Flame suppression device, hydrogen generator, gas separation membrane device, artificial photosynthesis plant, and flame suppression method

Abstract

This technology provides a solution that achieves both suppression of increased pressure loss and high flame suppression performance in equipment through which flammable gases flow. [Solution] In the flame suppression device (1), the flame suppression function unit (3) is a mesh laminate (33) and is housed in the flame suppression function mounting unit (50) of the housing unit (2). In the flame suppression function mounting unit (50), the mesh laminate (33) is the gas flow path. Also, the maximum inner diameter of the piping section (212, 213) in the housing unit (2) is smaller than the minimum inner diameter of the flame suppression function mounting unit.

Description

[Technical Field]

[0001] The present invention relates to a flame suppression device, a hydrogen generator, a gas separation device (hereinafter also referred to as a "gas separation membrane device"), an artificial photosynthesis plant, and a flame suppression method. [Background technology]

[0002] Various flame suppression devices may be installed in chemical plants where flammable gases are distributed, and in the various units that make up these chemical plants. Flame suppression devices are also used for purposes such as preventing flashback into cylinders that store flammable gases. Various flame suppression mechanisms and structures for realizing them are known for these flame suppression devices.

[0003] Such flame suppression devices include a flame suppression device that incorporates a reduction mechanism and a flame arrestor together, and which reduces explosive flames by installing multiple orifices within the flame suppression device (see, for example, Patent Document 1). Also known are flame suppression devices that have been improved to effectively suppress deflagration or explosive flames (see, for example, Patent Document 2). Furthermore, known are flame suppression devices that can detect and display the pressure difference between the upstream and downstream sides when the flame suppression function unit becomes clogged during use (see, for example, Patent Document 3). In addition, known flame suppression devices use a mesh arrestor to extinguish detonation flames when a hydrogen-air mixture gas is ignited (see, for example, Non-Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2018 / 079749 [Patent Document 2] International Publication No. 2021 / 253828 [Patent Document 3] Japanese Patent Publication No. 2007-17091 [Non-patent literature]

[0005] [Non-Patent Document 1] Toshihiro Hayashi, "Research Report of the Industrial Safety Research Institute: Research on Fire Prevention Devices (Part 2) - Prevention of Detonation by Multilayer Wire Mesh," Industrial Safety Research Institute, Ministry of Labor, 1974. [Non-Patent Document 2] Toshihiro Hayashi, "Research Report of the Industrial Safety Research Institute: Research on Fire Prevention Devices (4th Report) - Factors Affecting the Flame-Suppressing Ability of Wire Mesh (1) -", Industrial Safety Research Institute, Ministry of Labor, 1976. [Overview of the project] [Problems that the invention aims to solve]

[0006] On the other hand, technologies that produce hydrogen gas by water splitting, such as artificial photosynthesis plants, generate a mixture of hydrogen and oxygen gases. In such fields, if ignition occurs, the hydrogen-oxygen mixture gas with the most explosive chemical composition will circulate within the system.

[0007] Conventional technologies have focused on flame suppression devices for mixed gases containing flammable and combustion-supporting gases, such as hydrogen-air mixtures and methane-air mixtures. However, these technologies often did not target hydrogen-oxygen mixtures with the most explosive detonation at ignition, in order to suppress the aging increase in pressure loss due to clogging during normal use. Furthermore, conventional technologies sometimes focused solely on flame suppression at ignition, taking into account the increase in pressure loss during normal operation.

[0008] One aspect of the present invention aims to provide a technology that achieves both suppression of increased pressure loss and high flame suppression performance in a device through which a flammable gas flows. [Means for solving the problem]

[0009] To solve the above problems, the present invention has the following embodiments.

[0010] [1] A flame suppression device comprising a housing portion through which a gas flow path passes, and a flame suppression function portion that is permeable and held in the housing portion to suppress the detonation flame of the gas, wherein the housing portion includes a flame suppression function mounting portion which is part of the gas flow path and houses the flame suppression function portion, and a piping portion which is part of the gas flow path and connects the flame suppression function mounting portion to the outside of the housing portion, wherein the flame suppression function portion is a mesh laminate composed of a plurality of meshes that are in contact with and overlap each other, the mesh laminate is the gas flow path in the flame suppression function mounting portion, and the maximum inner diameter of the piping portion is smaller than the minimum inner diameter of the flame suppression function mounting portion.

[0011] [2] The flame suppression device according to [1], wherein when the total number of meshes in the mesh laminate is n, the first mesh and the nth mesh in the stacking direction of the mesh laminate are in contact with another mesh.

[0012] [3] The flame suppression device according to [1] or [2], wherein when the total area of ​​the planar shape including the opening portion of the mesh is defined as the opening surface area, the opening surface area of ​​each of the meshes in the mesh laminate is substantially the same.

[0013] [4] The flame suppression device according to any one of [1] to [3], wherein the mesh has a coarseness of 40 mesh or more and 80 mesh or less.

[0014] [5] The flame suppression device according to any one of [1] to [4], wherein the mesh is made of metal, and the metal comprises one or more metals selected from the group consisting of stainless steel, nickel, tungsten, molybdenum, zirconium, Hastelloy, titanium, and Inconel.

[0015] [6] The flame suppression device according to any one of [1] to [5], wherein the total number of meshes in the mesh laminate is 60 or more and 500 or less.

[0016] [7] The flame suppression device according to any one of [1] to [6], wherein the flame suppression function mounting portion further has a sealing function portion that is disposed between its inner circumferential wall surface and the outer edge of the flame suppression function portion and is in close contact with the inner circumferential wall surface.

[0017] [8] The flame suppression device according to [7], wherein the sealing function part is integrally composed of a cured resin or a molten metal.

[0018] [9] The flame suppression device according to any one of [1] to [8], wherein the housing portion includes metal and resin, or both.

[0019]

[10] The flame suppression device according to any one of [1] to [9], wherein the piping section includes a first piping section that connects the flame suppression function mounting section with the outside of the housing section at one end of the housing section, and a second piping section that connects the flame suppression function mounting section with the outside of the housing section at the other end of the housing section.

[0020]

[11] The flame suppression device according to any one of [1] to

[10] , wherein the inner diameter of the piping section is constant.

[0021]

[12] The flame suppression device according to any one of [1] to

[11] , wherein the maximum inner diameter of the piping section is 5 mm or more and 40 mm or less.

[0022]

[13] The flame suppression device according to any one of [1] to

[12] , further comprising an area limiting section having through holes that serve as a gas flow path, wherein the area limiting section is positioned in contact with one end face or both end faces of the flame suppression function section.

[0023]

[14] The flame suppression device according to

[13] , wherein the ratio of the total opening area of ​​the through-hole to the projected area of ​​the area limiting portion is 60% or more and 99% or less.

[0024]

[15] The flame suppression device according to

[13] or

[14] , wherein the flame suppression function mounting portion further comprises a sealing function portion disposed between its inner circumferential wall surface and the outer edge portion of the flame suppression function portion and in close contact with the inner circumferential wall surface, and the area limiting portion is integrated with the sealing function portion.

[0025]

[16] The flame suppression device according to any one of

[13] to

[15] , wherein, when the total number of meshes in the mesh laminate is n, the area limiting portion is positioned in contact with one or both of the first mesh and the nth mesh in the stacking direction of the mesh laminate.

[0026]

[17] A flame suppression device according to any of [1] to

[16] , wherein the pressure loss when circulating gas at a rate of 100 L / min is 10 kPa or less.

[0027] A hydrogen generator comprising a flame suppression device as described in any of [1] to

[17] , and a hydrogen generating unit for generating hydrogen gas, wherein the flame suppression device and the hydrogen generating unit are integrally configured such that the hydrogen gas generated in the hydrogen generating unit is supplied to the gas flow path of the flame suppression device.

[0028] A gas separation membrane apparatus comprising: a flame suppressor as described in any of [1] to

[17] ; and a separation membrane module for separating a specific gas component from a mixed gas, wherein the separation membrane module comprises a separation membrane for separating a specific gas component from a mixed gas; and a separation membrane module housing configured to house the separation membrane and to supply the mixed gas to the separation membrane, wherein the flame suppressor and the separation membrane module are integrally configured such that the gas flow path of the flame suppressor becomes the flow path of the mixed gas.

[0029]

[20] An artificial photosynthesis plant that generates and distributes hydrogen gas and oxygen gas by photocatalysis, wherein an anti-flame device described in any of [1] to

[17] is arranged in the gas flow path of the artificial photosynthesis plant.

[0030]

[21] A flame suppression method for suppressing flame propagation during an explosion of a combustible gas by arranging a flame suppression device in the flow path of the combustible gas, wherein the flame suppression device is one of the flame suppression devices described in any of [1] to

[17] .

[0031]

[22] The flame suppression method according to

[21] , wherein the flammable gas is a mixture of hydrogen gas and oxygen gas.

[0032]

[23] The flame suppression method according to

[21] or

[22] , wherein the flame propagation is the propagation of explosive flames. [Effects of the Invention]

[0033] According to one aspect of the present invention, it is possible to provide a technology that can achieve both suppression of increased pressure loss and high flame suppression performance in a device through which a flammable gas flows. [Brief explanation of the drawing]

[0034] [Figure 1] This figure schematically shows the cross-sectional structure of a flame suppression device according to the first embodiment of the present invention. [Figure 2] This is a schematic plan view showing a flame suppression device according to the first embodiment of the present invention. [Figure 3] This is a first explanatory diagram relating to the dimensions of the flame suppression device according to the present invention. [Figure 4] This is a second explanatory diagram relating to the dimensions of the flame suppression device according to the present invention. [Figure 5] This figure schematically shows the cross-sectional structure of a flame suppression device according to a second embodiment of the present invention. [Figure 6] This figure schematically shows an example of an area limiting section in a second embodiment of the present invention. [Figure 7] This figure schematically shows the metal mesh constituting the anti-flammation function part in an embodiment of the present invention. [Figure 8] This figure illustrates the first state in the manufacturing process of a flame suppression device according to an embodiment of the present invention. [Figure 9] This figure illustrates a second state in the manufacturing process of a flame suppressor according to an embodiment of the present invention. [Figure 10] This figure illustrates a third state in the manufacturing process of a flame suppression device according to an embodiment of the present invention. [Figure 11]This figure illustrates a fourth state in the manufacturing process of a flame suppression device according to an embodiment of the present invention. [Figure 12] This figure illustrates a fifth state in the manufacturing process of a flame suppression device according to an embodiment of the present invention. [Figure 13] This figure illustrates the sixth state (finished state) in the manufacturing process of a flame suppression device according to an embodiment of the present invention. [Figure 14] This diagram schematically shows the configuration of an artificial photosynthesis plant according to one embodiment of the present invention. [Figure 15] This is a schematic front view showing the configuration of a hydrogen generator according to one embodiment of the present invention. [Figure 16] This figure schematically shows the cross-sectional structure of a hydrogen generator according to one embodiment of the present invention. [Figure 17] This figure schematically shows the cross-sectional structure of a gas separation membrane apparatus according to one embodiment of the present invention. [Figure 18] This figure schematically shows the configuration of a device for confirming the flame suppression performance of a flame suppression device according to an embodiment of the present invention. [Figure 19] This figure schematically shows the cross-sectional structure of a flame suppression device according to one comparative example of the present invention. [Modes for carrying out the invention]

[0035] The embodiments of the present invention will be described in more detail below, but the description of the constituent elements described below is just one example of an embodiment of the present invention, and the present invention is not limited to these contents and can be implemented in various ways within the scope of its gist.

[0036] [Extinguishing device] [First Embodiment] A first embodiment of the flame suppression device of the present invention is shown in Figures 1 and 2. As shown in Figures 1 and 2, the flame suppression device 1 has a housing 2 and a flame suppression function unit 3.

[0037] The housing section 2 is composed of an outer housing 21 and an inner housing 22. The outer housing 21 has a cylindrical shape and includes a housing section 211, which is a cylindrical space for housing the inner housing 22, a first piping section 212 that connects the housing section 211 to the outside at one end, and a second piping section 213 that connects the housing section 211 to the outside at the other end.

[0038] The first piping section 212 and the second piping section 213 are holes that extend axially and have a circular cross-sectional shape of the same diameter. Thus, the inner diameter of both the first piping section 212 and the second piping section 213 is constant. The inner diameters of both the first piping section 212 and the second piping section 213 are both sufficiently smaller than the inner diameter of the inner housing 22 (smaller than the diameter inside the sealing function section 31 described later). Furthermore, the inner diameter of the first piping section 212 is smaller than that of the second piping section 213.

