JPH05296438A - Detonation deterrent - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a detonation suppressor that prevents the propagation of detonation waves and safely extinguishes flames. [Structure] A detonation suppressor that prevents a flame generated suddenly from propagating as a detonation wave in a pipe through which flammable gas such as hydrogen or acetylene flows. A partition plate 9 which is connected in series and has a mesh-like opening is arranged in the vicinity of the expansion pipe and the connection part of the expansion pipe, and the next expansion pipe is connected between the partition plate and the expansion pipe and the connection part of the expansion pipe. A gas vent hole 8 is provided, and a partition plate 9 having a mesh-like opening is provided at the outlet of the expansion tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents a flame generated suddenly from propagating as a detonation wave in a pipe through which a flammable gas such as hydrogen or acetylene flows and extinguishes it safely. It relates to detonation arresters (detonation arresters).

[0002]

2. Description of the Related Art Detonation is combustion accompanied by shock waves, and the temperature and pressure are higher than those of ordinary combustion waves, and once generated, there is a high possibility of causing a serious accident. Moreover, the propagation velocity of the detonation wave becomes supersonic, and it is characteristic that it propagates both upstream and downstream of the plant piping. To deter this harmful detonation, detonation deterrent devices have been devised for a long time.

There is a flame arrester as a flame propagation preventer, but the detonation suppressor is also the same in principle. In other words, it is a method of quenching the flame by lowering the temperature and pressure of the flame by using a solid flame-extinguishing element such as a wire net or a porous plate. For example, the Industrial Safety Research Institute technical data RIIS-TN-76-9, RIIS-TN-
77-8 etc.

FIG. 3 shows an example of a detonation suppressor, in which a housing 12 is arranged between pipes 11 and 19, and a perforated plate 13, a wire mesh 14, spacers 15 and 16 are inserted into the housing 12 in this order, and a holding gland 17 is provided.
Tighten them to fix them in the housing 12, insert the gasket 18 between the housing 12 and the flange of the pipe 19, and fasten the flange of the pipe 19 to the housing 12 with the bolt 20, and place the detonation suppressor in the middle of the pipe. It is composed.

On the other hand, as a method of lowering the temperature and pressure, a method using an expansion tube has been devised. When a detonation wave suddenly emerges (is dispersed) from a narrow space to a wide space,
The pressure drops rapidly. For example, Industrial Safety Research Institute technical data RIIS-TN-78-2, The Japan Society of Mechanical Engineers (B) 55
Volume 511, Paper No. 88-0572A, etc.

FIG. 4 shows how the temperature of the detonation wave can be lowered by arranging an expansion tube in the middle of the piping by calculation. In this example, (Proceedings of the Japan Society of Mechanical Engineers (B), Volume 55, 511)
No. 88-0572A), the temperature of the detonation wave is from 2200 ℃ to 1200
It has dropped to ℃.

[0007]

When a wire net is used as a detonator, it is necessary to stack the wire nets in multiple layers. RI
In IS-TN-77-8, the number of wire mesh is 30 or more. Also, when using a perforated plate, it is necessary to make the diameter of the holes sufficiently small, and in RIIS-TN-77-8, it is 1/10 or less of the normal pipe diameter. All of these are piping resistance (pressure loss)
There is a problem of increasing.

On the other hand, when an expansion tube is used as a detonation suppressor, it is necessary to increase the cross-sectional area ratio of the expansion tube inlet to the expansion tube in order to lower the temperature until the detonation wave is extinguished. , Will be quite large. In addition, if the gas flow has a knitting flow, a sufficient temperature drop cannot be obtained, and it does not serve as a reliable detonation deterrent.

According to the present invention, a plurality of expansion tubes are connected in series,
A partition plate having a mesh-like opening is arranged in the vicinity of the connection portion of the expansion pipe and the expansion pipe, and a gas vent hole communicating with the next expansion pipe is provided between the partition plate and the connection portion of the expansion pipe and the expansion pipe, Further, it is an object of the present invention to provide a detonation suppressor having a small pipe resistance by quenching detonation waves by providing a partition plate having a mesh-like opening at the outlet of the expansion tube.

