate having a plate thickness of, for example, about 4.5 mm, and is not attached with a structural reinforcing material such as a beam material for reinforcing the strength. For this reason, the mass of the piston 11 is determined by the plate thickness of the piston 11, and as a result, the gas pressure stored in the lower portion of the piston 11 is determined. As shown in FIG. 1, the piston 11 can move up and down in the holder in accordance with the amount of gas stored on the lower side thereof.

  The bottom plate 12 is configured, for example, by attaching a steel plate or the like in a dome shape on the upper surface of a base manufactured by placing concrete or the like. The bottom plate 12 and the piston 11 have substantially the same circular dome shape. As described above, since no structural reinforcing material is installed on the piston 11, when the gas holder 10 stops and the piston 11 reaches the bottom, the piston 11 and the bottom plate 12 come into contact with each other with almost no gap. Thus, even when there is no gap between the piston 11 and the bottom plate 12 and no gas flows into the holder, the pressure between the piston 11 and the bottom plate 12 is unlikely to be negative. The piston 11 can be prevented from being deformed and damaged.

  The side plate 13 and the roof 14 are constructed by, for example, joining a plurality of steel plates in an airtight manner by welding or the like. A ventilation port 15 is provided at the center of the roof 14, and a plurality of shell vents (not shown), which are small ventilation windows, are arranged on the side plate 13. When the piston 11 is raised, the seal rubber (outer seal 161) of the rubber seal mechanism 16 is pressed against the side plate 13 by the gas pressure, so that the air between the side plate 13 and the seal rubber can be smoothly extracted by the shell vent. In addition, the shape of the roof 14 is not limited to the example of a dome shape as shown in FIG.1 and FIG.2, For example, a flat disk shape or a cone shape may be sufficient.

  The piston 11 is connected to the side plate 13 via a rubber seal mechanism 16 so as to be movable up and down. The rubber seal mechanism 16 is disposed, for example, so as to be movable up and down with respect to the side plate 13 via the outer seal 161 and with respect to the T fender 162 via the inner seal 163. 11, and a T fender frame 165 disposed along the side plate 13 on the bottom outer edge of the holder. The outer seal 161 and the inner seal 163 are formed of rubber seals that can be elastically deformed, and thereby can seal between the side plate 13 and the T fender 162 and between the T fender 162 and the support portion 164.

  By sealing the piston 11 and the side plate 13 with the rubber seal mechanism 16, it is possible to prevent the gas stored in the storage space below the piston 11 from leaking between the piston 11 and the side plate 13 into the upper space of the piston 11. . Further, by using the rubber seal mechanism 16, it is not necessary to install a structural reinforcing member for supporting the structure of the piston 11 as described above. For this reason, the piston 11 and the bottom plate 12 can have a simple structure with substantially the same shape, and the piston 11 can reach the bottom of the holder without being restricted by the sealing mechanism. Therefore, when the piston 11 is bottomed, the piston 11 and the bottom plate 12 can come into contact with each other with almost no gap.

  In addition, the support 164 that supports the outer edge of the piston 11 supports the piston support 20 (outer piston support 210) during inspection / repair work of the inner surface (ie, the lower surface) of the piston 11 and the bottom plate 12 in contact with the stored gas. A piston support support tube (reference numeral 30 in FIGS. 4 to 6) is provided. Details of the structure of the piston support support tube will be described later.

  At the lower part of the side plate 13, a gas outflow inlet 17 is provided for inflow / outflow of gas into the gas holder 10. Gas flows into and out of the gas holder 10 by the external blower 19 through the gas inlet / outlet port 17, the holder inlet / outlet valve 18 and the pipe. In the present embodiment, only one gas outlet / inlet 17 is installed in the gas holder 10, but the present invention is not limited to this example, and the gas inlet and the gas outlet may be installed separately.

