CN110050158B - Speed reduction mechanism and flame arrester with speed reduction mechanism - Google Patents

Abstract

The purpose of the present invention is to provide a speed reduction mechanism and a flame arrester with a speed reduction mechanism that achieve both the securing of a desired fire extinguishing performance and the reduction of pressure loss (securing of a flow rate). A speed reduction mechanism (4) is provided on at least one side of a pipe (2) in the axial direction of a flame arrester (3) for extinguishing a flame propagating in the pipe (2) and is provided in the pipe (2) through which a combustible fluid flows, for reducing the speed of the flame propagating in the pipe (2), wherein the speed reduction mechanism (4) has a plurality of members and is configured in a cylindrical shape so as to communicate in the axial direction of the pipe (2), and an inner surface (40) of each member has at least one non-parallel surface (5B, 5C) that is not parallel to the axis, and the plurality of non-parallel surfaces are provided in parallel in the axial direction.

Description

Speed reduction mechanism and flame arrester with speed reduction mechanism

Technical Field

The present invention relates to a speed reduction mechanism and a flame arrester with a speed reduction mechanism.

Background

In a pipe for transporting a combustible gas, a tank for storing a combustible liquid, or the like, if a fire occurs for some reason, a flame propagates in the pipe or the tank, and there is a possibility that a serious accident such as explosion or deflagration may occur.

As a means for preventing this risk, for example, there is a flame arrester for extinguishing a flame propagating in a pipe in the middle. The principle is to subdivide the flame and deprive it of heat to extinguish it. Therefore, a conventional flame arrester is configured to have a predetermined axial dimension, and is configured by winding a metal plate having a wave shape into a spiral shape.

Such flame arrestors are required to pass a combustible gas in a normal case, but to exert a fire extinguishing performance in the case of generating a flame. Thus, both the fire extinguishing performance and the pressure loss need to be considered in its design.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-207108

Disclosure of Invention

Problems to be solved by the invention

However, in order to ensure the desired fire extinguishing performance, a distance for extinguishing a flame is required, so that it may be considered to increase the axial dimension of the flame arrester. That is, since the flame arrestor is increased in size in the axial direction of the pipe, the pressure loss is increased. In order to reduce the pressure loss, it is conceivable to miniaturize the flame arrester in the axial direction of the pipe, but in this case, the desired fire extinguishing performance cannot be ensured. That is, it is difficult to achieve reduction of pressure loss (securing of flow rate) while securing desired extinguishing performance.

An object of the present invention is to provide a speed reduction mechanism and a flame arrester with a speed reduction mechanism, which are intended to achieve both the securing of a desired extinguishing performance and the reduction of a pressure loss (securing of a flow rate).

Means for solving the problems

The speed reduction mechanism of the present invention is a speed reduction mechanism that is provided in a pipe through which a flammable fluid flows, is provided on at least one side in an axial direction of the pipe of a flame arrester for extinguishing a flame propagating in the pipe, and is configured to reduce a propagation speed of the flame propagating in the pipe, wherein the speed reduction mechanism has a cylindrical shape having a plurality of members communicating in the axial direction of the pipe, and an inner surface of each of the members has at least one non-parallel surface that is not parallel to an axis, and the non-parallel surfaces are provided in parallel in the axial direction.

According to the present invention as described above, the speed reduction mechanism has a plurality of members communicating in the axial direction of the pipe and is configured in a tubular shape, and the inner surface of each member has at least one non-parallel surface that is not parallel to the axis, and the non-parallel surfaces are provided in parallel in the axial direction. With this configuration, the number of components can be changed according to the required performance. Therefore, a mechanism with high versatility can be formed.

Here, when a flame is generated in the pipe, the flame flows forward or backward in the flow direction of the fluid, but by providing the non-parallel surface, the flame is turned back in the direction away from the central axis in the plane extending direction of the non-parallel surface. Since the non-parallel surfaces are arranged in parallel in the axial direction, a phenomenon in which the flame is wrapped back in a direction away from the central axis is repeated. In this way, the flame propagating through the pipe is decelerated by a phenomenon of the flame repeatedly winding back.

Further, the speed reduction mechanism for reducing the speed of the flame propagating through the pipe may be provided on the downstream side (one side in the axial direction) in the flow direction of the flammable fluid in the flame arrester, on the upstream side (the other side in the axial direction) in the flow direction of the flammable fluid in the flame arrester, or on both sides (both sides in the axial direction) in the flow direction of the flammable fluid in the flame arrester. For example, when there is a possibility that a flame is generated on the upstream side in the flow direction of the combustible fluid from the flame arrester, the speed reduction mechanism is preferably provided on the upstream side in the flow direction of the combustible fluid from the flame arrester, but may be provided on the downstream side in the flow direction. In addition, when there is a possibility that a flame is generated on the downstream side in the flow direction of the combustible fluid from the flame arrester, the speed reduction mechanism is preferably provided on the downstream side in the flow direction of the combustible fluid from the flame arrester, but may be provided on the upstream side in the flow direction. In the flame arrester, when there is a possibility that flames may occur on both sides in the flowing direction of the combustible fluid, the pair of speed reducing mechanisms are preferably provided on both sides in the flowing direction of the combustible fluid in the flame arrester, but the speed reducing mechanisms may be provided on either the upstream side or the downstream side.

When such a deceleration mechanism is provided on at least one side in the flow direction of the flammable fluid in the flame arrester, the flame reaching the flame arrester is decelerated. Therefore, even when the flame arrester is downsized in the axial direction of the pipe, desired fire extinguishing performance can be ensured while reducing pressure loss and ensuring a flow rate. Further, by providing such a deceleration mechanism on at least one side of the flame arrester in the flowing direction of the combustible fluid, the flame arrester can be formed with a structure that reduces the pressure loss while decelerating the flame, and can be downsized in the radial direction, and even in this case, it is possible to reduce the pressure loss (ensure the flow rate) and ensure the desired fire extinguishing performance. Therefore, by providing the speed reduction mechanism on at least one side in the flow direction of the flammable fluid in the flame arrester, it is possible to achieve both the securing of the desired extinguishing performance and the reduction of the pressure loss (securing of the flow rate).

The number of members constituting the speed reduction mechanism is preferably 4 or more. When the number of the members is 3 or less, it may be difficult to ensure desired fire extinguishing performance. Therefore, the number of the members is preferably 4 or more. This can achieve both the securing of the desired extinguishing performance and the reduction of the pressure loss (securing of the flow rate).

The number of members constituting the speed reduction mechanism is preferably 30 or less. When the number of the members is 31 or more, although a predetermined effect can be confirmed, the cost such as the manufacturing cost and the assembling work may be increased. Therefore, the number of the members is preferably 30 or less. This can suppress an increase in manufacturing cost, assembly work, and the like.

In the reduction mechanism of the present invention, it is preferable that the angle between the non-parallel surface and the shaft is substantially equal. According to such a configuration, the flame propagating through the pipe is decelerated by a phenomenon of repeatedly winding back the flame.

In the reduction mechanism of the present invention, it is preferable that the angle between the non-parallel surface and the shaft is substantially 90 degrees. According to such a configuration, the volume of the space having the non-parallel surface as the constituent surface can be set to a sufficient size, and thus the flame propagating through the pipe can be sufficiently decelerated.

In addition, the speed reducing mechanism of the present invention preferably has a plurality of space forming portions arranged eccentrically to each other, and the adjacent space forming portions communicate with each other, and the non-parallel surface is provided at a boundary therebetween. With this configuration, the flame propagating through the pipe is decelerated.

In another aspect, a flame arrester with a speed reduction mechanism according to the present invention includes the speed reduction mechanism and a flame arrester for extinguishing a flame propagating through the pipe.

According to the present invention as described above, the flame propagating through the pipe is decelerated by providing the deceleration mechanism for decelerating the flame propagating through the pipe. Therefore, even when the flame arrester is downsized in the axial direction of the pipe, it is possible to secure desired fire extinguishing performance while reducing pressure loss. Therefore, by providing the speed reduction mechanism on at least one side in the flow direction of the flammable fluid in the flame arrester, it is possible to achieve both the securing of the desired extinguishing performance and the reduction of the pressure loss (securing of the flow rate).

In the flame arrester with a deceleration mechanism of the present invention, the deceleration mechanism is preferably provided on both sides of the flame arrester in a direction in which a combustible fluid flows. With such a configuration, it is possible to sufficiently achieve both the securing of the desired fire extinguishing performance and the reduction of the pressure loss (securing of the flow rate).

Effects of the invention

According to the speed reducing mechanism and the flame arrester with the speed reducing mechanism of the present invention, it is possible to achieve both the securing of the desired extinguishing performance and the reduction of the pressure loss (securing of the flow rate).