[0010]

The gist of the present invention is to provide hydrogen,
In a pipe through which a flammable gas such as acetylene flows, a detonation suppressor that prevents a flame that suddenly occurs from propagating as a detonation wave, and connects a plurality of conical expansion pipes in series. A partition plate having a mesh-like opening is arranged in the vicinity of the connection portion of the expansion pipe and the expansion pipe, and a gas vent hole communicating with the next expansion pipe is provided between the partition plate and the connection portion of the expansion pipe and the expansion pipe,
Further, it is a detonation deterrent device in which a partition plate having a mesh-like opening is provided at the outlet of the expansion tube.

[0011]

The present invention will be described in detail below. The detonation wave can be dispersed by using a conical expansion tube, and the temperature and pressure of the detonation wave can be reduced sequentially by connecting multiple conical expansion tubes in series. Therefore, it is not necessary to increase the ratio of the sectional area of the inlet of the expansion tube to the sectional area of the expansion tube, and the detonation suppressor can be downsized.

The principle of quenching the detonation wave and the temperature change of the detonation suppressor in which a plurality of expansion tubes are connected in series will be described with reference to FIG. In FIG. 2, four expansion tubes are connected in series, and a partition plate 9 having a mesh-like opening is arranged in the vicinity of the expansion tube and the connecting portion of the expansion tube (tip of the expansion tube). Board 9
And the expansion pipe and the connecting part of the expansion pipe, a gas vent hole 8 communicating with the next expansion pipe is provided, and a partition plate 9 having a mesh-like opening is provided at the exit of the last expansion pipe. It is an example of a deterrent device. The detonation wave propagates from left to right in FIG.
Combustible gas is flowing from right to left.

In FIG. 2, the propagating detonation wave is the first
The temperature and pressure are reduced by being dispersed in the stage expansion pipe 3, and branched at the inlet of the second stage expansion pipe 4. The detonation wave that branches off at the inlet of the second-stage expansion tube and propagates outside the second-stage expansion tube is extinguished by the partition plate 9 having a mesh-like opening at the tip of the first-stage expansion tube. Similarly, the detonation wave passing through the second stage expansion tube 4 is further reduced in temperature and pressure in the second stage expansion tube and is branched at the third stage expansion tube inlet. The detonation wave propagating outside the third stage expansion tube is the second
The flame is extinguished by the partition plate 9 having a mesh-like opening at the tip of the step expansion tube.

As described above, since the temperature and pressure of the detonation wave passing through the expansion tubes of the first stage → the second stage → the third stage → the fourth stage are sufficiently lowered, the detonation wave exits at the last expansion pipe outlet. The partition plate 9 provided with the mesh-shaped openings provided therein extinguishes the flame. The crosses in the figure indicate the detonation of the detonation wave.

Between the partition plate 9 having a mesh-like opening and the expansion pipe and the connecting portion of the expansion pipe, a gas vent hole 8 leading to the next expansion pipe is provided.
Since it is provided, the pressure of the detonated wave that has extinguished the flame can be released to the next expansion tube.

As described above, since a plurality of expansion tubes are connected in series to branch and disperse the detonation wave, the temperature and pressure drop is large. Therefore, the number of partition plates with mesh-like openings at the outlet of the expansion tube can be small, and there is a sufficient gas flow path in the center of the expansion tube, resulting in piping resistance (pressure loss).
Is extremely small.

[0017]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an example of the detonation suppressor of the present invention. (A) is a longitudinal sectional view of the detonation suppressor in which four conical expansion tubes are connected in series,
(b) is a cross-sectional view of each portion.

In the figure, 1 is a downstream pipe, 2 is an upstream pipe, and a detonation suppressor is arranged between the downstream pipe 1 and the upstream pipe 2. In the detonation suppressor, four expansion tubes, a first expansion tube 3, a second expansion tube 4, a third expansion tube 5, and a fourth expansion tube 6, are connected in series. A plurality of wire meshes 7 are arranged in the vicinity of the expansion pipe and each connection portion of the expansion pipe (expansion pipe tip portion), and further, in the second stage expansion pipe 4, the third stage expansion pipe 5, and the fourth stage expansion pipe 6. Wire net 7
Between the expansion pipe and each connection portion of the expansion pipe, a gas vent hole 8
Is provided. Outlet of the fourth stage expansion pipe 6 (upstream pipe 2
A wire mesh 10 is provided at the connection portion).