  In the gas holder 10 having the above-described structure, when the inspection and repair work of the inner surface (ie, the lower surface) of the piston 11 and the bottom plate 12 in contact with the stored gas is performed, the piston 11 and the bottom plate as shown in FIG. A plurality of piston supports 20 are arranged upright between the two. By supporting the load of the piston 11 by the piston support 20 in this way, a work space can be secured below the piston 11. That is, the piston support 20 is a rod-like support member that is erected between the piston 11 and the bottom plate 12 and supports the piston 11. As the piston support 20, for example, a steel pipe having a circular cross-sectional shape can be used.

  As shown in FIG. 3, the piston support 20 has a plurality of piston supports 20 arranged at equal intervals along the circumferential direction on concentric circles centered on the center point of the planar circular piston 11. Further, as shown in FIG. 3, the plurality of piston supports 20 are also arranged at substantially equal intervals in the radial direction of the piston 11. As a result, the plurality of piston supports 20 are arranged substantially evenly between the piston 11 and the bottom plate 12, and the piston 11 can be supported with a good balance. In the present embodiment, the piston support 20 that is disposed along the side plate 13 on the outer edge of the bottom of the gas holder 10 is referred to as the outer piston support 210, and other than the outer piston support 210 (that is, the outer piston support 210). What is closer to the center of the piston 11) is called an inner piston support 220.

Here, the outer piston support 210 of the piston support 20 is inserted into the piston support support tube 30 embedded in the concrete dam 164a of the support 164 at the time of use. The piston support support tube 30 according to the present embodiment has a double tube structure including an outer tube and an inner tube. As a result, the piston support support tube 30 exposed to a gas containing moisture or CO ₂ is corroded for a long time, and the outer piston support 210 cannot be inserted or is difficult to insert due to unevenness or swelling caused by rust generated on the inner surface thereof. You can avoid that. The configuration of the piston support support tube 30 according to this embodiment will be described in detail below.

<2. Piston support support tube>
Based on FIGS. 4-7, the structure of the piston support support pipe 30 which concerns on this embodiment is demonstrated. FIG. 4 is a schematic explanatory diagram showing the state of the piston support support tube 30 during normal operation of the gas holder 10 according to the present embodiment. FIG. 5 is a schematic explanatory view showing a state of the piston support support tube 30 at the time of internal inspection of the gas holder 10 according to the present embodiment. FIG. 6 is a partial cross-sectional view showing a state of the piston support support pipe 30 when the outer piston support 210 shown in FIG. 5 is inserted. FIG. 7 is a partially enlarged cross-sectional view illustrating the positional relationship between the outer tube 310, the inner tube 320, and the outer piston support 210 of the piston support support tube 30 according to the present embodiment.

[2-1. Constitution]
As shown in FIG. 4, the piston support support tube 30 is embedded in a concrete dam 164 a of the support 164. The piston support support pipe 30 is installed so that the upper part of the piston support support pipe 30 protrudes from, for example, the upper side of the concrete dam 164a (the upper surface side of the piston 11). The piston support support tube 30 according to the present embodiment has a double tube structure including the outer tube 310 and the inner tube 320 as described above. The outer pipe 310 and the inner pipe 320 can be configured using, for example, a carbon steel pipe for pressure piping.

  The outer tube 310 is a cylindrical hollow member that is embedded and fixed in the concrete dam 164a. A flange 312 is formed at the upper end portion of the outer tube 310 protruding from the concrete dam 164 a, and a fixing plate 342 used for fixing the outer tube 310 and the inner tube 320 is disposed on the flange 312. The outer tube 310 is hollow, and the inner tube 320 is disposed in the hollow portion.

The inner tube 320 is inserted through the hollow portion of the outer tube 310 is a hollow cylindrical member which is fixed to the outer tube 310. The outer tube 310 and the inner tube 320 are fixed by welding via fixing plates 342 and 344 at the upper end and the lower end. The inner tube 320 may be welded and fixed to the outer tube 310 already fixed to the concrete dam 164a and installed in the gas holder 10. First, the outer tube 310 and the inner tube 320 are fixed by welding, The portion of the outer pipe 310 of the piston support supporting portion 30 that is made into a heavy pipe may be embedded in the concrete dam 164a.