[0039] The cross-sectional shapes of the first piping section 212 and the second piping section 213 (piping section described later) can be any shape, such as circular, elliptical, or polygonal. A circular cross-sectional shape is preferable from the viewpoint of strength, connectivity with external extension piping or external equipment, and ease of molding and processing the housing, as it ensures uniform pressure distribution inside the piping section. On the other hand, if the piping section has a non-circular cross-sectional shape such as an elliptical or polygonal shape, it can be appropriately selected and preferred, for example, when the flame suppressor 1 needs to be installed in a narrow space, in order to secure the cross-sectional area of ​​the piping section. Further details about the piping section will be provided later.

[0040] The outer casing 21 is divided in the axial direction into a first outer casing 214 having a first piping section 212 and one end of the housing section 211, and a second outer casing 215 having a second piping section 213 and the other end of the housing section 211. The first outer casing 214 and the second outer casing 215 are joined together by bolts 216.

[0041] The inner housing 22 is a cylindrical member and is housed in the housing section 211. In the axial direction of the housing section 2, an O-ring 23 is interposed between the end face of the inner housing 22 and the end face of the housing section 211, and the O-ring 23 is sufficiently compressed by the fastening of the first outer housing 214 and the second outer housing 215 by bolts 216. In this way, the inner housing 22 is airtightly housed in the housing section 211 of the outer housing 21.

[0042] The flame suppression function unit 3 is housed inside the inner casing 22. The flame suppression function unit 3 is a mesh laminate 33 composed of multiple meshes that are in contact with and overlapping each other. That is, the mesh laminate 33 is a structure in which multiple meshes are adjacent to each other and integrated over the entire plane of the mesh, when the direction in which two intersecting thin lines (e.g., vertical and horizontal lines) that constitute the mesh extend is considered the plane direction of the mesh, or it can be a single structure of multiple meshes that are tightly in contact with and overlapping each other. The axial dimensions of the flame suppression function unit 3 are substantially the same as those of the inner casing 22. The mesh is made of, for example, metal.

[0043] The material of the metal mesh can be appropriately selected after comprehensively considering factors such as heat dissipation, robustness when flames strike, availability of materials, and price. Specifically, it is preferable that the material be a metal selected from stainless steel, nickel, tungsten, molybdenum, zirconium, Hastelloy, titanium, and Inconel, with stainless steel being more preferable among these. Among stainless steels, SUS304, SUS304L, SUS310S, SUS316, SUS316L, SUS317L, or SUS321 are even more preferable, and considering corrosion resistance, oxidation resistance, heat resistance, adaptability, strength, and price, it is most preferable to select from SUS304, SUS304L, SUS310S, SUS316, and SUS316L.

[0044] In the flame suppression device 1, and especially in the flame suppression function section 3, minimizing the space other than the mesh openings in the flame suppression function section 3 (also referred to as "residual voids") is preferable from the viewpoint of suppressing the detonation flame of the hydrogen-oxygen mixed gas as the flame suppression function section 3. From this viewpoint, it is preferable that the first metal mesh abuts against the second metal mesh, the m-th metal mesh firmly abuts against the two adjacent metal meshes m-1 and m+1, and the n-th metal mesh tightly abuts against the n-1 metal mesh. Thus, when the total number of meshes in the mesh laminate 33 is n, it is preferable that the first mesh and the n-th mesh in the stacking direction of the mesh laminate 33 abut against another mesh. Such a configuration is preferable from the viewpoint of reducing residual voids that are observed during self-supporting stacking between metal meshes, as described later, and from the viewpoint of reducing residual voids in the flame suppression function section 3 and significantly improving flame suppression performance.

[0045] In the housing portion 211 of the flame suppressor 1, there is virtually no space other than the flame suppression function portion 3. A small space other than the flame suppression function portion 3 may be formed inside the crushed O-ring 23. If a space is formed, that space is the residual void of the flame suppressor 1. This space can be substantially eliminated by forming a groove of appropriate depth (for example, equivalent to the amount of crushing of the O-ring 23 or half of it) corresponding to the O-ring 23 in the portion of one or both of the first outer housing 214 and the inner housing 22 that the O-ring 23 contacts.

[0046] A metal mesh has a structure in which fine metal wires are woven together in a mesh-like pattern (see Figure 7). In this invention, the entire area of ​​the plane including the opening portion of the metal mesh is defined as the mesh opening surface area. For example, the mesh opening surface area S of a metal mesh whose periphery is formed into a circular shape. m The diameter length of the circle is L. mr Let π × (L mr / 2) 2In embodiments of the present invention, it is preferable that the opening surface area of ​​each mesh in the mesh laminate 33 is substantially the same. This configuration is preferable from the viewpoint of processability because it is easy to make the mesh adhere closely to the inner circumferential wall surface of the inner housing 22. Here, "the opening surface area of ​​the mesh is substantially the same" means that the opening surface area of ​​the mesh is the same to the extent that the desired flame suppression function is achieved, and for example, the opening surface area of ​​any mesh may be within ±10% of the opening surface area of ​​the first or nth mesh. More preferably, the opening surface area of ​​the mesh may be within ±5%.

[0047] Reducing the mesh opening improves the flame suppression function, but tends to increase pressure loss. The mesh coarseness is preferably 40 mesh or more, and preferably 80 mesh or less, in order to balance the expression of the flame suppression function and the suppression of pressure loss. For example, a metal mesh coarseness of 60 mesh is preferable from the viewpoint of being able to simultaneously satisfy the function of being able to suppress the detonation flame of a hydrogen-oxygen mixed gas and the pressure loss that is permissible in an artificial photosynthesis process.

[0048] In the mesh laminate 33, a large number of mesh layers is preferable from the viewpoint of fully exhibiting the flame suppression function. On the other hand, a small number of mesh layers is preferable from the viewpoint of reducing pressure loss when various gases are circulated, for example. As a result of the inventors' diligent studies, the number of mesh layers may be 60 or more, preferably 70 or more, more preferably 80 or more, even more preferably 90 or more, and most preferably 95 or more, from the viewpoint of maintaining the flame suppression function against the detonation flame of a hydrogen-oxygen mixed gas. On the other hand, from the viewpoint of the allowable range of pressure loss when a hydrogen-oxygen mixed gas is circulated in an artificial photosynthesis plant, for example, the number of mesh layers may be 500 or less, preferably 450 or less, more preferably 400 or less, even more preferably 350 or less, and most preferably 300 or less.

[0049] The number of mesh layers can be specifically derived from the pressure loss from the perspective of applications such as artificial photosynthesis plants. For example, in an artificial photosynthesis plant, a hydrogen-oxygen mixed gas is generated from a photocatalytic reactor and separated into hydrogen-rich gas and oxygen-rich gas in a gas separation section such as a separation membrane module or separation tower. In such a gas separation section, the pressure difference is used as the driving force to separate / concentrate the mixed gas, so a higher pressure of the gas to be separated at the inlet of the gas separation section results in higher separation performance. The flame suppressor 1 may be placed in one or more gas flow paths from the photocatalytic reactor, which is the gas generation section, to the separation membrane module or separation tower, which is the gas separation section, and it is preferable that the pressure loss in such flow paths is low. Therefore, it is preferable that the pressure loss due to the mesh layer 33 is low, and specifically, for the above applications (prevention of flame propagation in artificial photosynthesis plants, prevention of equipment damage, etc.), it is preferable that it be 10 kPa or less, more preferably 9 kPa or less, even more preferably 8 kPa or less, and most preferably 7 kPa or less.

[0050] For example, assuming that the amount of hydrogen-oxygen mixed gas generated from the photocatalytic reactor, which is the gas generation unit, is 100 L / min, if a metal mesh with a 60 mesh size and a wire diameter of 140 μm is used in the flame suppression function unit 3, up to 500 metal meshes can be mounted in order to keep the pressure loss of the mesh laminate 33 made of the metal mesh 10 kPa or less. The pressure loss of the mesh laminate 33 can be considered to be substantially the same as the pressure loss of the flame suppressor 1. Therefore, from the viewpoint of application to an artificial photosynthesis plant, it is preferable that the pressure loss when 100 L / min of gas is circulated in the flame suppressor 1 be 10 kPa or less.

[0051] The housing 2 may include either metal or resin, or both. While the housing 2 can be made of any material, metal is preferable from the viewpoint of ensuring heat dissipation when explosive flames enter the internal flame suppression function unit 3. On the other hand, when numerous flame suppression devices are installed in artificial photosynthesis plants, etc., it is also preferable to manufacture them from resin material from the viewpoint of cost reduction.

[0052] The flame suppression function unit 3 has a sealing function unit 31 that adheres closely to the inner circumferential wall surface of the inner housing 22. The sealing function unit 31 is a portion enclosed in the space between the inner circumferential wall surface of the inner housing 22 and the outer edge of the flame suppression function unit 3, and is made of, for example, a cured epoxy resin.

[0053] In the flame suppression device 1, the outer casing 21 and the inner casing 22 are in airtight contact with an O-ring 23, and the space between the inner circumferential surface of the inner casing 22 and the outer edge of the flame suppression function section 3, which is a mesh laminate 33, is sealed by a sealing function section 31. Therefore, the flame suppression device 1 is configured to allow gas to flow through the first piping section 212, the flame suppression function section 3, and the second piping section 213.

[0054] In this way, the flame suppression device 1 has an outer casing 21 and an inner casing 22 that constitute a casing section 2 through which a gas flow path passes. The inner casing 22, housed in the housing section 211 of the outer casing 21, becomes part of the gas flow path and also forms the flame suppression function mounting section 50 that houses the flame suppression function section 3. Furthermore, the first piping section 212 and the second piping section 213 of the outer casing 21 connect the inside of the inner casing 22 to the outside of the outer casing 21, respectively. Thus, in the flame suppression device 1, they are part of the gas flow path through the flame suppression device 1 and are piping sections that connect the flame suppression function mounting section 50 to the outside of the casing section 2.

[0055] The flame suppression unit 3 is breathable and is held in the housing unit 2. Because the flame suppression unit 3 is a mesh laminate 33, it has the function of suppressing the detonation flames of the gas flowing through the flame suppression device 1. The flame suppression function of the flame suppression unit 3 will be described later.

[0056] Furthermore, the space between the flame suppression function unit 3 and the inner housing 22 is sealed by the sealing function unit 31. In this way, the gas flow path inside the inner housing 22 (flame suppression function mounting section 50) is composed of the flame suppression function unit 3 (mesh laminate 33).

[0057] Here, the dimensions of the flame suppression device according to the embodiment of the present invention will be described with reference to Figures 3 and 4. For the upstream piping section (first piping section), the axial length is "L pf1", and the maximum radial length is represented by "L pr1 ", and the cross-sectional area at the position of the maximum length (maximum cross-sectional area) is represented by "S p1 ". Further, regarding the flame quenching function mounting portion 50, the axial length is represented by "L hf ", the minimum radial length is represented by "L hr ", and the cross-sectional area at the position of the minimum length (minimum cross-sectional area) is represented by "S h ". The minimum radial length (minimum inner diameter) of the flame quenching function mounting portion 50 as used herein refers to the inner diameter at the position where the inner diameter of the cross section perpendicular to the axial direction in the flame quenching function mounting portion 50 is the smallest. Further, regarding the downstream pipe portion (second pipe portion), the axial length is represented by "L pf2 ", the maximum radial length is represented by "L pr2 ", and the cross-sectional area at the position of the maximum length (maximum cross-sectional area) is represented by "S p2 ". It should be noted that, for all of the upstream and downstream pipe portions (the entire pipe portion of the flame quenching device), the axial length is represented by "L pf ", the maximum radial length (the longest length in the cross-sectional shape of the pipe portion) is represented by "L pr ", and the cross-sectional area at the position of the maximum length (maximum cross-sectional area) is represented by "S pt ".

[0058] In the present embodiment, L pr is smaller than the minimum inner diameter L of the flame quenching function mounting portion 50 hr . The minimum inner diameter L of the flame quenching function mounting portion 50 hr means the inner diameter at the position where the inner diameter is the smallest when the cross section of the flame quenching function mounting portion 50 is formed in the direction parallel to the mesh opening surface. In the studies conducted by the present inventors, since L pr and L hr satisfy the above-described relationship, it is possible to reduce the flame propagation velocity of the detonation flame rushing into the flame quenching function portion 3 from the pipe portion and to expand the area of the metal mesh in contact with the detonation flame, so that the flame quenching performance can be improved.

