Flashback prevention device and flashback prevention method

Abstract

To provide a porous ceramic flashback arrestor capable of suppressing pressure loss. [Solution] The flame suppression member has an inlet end for introducing flammable gas, an outlet end for discharging flammable gas, an overall flow path configured between the inlet end and the outlet end for circulating the flammable gas, a flow path partition made of porous ceramic that divides the overall flow path into a plurality of unit flow paths along an axis from the inlet end to the outlet end and allows the flammable gas to pass through, and a sealing portion provided at different positions in the flow direction of the flammable gas between adjacent unit flow paths, and an attachment member for attaching the flame suppression member to the flow path of the flammable gas.

Description

Technical Field

[0001] The present disclosure relates to a backfire prevention device and a backfire prevention method.

Background Art

[0002] Conventionally, a technique has been proposed in which a backfire prevention device is attached to a flow path of a combustible gas (including a mixed gas in which a combustible gas and air are premixed) to prevent backfire (flame propagation) of a flame generated for some reason. As the backfire prevention device, a metal crimp ribbon type (see Patent Document 1) and a porous ceramic type (see Patent Document 2) are known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The porous ceramic type can have a simple structure and reduce the holes through which gas flows compared to the metal crimp ribbon type. However, as in Patent Document 2, when a porous closing member is arranged so as to close the flow path, the pressure loss becomes large.

[0005] The present disclosure has been made in consideration of the above facts, and an object thereof is to provide a porous ceramic type backfire prevention device and a backfire prevention method capable of suppressing pressure loss.

Means for Solving the Problems

[0006] The flashback prevention device of the first embodiment comprises a flashback prevention member having an inlet end for introducing flammable gas, an outlet end for discharging flammable gas, an overall flow path configured between the inlet end and the outlet end for circulating the flammable gas, a flow path partition made of porous ceramics that divides the overall flow path into a plurality of unit flow paths along an axis from the inlet end to the outlet end and allows the flammable gas to pass through, and a sealing portion provided at different positions in the flow direction of the flammable gas between adjacent unit flow paths, and a mounting member for attaching the flashback prevention member to the flow path of the flammable gas.

[0007] In the flashback prevention device of the first embodiment, a flame suppressor is attached to the flow path of flammable gas by a mounting member. In the flame suppressor, flammable gas flowing in from the inlet end of a unit flow path is blocked by the sealing portion and moves through the flow path partition to the adjacent unit flow path. If the sealing portion of the destination unit flow path is on the inlet side, the flammable gas flows out from the outlet end of that unit flow path. If the sealing portion of the destination unit flow path is on the outlet side, the gas moves further through the flow path partition to a unit flow path with an open outlet end.

[0008] According to the flashback prevention device of the first embodiment, since the flow channel partition is formed from porous ceramics, it can be manufactured relatively easily. Furthermore, by allowing the flammable gas to flow through the flow channel partition, the area of ​​the flow channel partition through which the flammable gas permeates can be made larger than the cross-sectional area of ​​the unit flow channel into which the flammable gas flows, thereby reducing the pressure loss of the flammable gas. In addition, the sealing portion and the flow channel partition prevent flames from passing through, thus preventing flashback from the outlet end to the inlet end.

[0009] The flashback prevention device of the second embodiment is configured such that the sealing portion of the flashback prevention device of the first embodiment includes an inlet end sealing portion that seals the inlet end of a portion of the plurality of unit flow paths, and an outlet end sealing portion that seals the outlet end of the remaining portion of the plurality of unit flow paths.

[0010] According to the flashback prevention device of the second embodiment, since it is formed at the inlet end or outlet end, a sealing portion can be easily formed.

[0011] The flashback prevention device of the third embodiment is the flashback prevention device of the second embodiment, wherein the inlet end sealing portion and the outlet end sealing portion are alternately formed in adjacent unit flow paths.

[0012] According to the flashback prevention device of the third embodiment, the area of ​​the flow channel partition through which the flammable gas permeates can be increased in adjacent unit flow channels, and the flammable gas that flows in from one unit flow channel can be discharged from the adjacent unit flow channel, thereby further reducing the pressure loss of the flammable gas.