The flammable gas flows from the upstream pipe 2 to the downstream pipe 1. The detonation wave generated by some ignition on the downstream side propagates in the downstream pipe 1, is dispersed in the first stage expansion pipe 3 to lower the temperature and pressure, and is branched at the inlet of the second stage expansion pipe 4. The detonation wave that branches off at the inlet of the second stage expansion tube 4 and propagates outside the second stage expansion tube 4 is extinguished by the wire mesh 7 at the tip of the first stage expansion tube 4, and is discharged from the gas vent hole 8 to the second stage expansion tube 4. Pour into 4.

Similarly, the detonation wave passing through the second stage expansion tube 4 is further reduced in temperature and pressure in the second stage expansion tube 4 and is branched at the inlet of the third stage expansion tube 5. The detonation wave propagating outside the third stage expansion tube 5 is quenched by the wire mesh 7 at the tip of the second stage expansion tube 4, and flows into the third stage expansion tube 5 through the gas vent hole 8.

As described above, the detonation wave passing through the first-stage → second-stage → third-stage → fourth-stage expansion tubes has a sufficiently lowered temperature and pressure, so the fourth-stage expansion tube 6 It is extinguished by several wire meshes 10 installed at the exit of.

As described above, since the detonation suppressor of the present invention has a large gas passage in the central portion, the pressure loss in this portion is extremely small. In addition, the wire mesh 10 at the outlet of the expansion pipe is
A few sheets are enough compared to 30 sheets, so the pressure loss in this part is also small. Further, the detonation suppressor of the present invention can change the number of expansion tubes depending on the type of combustible gas.

[0023]

INDUSTRIAL APPLICABILITY The present invention is a detonation suppressor for preventing a flame generated suddenly from propagating as a detonation wave in a pipe through which a combustible gas such as hydrogen or acetylene flows. Connect the conical expansion pipes in series, and arrange the expansion pipes and partition plates with mesh openings near the connection of the expansion pipes.
A detonation suppressor provided with a gas vent hole leading to the next expansion tube between the partition plate and the expansion tube and the connection part of the expansion tube, and further provided with a partition plate having a mesh-like opening at the outlet of the expansion tube. Therefore, the temperature and pressure of the detonation wave can be reduced sufficiently,
The detonation can be prevented from propagating and the flame can be extinguished safely.
In addition, this detonation suppressor can secure a sufficient gas flow path in the center part and can reduce the number of wire meshes provided at the outlet of the expansion pipe, resulting in extremely small pressure loss and detonation. The suppressor itself can also be made smaller.

[Brief description of drawings]

1 is an example of a detonation suppressor of the present invention, (a) is a longitudinal sectional view of a detonation suppressor in which four expansion tubes are connected in series, (b)
[Fig. 3] is a cross-sectional view of each portion.

FIG. 2 is a diagram illustrating the detonation wave quenching principle and temperature change of the detonation suppressor of the present invention.

FIG. 3 is a diagram showing an example of a conventional detonation suppressor.

FIG. 4 is a diagram showing an example in which a temperature drop of a detonation wave caused by an expansion tube is calculated.

[Explanation of symbols]

1 ... Downstream piping, 2 ... Upstream piping, 3 ... First stage expansion tube, 4 ...
2nd stage expansion tube, 5 ... 3rd stage expansion tube, 6 ... 4th stage expansion tube,
7 ... Wire mesh, 8 ... Degassing hole, 9 ... Partition plate opened in a mesh shape, 10 ... Wire mesh, 11 ... Piping, 12 ... Housing, 13 ... Perforated plate, 14 ... Wire mesh, 15 ... Spacer, 16 ... Spacer, 17 ... Pressure gland, 18 ... Gasket, 19 ... Piping, 20 ... Bolt.

Claims (1)

[Claims] 1. A detonation suppressor for preventing a flame, which is suddenly generated, from propagating as a detonation wave in a pipe through which a flammable gas such as hydrogen or acetylene flows. The pipes are connected in series, and a partition plate with a mesh-like opening is arranged near the expansion pipe and the connection part of the expansion pipe, and the next expansion pipe is provided between the partition plate and the expansion pipe and the connection part of the expansion pipe. A detonation deterrent device characterized by having a vent hole communicating with it and further having a partition plate with a mesh-like opening at the outlet of the expansion tube.