[0059] L prIf the pipe is excessively narrow, the pressure loss in the piping section during steady gas flow will be large, which is undesirable. Conversely, if it is excessively wide, the amount of gas that can accumulate in the piping section will be large, resulting in greater energy during an explosion, which makes flame extinguishing difficult and is therefore undesirable.

[0060] As mentioned above, the cross-sectional shape of the piping section formed by the housing is preferably circular, and the maximum inner diameter L of the piping section is pr The diameter is preferably between 5 mm and 40 mm. The maximum inner diameter of the piping section is preferably 5 mm or more, more preferably 7 mm or more, even more preferably 9 mm or more, and most preferably 11 mm or more. Such a configuration is preferable from the viewpoint of avoiding an excessive increase in pressure loss due to a narrow piping section.

[0061] On the other hand, the maximum inner diameter of the piping section is preferably 40 mm or less, more preferably 38 mm or less, even more preferably 36 mm or less, and most preferably 34 mm or less. Such a configuration is preferable from the viewpoint of avoiding excessive gas accumulation due to a large piping section.

[0062] Furthermore, it is preferable that the piping section is positioned relative to the housing section 2 such that its cross-sectional center coincides with the cross-sectional center of the housing section 2, and that the flame suppression function section 3 is positioned relative to the housing section 2 such that its cross-sectional center coincides with the cross-sectional center of the housing section 2. Such a configuration is preferable from the viewpoint of realizing a flame suppression device with relatively low pressure loss.

[0063] Alternatively, the centers of the piping section and the housing section 2, and the centers of the flame suppression function section 3 and the housing section 2 may be offset. Such a configuration is preferable because it increases the flexibility of layout when integrating with various devices.

[0064] It is preferable that the cross-sectional area of ​​the piping section remains effectively constant at any position in the axial direction. If the cross-sectional area of ​​one part of the piping section is smaller or larger than that of other parts, the pressure loss in the piping section will increase mainly in the part with the relatively smaller cross-sectional area, and the volume of gas accumulating mainly in the part with the relatively larger cross-sectional area will increase, making it easier for the combustion of this gas, for example, the detonation flame of a hydrogen-oxygen mixed gas, to propagate. As a result, the flame suppression device may end up with a relatively large pressure loss or a relatively low flame suppression performance.

[0065] Minimum inner diameter L of the anti-flammation function section 50 hr The maximum inner diameter L of the piping section is pr It is preferable that it be longer compared to [another configuration]. This configuration reduces the flame propagation speed of the detonating flame entering the flame suppression function from the piping section and increases the area of ​​the mesh that comes into contact with the detonating flame, thereby further improving the flame suppression performance.

[0066] Furthermore, similar to the minimum inner diameter of the flame suppression function section 50, the minimum inner diameter L of the flame suppression function section 3 mr The maximum inner diameter L of the piping section is pr Compared to the above, a longer length is preferable. Minimum inner diameter L of the anti-flammation function part 3 mr This refers to the inner diameter at the position where the inner diameter is smallest in a cross-section perpendicular to the axial direction. From the viewpoint of efficiently exhibiting the flame suppression function against detonation flames of hydrogen-oxygen mixed gas, L mr / L pr It is preferably 1.25 or higher, more preferably 1.50 or higher, even more preferably 1.75 or higher, and most preferably 2.00 or higher. Such a configuration is preferred from the viewpoint of effectively reducing the flame propagation speed and simultaneously from the viewpoint of leading to a reduction in pressure loss.

[0067] On the other hand, L mr / L prIt is preferable that the value is 9 or less, more preferably 7 or less, even more preferably 5 or less, and most preferably 3 or less. Such a configuration is preferable from the viewpoint of avoiding excessive weight increase in the flame suppressor equipped with a large number of metal meshes, the resulting overload at the connection point with the extension piping, or increased costs.

[0068] As described above, in the present invention, the mesh laminate 33 becomes the gas flow path in the flame suppression function equipped section 50, so the volume of the flame suppression function equipped section 50 is V h Therefore, the volume V of the mesh stack 33 as defined below m V r (that is, V r =V m / V h The larger the value, the better. Here, the volume V of the mesh laminate 33. m This is obtained by volume-integrating the mesh opening surface area at a certain position in the direction of the total thickness of the mesh stack. For example, in the case of Figure 3, the mesh opening surface area that is uniform in the axial direction is S m The total thickness of the mesh laminate is L mf Therefore, the mesh stack volume V m is S m ×L mf It is defined as follows. In contrast, the volume of the flame suppression function equipped part 50 is V h Therefore, the defined volume ratio V r is V r =V m / V h =S m ×L mf / V h That is the case.

[0069] As mentioned above, the volume of the flame suppression function equipped part 50 is V h Therefore, the volume V of the mesh laminate 33 m V r The larger the value, the better. r The lower limit is preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, even more preferably 95% or more, and most preferably 98% or more.

[0070] [Second Embodiment] A second embodiment of the flame suppression device of the present invention is shown in Figure 5. As shown in Figure 5, the flame suppression device 11 is configured in the same manner as the flame suppression device 1 described above, except that it further has an area limiting portion 4 that abuts against one end of the flame suppression function portion 3 (mesh laminate 33).

[0071] The area limiting section 4 is a disc-shaped member having a plurality of independent through holes, as shown in Figure 6. The area limiting section 4 is composed of, for example, a main plate 41 and a plurality of vents 42 regularly arranged on the main plate 41. The vents 42 are through holes that serve as gas passages. The peripheral edge of the area limiting section 4 is in close contact with the sealing function section 31, and in this way it abuts one end of the flame suppression function section 3. The "abutment" of the area limiting section 4, similar to the "abutment" of the mesh in the mesh laminate 33, means that the area limiting section 4 is firmly in contact with the flame suppression function section 3 and substantially uniformly adjacent to it over the entire planar area of ​​the mesh at the outermost end of the flame suppression function section 3. In the present invention, a thin plate-shaped area limiting section 4, as shown in Figure 6, may be provided on the end face of the mesh laminate 33 to the extent that the mesh opening surface area can be substantially reduced.

[0072] The ratio of the total opening area of ​​the through-holes to the projected area of ​​the area limiting section 4 is preferably 60% or more and 99% or less. The opening ratio of such area limiting section 4 is preferably 60% or more, more preferably 65% ​​or more, even more preferably 70% or more, and most preferably 75% or more. On the other hand, the opening ratio is preferably 99% or less, more preferably 95% or less, even more preferably 90% or less, and most preferably 85% or less. If the opening ratio is excessively small, the pressure loss of the flame suppressor may increase. Conversely, if the opening ratio is excessively large, there is a concern that the robustness or durability when detonation flames enter the flame suppressor 11 will decrease.

[0073] Furthermore, when a shock wave or detonation flame enters the flame suppression function section 3, there is a concern that such integrated parts may be damaged if multiple metal meshes are pressurized and laminated together, or if there is an excessively small amount of epoxy resin used when integrating the flame suppression function mounting section 50 of the housing section 2, which also serves as the sealing function section 31. The same applies when the area limiting section 4 is arranged as a separate component. On the other hand, if the area limiting section 4 with an appropriate opening ratio is inherent in the flame suppression function section 3, the increase in pressure loss is small, and the effect of shock waves or detonation flames entering the metal mesh is suppressed. Therefore, effects such as extending the lifespan of the metal mesh can be expected.

[0074] On the other hand, a configuration in which numerous area-limiting sections 4 are inserted as independent components between the metal mesh in the flame-extinguishing section 3 can increase residual voids other than the mesh openings, which can hinder the flame-extinguishing function, particularly the extinguishing of detonation flames when a hydrogen-oxygen mixed gas is ignited.

[0075] The thickness of the area limiting portion 4 is preferably thin, preferably 1 mm or less, more preferably 0.9 mm or less, even more preferably 0.8 mm or less, and most preferably 0.7 mm or less. Such a configuration is preferable from the viewpoint of being able to adjust the mesh opening and opening ratio without excessively increasing the residual voids other than the mesh openings in the anti-flame function portion 3. On the other hand, the thickness of the area limiting portion 4 is preferably 0.3 mm or more, more preferably 0.4 mm or more, and most preferably 0.5 mm or more. Such a configuration is preferable from the viewpoint of reducing the "bending" or "twisting" of the mesh when the area limiting portion 4 and the mesh are pressed together during the manufacturing of the anti-flame function portion 3, which will be described later.

[0076] When the total number of meshes in the mesh laminate 33 of the flame-retardant function section 3 is n, it is preferable that the area limiting section 4 is in contact with either or both of the first mesh and the nth mesh in the stacking direction of the mesh laminate 33.

[0077] As mentioned above, from the viewpoint of not excessively increasing residual voids, it is undesirable to arrange multiple individual area limiting sections 4 as part of the flame suppression function section 3. When n meshes are stacked, it is preferable to arrange one area limiting section 4 so as to be in contact with only the first mesh or only the nth mesh.

[0078] Furthermore, from the viewpoint of ensuring a symmetrical configuration regardless of the direction from which flames enter, it is preferable to place one area limiting section 4 on both the first mesh and the nth mesh, for a total of two area limiting sections 4. In such cases, from the viewpoint of minimizing the increase in residual voids, it is preferable that the area limiting section 4 be made of a thin material such as a thin metal member.

[0079] Furthermore, if the flame suppression function unit 50 has a sealing function unit 31 that is positioned between its inner circumferential wall surface and the outer edge of the flame suppression function unit 3 and is in close contact with the inner circumferential wall surface, the area limiting unit 4 may be integrated with the sealing function unit 31. Such a configuration is also preferable in the manufacturing of the flame suppression function unit 3, which will be described later, from the viewpoint of making the manufacturing of the flame suppression function unit 3 easier.

[0080] Furthermore, the area limiting section 4 may be realized by reducing the opening surface area of ​​the mesh at the end of the flame suppression function section 3, either by a cured resin section using adhesive or by a welded section, without having to prepare it as a separate component. In this case, such an area limiting section 4 may be configured to perform the function of the sealing function section 31.

[0081] [Manufacturing method] The flame suppressor of this embodiment can be manufactured, for example, by the following method (Figures 7 to 13). Below, the manufacturing method of the flame suppressor will be described based on an example in which a mesh laminate is manufactured using metal mesh as the material and the flame suppressor is manufactured from that.

[0082] First, prepare the metal mesh 311 (Figure 7). For example, a 60-mesh wire mesh with a wire diameter of 140 μm is prepared with a diameter and length L mrIt is processed into a 35mm circle, and the mesh opening surface area is 10.99cm². 2 Prepare multiple circular metal meshes 311.

[0083] Next, multiple sheets (for example, 26 sheets) of metal mesh 311 are stacked (Figure 8). Generally, metal mesh has "bend" or "twist" due to its molding process. Therefore, the stacking thickness L when 26 sheets of metal mesh 311 are simply stacked (this state is also called "self-supporting stacking") mf This is greater than the sum of the thicknesses of the 26 individual metal meshes 311, for example, 11.0 mm. Thus, generally, metal meshes have "bends" or "twists" from the molding process, and because they are woven in a mesh-like structure, when n metal meshes 311 are stacked independently with the diameter of the metal wires of the metal mesh 311 being φ, the stacking thickness L of the metal mesh 311 when stacked independently is greater than the sum of the thicknesses of the 26 individual metal meshes 311. mf This becomes thicker than 2 × φ × n.

[0084] Next, the self-supporting laminate of metal mesh 311 is pressed in the lamination direction (Figure 9). The pressure applied here is sufficient to eliminate any "bending" or "twisting" of each metal mesh 311, and can be achieved by, for example, pressing by a manufacturing worker. The lamination thickness L of the metal mesh 311 laminate after pressing. mf For example, this would be 6.4 mm.

