Firefighting methods that reduce O2 concentration

Abstract

To suppress noise caused by sudden decompression and expansion of a fire extinguishing gas.SOLUTION: Provided is a gas injection apparatus including: an injection head (13) having a nozzle portion (12); a sound absorbing material (125) made of a porous metal into which the extinguishing gas discharged from the nozzle portion flows; a ring member (122) that comes into contact with the sound absorbing material and fixes the sound absorbing material; and a connecting member (129) that connects the injection head and the ring member; wherein the nozzle portion is provided with a nozzle hole (16), and the sound-absorbing material has one end face (125b) from which the extinguishing gas is discharged and the other end face (125a) facing the opening of the nozzle hole, so that the extinguishing gas discharged from the nozzle hole can flow directly into the porous metal from the other end face, and the connecting member includes a screw-fitting portion (123) that can be screwed into the injection head, and the one end face is open to the atmosphere except for the portion that is in contact with the ring member.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to a gas fire extinguishing facility that extinguishes a fire by discharging a fire extinguishing gas such as N2 gas or a halide gas as a fire extinguishing agent into a fire extinguishing target section in a building when a fire occurs, and more specifically, to a gas fire extinguishing facility that can be suitably implemented to reduce a loud noise generated when the fire extinguishing gas is ejected from an ejection head provided in the fire extinguishing target section.

Background Art

[0002] Conventionally, various buildings are equipped with gas fire extinguishing facilities that extinguish a fire by discharging a fire extinguishing gas such as CO2 gas, N2 gas, and a halide into a fire extinguishing target section and reducing the O2 concentration in the fire extinguishing target section.

[0003] FIG. 16 is a perspective view showing a fire extinguishing gas ejection unit 1 used in a conventional gas fire extinguishing facility. The fire extinguishing gas ejection unit 1 includes an ejection head 3 that ejects high-pressure fire extinguishing gas supplied during a fire from a fire extinguishing gas supply source 2, and a conduit 4 to which the ejection head 3 is connected.

[0004] The conduit 4 has a main pipe 5 connected to the fire extinguishing gas supply source 2, a branch pipe 6 interposed in the main pipe 5, and a branch pipe 7 through which the fire extinguishing gas from the main pipe 5 is guided and to which the ejection head 3 is connected. The main pipe 5 is fastened by a fastening tool 10 such as a U-bolt to a building frame or a base 8 and a bracket 9 fixed to the frame, and is installed in a state where the vibration and displacement of the ejection head 3 are suppressed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the conventional technology described above, a large amount of high-pressure fire extinguishing gas supplied from the fire extinguishing gas supply source 2 through the conduit 4 is injected from the spray head 3. As a result, the high-speed flow of fire extinguishing gas injected from the nozzle hole 116 formed in the nozzle portion 112 of the spray head 3 generates a loud noise that is like cutting through the air.

[0007] The object of the present invention is to provide a gas fire extinguishing system that can attenuate the sound caused by the jet stream of fire extinguishing gas from the spray head. [Means for solving the problem]