Drawings

Fig. 1 is a cross-sectional view showing a flame arrester with a deceleration mechanism according to a first embodiment of the present invention.

Fig. 2A is a cross-sectional view showing the speed reducing mechanism according to the first embodiment.

Fig. 2B is a plan view showing the speed reducing mechanism according to the first embodiment.

Fig. 3 is a graph showing the results of an experiment for confirming the effect of the present invention.

Fig. 4 is a cross-sectional view showing a modification of the flame arrester with a speed reducing mechanism shown in fig. 1.

Fig. 5A is a cross-sectional view showing a modification of the speed reducing mechanism.

Fig. 5B is a plan view showing a modification of the speed reducing mechanism.

Fig. 6A is a cross-sectional view showing another modification of the speed reducing mechanism.

Fig. 6B is a plan view showing another modification of the speed reducing mechanism.

Fig. 7 is a cross-sectional view showing another modification of the speed reducing mechanism.

Fig. 8 is a cross-sectional view showing a flame arrester with a deceleration mechanism according to a second embodiment of the present invention.

Fig. 9A is a cross-sectional view showing the speed reducing mechanism according to the second embodiment.

Fig. 9B is a plan view showing the speed reducing mechanism according to the second embodiment.

Fig. 10 is a cross-sectional view showing a modification of the flame arrester with a speed reducing mechanism shown in fig. 8.

Fig. 11 is a cross-sectional view showing a speed reducing mechanism according to a third embodiment of the present invention.

Fig. 12 is a cross-sectional view showing a modification of the speed reducing mechanism.

Fig. 13 is a cross-sectional view showing another modification of the speed reducing mechanism.

Fig. 14 is a cross-sectional view showing another modification of the speed reducing mechanism.

Fig. 15A is a cross-sectional view showing the speed reducing mechanism according to the fourth embodiment.

Fig. 15B is a plan view showing the speed reducing mechanism according to the fourth embodiment.

Fig. 16A is a cross-sectional view showing a modification of the speed reducing mechanism.

Fig. 16B is a plan view showing a modification of the speed reducing mechanism.

Fig. 17A is a cross-sectional view showing another modification of the speed reducing mechanism.

Fig. 17B is a plan view showing another modification of the speed reducing mechanism.

Detailed Description

(first embodiment)

A flame arrester with a speed reduction mechanism according to a first embodiment of the present invention will be described below with reference to fig. 1 and 2. As shown in fig. 1, a flame arrester 1 with a speed reduction mechanism according to the present embodiment includes a pipe 2 through which a combustible gas (combustible fluid) flows, a flame arrester 3 communicating with the pipe 2, a speed reduction mechanism 4 provided to communicate with the flame arrester 3, and an annular gasket 6 interposed between the pipe 2, the flame arrester 3, and the speed reduction mechanism 4. The flame arrester 3 is a mechanism for extinguishing a flame propagating in the pipe 2 in the flame propagation direction F2 in a manner of being in counter-current to the flow of the combustible gas when a fire occurs in the pipe 2 for some reason, and the speed reduction mechanism 4 is a mechanism for reducing the speed of the flame propagating in the pipe 2. Fig. 1 is a sectional view showing a flame arrester 1 with a deceleration mechanism according to a first embodiment of the present invention. In fig. 1, hatching showing a cross section of the pipe 2 and the flame arrester 3 is omitted.

The pipe 2 includes a pair of pipe shafts 20 and 21 and a fixing member 7 for fixing the pair of pipe shafts 20 and 21. The pair of tube bodies 20 and 21 are provided so as to be separated in the axial direction, and are fixed by the fixing member 7 in a state where the flame arrester 3 and the reduction mechanism 4 are supported therebetween. Of the pair of tube bodies 20 and 21, one side located on the upstream side in the fluid flow direction F1 is referred to as an "upstream-side tube body 20", and the other side located on the downstream side is referred to as a "downstream-side tube body 21".

The upstream pipe 20 is integrally formed with a cylindrical upstream pipe body 22 and an upstream flange 23 located on the downstream side in the flow direction of the upstream pipe body 22. The upstream side barrel body 22 is configured such that the outside and the inside communicate on both sides in the axial direction of the upstream side barrel body 22, and is formed such that the inside diameter becomes larger from the upstream toward the downstream in the flow direction.

A pair of upstream bolt holes 24 into which bolts 71 constituting the fixing member 7 are inserted are formed in the upstream flange 23. The pair of upstream bolt holes 24 are provided separately in the radial direction (direction orthogonal to the axis) of the upstream flange 23. Further, the upstream bolt hole 24 and the downstream bolt hole 25, which will be described later, of the downstream pipe body 21 are located at positions separated in the axial direction, and the bolt 71 of the fixing member 7 is inserted into the upstream bolt hole 24 and the downstream bolt hole 25. The upstream flange 23 has an orthogonal surface 23A orthogonal to the axis of the upstream pipe body 20 on the downstream side in the flow direction. The fire extinguishing element holder 31 of the fire arrestor 3 is abutted on the orthogonal surface 23A via the spacer 6.

The downstream pipe body 21 is configured to integrally include a cylindrical downstream pipe body 26 and a downstream flange 27 located on an upstream side in a flow direction of the downstream pipe body 26. The downstream pipe body 26 is configured such that the outside and the inside communicate with each other on both sides in the axial direction of the downstream pipe body 26, and an inner diameter Φ 4 is formed substantially constant from the upstream end to the downstream end in the flow direction. A pair of downstream-side bolt holes 25, 25 into which bolts 71 constituting the fixing member 7 are inserted are formed in the downstream flange 27. The pair of downstream bolt holes 25, 25 are provided separately in the radial direction (direction orthogonal to the axis) of the downstream flange 27. The downstream flange 27 has an orthogonal surface 27A orthogonal to the axis of the downstream pipe body 21 on the upstream side in the flow direction. The speed reducer frame 41 of the speed reduction mechanism 4 is abutted on the perpendicular surface 27A via a spacer 6.

The fixing member 7 includes a pair of bolts 71 and a pair of nuts 72, 72 screwed to both end portions of each bolt 71. In the assembled state of flame arrester 1 with a speed reducing mechanism, bolts 71 are inserted into upstream bolt holes 24 and downstream bolt holes 25, and nuts 72 are screwed to both end portions, respectively. In this way, the bolt 71 and the pair of nuts 72 and 72 fix the upstream-side barrel 20, the flame arrestor 3, the speed reduction mechanism 4, and the downstream-side barrel 21 coaxially with each other in the order of the upstream-side barrel 20, the flame arrestor 3, the speed reduction mechanism 4, and the downstream-side barrel 21 from the upstream side in the flow direction.

The flame arrester 3 is used for extinguishing a flame by subdividing the flame and capturing heat, and is configured to include a fire extinguishing element having air permeability. In the present embodiment, a fire extinguishing element 30 of a crimped (corrugated) sheet structure is used as the flame arrester 3. In the present embodiment, the fire extinguishing element 30 having a crimped (corrugated) band structure is used, but the present invention is not limited thereto. The flame arrester may have any shape or structure as long as it is configured to include a fire extinguishing element for finely dividing flames and capturing heat to extinguish the flames.

The flame arrester 3 is configured to include a plurality of (two in the illustrated example) fire extinguishing elements 30, a cylindrical fire extinguishing element holder 31 for accommodating the two fire extinguishing elements 30, and a fire extinguishing element partition plate 32 for positioning the fire extinguishing elements 30, 30. In the present embodiment, the flame arrester 3 is configured to include two fire extinguishing elements 30, but the present invention is not limited to this. The flame arrester may be configured to include one or more fire extinguishing elements 30.

The two fire extinguishing elements 30, 30 are configured to have substantially the same structure and substantially the same function. Each of the fire extinguishing elements 30 has a concave-convex shape in the plate thickness direction, the concave-convex shape being formed by spirally winding a metal plate arranged in parallel in the plate extending direction, and each of the fire extinguishing elements 30 is provided in a disk shape having a thickness in the axial direction of the pipe 2. Each of the fire extinguishing elements 30 is provided so as to communicate with the outside and the inside in the axial direction and so as to be coaxial with the central axis P of the pipe 2, so that the combustible gas passes through in the axial direction of the pipe 2.

The fire extinguishing element holder 31 is configured in a cylindrical shape having openings at both ends in the axial direction so that the exterior and the interior communicate with each other in the axial direction of the pipe 2.