[0085] Next, an epoxy-based adhesive is applied to the periphery of the pressurized laminate of metal mesh 311 in appropriate places and impregnated, thereby bonding adjacent (overlapping) metal meshes 311 in the lamination direction to each other at their periphery with the adhesive. In this way, mesh connecting portions 312 extending in the lamination direction of the metal mesh 311 are formed at the periphery of the metal mesh 311, and a mesh laminate 33 is formed (Figure 10). In particular, in order to extinguish the detonation flame of a hydrogen-oxygen mixed gas as a flame extinguishing function, the lamination thickness L when the metal mesh is laminated is important. mfThe mesh is pressurized to a degree that is as low as possible compared to when the mesh is self-supporting, and a mesh connecting portion 312 is provided to maintain this state. The mesh connecting portion 312 can also be formed by repeatedly applying adhesive and pressing when stacking the metal mesh 311 one sheet at a time. Alternatively, the mesh connecting portion 312 can also be formed by welding at the periphery of the pressurized laminate of metal mesh 311. Such a welded mesh connecting portion 312 is also preferable from the viewpoint of being applicable to extinguishing the detonation flame of a hydrogen-oxygen mixed gas. The mesh connecting portion 312 may be formed on a part of the periphery of the metal mesh 311 or around its entire circumference, within a range where the positional relationship of the metal mesh 311 in the stacking direction in the pressurized laminate of metal mesh 311 is maintained. Furthermore, the mesh connecting portion 312 may be continuous or intermittent in the stacking direction. As a result, the first metal mesh 311 makes very firm contact with the second metal mesh 311, the m-th metal mesh 311 makes contact with the adjacent m-1 and m+1 metal meshes 311, and the n-th metal mesh 311 makes secure contact with the n-1 metal mesh 311. Furthermore, this reduces the residual voids that occur when the metal meshes 311 are stacked independently, and dramatically improves the flame suppression performance.

[0086] Next, the pressurized laminate of the metal mesh 311, which is provided with mesh connecting portions 312, is housed inside the inner housing 22 (Figure 11). When using the area limiting portion 4, the area limiting portion 4 is placed on the end face of the laminate. For example, epoxy adhesive is applied thoroughly to the entire inner circumference of the inner housing 22, and the area limiting portion 4 and the pressurized laminate are housed inside the inner housing 22. In this way, the pressurized laminate is housed inside the inner housing 22 with the adhesive interposed between the outer circumferential surface of the area limiting portion 4 and the pressurized laminate and the inner circumferential surface of the inner housing 22.

[0087] Next, the adhesive applied to the inner circumferential surface of the inner housing 22 is cured, causing the pressurized laminate of the metal mesh 311 and the area limiting portion 4 to adhere closely to the inner circumferential surface of the inner housing 22. As a result, the adhesive applied to the inner circumferential surface of the inner housing 22 and the mesh connecting portion 312 become integrated to form the sealing function portion 31, and the pressurized laminate is arranged inside the inner housing 22 as a single unit of multiple meshes that are in contact with each other and overlapping, becoming a mesh laminate 33, which is mounted on the flame suppression function mounting portion 50 in the housing portion 2, and constitutes the flame suppression function portion 3 described above. In this way, similar to the second embodiment described above, a structure is formed in which the area limiting portion 4 is held on the end face of the flame suppression function portion 3 by the sealing function portion 31 (Figure 12).

[0088] The area limiting portion 4 may be bonded to the first metal mesh 311 of the press-molded body and its periphery with adhesive when forming the mesh connecting portion 312. In this case, an integral object is formed from the press-molded body of the metal mesh 311, the mesh connecting portion 312 at its periphery, and the area limiting portion 4 fixed to the end face of the press-molded body by the mesh connecting portion 312, and this integral object is housed in the inner housing 22.

[0089] Next, the inner housing 22, which integrally holds the flame suppression function unit 3, the sealing function unit 31, and the area limiting unit 4, is held axially between the first outer housing and the second outer housing via the O-ring 23, and the first outer housing is bolted to the second outer housing, thereby hermetically holding the inner housing inside the outer housing. In this way, a flame suppression device having the structure described in Embodiment 2 is obtained (Figure 13).

[0090] In the above manufacturing method, one metal mesh 311 may be placed inside the inner housing 22, bonded or welded under pressure, and this process may be repeated for a desired number of times to produce an integrated product of the inner housing 22 and the flame suppression function unit 3 as shown in Figure 12.

[0091] By the manufacturing method described above, the lamination thickness L of the self-supporting laminate of metal mesh 311 mf Compared to the axial length L hfThis makes it possible to obtain a sufficiently small flame suppression function unit 3 and a flame suppression device having the same.

[0092] [Application] The flame suppression device according to the embodiment of the present invention can suppress the detonation flame of a hydrogen-oxygen mixed gas, and therefore can be applied to flame suppression devices for equipment that handles such hydrogen-oxygen mixed gases. The flame suppression device of this embodiment becomes effective as a flame suppression device in the equipment when it is placed in an appropriate location in the gas flow path of the equipment. The equipment in which the flame suppression device of this embodiment is installed can be suitably placed, for example, in artificial photosynthesis plants, hydrogen production plants using electrolysis, hydrogen carriers, and hydrogen stations.

[0093] [Artificial photosynthesis plant] The artificial photosynthesis plant is an artificial photosynthesis plant that generates and circulates hydrogen gas and oxygen gas using a photocatalyst. The flame suppression device described above is appropriately positioned in the gas flow path of the artificial photosynthesis plant.

[0094] As shown in Figure 14, the artificial photosynthesis plant 1000 includes, for example, a photocatalytic reactor 2000 and a separation device 4000 for separating hydrogen and oxygen from the gas produced by the photocatalytic reactor 2000. The artificial photosynthesis plant 1000 further includes a flame suppressor 3000, a dehumidifier 5000, and a vacuum pump 6000, all located in the piping of the artificial photosynthesis plant 1000. The artificial photosynthesis plant 1000 has, for example, three sets of four photocatalytic reactors 2000 connected in series, with each set arranged in parallel. Thus, the artificial photosynthesis plant 1000 is configured such that, for example, twelve photocatalytic reactors 2000 are connected by a flow path for a hydrogen-oxygen mixed gas.

[0095] The artificial photosynthesis plant of this embodiment may include the aforementioned flame suppression device as part of it. For example, the flame suppression device 3000 may be the flame suppression device of this embodiment described above. Multiple flame suppression devices 3000 may be arranged in the artificial photosynthesis plant 1000, and some of these multiple flame suppression devices 3000 may be the aforementioned flame suppression devices of this embodiment (for example, the aforementioned flame suppression device 1 or flame suppression device 11), while the rest may be other types of flame suppression devices. Alternatively, all of the multiple flame suppression devices 3000 may be the flame suppression devices of this embodiment.

[0096] The flame suppression device of this embodiment may be integrated with various devices that constitute the artificial photosynthesis plant 1000. This configuration is preferable from the viewpoint of blocking the spread of the detonation flame of the hydrogen-oxygen mixed gas at the various devices and suppressing various damages associated with shock wave propagation or flame propagation. For example, in the case of the artificial photosynthesis plant 1000, as will be described later, the flame suppression device of this embodiment may be integrated with the photocatalytic reactor, or it may be integrated with the separation membrane module in the separation device 4000.

[0097] Multiple photocatalytic reactors 2000 may be arranged in the artificial photosynthesis plant 1000. Some of these multiple photocatalytic reactors 2000 may have a structure that is integrated with the flame suppressor of this embodiment described above, while the rest may be photocatalytic reactors of a different type (for example, those that do not have the flame suppressor). Alternatively, all of the multiple photocatalytic reactors 2000 may have a structure that is integrated with the flame suppressor of this embodiment described above.

[0098] Furthermore, multiple separation devices 4000 may be arranged in the artificial photosynthesis plant 1000, and some of these multiple separation devices 4000 may have a structure that is integrally configured with the flame suppressor of this embodiment described above, while the rest may be a different type of separation device (for example, one that does not have the flame suppressor). Alternatively, all of the multiple separation devices 4000 may have a photocatalytic reactor structure that is integrally configured with the flame suppressor of this embodiment described above.

[0099] Furthermore, the flame suppression device of this embodiment may also be integrally configured in other equipment installed within the artificial photosynthesis plant 1000 (for example, the dehumidification device 5000 (e.g., dehumidification tower), the temporary gas storage tower, and the piping mentioned above). In these configurations, even if ignition occurs in the artificial photosynthesis plant 1000, the flame suppression device can suppress the effects of shock waves and flame propagation. Therefore, it is preferable because it is possible to protect the artificial photosynthesis plant 1000. In addition, the flame suppression device of this embodiment can be manufactured at a cost equivalent to or lower than commercially available dry-type safety devices. Therefore, it is also preferable from the viewpoint of manufacturing cost.

[0100] The following describes in more detail the configuration in which the flame suppression device of this embodiment is integrated with a photocatalytic reactor, and the configuration in which the flame suppression device of this embodiment is integrated with a separation device.

[0101] [Hydrogen generator] An embodiment of the present invention comprises a flame suppressor of this embodiment and a hydrogen generation unit for generating hydrogen gas. The flame suppressor and the hydrogen generation unit are integrally configured so that the hydrogen gas generated in the hydrogen generation unit is supplied to the gas flow path of the flame suppressor. The photocatalytic reactor 2000 corresponds to the hydrogen generation unit, and the configuration in which the photocatalytic reactor 2000 and the flame suppressor of this embodiment are integrally configured corresponds to one form of the hydrogen generation device.

[0102] A schematic plan view of the hydrogen generator 2100 is shown in Figure 15. A cross-section of the hydrogen generator 2100 shown in Figure 15, taken along line AA, is shown in Figure 16. As shown in Figures 15 and 16, the hydrogen generator 2100 is composed of a photocatalytic reactor 2000 and a flame suppressor 70. The photocatalytic reactor 2000 has a roughly square shape when viewed from above and includes a plate-shaped substrate 61, a frame 62 arranged around the substrate 61, a seal 63 arranged inside the frame 62, a water splitting photocatalytic sheet 60 arranged inside the seal 63, a light-transmitting plate 64 arranged inside the frame 62 and on the seal 63, a water supply port 65 opening on one end when viewed from above through the substrate 61, and an exhaust port 66 opening on the other end when viewed from above through a part of the light-transmitting plate 64.

[0103] In the cross-sectional direction, the substrate portion 61 and the sealing portion 63 are in close contact, and the sealing portion 63 and the light-transmitting plate 64 are in close contact. In this state, the light-transmitting plate 64 is positioned inside the photocatalytic reactor 2000 with a small gap 67 (for example, several hundred μm or less) between it and the water-splitting photocatalytic sheet 60. The photocatalytic reactor 2000 is positioned at an angle with one end (water supply port side) facing downwards. The inclination angle θ is, for example, 30°. The water supply port 65 is connected to a water supply pipe, and the exhaust port 66 opens into the gap 67 and opens to the upper end surface when the photocatalytic reactor 2000 is installed, passing through a part of the light-transmitting plate 64 and the frame 62.

[0104] The flame suppressor 70 is connected to the exhaust port 66 of the photocatalytic reactor 2000. In this way, the hydrogen generator 2100 is connected via the flame suppressor 70 to piping for supplying the generated gas to the separation unit 4000.

[0105] The flame suppression device 70 has a housing 72 that airtightly houses the flame suppression function unit 73 and the area limiting unit 74 inside the housing 72. The housing 72 is directly fastened to a part of the base plate 61 and the frame 62 by bolts 75 such that the area limiting unit 74 is positioned directly opposite the exhaust port 66. The housing 72 has a piping section 76 on the side opposite the area limiting unit 74 in its axial direction, and the piping section 76 is connected to an external conduit 68. The external conduit 68 is connected to the piping for the generated gas (hydrogen-oxygen mixed gas) mentioned above.

[0106] Water from the water supply port 65 is introduced into the gap 67 via the water-splitting photocatalyst sheet 60. As a result, water from the water supply port 65 is supplied in a film-like manner between the light-transmitting plate 64 and the water-splitting photocatalyst sheet 60. When the water-splitting photocatalyst sheet 60 is irradiated with light (e.g., sunlight) through the light-transmitting plate 64, the water is decomposed by photocatalysis, and hydrogen gas and oxygen gas are produced. The produced gases float in the water filling the gap 67, reach the exhaust port 66, and are discharged outside the photocatalytic reactor 2000 from the exhaust port 66. Water is consumed in accordance with the gas production, and water is supplied from the water supply port 65 to replenish the consumed water (for example, to maintain a constant water level in the gap 67).

[0107] The generated hydrogen-oxygen mixed gas is introduced into the separation unit 4000, after passing through a piping system for recovering the generated gas and then through a dehumidifier 5000 and a flame suppressor 3000.