Between the outer tube 310 and inner tube 320, as shown in FIG. 7, a space is formed to have a predetermined interval t _2. The inner surface of the inner pipe 320 of the piston support support pipe 30 is corroded by contact with gas containing moisture and CO ₂ to generate rust (the rust portion 4 on the lower side of FIG. 7). The volume of the generated rust expands to about 2.5 to 2.7 times. When the outer piston support 210 is inserted, the outer piston support 210 pushes the rust portion 4 generated on the inner surface of the piston support support tube 30 radially outward, whereby the rust and blister generation portion of the inner tube 320 of the piston support support tube 210 is reduced. Deforms radially outward. This deformation is mainly elastic deformation, but also includes deformation such as plastic deformation. A space formed by the inner surface of the outer tube 310 and the outer surface of the inner tube 320 is provided to absorb the deformation of the inner tube 320 outward in the radial direction.

  That is, the inner tube 320 of the piston support support tube 30 is elastically deformed by receiving a force from the outer piston support 210, and the space portion provided between the outer tube 310 and the inner tube 320 can be deformed. Therefore, the inner surface of the outer tube 310 and the outer surface of the inner tube 320 are separated by more than the maximum deformation allowance that the inner tube 320 has, so that even if the inner tube 320 is deformed to the maximum, the inner tube 320 is deformed due to the deformation. The tube 310 is not pushed radially outward. The maximum deformation margin of the inner tube 320 is determined according to the size and material of the inner tube 320, the position where rust is generated, and the like. For example, when the maximum deformation margin of the inner tube 320 is 0.5 mm, the maximum deformation amount of the inner tube 320 can be 0.5 mm or less by setting the thickness of the inner tube 320 to 6.15 mm or less. Become.

  Thus, by providing a space formed by the inner surface of the outer tube 310 and the outer surface of the inner tube 320, even if there is no space between the outer piston support 210 and the inner tube 320 due to an increase in thickness due to rust or swelling. The outer piston support 210 can be inserted.

  In the present embodiment, the inner tube 320 is provided so that the upper portion protrudes longer than the outer tube 310, and a flange 322 is formed at the upper end. The flange 322 is provided to fix the lid 330 installed during normal operation of the gas holder 10 or the flange of the outer piston support 210. By providing the flange 322 at a position away from the upper end portion of the outer tube 310, when the lid 322 or the outer piston support 210 is provided, these are fixed to the piston support support tube 30 (specifically, the flange 322). It is possible to facilitate the work.

  As shown in FIG. 4, the lid 330 installed during normal operation of the gas holder 10 is provided so as to cover the upper opening of the hollow piston support support tube 30. As shown in FIG. 2, the lid 330 is removed when the outer piston support 210 is installed at the time of internal inspection, and is installed during normal operation or when the outer piston support 210 is not installed. In order to facilitate this operation, a handle 332 is provided on the top of the lid 330. When the lid 330 is installed on the piston support support tube 30, the lid 330 is fixed to the flange 322 of the inner tube 320 by a fixing member such as a bolt.

  On the other hand, when the outer piston support 210 is installed in the piston support support pipe 30, a space is formed between the piston 11 and the bottom plate 12 of the gas holder 10, as shown in FIG. As shown in FIG. 5, the outer piston support 210 may include a flange 212 having a handle 214 at the upper end. When the outer piston support 210 is installed on the piston support support pipe 30, the flange 212 is fixed to the flange 322 of the inner pipe 320 by a fixing member such as a bolt. The handle 214 is provided to facilitate installation and removal work on the piston support support tube 30.