The fire extinguishing element holder 31 is configured to include: the first fire extinguishing space 33 having a first inside diameter dimension Φ 2 equal to or smaller than the inside diameter dimension Φ 1 of the downstream opening portion 20a of the upstream pipe body 20, the second fire extinguishing space 34 having a second inside diameter dimension Φ 3 larger than the first inside diameter dimension Φ 2 and substantially equal to the outside diameter dimension of the fire extinguishing element 30, and the third fire extinguishing space 35 having a third inside diameter dimension Φ 5 larger than the second inside diameter dimension Φ 3 and substantially equal to the outside diameter dimension of the reduction gear frame 41 of the reduction mechanism 4. In the fire extinguishing element holder 31, a first fire extinguishing space 33, a second fire extinguishing space 34, and a third fire extinguishing space 35 are provided in this order from the upstream side in the flow direction.

The second extinguishing space 34 is configured to be able to accommodate the two extinguishing elements 30, 30 and the extinguishing element partition 32. In addition, the axial dimension of the second fire extinguishing space 34 is formed to a dimension that forms a gap with the third fire extinguishing space 35 in a state where the two fire extinguishing elements 30, 30 and the fire extinguishing element partition 32 are accommodated. The circumferential surface of the second fire extinguishing space 34 is threaded from a position separated from the upstream end of the second fire extinguishing space 34 by the axial dimension of the size of two fire extinguishing elements to the downstream end so that the fire extinguishing element partition plate 32 can be screwed.

The third fire extinguishing space 35 is configured to be able to accommodate the gasket 6 and an upstream opening 41A of a speed reducer frame 41 (described later) of the speed reducing mechanism 4.

The fire extinguishing element partition plate 32 is provided in a disk shape having a thickness in the axial direction of the pipe 2. The fire extinguishing element partition plate 32 is provided so that the outside and the inside thereof in the axial direction communicate with each other, and a combustible gas passes through the pipe 2 in the axial direction. The fire extinguishing element partition 32 is configured as a threaded portion that can be screwed into the peripheral surface of the second fire extinguishing space 34 of the fire extinguishing element holder 31. In a state where two fire extinguishing elements 30 and 30 are accommodated in the second fire extinguishing space 34 of the fire extinguishing element holder 31, the fire extinguishing element partition plate 32 is screwed to a portion where a thread is engraved in the peripheral surface of the second fire extinguishing space 34. The two extinguishing elements 30, 30 are fixed in a defined position in the second extinguishing space 34 by means of extinguishing element partitions 32. In a state where the fire extinguishing element partition plate 32 is screwed to the peripheral surface of the second fire extinguishing space 34, a space in which no component is accommodated is formed between the fire extinguishing element partition plate 32 and the third fire extinguishing space 35 in the axial direction.

In the present embodiment, the axial dimension of the second fire extinguishing space 34 is formed to the dimension of the space S in which no member is accommodated between the third fire extinguishing space 35 and the state in which the two fire extinguishing elements 30 and the fire extinguishing element partition 32 are accommodated, but the present invention is not limited thereto. The axial dimension of the second extinguishing space 34 may also be formed to a dimension that does not form a space S with the third extinguishing space 35 in a state where the two extinguishing elements 30, 30 and the extinguishing element partition 32 are accommodated. That is, the axial dimension of the second fire extinguishing space 34 may be formed to be substantially equal to the axial dimensions of the two fire extinguishing elements 30, 30 and the fire extinguishing element partition 32.

In the flame arrester 3, the two fire extinguishing elements 30 and 30 are inserted into the second fire extinguishing space 34 through the third fire extinguishing space 35 from the downstream side opening 31B of the fire extinguishing element holder 31, and the fire extinguishing element partition plate 32 is screwed to the threaded portion in the peripheral surface of the second fire extinguishing space 34. Flame arrestor 3 is thereby assembled. In the flame arrester 3 in such an assembled state, the upstream opening 31A of the fire extinguishing element holder 31 is supported by the upstream pipe body 20 by coming into contact with the perpendicular surface 23A of the upstream flange 23 of the upstream pipe body 20 with the spacer 6 interposed therebetween, and the downstream opening 31B of the fire extinguishing element holder 31 is supported by the speed reducing mechanism 4 by inserting the spacer 6 and the upstream opening 41A of the speed reducing mechanism 4 in the flow direction in the third fire extinguishing space 35. The fire extinguishing element 30, the fire extinguishing element holder 31, and the fire extinguishing element partition 32 are fixed coaxially with the central axis P of the pipe 2 in a state where the flame arrester 3 is supported between the upstream pipe body 20 and the speed reducing mechanism 4.

In the present embodiment, the two fire extinguishing elements 30 and the fire extinguishing element partition 32 are fixed to the fire extinguishing element holder 31 by directly screwing the fire extinguishing element partition 32 to the fire extinguishing element holder 31, but the present invention is not limited thereto. The two fire extinguishing elements 30 and the fire extinguishing element partition 32 may be fixed to the fire extinguishing element holder 31 by using a fixing member such as a bolt, or may be fixed by a known fixing method different from this. Further, the flame arrester 3 and the speed reduction mechanism 4 may be configured to be held in close contact with each other via a gasket by being sandwiched between the upstream flange 23 of the upstream pipe body 20 and the downstream flange 27 of the downstream pipe body 21 and fastened by a pair of bolts 71, thereby fixing the fire extinguishing elements 30 and 30.

As shown in fig. 1, the reduction gear mechanism 4 is configured to include a plurality of (four in the illustrated example) orifice members 15 (members), a cylindrical reduction gear frame 41 for housing the four orifice members 15, and an orifice partition plate 42 for positioning the four orifice members 15. In the present embodiment, the speed reduction mechanism 4 is provided at a position adjacent to the downstream side in the flow direction of the flame arrester 3. In the present embodiment, the reduction mechanism 4 is configured to include four orifice members 15, but the present invention is not limited to this. The reduction mechanism may be configured to include two or more orifice members (members).

As shown in fig. 1, the four orifice members 15 have substantially the same structure and substantially the same function. The four orifice members 15 are configured to be separated from each other in a state before assembly. Each orifice member 15 is formed in a disk shape having a thickness in the axial direction. Each orifice member 15 is provided so that the outside and the inside of each orifice member 15 in the axial direction communicate with each other and are coaxial with the central axis P of the pipe 2 so that the combustible gas passes through in the axial direction.

As shown in fig. 2A and 2B, each orifice member 15 has an outer peripheral surface 5A which is a cylindrical surface in contact with a peripheral surface constituting the first decelerating space 43 in the reducer frame 41, and each orifice member 15 is formed in a disk shape having an outer diameter dimension Φ 6 (shown in fig. 2B). As shown in fig. 1 and 2A, each orifice member 15 includes a first orifice space 50A through which the combustible gas passes, and a second orifice space 150B provided downstream of the first orifice space 50A in the flow direction and continuous with the first orifice space 50A. In the present embodiment, as shown in fig. 1, the axial dimension L1 of the first orifice space 50A and the axial dimension L2 of the second orifice space 150B are formed to be substantially equal to each other, and the axial dimensions L1 and L2 are formed to be about 30 mm. As shown in fig. 2B, the inner diameter of the first orifice space 50A is about 150 mm. In addition, the volume of the first orifice space 50A is formed larger than the volume of the second orifice space 150B. In the assembled state, the four orifice members 15 are arranged in parallel so that the first orifice space 50A and the second orifice space 150B are alternately repeated from the upper side in the flow direction.

As shown in fig. 1, such an orifice member 15 constitutes a part of the inner surface 40 (orifice inner surface 4A) through which the combustible gas passes in an assembled state. As shown in fig. 2A, the orifice inner surface 4A includes orthogonal surfaces 5B and 5C (non-parallel surfaces) orthogonal to the axis and located at a boundary between the first orifice space 50A and the second orifice space 150B, an upstream inner peripheral surface 5D extending parallel to the axis from an outer edge B of the orthogonal surface 5C, and through holes 150 extending parallel to the axis and located in a through region T formed between the orthogonal surfaces 5B and 5C and surrounded by an inner edge a of the orthogonal surface 5C, and the orifice inner surface 4A is configured by continuously and repeatedly providing the upstream inner peripheral surface 5D, the orthogonal surface 5C, the through portion 5E, and the orthogonal surface 5B in this order from the upper side in the flow direction. In each orifice member 15, the first orifice space 50A is a space located inside the upstream inner peripheral surface 5D, and the second orifice space 150B is a space located inside the through portion 5E. The second orifice space 150B is constituted by a plurality of (37) through holes 150 formed in the through portion 5E. Hereinafter, a region of the penetrating portion 5E viewed from a direction orthogonal to the central axis P (axis) is referred to as a penetrating region T. In the present embodiment, the through region T is formed in a circular shape as shown by a one-dot chain line in fig. 2B. The diameter of the through portion 5E (through region T) is about 20 mm. As shown in fig. 2B, each through hole 150 is formed in a circular shape in cross section perpendicular to the axis of the orifice member 15. In the present embodiment, each through-hole 150 is formed to have an inner diameter of approximately 2mm in diameter Φ 10. The through portion 5E (through region T) has 37 through holes 150 formed therein.