[0013] In the fourth embodiment of the flashback prevention device, the plurality of unit flow paths have a polygonal cross-section.

[0014] According to the flashback prevention device of the fourth embodiment, the flow channel partitions between adjacent unit flow channels can be made of a constant thickness, thereby reducing the pressure loss of the flammable gas.

[0015] A flashback prevention method of the fifth embodiment involves placing a flame suppression member in the flow path of a combustible gas to prevent flashback from the outlet end to the inlet end. The flame suppression member has an inlet end for introducing combustible gas, an outlet end for discharging combustible gas, an overall flow path configured between the inlet end and the outlet end for circulating the combustible gas, a flow path partition made of porous ceramic that allows the combustible gas to pass through, dividing the overall flow path into a plurality of unit flow paths along an axis from the inlet end to the outlet end, and sealing portions provided at different positions in the flow direction of the combustible gas between adjacent unit flow paths, thereby preventing flashback from the outlet end to the inlet end.

[0016] According to the backfire prevention method of the fifth aspect, the combustible gas flowing in from the inlet end side of the unit flow path is blocked by the sealing portion and moves through the flow path partition wall to the adjacent unit flow path. If the sealing portion of the unit flow path at the moving destination is on the inlet side, the combustible gas flows out from the outlet end of the unit flow path. If the sealing portion of the unit flow path at the moving destination is on the outlet side, it further moves through the flow path partition wall to the unit flow path with the outlet end open.

[0017] In this way, by allowing the combustible gas to flow through the flow path partition wall, the area of the flow path partition wall through which the combustible gas permeates can be made larger than the cross-sectional area of the unit flow path into which the combustible gas flows, and the pressure loss of the combustible gas can be reduced. Further, the flame is made non-permeable by the flow path partition wall, and backfire from the outlet end side to the inlet end side can be prevented.

Effect of the Invention

[0018] According to the technology of the present disclosure, it is possible to reduce the holes through which the gas flows with a simple configuration while suppressing the pressure loss.

Brief Description of the Drawings

[0019] [Figure 1] It is a schematic diagram showing a state where the backfire prevention device of this embodiment is attached to the flow path of the combustible gas. [Figure 2] Regarding the backfire prevention device of this embodiment, (A) is a partial configuration diagram of the upstream side, and (B) is a plan view of the backfire prevention device seen from the upstream side. [Figure 3] It is a front view of the flame extinguishing member of this embodiment. [Figure 4] It is a perspective view of the flame extinguishing member of this embodiment. [Figure 5] [[ID=三十一]]It is a longitudinal sectional view of the flame extinguishing member of this embodiment. [Figure 6] It is a longitudinal sectional view of the flame extinguishing member of a modified example of this embodiment. [Figure 7] It is a perspective view of the flame extinguishing member of another modified example of this embodiment. [Figure 8] It is a front view of the flame extinguishing member of another modified example of this embodiment. [Figure 9]This is a perspective view of a flame suppression member of another modified embodiment. [Modes for carrying out the invention]

[0020] The flashback prevention device related to this disclosure will be described below with reference to the drawings.

[0021] The flashback arrestor 10 according to this disclosure is attached to the flammable gas flow path 12, as shown in Figure 1. The flammable gas flow path 12 delivers flammable gas, such as hydrogen gas, methane gas, city gas, LP gas, and butane gas (including a mixed gas in which flammable gas and air are premixed), toward the burner 14.

[0022] The flashback prevention device 10 comprises a flame suppression member 20 and a mounting member 22 for attaching the flame suppression member 20 to the combustible gas flow path 12. The mounting member 22 is a hollow rectangular tube with connecting flange portions 22A at one end and the other, and houses the flame suppression member 20 inside. The mounting member 22 can have various structures as long as it is configured to allow the flame suppression member 20 to be attached to the combustible gas flow path 12.