[2-2. About maintainability]
The piston support support tube 30 according to the present embodiment has a double tube structure composed of an outer tube 310 and an inner tube 320, so that the inner surface of the outer tube 310 faces the outer surface of the inner tube 320 and does not touch the gas. It becomes composition. Therefore, corrosion and deformation due to gas occur in the inner tube 320 of the piston support support tube 30. Further, only the outer pipe 310 is fixed to the concrete block 164a, and the inner pipe 320 is provided independently of the concrete block 164a.

  Accordingly, when corrosion or deformation of the inner tube 320 proceeds in the piston support support tube 30 and replacement is necessary, only the inner tube 320 welded to the outer tube 310 is removed, and a new inner tube 320 is attached. The piston support support tube 30 can be repaired by welding and fixing to the outer tube 310 fixed to the concrete block 164a. Accordingly, the piston support support tube 30 can be replaced without destroying the concrete block 164a.

<3. Summary>
The configuration and the operation of the piston support support tube 30 that supports the piston support of the gas holder according to the present embodiment have been described above. According to this embodiment, the piston support support tube 30 has a double tube structure including the outer tube 310 and the inner tube 320, and a space is provided between them. As a result, even if the inner surface of the inner tube 320 is rusted by the corrosion of the inner surface of the inner tube 320, the inner tube 320 is mainly elastically deformed to absorb the thickness of the rust portion when the outer piston support 210 is inserted. Therefore, the resistance when the outer piston support 210 is inserted is reduced.

  Further, even when the inner pipe 320 is corroded and needs to be replaced, it is not necessary to destroy the concrete block 164a in which the piston support support pipe 30 is embedded as in the prior art, only replacement of the inner pipe 320. Can be repaired.

  As an example, the absorption effect of swelling by verifying the double pipe of the piston support support pipe was verified. Here, the piston support support tube having the configuration according to the present invention described based on FIGS. 4 to 7 is an example, and the conventional piston support support tube having a single tube configuration is a comparative example. The amount of deformation of the piston support was calculated by numerical simulation in the case where the phenomenon occurred locally in the center of the piston support support tube. Moreover, when the rust of thickness exceeding 0.35 mm generate | occur | produced in the inner surface of a piston support support pipe, the insertability of the outer piston support to the piston support support pipe in an Example and a comparative example was verified. The results are shown in Table 1 below.

[Prerequisites]
Outer tube of support tube: 125A STPG (Sch40)
Support tube (comparative example), inner tube of support tube (example): 100A STPG (Sch40)
Outer piston support: 90A STPG (Sch40)
Corrosion rate: 132 μm / Y
(CO ₂ , converter gas containing moisture 30 to 70 ° C, actual corrosion maximum rate under atmospheric environment)
Maximum volume expansion speed of rust: 356 μm / Y (maximum actual expansion speed)
Longitudinal elastic modulus: 196,000 N / mm ²
Allowable stress: 206 N / mm ²
Support support pipe length (outer pipe, inner pipe): 1.6m

First, in the comparative example, since the piston support support pipe is formed of one pipe, the rust thickness is obtained when the interval t ₁ between the outer piston support and the piston support support pipe inner surface is 0.35 mm (0.7 mm / 2). If it exceeds 0.35 mm, it is considered that strong hammering is required to insert the outer piston support or insertion is impossible. Moreover, when the durability time when using the piston support support tube of this comparative example is simulated based on the above corrosion rate, the maximum volume expansion rate of the rust portion, etc., the outer piston support is inserted in about 1.6 years from the start of use. It turned out that something difficult would occur.

On the other hand, it exceeds blistering 0.35mm inner tube by local generation of rust on the inner tube side in the embodiment, since there is a space interval t ₂ between the outer tube and the inner tube, the inner tube radius Deforms outward in the direction and absorbs blisters. For this reason, even if a rust part generate | occur | produces, it is thought that an outer piston support can be inserted with a light hammering.