In the present embodiment, each through-hole 150 is formed to have an inner diameter of approximately 2mm in diameter Φ 10, but the present invention is not limited thereto. The inner diameter φ 10 of each through hole 150 may be 2mm or less. The inner diameter φ 10 of each through hole 150 may be 1mm or more. Further, the inner diameter φ 10 of each through hole 150 may be 2mm or more. The inner diameter Φ 10 of each through-hole 150 may be 5mm or more, or 8mm or more. The inner diameter φ 10 of each through hole 150 may be 10mm or less.

The orthogonal surface 5C of each orifice member 15 is provided substantially orthogonal to the central axis P of the orifice member 15. That is, the orthogonal surface 5C of each orifice member 15 is a surface (flat surface) that is not parallel to the central axis P of the orifice member 15. The upstream inner peripheral surface 5D of each orifice member 15 is configured to have a cylindrical surface with the central axis P of the orifice member 15 as the axis. The upstream inner peripheral surface 5D of each orifice member 15 is formed by a surface (curved surface) parallel to the central axis P of the orifice member 15. As shown in fig. 1 and 2B, the radial dimension Φ 8 (shown in fig. 2B) of the through portion 5E of each orifice member 15 and the inner diameter dimension Φ 4 (shown in fig. 1) of the downstream side barrel 21 are formed to be substantially equal to each other. In the present embodiment, the "plane (curved surface) parallel to the central axis P" means a plane having a substantially equal distance from the central axis P at any position in the axial direction of the plane, and the "plane (flat surface) not parallel to the central axis P" means a plane having a predetermined angle with respect to the central axis P.

In the present embodiment, the inner diameter Φ 7 (as shown in fig. 2B) of the first orifice space 50A is defined to be about 150mm, but the present invention is not limited thereto. The inner diameter φ 7 may be 100mm or less. The inner diameter φ 7 may be substantially 100mm or less, or may be 80mm or less. The inner diameter Φ 7 of the first orifice space 50A may be 60mm or more. The inner diameter of the first orifice space 50A, i.e., the dimension Φ 7, may be 100mm or more. The inner diameter φ 7 may be 100mm or more, or may be 200mm or more. The inner diameter of the first orifice space 50A, i.e., the diameter 7, may be substantially 300mm or less.

In the present embodiment, the axial dimensions L1 and L2 of the orifice members 15 are defined to be about 30mm, but the present invention is not limited to this. The axial dimensions L1 and L2 may be 30mm or less. The axial dimensions L1 and L2 may be 20mm or less, 10mm or less, or 5mm or less. The axial dimensions L1 and L2 of the orifice members 15 may be substantially 2mm or more.

As shown in fig. 1, the speed reducer frame 41 is configured in a tubular shape having openings 41A and 41B at both ends in the axial direction so that the outside and the inside communicate with each other in the axial direction of the upstream pipe barrel 20 and the downstream pipe barrel 21. Of the openings 41A and 41B of the reduction gear frame 41, one positioned on the upstream side in the fluid flow direction F1 is referred to as an "upstream-side opening 41A", and the other positioned on the downstream side is referred to as a "downstream-side opening 41B".

As shown in fig. 1 and 2B, the reduction gear frame 41 includes: a first decelerating space 43 having an inner diameter dimension substantially equal to the outer diameter dimension Φ 6 (shown in fig. 2B) of each orifice member 15, and a second decelerating space 44 having a fifth inner diameter dimension Φ 9 smaller than the inner diameter dimension of the first decelerating space 43. The first decelerating space 43 is provided on the upstream side in the flow direction of the second decelerating space 44. The inner peripheral surface 44A constituting the second decelerating space 44 is formed by a curved surface parallel to the central axis P of each orifice member 15. The inner peripheral surface 44A constituting the second decelerating space 44 and the upstream inner peripheral surface 5D of each orifice member 15 are formed as follows: the distance D1 from the central axis P of the reduction gear frame 41 and the orifice members 15 to the inner circumferential surfaces 44A and 5D is substantially equal.

The first decelerating space 43 is configured to accommodate the four orifice members 15 and the orifice partition plate 42. The axial dimension of the first decelerating space 43 is set to a dimension that forms a gap with the upstream opening 41A of the reducer frame 41 in a state where the four orifice members 15 and the orifice partition plate 42 are accommodated. The circumferential surface of the first decelerating space 43 is threaded from a position separated from the downstream opening 41B by the axial dimension of four orifice members 15 to the upstream opening 41A so as to be able to screw the orifice partition plate 42.

As shown in fig. 1, the orifice partition plate 42 is formed in a disk shape having a thickness in the axial direction of the pipe 2. The orifice partition plate 42 is provided so that the outside and the inside in the axial direction communicate with each other, and the combustible gas passes through the pipe 2 in the axial direction.

The orifice partition plate 42 includes an upstream orthogonal surface 42A and a downstream orthogonal surface 42C that face each other, and an inner circumferential surface 42B that is continuous with each inner edge of the upstream orthogonal surface 42A and the downstream orthogonal surface 42C. The upstream orthogonal surface 42A and the downstream orthogonal surface 42C are provided orthogonal to the axis of the orifice partition 42, and the inner peripheral surface 42B is provided parallel to the axis. The distance (dimension) D2 from the center axis P to the inner peripheral surface 42B of the orifice partition plate 42 and the radial dimension Φ 8 of the through portion 5E (through region T) of each orifice member 15 are formed to be substantially equal.

The orifice partition 42 is configured to be capable of being screwed with a threaded portion in the circumferential surface of the first decelerating space 43 of the reducer frame 41. In a state where four orifice members 15 are accommodated in the first decelerating space 43 of the reducer frame 41, the orifice partition plate 42 is screwed to a threaded portion in the circumferential surface of the first decelerating space 43. The four orifice members 15 are fixed at predetermined positions in the first decelerating space 43 by the orifice partition plate 42.

As shown in fig. 1, in the assembled state, the orifice partition 42 constitutes a part of the inner surface 40 (partition inner surface 4B) of the speed reduction mechanism 4 through which the combustible gas passes. The partition inner surface 4B is configured to have a downstream-side orthogonal surface 42C that is continuous with the upstream-side inner peripheral surface 5D of the orifice member 52(15) located on the most upstream side in the assembled state, an inner peripheral surface 42B that extends parallel to the axis from the inner edge of the downstream-side orthogonal surface 42C, and an upstream-side orthogonal surface 42A that is continuous with the upper edge of the inner peripheral surface 42B and orthogonal to the axis.

In the speed reducing mechanism 4, four orifice members 15 are inserted into the first speed reducing space 43 from the upstream opening 41A of the speed reducer frame 41, and in this state, the orifice partition plate 42 is screwed to the peripheral surface of the first speed reducing space 43. In this manner, the four orifice members 15 and the orifice partition plate 42 are fixed to the reducer frame 41.

In the present embodiment, the four orifice members 15 and the orifice partition plate 42 are fixed to the reduction gear frame 41 by directly screwing the orifice partition plate 42 to the reduction gear frame 41, but the present invention is not limited to this. The four orifice members 15 and the orifice partition plate 42 may be fixed to the reduction gear frame 41 by using a fixing member such as a bolt, or a known fixing method different from this may be used. Further, the orifice member 15 may be fixed by clamping the flame arrestor 3 and the speed reducing mechanism 4 via the gasket between the upstream flange 23 of the upstream pipe body 20 and the downstream flange 27 of the downstream pipe body 21 and fastening them with a pair of bolts 71 in a state where they are in close contact with each other.

In a state where the orifice partition plate 42 is screwed to the peripheral surface of the first decelerating space 43, a space in which no member is accommodated is formed between the screwing position of the orifice partition plate 42 and the upstream side opening portion 41A of the reducer frame 41. That is, in the assembled state of the reduction mechanism 4, a space (space) between the screwing position of the orifice partition plate 42 and the upstream side opening portion 41A of the reduction gear frame 41 is constituted by the upstream side portion 43A of the circumferential surface of the first reduction space 43 of the reduction gear frame 41. The upstream-side portion 43A is continuous with the upstream-side orthogonal surface 42A of the orifice partition 42, and constitutes a portion of the inner surface 40 of the reduction mechanism 4.

In the present embodiment, the upstream side portion 43A of the circumferential surface of the first decelerating space 43 of the reducer frame 41 is a space in which any member is not accommodated. There may be no space at a part 43A on the upstream side in the circumferential surface of the first decelerating space 43 of the reducer frame 41. That is, the axial dimension of the first decelerating space 43 may be formed to be substantially equal to the axial dimensions of the four orifice members 15 and the orifice partition plate 42.