[0108] Since the generated gas is a hydrogen-oxygen mixture, ignition of these gases can result in detonation. In the photocatalytic reactor 2000, since the photocatalytic reactor 2000 is integrally configured with the flame suppressor 70, even if a detonation flame reaches the flame suppressor 70 from within the photocatalytic reactor 2000 (upstream side of the flame suppressor) or from the external conduit 68 side, it is suppressed by the flame suppression function unit 73, and the detonation flame is prevented from reaching the other side by the flame suppressor 70. Furthermore, in the flame suppressor 70, since the flame suppression function unit 73 is made of a mesh laminate, the increase in pressure loss is sufficiently suppressed during normal ventilation of the hydrogen-oxygen mixture gas when no explosion / detonation occurs, and a pressure rise in the photocatalytic reactor can be avoided.

[0109] [Gas separation membrane apparatus] A gas separation membrane apparatus according to an embodiment of the present invention comprises a flame suppressor according to this embodiment and a separation membrane module for separating / recovering specific gas components from a mixed gas. The separation membrane module comprises a separation membrane for separating specific gas components from a mixed gas and a separation membrane module housing that houses the separation membrane and is configured to supply the mixed gas to the separation membrane. The flame suppressor according to this embodiment is configured integrally with the separation membrane module such that the gas flow path in the flame suppressor becomes the flow path for the mixed gas.

[0110] In this embodiment, the separation device 4000 may be the gas separation membrane device of this embodiment (separation membrane module + flame suppression device of this embodiment), or it may be a separation membrane module if the artificial photosynthesis plant 1000 is equipped with the flame suppression device of this embodiment in addition to the separation device 4000. If the separation device 4000 is a device equipped with a plurality of separation membrane modules, at least a portion of the plurality of separation membrane modules may be replaced with the gas separation membrane device of this embodiment.

[0111] Figure 17 schematically shows an example of the configuration of the gas separation membrane apparatus of this embodiment. The gas separation membrane apparatus 4100 consists of a separation membrane module 80 and flame suppression devices 90A, 90B, and 90C which are integrally attached to the separation membrane module 80.

[0112] The separation membrane module 80 comprises a separation membrane module housing 81 and a plurality of separation membranes 82 housed in the separation membrane module housing 81. The separation membrane module housing 81 is, for example, a substantially cylindrical member. The separation membrane 82 may be, for example, an inorganic support that serves as a gas flow path and an inorganic separation active layer formed on its surface. Specifically, it may be an inorganic membrane such as a zeolite membrane, silica membrane, or carbon membrane formed on an alumina support. On the other hand, the separation membrane 82 may also be, for example, an organic material that serves as a gas flow path and an organic separation active layer formed on its surface. Specifically, it may be a polyamide membrane or a polyimide membrane. Among these, inorganic membrane separation membranes are preferred from the viewpoint of flame resistance, zeolite membranes and silica membranes are more preferred, and zeolite membranes are even more preferred. A branch pipe 83 is connected to the separation membrane module housing 81, and the branch pipe 83 is provided with a valve 85 for opening and closing the branch pipe 83.

[0113] The flame suppression devices 90A, 90B, and 90C are integrally arranged at both ends of the separation membrane module housing 81 and at the tip of the branch pipe 83, respectively.

[0114] The flame suppressor 90A is positioned at one end of the separation membrane module housing 81, so as to airtightly seal the separation membrane module housing 81. In this case, the flame suppressor is configured such that the piping section included in the housing section 92A is formed only at one end. In the flame suppressor 90A, the housing section 92A airtightly houses the flame suppression function section 93A and the area limiting section 94A inside the housing section 92A. The area limiting section 94A has a vent opening that opens to the space on the separation membrane module housing 81 where the separation membrane 82 is mounted, and is fixed to one end of the separation membrane module housing 81. The housing section 92A has a piping section 91A on the side opposite to the area limiting section 94A in its axial direction. The piping section 91A is connected to an external conduit 84A, and the external conduit 84A is connected to the aforementioned piping for the generated gas (hydrogen-oxygen mixed gas). In other words, from the viewpoint of the separation process, the flame suppressor 90A is a flame suppressor positioned on the gas supply side.

[0115] The flame suppressor 90B is positioned at the other end of the separation membrane module housing 81, so as to hermetically seal the separation membrane module housing 81. In this case, the flame suppressor also has a piping section included in the housing section 92B that is formed at only one end. In the flame suppressor 90B, the housing section 92B hermetically houses the flame suppression function section 93B and the area limiting section 94B inside the housing section 92B. The area limiting section 94B has a vent opening that opens to the space in which the separation membrane 82 is mounted, and is fixed to the other end of the separation membrane module housing 81. The housing section 92B has a piping section 91B on the side opposite to the area limiting section 94B in its axial direction. The piping section 91B is connected to an external conduit 84B, and the external conduit 84B is connected to a pipe for the gas of one of the separated components (e.g., a hydrogen-rich hydrogen-oxygen mixed gas). In other words, from the viewpoint of the separation process, the flame suppressor 90B is a flame suppressor positioned on the gas permeation side.

[0116] The flame suppressor 90C is located at the end of the branch pipe 83. In the flame suppressor 90C, the housing 92C houses the flame suppression function unit 93C inside the housing 92C in an airtight manner. The housing 92C has a piping section 91C on the branch pipe 83 side in its axial direction, and a piping section 95C on the opposite side from the branch pipe 83. Therefore, in this case, the flame suppressor is configured such that the piping sections included in the housing 92C are formed at both ends. The piping section 91C is connected to the branch pipe 83, and the piping section 95C is connected to the external conduit 84C. The external conduit 84C is connected to piping for the gas of the other separated component (e.g., an oxygen-rich hydrogen-oxygen mixed gas). In other words, from the viewpoint of the separation process, the flame suppressor 90C is a flame suppressor located on the gas-impermeable side.

[0117] Thus, a configuration in which the flame suppression device of this embodiment is integrated with a separation membrane module that separates the generated hydrogen-oxygen mixed gas into a hydrogen-rich gas (ideally hydrogen gas) and an oxygen-rich gas (ideally oxygen gas) is also suitable as one embodiment of the present invention.

[0118] In the gas separation membrane apparatus 4100, the flame suppression devices of this embodiment (90A, 90B, and 90C, respectively) are installed on the gas supply side, gas permeate side, and gas non-permeate side of the separation membrane. As a result, the flame suppression function units 93A and 93B sandwich the separation membrane module from both sides, and the piping units 91A and 91B sandwich the flame suppression function units 93A and 93B from both sides. Furthermore, in the flame suppression function unit 93C, the piping units 91C and 95C sandwich the flame suppression function units 93A and 93C. As can be seen in this example, the length, arrangement, or direction of the piping of this flame suppression device can be appropriately selected depending on the installation location and connection requirements.

[0119] The hydrogen-oxygen mixed gas supplied to the gas separation membrane device 4100 is supplied to the inside of the separation membrane module housing 81. Here, most of the hydrogen gas permeates through the separation membrane 82, passes through the flame suppression function section 93B and the piping section 91B, and reaches the external conduit 84B. On the other hand, most of the oxygen gas cannot permeate through the separation membrane 82 and passes through the branch pipe 83, the piping section 91C, the flame suppression function section 93C, and the piping section 95C, and reaches the external conduit 84C. In this way, the hydrogen-rich gas and oxygen-rich gas are supplied to the downstream equipment, respectively.

[0120] Since the hydrogen-oxygen mixed gas reaches the flame suppressor 90A, it is highly likely to be exposed to explosive flames in the event of ignition. However, even in such a case, the flame suppression function unit 93A will extinguish the flame. Furthermore, because the flame suppression function unit 93A is composed of a mesh laminate, the increase in pressure loss of the passing gas is sufficiently suppressed.

[0121] Since the flame suppressors 90B and 90C receive gas rich in one of the separated components, the resulting mixed gas composition may cause either deflagration or detonation in the event of ignition. However, because the flame suppressors 90B and 90C each have flame suppression functions 93B and 93C, even if detonation occurs, the flame will be extinguished by the flame suppression functions 93B and 93C. Furthermore, since the flame suppression functions 93B and 93C are each composed of a mesh laminate, the increase in pressure loss of the passing gas is sufficiently suppressed.

[0122] In this embodiment, the gas separation membrane apparatus only needs to have at least one of the flame suppressors 90A, 90B, and 90C, and can achieve the above effects depending on the flame suppressor it has.

[0123] [Anti-inflammatory method] The flame suppression method according to an embodiment of the present invention involves placing the flame suppression device of this embodiment in the flow path of a combustible gas to suppress flame propagation during an explosion of the combustible gas. The combustible gas may be a mixture of hydrogen gas and oxygen gas (hydrogen-oxygen mixed gas), and this flame suppression device can be applied whether the phenomenon generated by the ignition of the combustible gas is a normal deflagration or a detonation. As described above, using the flame suppression device of this embodiment makes it possible to suppress even a detonation flame of a hydrogen-oxygen mixed gas. Naturally, it can suppress flames from both deflagration and detonation caused by ordinary combustible gases.

[0124] Figure 18 schematically shows the configuration of a device for evaluating the performance of a flame suppressor. This evaluation device includes a flame suppressor 301, an experimental upstream extension pipe 302 installed upstream of the flame suppressor 301 with respect to the gas flow, and an experimental downstream extension pipe 303 installed downstream. The upstream end of the experimental upstream extension pipe 302 is the ignition position 304, and for example, an ignition device is located at this upstream end. The downstream end of the experimental downstream extension pipe 303 is the detection position for the propagation of pressure / flame, etc., and for example, a pressure sensor 305 is located at this downstream end, as well as a high-speed camera 306 for photographing the inside of the pipe. Both extension pipes 302 and 303 may be made of transparent resin so as to allow observation of the flame propagation.

[0125] During performance evaluation of the flame suppression device, the internal atmosphere of the evaluation device is replaced with a hydrogen-oxygen mixed gas adjusted to a 2:1 ratio of hydrogen to oxygen. Then, at the ignition point, the gas is ignited to generate a detonating flame.

[0126] Detonation flames are extremely high-speed reactions, and their propagation is extremely fast, making it difficult to capture their progression visually or with a conventional video camera. Therefore, a high-speed camera 306 is used to capture the propagation of detonation flames. In addition, the pressure sensor 305 employs a sensor with a strain gauge or piezoelectric element capable of detecting pressure waves with high precision. Furthermore, detecting temperature is also effective in evaluation, and the temperature rise may be further observed using a thermometer such as a thermocouple. By checking the state downstream of the flame suppressor when the flame has propagated using the evaluation device shown in Figure 18, it is possible to evaluate whether the flame suppressor was able to suppress the detonation flame.

[0127] From the viewpoint of sufficiently and clearly detecting the anti-flammation effect in the evaluation device described above, the length of the experimental downstream extension pipe is preferably 20 cm or more, more preferably 30 cm or more, even more preferably 40 cm or more, and most preferably 50 cm or more.

[0128] When a detonating flame passes through, a pressure increase of, for example, about 20 times the initial pressure is observed at that location. On the other hand, when the detonating flame is extinguished by installing the flame suppression device 301, the pressure in the experimental downstream extension pipe 303 is reduced to only the initial, very short-duration pressure increase caused by the shock wave. Therefore, from the viewpoint of more clearly determining the disappearance of the detonating flame, the installation of the pressure sensor 305 is preferable.

[0129] Furthermore, when verifying the flame suppression performance of this flame suppressor against a hydrogen-oxygen mixed gas, the following pressure fluctuations are observed, particularly when suppressing detonation flames. Specifically, when ignition occurs in the experimental upstream extension pipe 302, water is produced by the reaction of hydrogen and oxygen, but the number of moles of gas decreases due to the explosion and detonation reaction. Therefore, when the detonation flame passes through and is suppressed by the flame suppressor 301, the temperature inside the experimental upstream extension pipe 302 also decreases, and the pressure drops below the initial pressure. As a result, the pressure balance between the experimental downstream extension pipe 303 and the experimental upstream extension pipe 302 of the flame suppressor 301 becomes downstream > upstream. Therefore, it is observed that unburned hydrogen-oxygen mixed gas present in the experimental downstream extension pipe 303 flows upstream through the flame suppressor 301, resulting in a pressure equalization state within the experimental apparatus. The extinction of the detonation flame can also be determined by confirming these pressure fluctuations, so the installation of the pressure sensor 305 is preferable.