[0023] As shown in Figures 2(A) and 2(B), a check valve member 22B, which has a smaller inner diameter than the outer diameter of the flame suppressor member 20 (described later) and is shaped like a rectangular ring, is positioned inside the mounting member 22. The check valve member 22B is positioned on the inlet end 20A side of the flame suppressor member 20 (described later), that is, upstream of the flame suppressor member 20 in the flammable gas flow path 12. The check valve member 22B is welded to the mounting member 22.

[0024] As shown in Figures 3 and 4, the flame suppression member 20 has an outer wall portion 24 that is a rectangular tube with a slightly smaller diameter than the mounting member 22. As shown in Figure 5, the opening at one end of the outer wall portion 24 (left side in Figure 5) becomes the inlet end 20A, and the opening at the other end of the outer wall portion 24 (right side in Figure 5) becomes the outlet end 20B. The axis (tubular axis) of the outer wall portion 24 from the inlet end 20A to the outlet end 20B is defined as the axial direction S.

[0025] Multiple unit channels 26A and 26B are formed inside the outer wall portion 24. The multiple unit channels 26A and 26B are divided into multiple rows alternately in the vertical and horizontal directions by channel partitions 28, and have a rectangular cross-section. The multiple unit channels 26A and 26B have the same cross-sectional shape. The multiple unit channels 26A and 26B form a channel 26 inside the flame suppressor member 20, extending from one end of the cylinder to the other. The flame suppressor member 20 is arranged such that the direction of the openings of the multiple unit channels 26A and 26B coincides with the direction of the opening of the mounting member 22. The thickness T1 of the channel partitions 28 is formed to be thinner than the horizontal length L1 and vertical length L2 of the cross-section of the unit channels 26A and 26B.

[0026] The thickness T1 of the flow channel partition wall 28 is preferably formed to an average of 0.2 mm to 0.8 mm. If it is thinner than 0.2 mm, the partition wall strength will not be sufficient and it will be prone to damage, and if it is thicker than 0.8 mm, the pressure loss will tend to be high. The lateral length L1 and vertical length L2 of the cross-section of the unit flow channels 26A and 26B are preferably formed to an average of 50 mm to 150 mm. If it is shorter than 50 mm, the gas passage area will be small and the pressure loss will tend to be high, and if it is longer than 150 mm, the device will be large and difficult to handle.

[0027] The channel partition wall 28 is formed of porous ceramics. The outer wall portion 24 is also formed of the same porous ceramics, and the outer wall portion 24 and the channel partition wall 28 are integrally molded. The porous ceramics forming the channel partition wall 28 preferably consists mainly of silicon carbide, cordierite, mullite, and alumina, with a porosity of 30-50% and an average pore diameter of 5-20 μm. If the porosity is less than 30%, the pressure loss tends to be high, and if it is greater than 50%, the strength of the partition wall tends to be insufficient. If the average pore diameter is less than 5 μm, the pressure loss tends to be high, and if it is greater than 20 μm, it can lead to insufficient strength or an increased likelihood of crack initiation.

[0028] The unit flow path 26A has an inlet end sealing portion 30A that seals the inlet end 20A side. The inlet end sealing portion 30A prevents the unit flow path 26A from passing through from the inlet end 20A to the outlet end 20B. The unit flow path 26B has an outlet end sealing portion 30B that seals the outlet end 20B side. The outlet end sealing portion 30B prevents the unit flow path 26B from passing through from the inlet end 20A to the outlet end 20B.

[0029] The inlet end sealing portion 30A and the outlet end sealing portion 30B are formed of porous ceramics.

[0030] It is preferable that the porous ceramics forming the inlet end sealing portion 30A and the outlet end sealing portion 30B be made of the same material as the porous ceramics forming the flow channel partition wall 28. By using the same material, the coefficient of thermal expansion will be the same, thus preventing cracks from starting during heating.