  More specifically, when the inner tube is deformed by 0.5 mm (maximum deformation of the inner tube under the above conditions), the rust portion exerts a force in the inner diameter direction on the outer piston support of 108,584 N, and the static friction coefficient is 0. .52, the frictional resistance applied to the outer piston support is 56,464N (108,584N × 0.52). The static friction coefficient 0.52 is a value used as a static friction coefficient between general steel materials. If the weight of the hammer is 5 kg and the distance at which the outer piston support is pushed down by one hammering is 5 mm, the required hammering speed is 27.1 km / h, and this work is actually easy to perform. It is considered possible.

  In this embodiment, the thickness of the inner tube is 6 mm. When the support tube length is about 1 to 2 m (1.6 m in the present invention example), the piston support can be inserted by deformation of the inner tube due to light hammering. Is possible. In the study by the inventors of the present application, if the inner tube thickness is 6.15 mm or less, it is considered that the inner tube can be deformed so that the piston support can be inserted by manual hammering. Considering the general number of piston supports, if the lower limit value of the inner pipe wall thickness is 2 mm, the strength to support the piston can be secured and used.

  Further, in the examples, the deformation allowance (maximum deformation allowance) that the inner tube can be permitted by elastic deformation was 0.5 mm from the conditions of the dimensions, material, and rust generation position. Therefore, by making the piston support support pipe into a double pipe, the outer piston support and the inner pipe can be combined with a distance of 0.35 mm to a maximum deformation of 0.5 mm, and an allowable rust thickness of 0.85 mm is possible. Conceivable.

  As for the endurance time when using the piston support support tube of the embodiment, the outer piston support is surely secured until about 3.8 years from the start of use, when simulated based on the above corrosion rate, the maximum volume expansion rate of the rust portion, etc. It turns out that it can be inserted. According to the simulation, it was found that the piston support support tube can be used for a period longer than twice that of the comparative example.

  As described above, the piston support support tube is configured as the configuration of the present invention according to the above-described embodiment, so that the piston support can be easily inserted even if rust is generated on the inner surface of the piston support support tube. Moreover, in the piston support support pipe of the structure of this invention, the allowable rust thickness which can insert an outer piston support becomes large. Thereby, it becomes possible to prolong the replacement period of a piston support support pipe.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, the piston support has been described as using a steel pipe having a circular cross-sectional shape, for example, from the viewpoint of strength and ease of manufacture, but the present invention is not limited to such an example. For example, the piston support may have an arbitrary cross-sectional shape such as a square, a polygon, or an ellipse. The shapes of the outer tube and the inner tube of the piston support support tube can be appropriately changed according to the shape of the piston support.

4 Rust Part 10 Gas Holder 11 Piston 12 Bottom Plate 13 Side Plate 14 Roof 15 Ventilation Port 16 Rubber Seal Mechanism 17 Gas Outlet / Inlet 18 Holder Inlet / Outlet Valve 19 Blower 20 Piston Support 30 Piston Support Support Pipe 164 Support 164a Concrete Block 210 Outer Piston Support 220 Inner Piston support 310 Outer tube 320 Inner tube 330 Lid 342, 344 Fixing plate

Claims (4)

A gas holder for storing gas, wherein the piston support is disposed between the piston of the gas holder and the bottom plate, and supports a piston support disposed on an outer edge of the bottom plate among piston supports that support the piston at a position separated from the bottom plate. A piston support support tube,
And the outer tube of the hollow, Ri Do and a hollow inner tube disposed in the hollow portion of the outer tube, characterized that you form a space by the outer surface of the inner tube and the inner surface of the outer tube, a piston support Support tube.   The piston support support pipe according to claim 1, wherein the inner pipe has a wall thickness of 6.15 mm or less.   3. The piston support support pipe according to claim 1, wherein a space greater than a maximum deformation allowance of the inner pipe is provided between an inner surface of the outer pipe and an outer surface of the inner pipe. The outer tube is fixed to a support that supports the outer edge of the piston of the gas holder,
The piston support support pipe according to any one of claims 1 to 3, wherein the outer pipe and the inner pipe are fixed by welding.

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