[0130] [Other Embodiments] In this embodiment, the flame suppressor may have fasteners such as bolts to maintain the airtightness of the housing or the unity of the housing and the flame suppression function, and supports to hold the flame suppressor. Furthermore, there are no restrictions on the material and size as long as it has pressure resistance to maintain its shape, form and airtightness when detonating flames enter the flame suppressor. For example, metal gaskets, O-rings, sealing tape, or adhesives can be used as appropriate to maintain airtightness.

[0131] In this embodiment, the sealing function portion of the flame suppression device may be integrally formed with the flame suppression function portion using molten metal.

[0132] It is preferable that the piping section formed in the housing be formed at both ends of the flame suppression function mounting section in the axial direction, from the viewpoint of making installation into the main pipe on the artificial photosynthesis plant side easier, for example.

[0133] Alternatively, the piping section formed in the housing may be formed only on one end of the flame suppression function mounting section in the axial direction. Such a configuration is suitable for integrating various equipment installed in an artificial photosynthesis plant with the flame suppression device, and is also preferable from the viewpoint of avoiding direct exposure of separation membranes, such as inorganic or organic membranes mounted in a separation membrane module, to detonation flames.

[0134] The cross-sectional shape of the flame suppression function mounting section in the housing can be any shape other than circular, such as elliptical or polygonal. A circular cross-sectional shape is preferable from the viewpoint of effectively suppressing detonation flames, as the detonation flames entering from the piping section expand concentrically. An elliptical cross-sectional shape is preferable from the viewpoint of ensuring sufficient cross-sectional area, for example, when the flame suppression device needs to be installed in a narrow space. A polygonal cross-sectional shape is preferable from the viewpoint of facilitating the processing of the flame suppression function mounting section or bonding the housing section and the flame suppression function mounting section. It is even more preferable that the cross-sectional shapes of the piping section and the flame suppression function mounting section are similar. This is because it is thought that the detonation flames enter the flame suppression function section from the piping section and expand while maintaining their shape, which is preferable from the viewpoint of dispersing the axial propulsion force of the flames in the flame suppression function section.

[0135] The sealing function section can take various forms, as long as it is configured to guide all gases, shock waves, and detonation flames flowing through the piping section to the flame suppression function section without fail. For example, if multiple metal meshes are individually pressure-bonded and repeatedly mounted on the flame suppression function section, or if all multiple metal meshes are pressure-bonded and the surrounding area is bonded at once with epoxy resin, the sealing function section may be formed with the epoxy resin. Furthermore, the epoxy resin may also serve as the aforementioned area limiting section. In addition, multiple layers of sealing tape may be wrapped around the metal mesh integrated with epoxy resin to create a double sealing function section.

[0136] On the other hand, after integrating multiple metal meshes, the surrounding area is welded to a metal housing to seal it, but O-links or metal gaskets may be added to completely cover the surrounding area itself, and multiple sealing functions may be formed in this way. In either case, it is important to improve the sealing function in the flame suppression function without excessively increasing the residual voids other than the mesh openings in the flame suppression function.

[0137] One of the structural features of this flame suppressor compared to commercially available dry-type safety devices is its excellent symmetry in shape when viewed from one piping section to the other. Even if the other piping section is absent, and the metal mesh constituting the flame suppression function section does not have the same diameter, its structural symmetry is still good compared to commercially available dry-type safety devices. Therefore, considering its use in artificial photosynthesis plants where a hydrogen-oxygen mixed gas flows even in a steady state, the structure of this flame suppressor is preferable because it can suppress flames regardless of whether ignition occurs on one side of the piping section or the other, resulting in a detonation flame. Accordingly, in this flame suppressor, it is preferable that the one piping section and the other piping section are the same size and are arranged symmetrically in the housing, and that the metal mesh mounted on the flame suppression function section is also the same size in the direction perpendicular to the mesh opening surface.

[0138] 〔summary〕 Patent Document 1, mentioned above, discloses a deceleration mechanism and a flame suppression device that incorporates it together with a flame arrestor, in order to reduce pressure loss while ensuring the desired flame suppression performance. On the other hand, the only description of the performance of the flame suppression device disclosed therein is in Figure 3, which shows that the explosive flame can be slowed down by installing multiple orifices in the flame suppression device, and that the number of orifices required to slow down the explosive flame differs depending on the opening ratio. In other words, Patent Document 1 only discloses the slowing down of the explosive flame, and does not disclose any description of flame suppression. Furthermore, since installing orifices excessively increases pressure loss, it may be difficult to install them in gas flow systems such as gas piping and gas separation membrane devices.

[0139] Patent Document 2, mentioned above, discloses an improved flame suppression device for effectively suppressing deflagration or explosive flames. However, Patent Document 2 does not disclose the performance of the flame suppression device.

[0140] The aforementioned Patent Document 3 discloses a flame suppression device capable of detecting and displaying the pressure difference between the upstream and downstream sides when the flame suppression function unit becomes clogged during use.

[0141] Looking at these from a broader perspective, Patent Documents 1 and 2 include not only a flame suppression mechanism (a flame arrester in Patent Document 1 and a flame-retardant core in Patent Document 2), but also a reduction gear orifice (Patent Document 1) or a flame-retardant plate assembly (Patent Document 2) within the flame suppression device. As a result, there is a lot of space (gaps) inside the flame suppression device housing. The same situation is observed in Patent Document 3.

[0142] As described in Patent Document 3, a configuration in which space (gap) exists within the flame suppressor is necessary to suppress clogging of the flame suppression mechanism when it is installed in a flow path for flammable gases and used for a long period of time, and also to facilitate replacement when such a situation occurs. However, according to the inventors' studies, such a configuration is not necessarily suitable, especially when suppressing detonation flames that may be generated when a hydrogen-oxygen mixed gas is ignited.

[0143] One example of a scenario where flame suppression for hydrogen-oxygen mixed gas is anticipated is an artificial photosynthesis plant. In this scenario, a process may be involved in which water is decomposed into hydrogen and oxygen using a photocatalyst, then separated into hydrogen-rich and oxygen-rich gases using a separation membrane, and subsequently the purity of the hydrogen is improved by various methods. Furthermore, since the hydrogen-oxygen mixed gas generated in the photocatalytic reactor of an artificial photosynthesis plant contains water vapor corresponding to the saturated water vapor pressure, a process may be included in which a dehumidification tower or similar device is installed as appropriate to produce a dry hydrogen-oxygen mixed gas. Therefore, realizing a flame suppression device for hydrogen-oxygen mixed gas in the event of accidental ignition is an important issue.

[0144] The hydrogen-oxygen mixture produced in artificial photosynthesis plants has a stoichiometric composition ratio of 2:1, making it one of the most powerful mixtures of all combustible and combustion-supporting gases. When a stoichiometric mixture ignites and combustion occurs, the heat of combustion heats the unburned gas, causing an oxidation reaction, which continues and propagates the flame. When this phenomenon occurs inside a nearly sealed tube, the pressure wave propagates through the unburned gas, compressing and heating it one after another, growing into a supersonic shock wave, and then transitioning to detonation, where the shock wave and combustion wave proceed together. Theoretical calculations estimate that when a stoichiometric hydrogen-oxygen mixture undergoes detonation, the detonation velocity will be 2842 m / sec, the temperature will be 3682 K (approximately 3400 °C), and the detonation pressure will be nearly 20 times the initial pressure. These calculated values ​​are known to agree relatively well with many experimental values ​​around the stoichiometric composition.

[0145] On the other hand, flame suppression devices are generally installed in locations connected to flammable gas piping, where only flammable gas flows. In other words, a state in which flammable gas and combustion-supporting gas are mixed does not occur under normal conditions. Furthermore, even if flammable gas and combustion-supporting gas were to be mixed, this would only occur in situations such as pipe damage, and the combustion-supporting gas would be assumed to be air. The detonation velocity of a stoichiometric hydrogen-air mixture gas is slower and the flame temperature is lower compared to the aforementioned hydrogen-oxygen mixture gas, at 1977 m / sec and 2961 K (approximately 2700 °C).

[0146] As is clear from these observations, the detonation phenomenon of hydrogen-oxygen mixed gases is the most difficult to extinguish among all mixed gases of flammable and combustion-supporting gases. Therefore, simply applying general safety devices to hydrogen-oxygen mixed gases is inappropriate, and flame suppression devices, as safety devices for hydrogen-oxygen mixed gases, which have high detonation speed and energy, play an important role in ensuring the safety of artificial photosynthesis processes.

[0147] From the perspective of suppressing detonation flames, studies on such suppression are disclosed in the aforementioned Non-Patent Documents 1 and 2. However, these only show the results of using a mesh arrester to suppress detonation flames when a hydrogen-air mixture gas is ignited. Furthermore, the configuration described in Non-Patent Document 1 raises concerns about high pressure loss due to the reinforcing perforated plate, and does not describe the flame suppression performance against detonation flames such as hydrogen-oxygen mixture gases. Non-Patent Document 2 is similar in this respect.

[0148] This invention is the result of diligent research in light of these circumstances, and provides a flame suppression device that can be suitably used in systems where a hydrogen-oxygen mixed gas flows through the plant, such as artificial photosynthesis plants, in preparation for the event of ignition. Specifically, this flame suppression device is capable of both high flame suppression performance that can extinguish the detonation flames of a hydrogen-oxygen mixed gas and low pressure loss under normal conditions.

[0149] The present invention provides a flame suppression device that can extinguish a detonation flame even when a hydrogen-oxygen mixed gas with a high detonation velocity and energy ignites among a combination of flammable gases and combustion-supporting gases, and that achieves both high flame suppression capability and low pressure loss, such that the pressure loss during normal gas flow is within a practically acceptable range.

[0150] Furthermore, by integrating the flame suppression device of the present invention with various equipment such as piping, separation membrane modules, or dehumidification towers, the safety of each piece of equipment can be significantly enhanced. In particular, by installing it as a safety device in an artificial photosynthesis plant where a hydrogen-oxygen mixed gas flows under steady conditions, the propagation of detonation flames can be blocked, and the pressure rise downstream of the flame suppression device can be prevented, thereby significantly enhancing safety.

[0151] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Examples]

[0152] One embodiment of the present invention is described below.

[0153] [Example 1] A flame suppression device having the structure schematically shown in Figures 1 and 2 was prepared as follows.

[0154] As part of the flame-extinguishing function, a 60-mesh SUS304 metal material is used, and the overall shape of the mesh opening surface has a diameter L mr 50.0 mm circular (mesh opening surface area S) m 1963.5mm 2 The metal mesh was processed to be as follows. After processing, without applying any weight to the metal mesh, a total of 60 pieces were simply stacked perpendicular to the mesh opening surface, and the total length when self-supporting stacking was L mf The following was measured. As a result, the total length L when stacked independently was obtained. mf The thickness was 27 mm. The layer thickness L was achieved by applying pressure to the metal mesh perpendicular to the mesh opening surface. mf The measurement results showed that the total length L during pressure lamination was mf It was 16.8 mm.

[0155] Next, an inner housing made of polyvinyl chloride (PVC) having a straight cylindrical shape as part of the housing is provided, with a length L in the straight direction. hf The total length L of the metal mesh when it is compressed and laminated. mf Similarly, 16.8 mm, cylindrical inner diameter length L hr 50.0 mm (Cylindrical internal area S) h It is 1963.5mm 2 I prepared it so that it would be as follows.

[0156] Next, epoxy resin was used as the sealing component, which is part of the flame-retardant function, to integrate 60 metal meshes into the inner casing. Specifically, epoxy resin was applied without gaps only to the periphery of the metal meshes, and the metal meshes were pressed down to adhere to the inner casing. Care was taken to ensure that no gaps were left around the periphery.

[0157] As a result, a structure was achieved in which the first metal mesh is in contact with the second metal mesh, the m-th metal mesh is in firm contact with the m-1 and m+1 metal meshes, and the 60th metal mesh is in tight contact with the 59th metal mesh. In addition, the mesh opening surface area S of the metal mesh was achieved by applying epoxy resin. m This was reduced by 4%. Therefore, the epoxy resin is configured to also function as an area limiting part as part of the flame suppression part, and as a result the opening ratio R of the metal mesh m The percentage was 96%.

[0158] Next, the first outer housing 214 and the second outer housing 215, made of polyvinyl chloride (PVC) and constituting the outermost outer housing as part of the housing section, were formed to enclose the inner housing 22. As shown in Figure 1, the first and second outer housings were made to have similar shapes, and the inner housing served as the flame suppression function mounting section and was shaped to form a straight cylindrical piping section. O-rings were placed at the connection points between the first outer housing, the inner housing integrated with the flame suppression function section, and the second outer housing to ensure airtightness. Furthermore, these three housings were integrated by bolting the first and second outer housings together with the inner housing enclosed inside.