[0031] The axial length S L of the inlet end sealing portion 30A and the outlet end sealing portion 30B is longer than the thickness T1 of the flow path partition wall 28. It is preferable that the length L be formed to be about 2 mm to 10 mm. If it is shorter than 2 mm, there is a possibility of sealing failure, and if it is longer than 10 mm, the effective area of ​​the partition wall becomes small, which tends to increase pressure loss. In addition, the area of ​​the flow path partition wall 28 along the axial direction S of adjacent unit flow paths 26A and 26B is set to be larger than the sum of the cross-sectional areas of unit flow paths 26A and 26B.

[0032] An elastically deformable expandable / contractable member 40 is positioned across the entire surface between the inner circumferential surface of the mounting member 22 and the outer circumferential surface of the flame suppressor member 20 (see Figure 3). By contracting the expandable / contractable member 40 and positioning the flame suppressor member 20 inside the mounting member 22, the flame suppressor member 20 can be press-fitted into the mounting member 22. The expandable / contractable member 40 also deforms in accordance with the expansion and contraction of the flame suppressor member 20 and the mounting member 22, absorbing such expansion and contraction. As the expandable / contractable member 40, a fiber mat material mainly composed of alumina or silica can be used.

[0033] Next, the operation and effects of the flashback prevention device 10 of this embodiment will be described.

[0034] In this embodiment, since an inlet end sealing portion 30A and an outlet end sealing portion 30B are formed in adjacent unit flow paths 26A and 26B, flammable gas flowing in from one unit flow path 26B can be discharged downstream from the adjacent unit flow path 26A. The flammable gas flowing through the flammable gas flow path 12 is supplied from the inlet end 20A side of the flame suppressor 20 and flows into the unit flow path 26B. The incoming flammable gas permeates through the flow path partition wall 28 and moves to the adjacent unit flow path 26A, and is discharged from the outlet end 20B side of the unit flow path 26A. Since the area of ​​the flow path partition wall 28 is set to be larger than the sum of the cross-sectional areas of the unit flow path 26A and the unit flow path 26B, pressure loss can be reduced.

[0035] Even if the flame from the burner 14 were to travel backward through the combustible gas flow path 12, the unit flow paths 26A and 26B of the flame suppression member 20 are designed to be non-penetrating from the inlet end 20A to the outlet end 20B. The inlet end sealing portion 30A, the outlet end sealing portion 30B, and the flow path partition wall 28 prevent the transmission of flashback.

[0036] In this embodiment, an inlet end sealing portion 30A and an outlet end sealing portion 30B are formed, but sealing portions may be formed at positions other than the ends. In this case, as shown in Figure 6, sealing portions 32A are formed in the unit flow path 26A and sealing portion 32B is formed in the unit flow path 26B, and are formed at different positions in the axial direction S within a range in which the area of ​​the flow path partition through which the flammable gas permeates is greater than the cross-sectional area of ​​the unit flow path into which the flammable gas flows.

[0037] Furthermore, in this embodiment, the unit flow paths 26A and 26B have a rectangular cross-section, but the cross-section may be a polygon other than a rectangle (pentagon, hexagon, etc.). It may also be a circular cross-section. As in this embodiment, by using a polygonal shape, the flow path partition wall 28 between adjacent unit flow paths 26A and 26B can be made of a constant thickness, thereby reducing the pressure loss of the flammable gas.

[0038] Furthermore, in this embodiment, since a check valve member 22B is provided, even if an impact is applied to the flame suppressor member 20 from the downstream side to the upstream side, the check valve member 22B can prevent the flame suppressor member 20 from moving upstream.

[0039] Furthermore, in this embodiment, the mounting member 22 and the flame suppression member 20 have a rectangular cross-section, but as shown in Figures 7 and 8, the flame suppression member 20R may have a circular cross-section. In this case, a cylindrical outer wall portion 24R corresponding to the outer wall portion 24 is formed, and a circular cross-sectional flow path 26R is formed by the unit flow paths 26A and 26B. In addition, an expandable member 40R is arranged on the outer circumferential surface of the flame suppression member 20R.