In addition, in a state where the orifice partition plate 42 is screwed to the peripheral surface of the first decelerating space 43, a space (second decelerating space 44) in which no member is accommodated is formed between the orifice member 51(15) located on the most downstream side and the downstream side opening portion 41B of the reducer frame 41. That is, the second decelerating space 44 is constituted by an inner peripheral surface 44A constituting the space 44. The inner peripheral surface 44A is continuous with the perpendicular surface 5B of the orifice member 51 located on the most downstream side, and constitutes a part of the inner surface 40 of the speed reducing mechanism.

The reduction mechanism 4 having the inner surface 40 having the portion 43A of the circumferential surface of the reduction gear frame 41, the partition inner surface 4B, the orifice inner surface 4A, and the inner circumferential surface 44A of the reduction gear frame 41 is assembled in this manner.

In the assembled state of the speed reduction mechanism 4, the orthogonal surfaces 5B and 5C of the orifice members 15 and the downstream orthogonal surface 42C of the orifice spacer 42 function as "non-parallel surfaces". Hereinafter, the perpendicular surfaces 5B and 5C of the orifice members 15 and the downstream perpendicular surface 42C of the orifice spacer 42 may be collectively referred to as "non-parallel surfaces".

Next, a procedure of assembling the flame arrester with a speed reducing mechanism 1 will be explained.

The flame arrester 3 and the reduction mechanism 4 are assembled in advance, respectively. In the flame arrester 3, the upstream opening 31A of the fire extinguishing element holder 31 is brought into contact with the perpendicular surface 23A of the upstream flange 23 of the upstream pipe body 20 with the spacer 6 interposed therebetween, and the downstream opening 31B of the fire extinguishing element holder 31 is inserted into the third fire extinguishing space 35. In the speed reducing mechanism 4, the downstream opening 41B of the speed reducer frame 41 is brought into contact with the perpendicular surface 27A of the downstream flange 27 of the downstream pipe body 21 so as to sandwich the gasket 6. In this state, bolts 71 are inserted into the bolt holes 24 and 25 of the upstream pipe 20 and the downstream pipe 21, and nuts 72 are screwed to both ends of the bolts 71. In this way, the pipe 2 including the upstream pipe body 20 and the downstream pipe body 21, the flame arrester 3, and the speed reduction mechanism 4 are assembled to form the flame arrester 1 with a speed reduction mechanism provided coaxially with the central axis P of the pipe 2.

According to the flame arrester 1 with the speed reducing mechanism having a plurality of orifice members 15 (members) communicating in the axial direction of the pipe 2 and configured in a cylindrical shape, the inner surface of each orifice member 15 (member) has at least one non-parallel surface 5B, 5C, 42C non-parallel to the axis, and the non-parallel surfaces 5B, 5C, 42C are provided in parallel in the axial direction. With this configuration, the number of components can be changed according to the required performance. Therefore, a mechanism with high versatility can be formed.

When a flame is generated in the pipe 2, the flame flows forward or backward in the fluid flow direction F1, but by providing the non-parallel surfaces 5B, 5C, and 42C, the flame is turned around in the surface extending direction of the non-parallel surfaces 5B, 5C, and 42C (the radial direction of the pipe 2) in the direction away from the central axis P. Since the non-parallel surfaces 5B, 5C, and 42C are arranged in parallel in the axial direction, a phenomenon in which the flame winds back in a direction away from the center axis P repeatedly occurs. In this way, the flame propagating through the pipe 2 is decelerated by the occurrence of the wraparound phenomenon repeatedly. By providing the speed reduction mechanism 4 for reducing the speed of the flame propagating through the pipe 2 on the side of the flow direction F1 (one side in the axial direction) of the flammable fluid in the flame arrester 3, the speed of the flame reaching the flame arrester 3 is reduced. Therefore, even when the flame arrestor 3 is downsized in the axial direction of the pipe 2, desired fire extinguishing performance can be ensured while reducing pressure loss and ensuring a flow rate. Further, by providing such a speed reducing mechanism 4 on at least one side of the flame arrester 3 in the flowing direction F1 of the combustible fluid, the flame arrester 3 can be made small in the radial direction of the pipe 2, and even in this case, it is possible to achieve reduction in pressure loss and securing of the flow rate, and to secure desired fire extinguishing performance. Therefore, by providing the speed reduction mechanism 4 on at least one side in the flow direction F1 of the combustible fluid in the flame arrester 3, it is possible to achieve both the securing of the desired extinguishing performance and the reduction of the pressure loss (securing of the flow rate).

Further, the reduction gear mechanism 4 includes a first orifice space 50A and a second orifice space 150B that communicate with each other in the axial direction of the pipe 2 alternately, the first orifice space 50A is configured with one opening, and the second orifice space 150B is configured with a plurality of (37) through holes 150 penetrating through a penetration region T that is narrower than the opening. According to such a configuration, a first orifice space 50A having a large volume and including the non-parallel surfaces 5B and 5C and being constituted by one opening, and a second orifice space 150B having a small volume and being constituted by a plurality of (37) through holes 150 are alternately and continuously formed in the axial direction. Thereby, the flame propagating through the pipe 2 repeatedly passes through the large and small spaces. Therefore, the flame propagation speed of the flame propagating through the pipe 2 can be sufficiently reduced.

Next, the inventors of the present invention conducted a large number of experiments and simulations and found an appropriate range of the number of orifice members (members). That is, the number of orifice members 15 (members) constituting the reduction gear mechanism 4 is preferably 4 or more. When the number of orifice members 15 is 3 or less, it may be difficult to ensure desired fire extinguishing performance. Therefore, the number of orifice members 15 (members) is preferably 4 or more, and more preferably 7 or more.

The number of orifice members 15 (members) constituting the reduction gear mechanism 4 is preferably 30 or less. When the number of orifice members 15 (members) is 31 or more, although a predetermined effect can be confirmed, there is a case where the manufacturing cost, the assembly work, and the like increase. Therefore, the number of orifice members 15 (members) is preferably 30 or less, and more preferably 15 or less.

In the speed reducing mechanism 4 of the present embodiment, the plurality of non-parallel surfaces 5B, 5C, and 42C are formed such that the angles between the non-parallel surfaces 5B, 5C, and 42C and the central axis P (axis) are substantially equal to each other. According to such a configuration, the flame propagating through the pipe 2 can be decelerated by repeatedly causing a wraparound phenomenon.

In the speed reducing mechanism 4 of the present embodiment, the angles between the non-parallel surfaces 5B, 5C, and 42C and the central axis P (axis) are formed to be substantially 90 degrees. With this configuration, the volume of the space having the non-parallel surfaces 5B, 5C, and 42C as the constituent surfaces can be set to a sufficient size, and thus the flame propagating through the pipe 2 can be sufficiently decelerated.

The following describes a part of numerous experiments and simulations performed by the inventors of the present invention. In the flame arrester 1 with a speed reducing mechanism of the present embodiment, the inner diameter dimension Φ 7 of the first orifice space 50A is appropriately set in the range of 30mm to 60mm, the radial dimension Φ 8 of the through portion 5E is set to 20mm, the axial dimension L1 of each orifice member 15 is appropriately set in the range of 7mm to 42mm, each through hole 150 is set to have a diameter of 2mm, and 37 through holes 150 are formed in the through portion 5E.

The number of orifice members 15 constituting the speed reduction mechanism 4 is appropriately set in the range of 1 to 15, and the flame propagation speed is measured. The results are shown in FIG. 3. The number (n) of orifice members 15 was set to 1 to 15, and data was acquired 3 times for each number. Only when the number (n) of orifice members 15 was 5, 10, 15, data was acquired 5 times each.

In FIG. 3, the vertical axis represents the Flame propagation velocity (m/s), and the horizontal axis represents the Number of Orifice members (Number of Orifice: n). When the inner diameter dimension Φ 7 of the first orifice space 50A was set to 60mm, the axial dimension L1 of each orifice member 15 was set to 14mm, the radial dimension Φ 8 of the through portion 5E was set to 20mm, and the aperture ratio in the through portion 5E was set to 37%, it was confirmed that the propagation velocity of the flame was decelerated. When the aperture ratio of the through portion 5E was set to 58%, it was confirmed that the propagation speed of the flame was reduced.

It was confirmed that the flame propagation speed was reduced when the number of the orifice members 15 constituting the speed reduction mechanism 4 was 2 or more. In addition, it was confirmed that the effect becomes more stable in the case of 4 or more, and a higher effect can be obtained in the case of 7 or more. When the number of the orifice members 15 is 8 or more, it is confirmed that the flame propagation speed is further reduced as the number of the orifice members is increased.

The present invention is not limited to the above-described embodiments, and includes other configurations that can achieve the object of the present invention, and modifications shown below are also included in the present invention.