[0159] Here, the straight pipe length L is formed by the first outer casing. pf1 25.0 mm, cylindrical inner diameter length L pr1 25.0 mm (Cylindrical internal area S) p1 490.9mm 2 This was done so that the straight pipe length L formed by the second outer casing would be... pf2 40.2 mm, cylindrical inner diameter length L pr2 25.0 mm (Cylindrical internal area S) p2 490.9mm 2 )

[0160] In this way, a structure was completed in which all fluids flowing through the piping section pass through the metal mesh section.

[0161] [Example 2] The pressure drop of the flame suppressor prepared as described in Example 1 was measured. As a result, the pressure drop of the flame suppressor was 0.6 kPa when 100 L / min of air was flowed through it. On the other hand, when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min (66.7 L / min of hydrogen and 33.3 L / min of oxygen), the pressure drop was 0.3 to 0.4 kPa.

[0162] After confirming the pressure loss of the flame suppressor, a flame suppression verification experiment was conducted using the flame suppressor against a hydrogen-oxygen mixed gas (hydrogen detonator) with a volume ratio of hydrogen:oxygen = 2:1. During the experiment, long pipes were airtightly connected to two locations in the piping section of the flame suppressor, so that when the hydrogen detonator was intentionally ignited, a transition from deflagration to detonation would reliably occur, and the steady-state detonation flame of the hydrogen detonator would enter the flame suppressor. Specifically, the experimental upstream extension pipe connected to the piping section formed by the first outer casing was a straight cylindrical pipe with a length of over 2m. On the other hand, the experimental downstream extension pipe connected to the piping section formed by the second outer casing was a straight cylindrical pipe with a length of over 1m.

[0163] In the flame suppression confirmation experiment, as shown in Figure 18, hydrogen at 1 L / min and oxygen at 0.5 L / min were circulated for more than 5 minutes from the end of the experimental upstream extension pipe connected to the piping section formed by the outer casing, and these gases were released from the end of the experimental downstream extension pipe connected to the piping section formed by the second outer casing, completely replacing the inside of the pipe with hydrogen detonation gas in a hydrogen:oxygen ratio of 2:1. Next, the experimental upstream extension pipe and the experimental downstream extension pipe were closed with valves, and the gas was sealed into the entire flame suppression device experimental system at a pressure of 0.1 MPaA. After that, a spark plug installed in the experimental upstream extension pipe, more than 2 m away from the flame suppression device, was discharged, causing a flame to enter the flame suppression device. Analysis of the flame propagation velocity showed that it was approximately 2800 m / sec just before the flame suppression device, confirming that a steady-state detonation flame entered the flame suppression device.

[0164] After the flame entered the flame quenching device, image analysis was performed using a high-speed camera. It was confirmed that the flame did not propagate to the experimental downstream extension pipe connected to the pipe portion formed by the second outer casing, and detonation flame of the hydrogen oxyhydrogen gas was quenched by the flame quenching device. In addition, no pressure rise was confirmed by the pressure sensor installed in the experimental downstream extension pipe, and quenching of the detonation flame of the hydrogen oxyhydrogen gas by the flame quenching device was also confirmed.

[0165] [Example 3] A flame quenching device having the structure schematically shown in Figure 5 and Figure 6 was prepared as follows.

[0166] As a part of the flame quenching functional part, a 60-mesh SUS304 metal material was processed such that the overall shape of the mesh opening surface was a circle with a diameter L mr of 30.0 mm (the area S of the mesh opening surface m was 706.9 mm 2 ). After processing, a total of 96 sheets were simply stacked in the direction perpendicular to the mesh opening surface without applying load or the like to the metal mesh, and the total length L when freely stacked to stand on its own was measured mf . As a result, the total length L when freely stacked to stand on its own mf was 51 mm. The laminated thickness L in a state where the metal mesh was pressed in the direction perpendicular to the mesh opening surface mf was measured, and as a result, the total length L when pressed and laminated mf was 26.9 mm.

[0167] Next, as a part of the casing part, a straight cylindrical inner casing made of SUS304 was prepared such that the length L in the straight pipe direction hf was 27.9 mm, which is the total length L when the metal mesh was pressed and laminated mf +1 mm, and the inner diameter length L of the cylindrical shape hr was 30.0 mm (the inner area S of the cylindrical shape h was 706.9 mm 2 ).

[0168] Next, epoxy resin was used as the sealing component, which is part of the flame-retardant function, to integrate 96 metal meshes into the inner casing. Specifically, epoxy resin was applied without gaps only to the periphery of the metal meshes, and the metal meshes were pressed down to adhere to the inner casing. Care was taken to ensure that no gaps were left around the periphery.

[0169] As a result, the first metal mesh contacts the second metal mesh, the m-th metal mesh makes firm contact with the m-1 and m+1 metal meshes, and the 96th metal mesh makes tight contact with the 95th metal mesh, creating a structure. Furthermore, a circular retaining plate with a diameter of 30.0 mm and a thickness of 1 mm is integrated with the inner housing to contact the first metal mesh, and this retaining plate has an opening area equivalent to 21 to 22 circular openings with a diameter of 5 mm. The epoxy resin and the retaining plate function as an area limiting section as part of the flame-retardant section, resulting in a tight opening ratio R of the metal mesh. m The percentage was 60%. The volume of residual voids in the flame-extinguishing section formed by the retaining plate was 424.1 mm³. 3 That is the case.

[0170] Next, the first and second outer casings, made of SUS304, which constitute the outermost outer casing as part of the housing, were prepared to enclose the inner casing. As shown in Figure 5, the first and second outer casings were made to have similar shapes, and the inner casing served as the part where the flame suppression function was installed, and was shaped to form a cylindrical piping section. The cylindrical piping section formed by the outer casing has an inner diameter length L of the cylindrical shape. pr The maximum value is the inner diameter length L of the cylindrical shape of the inner housing. hr The dimensions may be enlarged or reduced within the following range. O-rings were placed at the connection between the first outer casing, the inner casing integrated with the flame suppression function unit, and the second outer casing to ensure airtightness. Furthermore, the three components were integrated by bolting the first and second outer casings together with the inner casing enclosed. Here, the piping length L formed by the first outer casing was used. pf1 18.0 mm, cylindrical inner diameter length L pr1 The maximum value is 21.0 mm (internal area S of the cylindrical shape) p1 The maximum value is 346.4 mm 2This was done so that the piping length L formed by the second outer casing would be... pf2 44.1 mm, cylindrical inner diameter length L pr2 The maximum value is 30.0 mm (internal area S of the cylindrical shape) p2 The maximum value is 706.9 mm 2 )

[0171] In this way, a structure was completed in which all fluids flowing through the piping section pass through the metal mesh section.

[0172] [Example 4] The pressure drop of the flame suppressor was measured using the flame suppressor prepared as described in Example 3. As a result, the pressure drop of the flame suppressor was 1.9 kPa when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min, with 66.7 L / min of hydrogen and 33.3 L / min of oxygen.

[0173] The flame suppression experiment was conducted in the same manner as in Example 2, except that the flowing gas rates were set to 40 L / min of hydrogen and 20 L / min of oxygen, and after gas replacement, the experimental upstream extension pipe and experimental downstream extension pipe were left open with valves to allow gas flow, and the flame was ignited and the flame was directed into the flame suppression device. As a result, the flame suppression of the detonation flame of hydrogen detonation gas by the flame suppression device was confirmed using the same confirmation method as in Example 2.

[0174] [Example 5] As shown in Figure 1, the number of stacked metal mesh layers is 100 (total length L when self-supporting stacking). mf 45mm, total length L when pressure lamination is applied. mf The diameter is 28.0 mm, the material of the inner housing is SUS304, and the length in the straight pipe direction is L. hf The diameter is set to 28.0 mm, the outer casing is made of SUS304, and the cylindrical piping section formed by the outer casing has a cylindrical inner diameter length L pr The maximum value is the inner diameter length L of the cylindrical shape of the inner housing. hr The pipe length L formed by the first outer casing may be enlarged or reduced within the following range. pf1 25.0 mm, cylindrical inner diameter length L pr1 The maximum value is 21.0 mm (internal area S of the cylindrical shape) p1The maximum value is 346.4 mm 2 ) and the piping length L formed by the second outer casing is set to ). pf2 28.0 mm, cylindrical inner diameter length L pr2 The maximum value is 25.0 mm (internal area S of the cylindrical shape) p2 The maximum value is 490.9 mm 2 Except for the above, the flame suppression device was prepared in the same manner as in Example 1.

[0175] [Example 6] The pressure drop of the flame suppressor was measured using the flame suppressor prepared as described in Example 5. As a result, the pressure drop of the flame suppressor was 1.0 kPa when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min, with 66.7 L / min of hydrogen and 33.3 L / min of oxygen.

[0176] The flame suppression experiment was conducted in the same manner as in Example 4, and the flame suppression of the detonation flame of hydrogen fumes by the flame suppression device was confirmed using the same confirmation method as in Example 2.

[0177] [Example 7] The number of layers of metal mesh is 60 (total length L when self-supporting stacking). mf 27mm, total length L when pressure lamination is applied. mf (16.8 mm), and the length L in the straight direction of the inner housing. hf The length is set to 16.8 mm, and the pipe length L is formed by the second outer housing. pf2 Except for setting the diameter to 39.2 mm, the flame suppression device was prepared in the same manner as in Example 5.

[0178] [Example 8] The pressure drop of the flame suppressor was measured using the flame suppressor prepared according to Example 7. As a result, the pressure drop of the flame suppressor was 0.7 kPa when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min, with 66.7 L / min of hydrogen and 33.3 L / min of oxygen.

[0179] The flame suppression experiment was conducted in the same manner as in Example 4, and the flame suppression of the detonation flame of hydrogen fumes by the flame suppression device was confirmed using the same confirmation method as in Example 2.

[0180] [Example 9] The number of layers of metal mesh is 120 (total length L when self-supporting stacking). mf 64mm, total length L when pressure lamination is performed mf (33.6 mm), and the length L in the straight direction of the inner housing. hf The length is set to 34.6 mm, and the pipe length L is formed by the second outer casing. pf2 Except for setting the diameter to 37.4 mm, the flame suppression device was prepared in the same manner as in Example 3.

[0181] [Example 10] The pressure drop of the flame suppressor was measured using the flame suppressor prepared according to Example 9. As a result, the pressure drop of the flame suppressor was 3.7 kPa when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min, with 66.7 L / min of hydrogen and 33.3 L / min of oxygen.

[0182] The flame suppression experiment was conducted in the same manner as in Example 4, and the flame suppression of the detonation flame of hydrogen fumes by the flame suppression device was confirmed using the same confirmation method as in Example 2.

[0183] [Example 11] The number of layers of metal mesh is 144 (total length L when self-supporting stacking). mf 77mm, total length L when pressure lamination is applied. mf (40.3 mm), and the length L in the straight direction of the inner housing. hf The length is set to 41.3 mm, and the pipe length L is formed by the second outer casing. pf2 Except for setting the diameter to 30.7 mm, the flame suppression device was prepared in the same manner as in Example 3.

[0184] [Example 12] The pressure drop of the flame suppressor was measured using the flame suppressor prepared according to Example 11. As a result, the pressure drop of the flame suppressor was 4.6 kPa when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min, with 66.7 L / min of hydrogen and 33.3 L / min of oxygen.

[0185] The flame suppression experiment was conducted in the same manner as in Example 4, and the flame suppression of the detonation flame of hydrogen fumes by the flame suppression device was confirmed using the same confirmation method as in Example 2.

[0186] [Example 13] A hydrogen-oxygen separation membrane module with an integrated flame suppressor, as shown in Figure 17, was prepared as follows.

[0187] For the flame suppression function section of the flame suppression device to be placed on the gas supply side of the separation membrane module, 260 sheets of SUS316 mesh with a mesh opening diameter of 50 mm and a wire diameter of 140 μm were stacked together. The entire circumference of this stack was then bonded together without gaps using epoxy resin under pressure to complete the metal mesh stacking. Here, the epoxy resin section served as both part of the area limiting section and part of the sealing section. Next, as a further sealing section, the periphery was wrapped multiple times with Teflon® tape, and then firmly pressed into the SUS304 housing of the flame suppression device to prevent gas flow around it and integrate it.