[0040] Furthermore, the flame suppressor member 20 of this embodiment and the flame suppressor member 20R of the modified example may be formed as a flame suppressor member 20X by joining segments 36A to 36D, which are divided along the axial direction S, with a joining member 42, as shown in Figure 9. In this case, the joining member 42 is a member that can expand and contract, similar to the expandable member 40R. With this configuration, the expansion and contraction of the flame suppressor member 20X can also be absorbed by the joining member 42. In addition, since the volume of each of the integrally molded segments 36A to 36D can be reduced, the amount of expansion and contraction can also be reduced.

[0041] The cross-sectional area of ​​each of the flame-extinguishing member 20 and the subdivisions 36A to 36D is 500 mm². 2 ~10000mm 2 It is preferable that it be within the range of 500mm. 2 Smaller sizes tend to result in higher pressure loss, such as 10,000 mm. 2 If the size is larger, it tends to become more difficult to manufacture in terms of moldability and other factors. [Explanation of symbols]

[0042] 10 Flashback prevention device 20 Flame suppression material 20A inlet end 20B outlet end 22 Mounting components 26 channels 26A Unit channel 26B Unit channel 28 Next door to the flow path 30A Inlet End Sealing Section 30B Export end sealing section 32A Sealing Section 32B Sealing Section

Claims

1. The inlet end into which the flammable gas flows, An outlet end from which flammable gas is discharged, A whole flow path is formed between the inlet end and the outlet end, through which the flammable gas flows, The overall flow path is divided vertically and horizontally along an axis from the inlet end to the outlet end into multiple unit flow paths with a rectangular cross-section, and the flow path partitions are made of porous ceramics that allow the flammable gas to pass through. Each of the aforementioned unit flow paths has a non-penetrating inlet end and outlet end, and adjacent unit flow paths are provided with sealing portions at different positions in the flow direction of the flammable gas, A flame suppression member having, A mounting member for attaching the flame suppression member to the flow path of the flammable gas, A flashback arrestor is provided.

2. The inlet end into which the flammable gas flows, An outlet end from which flammable gas is discharged, A whole flow path is formed between the inlet end and the outlet end, through which the flammable gas flows, The overall flow path is divided vertically and horizontally along an axis from the inlet end to the outlet end into multiple unit flow paths with a rectangular cross-section, and the flow path partitions are made of porous ceramics that allow the flammable gas to pass through. Each of the aforementioned unit flow channels has a non-penetrating inlet end and outlet end, and adjacent units A sealing portion provided at different positions in the flow direction of the flammable gas between the flow paths, A flame suppression member having, A mounting member for attaching the flame suppression member to the flow path of the flammable gas, Equipped with, An elastically deformable expandable member is disposed between the inner circumferential surface of the mounting member and the outer circumferential surface of the flame suppressing member. Flashback prevention device.

3. The sealing portion includes an inlet end sealing portion that seals the inlet ends of some of the unit flow paths, and an outlet end sealing portion that seals the outlet ends of the remaining unit flow paths. A flashback prevention device according to claim 1 or claim 2.

4. The inlet end sealing portion and the outlet end sealing portion are formed of porous ceramics of the same material as the flow channel partition. The flashback prevention device according to claim 3.

5. The flashback prevention device according to claim 3, wherein the inlet end sealing portion and the outlet end sealing portion are alternately formed in adjacent unit flow paths.

6. The inlet end into which the flammable gas flows, An outlet end from which flammable gas is discharged, A whole flow path is formed between the inlet end and the outlet end, through which the flammable gas flows, The overall flow path is divided vertically and horizontally along an axis from the inlet end to the outlet end into multiple unit flow paths with a rectangular cross-section, and the flow path partitions are made of porous ceramics that allow the flammable gas to pass through. Each of the aforementioned unit flow paths has a non-penetrating inlet end and outlet end, and adjacent unit flow paths are provided with sealing portions at different positions in the flow direction of the flammable gas, A flame suppression member having, A flashback prevention method, which is placed in a flow path for a flammable gas to prevent flashback from the outlet end to the inlet end.

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