In the first embodiment described above, the four orifice members 15 are alternately and repeatedly provided in parallel with the first orifice space 50A and the second orifice space 150B from the upper side in the flow direction in the assembled state of the reduction mechanism 4, but the present invention is not limited to this. The reduction mechanism 4 may be used by reversing one end and the other end in the axial direction so that the four orifice members 15 are alternately and repeatedly provided in parallel with the second orifice space 150B and the first orifice space 50A from the upper side in the flow direction.

In the first embodiment, the speed reduction mechanism 4 is provided at a position adjacent to the downstream side in the flow direction of the flame arrester 3, but the present invention is not limited to this. As shown in fig. 4, the retarding mechanism 4 may be arranged adjacent to the flame arrester 3 on both sides of the flame arrester 3. That is, as shown in fig. 4, the flame arrester 10 with a deceleration mechanism may be configured to have: a pipe 2 through which a combustible gas (combustible fluid) flows, a flame arrester 3 communicating with the pipe 2, a pair of speed reduction mechanisms 4, 4 provided on both sides of the flame arrester 3 and communicating with the flame arrester 3, and an annular gasket 6 interposed between the pipe 2 and the flame arrester 3 and speed reduction mechanisms 4. In addition, the speed reduction mechanism 4 may be provided on the downstream side in the flow direction of the flame arrester 3. In addition, the reduction mechanism 4 and the flame arrester 3 may not be in an abutting position. That is, other members may be provided between the reduction mechanism 4 and the flame arrester 3. Fig. 4 is a cross-sectional view showing a modification of the flame arrester 1 with a speed reducing mechanism shown in fig. 1. In fig. 4, members having substantially the same functions and substantially the same configurations as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. According to such a configuration, the pressure loss can be reduced while sufficiently ensuring the desired fire extinguishing performance.

In each orifice member 15 ', the first orifice space 50A may be a space located inside the upstream inner peripheral surface 5D, the second orifice space 150B may be a space located inside the through portion 5E ', and the through portion 5E ' may be formed in a regular hexagon as shown by a one-dot chain line in fig. 5B. Fig. 5A and 5B are views showing modifications of the speed reducing mechanism 4 shown in fig. 2. In fig. 5A and 5B, members having substantially the same functions and substantially the same configurations as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. This provides substantially the same effect as the first embodiment.

In the first embodiment described above, each through hole 150 is formed in a circular shape in cross section orthogonal to the axis of the orifice member 15, but the present invention is not limited to this. As shown in fig. 6A and 6B, each through hole 250B formed in the through portion 5E ″ may be formed in a regular hexagon (regular polygon) in cross section orthogonal to the axis of the orifice member 15 ″. Alternatively, the cross section of each through hole orthogonal to the axis of the orifice member may be polygonal, elliptical, or irregular. In this case, the equivalent circle diameter of each through hole may be substantially equal to the inner diameter Φ 10 of each through hole 150. This provides substantially the same effect as the first embodiment.

In the first embodiment, the orifice member 15 in the assembled state is configured by successively and repeatedly disposing the upstream inner peripheral surface 5D, the perpendicular surface 5C, the penetrating portion 5E, and the perpendicular surface 5B in this order from the upper side in the flow direction, but the present invention is not limited to this. As shown in fig. 7, the orifice member 105 in the assembled state may be configured by successively and repeatedly arranging an upstream inner peripheral surface 105E (non-parallel surface), a through portion 105F, and an orthogonal surface 105C (non-parallel surface) in this order from the upstream side in the flow direction. The boundary m between the upstream inner peripheral surface 105E of each orifice member 105 and the through portion 105F is located at the middle in the axial direction of each orifice member 105. The upstream inner peripheral surface 105E is configured to have an inclination such that the radial dimension gradually decreases toward the downstream in the fluid flow direction F1. The through holes 350 of the through portion 105F extend parallel to the central axis P of the pipe 2.

In each orifice member 105, the first orifice space 350A may be a space located inside the upstream inner peripheral surface 105E, the second orifice space 350B may be a space located inside the through portion 105F, and the through portion 105F may be configured to have a plurality of through holes 350. Each through hole 350 may be formed to have a circular cross section perpendicular to the axis of the orifice member 105. This provides substantially the same effect as the first embodiment.

(second embodiment)

Next, a speed reducing mechanism according to a second embodiment will be described with reference to fig. 8, 9A, and 9B. Fig. 9A is a sectional view showing the speed reducing mechanism 14, and fig. 9B is a plan view of fig. 9A. In fig. 8, 9A, and 9B, members having substantially the same functions and substantially the same structures as those of the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in fig. 8, the reduction gear mechanism 14 according to the second embodiment includes a plurality of (four in the illustrated example) orifice members 5 (members), a tubular reduction gear frame 41 for housing the four orifice members 5, and orifice spacers 42 for positioning the four orifice members 5. In the present embodiment, the speed reduction mechanism 14 is provided at a position adjacent to the downstream side in the flow direction of the flame arrester 3. In the present embodiment, the reduction mechanism 14 is configured to include four orifice members 5, but the present invention is not limited to this. The reduction mechanism may be configured to include one or more orifice members (members).

As shown in fig. 8, the four orifice members 5 have substantially the same structure and substantially the same function. The four orifice members 5 are configured to be separated from each other in a state before assembly. Each orifice member 5 is provided in a disk shape having a thickness in the axial direction. The orifice members 5 are arranged so that the outside and inside of each orifice member 5 in the axial direction communicate with each other, and are arranged coaxially with the central axis P of the pipe 2 so as to pass the combustible gas in the axial direction.

As shown in fig. 9A and 9B, each orifice member 5 has an outer peripheral surface 5A which is a cylindrical surface in contact with the peripheral surface constituting the first decelerating space 43 in the reducer frame 41, and each orifice member 5 is formed in a disk shape having an outer diameter dimension Φ 6. As shown in fig. 8, each orifice member 5 has a first orifice space 50A through which the combustible gas passes, and a second orifice space 50B provided downstream of the first orifice space 50A in the flow direction and continuous with the first orifice space 50A. In the present embodiment, the axial dimension L1 of the first orifice space 50A and the axial dimension L2 of the second orifice space 50B are formed to be substantially equal in size and to be substantially about 30mm, the inner diameter dimension Φ 7 of the first orifice space 50A is formed to be substantially about 150mm, and the inner diameter dimension Φ 8 of the second orifice space 50B is formed to be substantially about 50 mm. That is, the volume of the first orifice space 50A is formed larger than the volume of the second orifice space 50B. The four orifice members 5 are provided in parallel so as to alternately repeat the first orifice space 50A and the second orifice space 50B from the upper side in the flow direction in the assembled state.

As shown in fig. 8, such an orifice member 5 constitutes, in an assembled state, a part of the inner surface 40 (orifice inner surface 4A) of the speed reduction mechanism 14 through which the combustible gas passes. The orifice inner surface 4A has a boundary surface 5C (non-parallel surface) located at the boundary between the first orifice space 50A and the second orifice space 50B, an upstream-side inner peripheral surface 5D extending parallel to the axis from an outer edge B of the boundary surface 5C, a downstream-side inner peripheral surface 5E extending parallel to the axis from an inner edge a of the boundary surface 5C, and an orthogonal surface 5B (non-parallel surface) continuing to the downstream-side inner peripheral surface 5E and orthogonal to the axis, and the orifice inner surface 4A is configured by repeating these surfaces continuously from the upper side in the flow direction in the order of the upstream-side inner peripheral surface 5D, the boundary surface 5C, the downstream-side inner peripheral surface 5E, and the orthogonal surface 5B. In each orifice member 5, the first orifice space 50A is a space located inside the upstream inner peripheral surface 5D, and the second orifice space 50B is a space located inside the downstream inner peripheral surface 5E.

The boundary surface 5C of each orifice member 5 is provided substantially orthogonal to the central axis P of the orifice member 5. That is, the boundary surface 5C of each orifice member 5 is a surface (plane) that is not parallel to the central axis P of the orifice member 5. The upstream inner peripheral surface 5D and the downstream inner peripheral surface 5E of each orifice member 5 are each configured as a cylindrical surface having the central axis P of the orifice member 5 as an axis. The upstream inner peripheral surface 5D and the downstream inner peripheral surface 5E of each orifice member 5 are each formed by a surface (curved surface) parallel to the central axis P of the orifice member 5. As shown in fig. 8 and 9B, the inner diameter Φ 8 (shown in fig. 9B) of the downstream inner peripheral surface 5E of each orifice member 5 and the inner diameter Φ 4 (shown in fig. 8) of the downstream tubular member 21 are formed to be substantially equal. In the present embodiment, the "plane (curved surface) parallel to the central axis P" means a plane having a substantially equal distance from the central axis P at any position in the axial direction of the plane, and the "plane (flat surface) not parallel to the central axis P" means a plane having a predetermined angle with respect to the central axis P.