[0188] Here, the thickness of the metal mesh when it was mounted on the flame suppressor was significantly thinner than the thickness when it was self-supporting and laminated. Also, the length of the metal mesh in the lamination direction of the flame suppressor function mounting section of the flame suppressor was significantly shorter than the thickness of the metal mesh when it was self-supporting and laminated.

[0189] Next, a 1.5 mm thick perforated plate was mounted on one side of the flame suppression function section of the housing as part of the area limiting section. Furthermore, the outer cylinder of the separation membrane module, on which multiple separation membranes were mounted, was directly connected using flat plate packing, metal gaskets, bolts, etc. Then, the supply side extension piping was connected to the piping section formed by the housing, completing the supply side configuration.

[0190] Similarly, another flame suppression device containing 260 pressure-laminated SUS316 mesh sheets was also placed on the permeable side of the outer cylinder of the separation membrane module. Furthermore, another flame suppression device containing 260 pressure-laminated SUS316 mesh sheets, prepared in the same manner, was connected to the non-permeable side piping of the separation membrane module via a connecting valve. This flame suppression device is configured to connect to the separation membrane module by connecting a non-permeable side extension pipe A to one end of the flame suppression function mounting section of the flame suppression device housing, and another non-permeable side extension pipe B to the other end.

[0191] [Example 14] For the flame suppressor-integrated separation membrane module prepared as in Example 13, first, only the flame suppressor connected to the non-permeable side was removed, and the pressure loss of the device alone was measured. As a result, the pressure loss of the flame suppressor was 1.9 kPa when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min, with hydrogen at 66.7 L / min and oxygen at 33.3 L / min.

[0192] Next, the flame suppression device, which had been connected to the impermeable side, was integrated with the separation membrane module again. Similar to Example 2, a hydrogen:oxygen mixed gas in a 2:1 ratio was filled into the module and the separation membrane, and an ignition experiment was first conducted from the supply side. As a result, it was confirmed that the flame suppression device extinguished the detonation flame of the hydrogen detonation gas using the same verification method as in Example 2.

[0193] Next, similar to Example 2, a hydrogen-oxygen mixed gas with a hydrogen:oxygen ratio of 2:1 was again filled into the module, the separation membrane, etc., and an ignition experiment was conducted from the impermeable side. As a result, it was confirmed that the detonation flame of the hydrogen detonation gas was extinguished by the flame extinguishing device using the same confirmation method as in Example 2.

[0194] Finally, the hydrogen-oxygen mixed gas was refilled into the module, the separation membrane, etc., and an ignition experiment was conducted from the permeate side. As a result, it was confirmed that the detonation flame of the hydrogen detonation gas was extinguished by the flame extinguishing device using the same confirmation method as in Example 2.

[0195] [Example 15] In order to change the number of metal meshes mounted on each of the three flame suppression devices installed in different locations to 62, the thickness of the flame suppression function mounting section perpendicular to the mesh opening surface was reduced, and the number of metal meshes was also reduced to 62. In addition to these modifications, a flame suppression device-integrated hydrogen-oxygen separation membrane module was prepared in the same manner as in Example 13.

[0196] [Example 16] For the flame suppressor-integrated separation membrane module prepared according to Example 15, only the flame suppressor connected to the non-permeable side was removed, as in Example 14, and the pressure loss of the device alone was measured. As a result, the pressure loss was 1.0 kPa.

[0197] Next, a flame extinguishing experiment was conducted in the same manner as in Example 14. The results showed that the detonation flame was extinguished regardless of whether ignition was from the supply side, the permeation side, or the non-permeation side.

[0198] [Comparative Example 1] A flame suppression device 400 having the structure schematically shown in Figure 19 was prepared as follows. The flame suppression device 400 has the same configuration as the flame suppression device 1 shown in Figure 1, except that the configuration of the flame suppression function unit 3 is different.

[0199] A mesh laminate consisting of 12 layers of metal mesh (total length L when self-supporting). mf 6.4 mm, total length L when pressure lamination is performed. mf 3.5 mm), an area limiting section 440 (opening ratio R) is located on one end of the mesh laminate. m Seven flame suppression function units were prepared, each consisting of a 60% inner housing 422 with a straight cylindrical shape and a length in the straight direction of the inner housing 422, a sealing function part 431 interposed between the outer edge of the mesh laminate and area limiting part 440 and the inner circumferential wall of the inner housing 422, and an O-ring 423 that abuts against the other end of the inner housing 422. These flame suppression function units were stacked in the housing part 211 with O-rings interposed between them to form the flame suppression function unit. The total thickness of one inner housing 422 and O-ring 423 is 1.7 mm, and the total volume of residual void in the entire flame suppression function unit formed from seven inner housings 422 and six O-rings 423 is 5937.6 mm². 3 And the length of the straight pipe L of the flame suppression function section of the outer casing was... hf The pipe length L is 35.7 mm and is formed by the second outer housing. pr2 The flame suppression device was prepared in the same manner as in Example 3, except that the diameter was set to 36.3 mm. The total volume of residual voids at this time was approximately 14 times the volume of residual voids in Example 3.

[0200] [Comparative Example 2] Using the flame suppression device prepared as in Comparative Example 1, a flame suppression confirmation experiment was conducted in the same manner as in Example 4. High-speed camera image analysis after the flame entered the flame suppression device confirmed that the flame propagated to the experimental downstream extension pipe connected to the piping section formed by the second outer casing, confirming that the flame suppression device does not have the ability to suppress the detonation flame of hydrogen volcanic gas. Furthermore, a pressure increase was confirmed by a pressure sensor installed in the experimental downstream extension pipe, confirming that the flame suppression device does not have the ability to suppress the detonation flame of hydrogen volcanic gas.

[0201] [Other experimental examples] When the number of metal mesh layers in the flame suppressor of Example 3 was changed to 600, the pressure loss was calculated to be 11.4 kPa when a hydrogen-oxygen mixed gas was flowed at a total rate of 100 L / min (66.7 L / min hydrogen and 33.3 L / min oxygen), which was estimated to exceed the allowable pressure loss of 10 kPa. Such a flame suppressor has an excessive pressure loss during normal gas flow and is not suitable as a flame suppressor. [Explanation of Symbols]

[0202] 1, 11, 70, 90A, 90B, 90C, 301, 400, 3000 Flame extinguishing device 2, 72, 92A, 92B, 92C Enclosure 3, 73, 93A, 93B, 93C Anti-inflammatory function section 4, 74, 94A, 94B, 440 Area limiting section 21 Outer casing 22,422 Internal enclosure 23,423 O-rings 31, 431 Sealing function part 33 Mesh Laminate 41 Main plate 42 Ventilation holes 50 Anti-inflammatory function section 60 Water-splitting photocatalytic sheets 61 Circuit board section 62 Frame 63 Seal part 64 Light transmission plate 65 Water supply port 66 Exhaust vents 67 gaps 68, 84A, 84B, 84C External conduit 75,216 volts 76, 91A, 91B, 91C, 95C Piping section 80 Separation Membrane Modules 81 Separation membrane module housing 82 Separation membrane 83 Branch pipe 85 valves 211 Storage Unit 212 First piping section 213 Second piping section 214 First outer casing 215 Second outer casing 302 Experimental upstream extension piping 303 Experimental downstream extension piping 304 Ignition position 305 Pressure Sensor 306 High-Speed ​​Camera 311 Metal Mesh 312 Mesh connection section 1000 Artificial Photosynthesis Plants 2000 Photocatalytic reactor 2100 Hydrogen Generator 4000 separation equipment 4100 Gas Separation Unit 5000 Dehumidifier 6000 Vacuum Pump

Claims

1. It has a housing portion through which a gas passage is passed, and a flame suppression function portion that is breathable and held in the housing portion to suppress the detonation flame of the gas, The aforementioned housing portion is A portion of the gas flow path, comprising a flame suppression function mounting section that houses the flame suppression function unit, It includes a piping section which is part of the gas flow path and connects the flame suppression function section with the outside of the housing section, The flame-suppressing functional part is a mesh laminate composed of a plurality of meshes that are in contact with and overlapping each other. In the flame suppression function equipped section, the mesh laminate is the gas flow path. A flame suppression device in which the maximum inner diameter of the aforementioned piping section is smaller than the minimum inner diameter of the section equipped with the flame suppression function.

2. The flame suppression device according to claim 1, wherein, when the total number of meshes in the mesh laminate is n, the first mesh and the nth mesh in the stacking direction of the mesh laminate are in contact with another mesh.

3. The flame suppression device according to claim 1, wherein when the total area of ​​the planar shape including the mesh opening is defined as the opening surface area, the opening surface area of ​​each of the meshes in the mesh laminate is substantially the same.

4. The flame suppression device according to claim 1, wherein the mesh has a coarseness of 40 mesh or more and 80 mesh or less.

5. The flame suppressor according to claim 1, wherein the mesh is made of metal, and the metal comprises one or more metals selected from the group consisting of stainless steel, nickel, tungsten, molybdenum, zirconium, Hastelloy, titanium, and Inconel.

6. The flame suppression device according to claim 1, wherein the total number of meshes in the mesh laminate is 60 or more and 500 or less.

7. The flame suppression device according to claim 1, wherein the flame suppression function portion further comprises a sealing function portion disposed between its inner circumferential wall surface and the outer edge of the flame suppression function portion, and in close contact with the inner circumferential wall surface.

8. The flame suppression device according to claim 7, wherein the sealing function part is integrally composed of a cured resin or a molten metal.

9. The flame suppression device according to claim 1, wherein the housing portion includes one or both of metal and resin.

10. The flame suppression device according to claim 1, wherein the piping section includes a first piping section that connects the flame suppression function mounting section with the outside of the housing section at one end of the housing section, and a second piping section that connects the flame suppression function mounting section with the outside of the housing section at the other end of the housing section.

11. The flame suppression device according to claim 1, wherein the inner diameter of the piping section is constant.

12. The flame suppression device according to claim 1, wherein the maximum inner diameter of the piping section is 5 mm or more and 40 mm or less.

13. The flame suppression device according to claim 1, further comprising an area limiting portion having a through-hole that serves as a gas flow path, wherein the area limiting portion is in contact with one end face or both end faces of the flame suppression function portion.

14. The flame suppression device according to claim 13, wherein the ratio of the total opening area of ​​the through-hole to the projected area of ​​the area limiting portion is 60% or more and 99% or less.

15. The flame suppression function portion further includes a sealing function portion that is positioned between its inner circumferential wall surface and the outer edge of the flame suppression function portion and is in close contact with the inner circumferential wall surface. The flame suppression device according to claim 13, wherein the area limiting portion is integrated with the sealing function portion.

16. The flame suppression device according to claim 13, wherein, when the total number of meshes in the mesh laminate is n, the area limiting portion is in contact with one or both of the first mesh and the nth mesh in the stacking direction of the mesh laminate.

17. The flame suppression device according to claim 1, wherein the pressure loss when circulating 100 L / min of gas is 10 kPa or less.

18. The device comprises a flame suppression device according to any one of claims 1 to 17, and a hydrogen generating unit for generating hydrogen gas, A hydrogen generator in which the flame suppressor and the hydrogen generator are integrally configured such that the hydrogen gas generated in the hydrogen generator is supplied to the gas flow path of the flame suppressor.

19. The device comprises a flame suppression device according to any one of claims 1 to 17, and a separation membrane module for separating a specific gas component from a mixed gas, The separation membrane module comprises a separation membrane for separating a specific gas component from a mixed gas, and a separation membrane module housing that houses the separation membrane and is configured to supply the mixed gas to the separation membrane. A gas separation membrane apparatus in which the flame suppressor and the separation membrane module are integrally configured such that the gas flow path of the flame suppressor becomes the flow path of the mixed gas.

20. An artificial photosynthesis plant that generates and distributes hydrogen gas and oxygen gas by photocatalysis, wherein a flame suppression device according to any one of claims 1 to 17 is arranged in the gas flow path of the artificial photosynthesis plant.

21. A flame suppression method for suppressing flame propagation during an explosion of a combustible gas by arranging a flame suppression device in the flow path of the combustible gas, wherein the flame suppression device is a flame suppression device described in any one of claims 1 to 17.

22. The flame suppression method according to claim 21, wherein the flammable gas is a mixture of hydrogen gas and oxygen gas.

23. The flame suppression method according to claim 22, wherein the flame propagation is the propagation of a detonation flame.

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