Although the inner diameter of the first orifice space 50A is defined to be approximately 150mm in diameter Φ 7 in the present embodiment, the present invention is not limited thereto. The inner diameter φ 7 may be 100mm or less. The inner diameter φ 7 may be approximately 100mm or less, or may be 80mm or less. The inner diameter Φ 7 of the first orifice space 50A may be 60mm or more. The inner diameter of the first orifice space 50A, i.e., the dimension Φ 7, may be 100mm or more. The inner diameter φ 7 may be 100mm or more, or may be 200mm or more. The inner diameter of the first orifice space 50A, i.e., the diameter 7, may be substantially 300mm or less.

In the present embodiment, the axial dimensions L1 and L2 of the orifice members 5 are defined to be about 30mm, but the present invention is not limited to this. The axial dimensions L1 and L2 may be 30mm or less. The axial dimensions L1 and L2 may be 20mm or less, 10mm or less, or 5mm or less. The axial dimensions L1 and L2 of the orifice members 5 may be substantially 2mm or more.

The present invention is not limited to the above-described embodiments, and includes other configurations that can achieve the object of the present invention, and modifications shown below are also included in the present invention.

In the second embodiment described above, the four orifice members 5 are provided in parallel with the first orifice space 50A and the second orifice space 50B alternately and repeatedly from the upper side in the flow direction in the assembled state of the reduction mechanism 14, but the present invention is not limited to this. The reduction gear mechanism 14 may be used by reversing one end and the other end in the axial direction so that the four orifice members 5 are alternately and repeatedly provided in parallel with the second orifice space 50B and the first orifice space 50A from the upper side in the flow direction.

In the second embodiment described above, the speed reduction mechanism 14 is provided at a position adjacent to the downstream side in the flow direction of the flame arrester 3, but the present invention is not limited to this. As shown in fig. 10, a retarding mechanism 14 may be provided adjacent the flame arrestor 3 on both sides of the flame arrestor 3. That is, as shown in fig. 10, the flame arrester 10 with a deceleration mechanism may be configured to have: a pipe 2 through which a combustible gas (combustible fluid) flows; a flame arrester 3 communicating with the pipe 2; a pair of speed reduction mechanisms 14, 14 provided on both sides of the flame arrester 3 in communication with the flame arrester 3; and an annular gasket 6 interposed between the pipe 2, the flame arrester 3, and the speed reduction mechanism 14. In addition, the speed reduction mechanism 14 may be provided on the downstream side in the flow direction of the flame arrester 3. In addition, the retarding mechanism 14 and flame arrestor 3 may not be in an abutting position. That is, other components may be provided between the retarding mechanism 14 and the flame arrestor 3. Fig. 10 is a cross-sectional view showing a modification of the flame arrester 1 with a deceleration mechanism shown in fig. 8. In fig. 10, members having substantially the same functions and substantially the same configurations as those of the second embodiment are denoted by the same reference numerals, and description thereof is omitted. According to such a configuration, the pressure loss can be reduced while sufficiently ensuring the desired fire extinguishing performance.

(third embodiment)

Next, a speed reducing mechanism according to a third embodiment will be described with reference to fig. 11. Fig. 11 is a cross-sectional view showing a speed reducing mechanism 104' according to a third embodiment of the present invention. In fig. 11, members having substantially the same functions and substantially the same configurations as those of the second embodiment are denoted by the same reference numerals, and the description thereof is omitted. The reduction gear mechanism 14 according to the second embodiment and the reduction gear mechanism 104 'according to the third embodiment have different orifice members 5 and 105' in shape. Therefore, in the third embodiment, each orifice member 105' will be described.

In the third embodiment, as shown in fig. 11, the inner surface of the orifice member 105 'in the assembled state is configured by successively and repeatedly providing an upstream inner peripheral surface 105E' (non-parallel surface), a downstream inner peripheral surface 105F ', and an orthogonal surface 105C' (non-parallel surface) in this order from the upper side in the flow direction. The boundary m between the upstream inner peripheral surface 105E 'and the downstream inner peripheral surface 105F' of each orifice member 105 'is located at the middle in the axial direction of each orifice member 105'. The upstream inner peripheral surface 105E' is configured to have an inclination such that the radial dimension gradually decreases downstream in the fluid flow direction F1. The downstream inner circumferential surface 105F' extends parallel to the central axis P of the pipe 2.

Alternatively, as shown in fig. 12, the inner surface of the orifice member 115 in the assembled state may be configured by arranging the inclined surface 115D (non-parallel surface) and the orthogonal surface 115C (non-parallel surface) in this order from the upstream side in the flow direction, and repeating the above-described steps. In this case, the inclined surface 115D of the speed reducing mechanism 114 may be formed to have an inclination such that the radial dimension gradually decreases toward the downstream in the flow direction, and the orthogonal surface 115C may be provided to be orthogonal to the axis. Fig. 12 is a cross-sectional view showing a modification of the speed reducing mechanism according to the third embodiment of the present invention. In fig. 12, members having substantially the same functions and substantially the same configurations as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

Alternatively, as shown in fig. 13, the inner surface of the orifice member 125 in the assembled state may be configured by repeatedly providing the upstream-side inclined surface 125E (non-parallel surface) and the downstream-side inclined surface 125F (non-parallel surface) in this order from the upstream side in the flow direction. In this case, the upstream-side inclined surface 125E may be configured to have an inclination in which the radial dimension gradually decreases downstream in the fluid flow direction F1, and the downstream-side inclined surface 125F may be configured to have an inclination in which the radial dimension gradually increases downstream in the fluid flow direction F1. That is, in the speed reducing mechanism 124, the orifice member 125 may have a ridge portion formed at a boundary m where the upstream inclined surface 125E and the downstream inclined surface 125F intersect, and a valley portion formed at a boundary n where the upstream inclined surface 125E and the downstream inclined surface 125F intersect, respectively, of the adjacent orifice members 125, and these ridge portion and valley portion may be alternately arranged in parallel in the axial direction. Further, the boundary m between the upstream-side inclined surface 125E and the downstream-side inclined surface 125F may be located at the middle in the axial direction of each orifice member 125. Fig. 13 is a cross-sectional view showing another modification of the speed reducing mechanism according to the third embodiment of the present invention. In fig. 13, members having substantially the same functions and substantially the same configurations as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 13, in the inner surface of the orifice member 125 in the assembled state, the upstream-side inclined surface 125E is configured to have an inclination such that the radial dimension thereof gradually decreases toward the downstream in the fluid flow direction F1, and the downstream-side inclined surface 125F is configured to have an inclination such that the radial dimension thereof gradually increases toward the downstream in the fluid flow direction F1. That is, the upstream inclined surface 125E and the downstream inclined surface 125F are each formed of a flat surface, but the present invention is not limited thereto. In the inner surface of the orifice member 135 in the assembled state, as shown in fig. 14, the upstream-side inclined surface 135E and the downstream-side inclined surface 135F may be formed of curved surfaces, respectively, in the speed reduction mechanism 134. In this case, it may have a wave-like shape as follows: a boundary m at which the upstream inclined surface 135E and the downstream inclined surface 135F intersect is formed as a peak portion, a boundary n at which the downstream inclined surface 135F and the upstream inclined surface 135E of each orifice member 135 adjacent to each other intersect is formed as a valley portion, and these peak portions and valley portions are alternately arranged in parallel in the axial direction to form a wave shape. Fig. 14 is a cross-sectional view showing another modification of the speed reducing mechanism according to the third embodiment of the present invention. In fig. 14, members having substantially the same functions and substantially the same configurations as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

(fourth embodiment)

Next, a speed reducing mechanism according to a fourth embodiment will be described with reference to fig. 15A and 15B. Fig. 15A is a sectional view showing the speed reducing mechanism 144, and fig. 15B is a plan view of fig. 15A. In fig. 15A and 15B, members having substantially the same functions and substantially the same structures as those of the second embodiment are denoted by the same reference numerals, and descriptions thereof are omitted. The speed reduction mechanism 144 according to the fourth embodiment is configured to include one orifice member 145, and the orifice member 145 includes a plurality of spaces 145A to 145D inside and is configured by one continuous member.

As shown in fig. 15A, the orifice member 145 is provided so that the outside and the inside in the axial direction communicate with each other, and is provided coaxially with the central axis P of the pipe 2 so that the combustible gas passes through in the axial direction of the pipe 2. The orifice member 145 has a first orifice space 145A, a second orifice space 145B provided on the downstream side in the flow direction F1 of the fluid in the first orifice space 145A and continuous with the first orifice space 145A, a third orifice space 145C provided on the downstream side in the flow direction of the second orifice space 145B and continuous with the second orifice space 145B, and a fourth orifice space 145D provided on the downstream side in the flow direction of the third orifice space 145C and continuous with the third orifice space 145C, and the spaces 145A, 145B, 145C, 145D are repeatedly formed. The orifice spaces 145A to 145D are spaces having substantially the same volume.

The four space forming portions forming the orifice spaces 145A to 145D are provided at positions shifted by 90 degrees clockwise, respectively, as viewed from above in the flow direction. That is, four space forming portions forming the orifice spaces 145A to 145D are provided eccentrically to each other.

The first orifice space 145A is an internal space of a space forming portion configured to have an inner surface 14a1 parallel to the central axis P and orthogonal surfaces 14a2 and 14A3 (non-parallel surfaces) continuous with both ends of the inner surface 14a1 in the axial direction and orthogonal to the central axis P. The orthogonal surface 14a2 is provided on the upstream side in the flow direction, and the orthogonal surface 14A3 is provided on the downstream side in the flow direction from the orthogonal surface 14a 2. The second orifice space 145B is an internal space of a space forming portion configured to have an inner surface 14B1 parallel to the central axis P and orthogonal surfaces 14B2 and 14B3 (non-parallel surfaces) continuous with both ends in the axial direction of the inner surface 14B1 and orthogonal to the central axis P. The orthogonal surface 14B2 is provided on the upstream side in the flow direction, and the orthogonal surface 14B3 is provided on the downstream side in the flow direction from the orthogonal surface 14B 2. The third orifice space 145C is an internal space of a space forming portion configured to have an inner surface 14C1 parallel to the central axis P and orthogonal surfaces 14C2 and 14C3 (non-parallel surfaces) continuous with both ends of the inner surface 14C1 in the axial direction and orthogonal to the central axis P. The orthogonal surface 14C2 is provided on the upstream side in the flow direction, and the orthogonal surface 14C3 is provided on the downstream side in the flow direction from the orthogonal surface 14C 2. The fourth orifice space 145D is an internal space of a space forming portion configured to have an inner surface 14D1 parallel to the central axis P and orthogonal surfaces 14D2 and 14D3 (non-parallel surfaces) continuous with both ends in the axial direction of the inner surface 14D1 and orthogonal to the central axis P. The orthogonal surface 14D2 is provided on the upstream side in the flow direction, and the orthogonal surface 14D3 is provided on the downstream side in the flow direction from the orthogonal surface 14D 2.

According to the speed reducing mechanism 144 having such an orifice member 145, the flame can be sufficiently reduced. That is, in the speed reducing mechanism 14 of the second embodiment, the large-volume orifice spaces 50A and the small-volume orifice spaces 50B are formed so as to be alternately continuous in the axial direction, and the flame propagating through the pipe 2 repeatedly passes through the large-volume spaces 50A and the small-volume spaces 50B to sufficiently reduce the speed of the flame propagating through the pipe 2, but the present invention is not limited thereto. Even when the flow of the fluid repeatedly passes through the orifice spaces 145A to 145D having substantially the same volume, substantially the same effect as that of the speed reducing mechanism 14 of the second embodiment can be obtained.

In the fourth embodiment, the four space forming portions forming the orifice spaces 145A to 145D are provided at positions shifted by 90 degrees clockwise as viewed from above in the flow direction, but the present invention is not limited to this. For example, as shown in fig. 16A and 16B, the orifice member 245 of the reduction gear 244 may have orifice spaces 245A to 245D formed in the order of the orifice space 245A, the orifice space 245C, the orifice space 245B, and the orifice space 245D in the axial direction from the upper side in the flow direction, and the orifice space 245A and the orifice space 245C located at the positions facing each other with the central axis P therebetween, and the orifice space 245B and the orifice space 245D located at the positions facing each other with the central axis P therebetween may be located at positions shifted by 90 degrees around the central axis P. Fig. 16 is a view showing a modification of the speed reducing mechanism shown in fig. 15, fig. 16A is a sectional view showing the speed reducing mechanism, and fig. 16B is a plan view of fig. 16A. This provides substantially the same effect as the speed reducing mechanism 14 of the second embodiment.

As shown in fig. 17A and 17B, for example, the orifice spaces 345A and 345C of the orifice member 345 of the speed reducing mechanism 344 may be formed in the axial direction in the order of the orifice space 345A and the orifice space 345C from the upper side in the flow direction, and the orifice spaces 345A and 345C may be arranged in parallel so as to be located at opposing positions with the central axis P therebetween. Fig. 17 is a view showing a modification of the speed reducing mechanism shown in fig. 15, fig. 17A is a sectional view showing the speed reducing mechanism, and fig. 17B is a plan view of fig. 17A. This provides substantially the same effect as the speed reducing mechanism 14 of the second embodiment.

In the present embodiment, the reduction mechanisms 144, 244, and 344 are configured to have four space forming portions, but the present invention is not limited to this. The speed reduction mechanism may be configured to include two or more (a plurality of) space forming portions.

The plurality of space forming portions may be arranged to be eccentric to each other in the axial direction so as to include the central axis P from the upper side in the flow direction, and the space forming portions may be arranged in the axial direction at random (randomly). This provides substantially the same effect as the speed reducing mechanism 14 of the second embodiment.

In addition, although the above description discloses the best configuration, method and the like for carrying out the present invention, the present invention is not limited thereto. That is, although the present invention has been described with particular reference to specific embodiments, it is possible for those skilled in the art to add various modifications to the shape, material, number, and other detailed configurations of the above-described embodiments without departing from the technical concept and the intended scope of the present invention. Therefore, the description of the shape, material, and the like disclosed above is an exemplary description for facilitating understanding of the present invention, and is not intended to limit the present invention, and therefore, the description of the name of a member beyond a part or all of the limitations of the shape, material, and the like is also included in the present invention.

Description of the reference numerals

1. 10 flame arrester with speed reducing mechanism

2 piping

3 flame arrester

4. 14, 104', 114, 124, 134, 144, 244, 344 deceleration mechanism

5. 15, 15 ', 105', 115, 125, 135, 145, 245, 345 orifice member (member)

5B orthogonal plane (non-parallel plane)

5C boundary surface (non-parallel surface)

Downstream side orthogonal surface (non-parallel surface) of 42C orifice spacer

P center shaft

Claims (11)

1. A speed reduction mechanism that is provided in a pipe through which a flammable fluid flows, that is provided at least on one side in an axial direction of the pipe of a flame arrester for extinguishing a flame propagating in the pipe, and that reduces a propagation speed of the flame propagating in the pipe, the speed reduction mechanism being characterized in that,

the speed reduction mechanism is configured in a tubular shape having a plurality of members communicating with each other in an axial direction of the pipe,

the inner surface of each member has at least one non-parallel surface including at least one of an inclined surface which is not parallel to an axis and in which an inner diameter dimension of each member gradually decreases toward one of the axial directions, a curved surface in which the inner diameter dimension of each member gradually decreases toward one of the axial directions, an inclined surface in which the inner diameter dimension of each member gradually increases toward one of the axial directions, and a curved surface in which the inner diameter dimension of each member gradually increases toward one of the axial directions,

the non-parallel surfaces are arranged side by side in the axial direction,

a peak portion protruding inward in the radial direction of the pipe is formed on an inner surface of any one of the members, and a boundary between adjacent members is formed as a valley portion recessed outward in the radial direction.

2. The reduction mechanism according to claim 1, wherein the number of the members is 4 or more.

3. The reduction mechanism according to claim 1 or 2, wherein the number of the members is 30 or less.

4. A reduction mechanism according to claim 1 or 2, wherein the non-parallel surfaces are at substantially equal angles to the axis.

5. The reduction mechanism according to claim 1 or 2,

having a plurality of space forming portions arranged eccentrically to each other,

the adjacent space forming portions communicate and are provided with the non-parallel faces at their boundaries.

6. A flame arrester with a speed reduction mechanism is characterized by comprising:

the reduction mechanism of claim 1; and

the flame arrestor for extinguishing a flame propagating within the pipe.

7. A flame arrester with a speed reduction mechanism is characterized by comprising:

the reduction mechanism of claim 2; and

the flame arrestor for extinguishing a flame propagating within the pipe.

8. A flame arrester with a speed reduction mechanism is characterized by comprising:

a reduction mechanism according to claim 3; and

the flame arrestor for extinguishing a flame propagating within the pipe.

9. A flame arrester with a speed reduction mechanism is characterized by comprising:

the reduction mechanism of claim 4; and

the flame arrestor for extinguishing a flame propagating within the pipe.

10. A flame arrester with a speed reduction mechanism is characterized by comprising:

the reduction mechanism of claim 5; and

the flame arrestor for extinguishing a flame propagating within the pipe.

11. A flame arrester as claimed in any of claims 6 to 10 wherein the retarding mechanism is provided on both sides of the flame arrester in the axial direction of the pipe.

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