[0008] The present invention (a) A conduit 14 for guiding high-pressure fire extinguishing gas, (b) A fire extinguishing gas supply source 15 that supplies high-pressure fire extinguishing gas to the conduit 14, (c) The injection head 13, A nozzle section 12 having nozzle holes 16 for spraying high-pressure fire extinguishing gas into the space within the fire-fighting area of ​​a building, An injection head 13 having an injection head end connected to the end of the conduit 14, (d) Sound-dampening devices 17, 17b, 17c, 17f, 17g, 17h that reduce the sound produced by the discharge of fire extinguishing gas from the nozzle section 12 and spray it into the space within the area to be extinguished, Silencers 17, 17b, 17c having a mounting portion 43 that can be attached to the spray head 13, This gas fire extinguishing system is characterized by being equipped with 17f, 17g, and 17h. The present invention also, The nozzle portion 12 of the spray head 13 is located on the downstream side of the spray direction of the fire extinguishing gas in the spray head 13. It is located on the left side of Figures 2, 4, 5, 13, 14, and 15. The injection head end is on the upstream side of the injection direction of the fire extinguishing gas in the injection head 13 (Figures 2, 4, Located to the right of 5, 13, 14, 15, The nozzle hole 16 and the end of the spray head are characterized in that they extend along the axis of the end of the conduit 14. The present invention also, The end of the spray head is connected to the end of the conduit 14 by the first thread, The silencers 17, 17b, 17c, 17f, 17g, and 17h are detachable from the nozzle portion 12 of the spray head 13 by a second screw. The silencing devices 17, 17b, 17c, 17f, 17g, and 17h are characterized by having an axis that extends along the axis of the end of the conduit 14. The present invention, as shown in Figure 2, The silencing device 17 includes a cylindrical peripheral wall 25, an end wall 26 formed perpendicular to the axis of the peripheral wall 25 at one axial end of the peripheral wall 25, and a mounting portion 27 formed detachably for attachment to the injection head 13 at the other axial end of the peripheral wall 25. In the end wall 26, a gas release hole 34 is formed on the axis of the peripheral wall 25, penetrating in the thickness direction of the end wall. The internal space defined by the peripheral wall 25, the end wall 26, and the mounting portion 27 is characterized in that a cylindrical sound-absorbing material 33, mounted along the inner surface of the peripheral wall 25, is housed within it. As shown in Figure 4, the present invention is, The sound-dampening device 17b is (e) A cylindrical peripheral wall 35 having an axis extending along the axis of the nozzle hole 16, A peripheral wall 35 forms an internal space 39 that extends downstream from the outlet of the nozzle hole 16 in the direction of fire extinguishing gas injection, (f) An end wall 36 formed at one end of the peripheral wall 35 away from the nozzle portion 12 in the axial direction, which together defines the internal space 39 with the peripheral wall 35, and which has a plurality of ventilation holes 38 formed penetrating through the thickness direction of the end wall 36, (g) A mounting portion 37 formed at the other end of the peripheral wall 35 near the nozzle portion 12 in the axial direction, which is detachably attached to the spray head 13, (h) Sound-absorbing material 40 that is packed and loaded into the internal space 39, It has minute voids, The invention is characterized by including a sound-absorbing material 40 that diffuses the fire extinguishing gas, which is sprayed at high speed from the nozzle portion 12 of the spray head 13, in the sound-absorbing material 40 contained in the internal space 39, gradually reducing its pressure and expanding it to lower its flow velocity, absorbing vibrations in the sprayed flow of the fire extinguishing gas, and releasing it into the space within the fire-extinguishing target area through the ventilation holes 38. As shown in Figure 5, the present invention is as follows: The silencing device 17c is, (i) A cylindrical peripheral wall 41 having an axis that extends along the axis of the end of the conduit 14, An internal space 45 is formed downstream from the outlet of the nozzle hole 16 in the direction of injection of the fire extinguishing gas. (j) A circumferential wall 41 formed by distributing multiple ventilation holes 44 and penetrating in the thickness direction of the circumferential wall 41, and an end wall 42 formed perpendicular to the axis of the circumferential wall 41 at one end of the circumferential wall 41 away from the nozzle portion 12 in the axial direction, which together with the circumferential wall 41 defines the internal space 45, (k) A mounting portion 43 formed at the other end of the peripheral wall 41 near the nozzle portion 12 in the axial direction, the mounting portion 43 being detachable from the nozzle portion 12 of the spray head 13 by the second screw, (l) Sound-absorbing material 46 that is packed and contained in the internal space 45 without any gaps, The invention is characterized by including a sound-absorbing material 46 having fine voids, which diffuses the fire extinguishing gas sprayed at high speed from the nozzle portion 12 of the spray head 13 within the internal space 45, gradually reducing its flow velocity by depressurizing and expanding it, absorbing vibrations in the sprayed flow of the fire extinguishing gas, and releasing it into the space within the fire-extinguishing target area through the ventilation holes 44. As shown in Figure 13, the present invention is as follows: The nozzle hole 16 has a nozzle hole axis L12 that extends along the conduit axis at the end of the conduit 14, and the cross section of the nozzle hole 16 perpendicular to the nozzle hole axis L12 is uniform along the nozzle hole axis L12. The end face 12a around the outlet end of the nozzle hole 16 in the nozzle portion 12 of the spray head 13 is formed on a virtual plane perpendicular to the nozzle hole axis L12. The sound-dampening device 17f is (m) A cylindrical circumferential wall 121 having a circumferential wall axis L121 that extends along the nozzle hole axis L12, A peripheral wall 121 that forms an internal space 124 that expands downstream in the injection direction of the fire extinguishing gas from the outlet of the nozzle hole 16, (n) An end wall 122 that is formed continuously at one end of the peripheral wall 121 in the direction of the peripheral wall axis L121 away from the nozzle portion 12, defines the internal space 124 together with the peripheral wall 121, and has a through hole 122b formed therethrough in the direction of the peripheral wall axis L121, (o) A mounting portion 123 that is formed at the other end of the peripheral wall 121 in the direction of the peripheral wall axis L121 close to the nozzle portion 12 and is attached to the injection head 13, (p) A sound-absorbing material 125 that is packed and housed in the internal space 124 without gaps, which is made of a porous material, is columnar with a sound-absorbing material axis L125 that coincides with the peripheral wall axis L121, has one end face 125b of the sound-absorbing material 125 that is far from the nozzle portion 12 and the other end face 125c that is close to the nozzle portion 12, The other end face 125c of the sound-absorbing material 125 that is close to the nozzle portion 12 is formed on a virtual plane perpendicular to the sound-absorbing material axis L125, When the mounting portion 123 is attached to the injection head 13, the one end face 125b side is supported by the end wall 122, and the other end face 125c and the end face 12a of the nozzle portion 12 are in surface contact, has fine voids, and includes a sound-absorbing material 125 that diffuses the fire extinguishing gas injected at high speed from the nozzle portion 12 of the injection head 13 with the sound-absorbing material 125 housed in the internal space 124, gradually decompresses and expands it to reduce its flow velocity, absorbs the vibration of the injection flow of the fire extinguishing gas, and discharges it from the through hole 122b to the space in the fire extinguishing target section. As shown in FIG. 14, the present invention The end face around the outlet end of the nozzle hole 16 where the nozzle hole 16 in the nozzle portion 12 of the injection head 13 opens is formed on a virtual plane perpendicular to the axis of the nozzle hole 16, The sound silencer 17g (q) A cylindrical peripheral wall 131 having an axis extending along the axis of the nozzle hole 16, A peripheral wall 131 forms an internal space 140 that extends downstream from the outlet of the nozzle hole 16 in the direction of fire extinguishing gas injection, (r) An end wall 143 formed at one end of the peripheral wall 131 away from the nozzle portion 12 in the axial direction, which together with the peripheral wall 131 defines the internal space 140, and through holes that penetrate the peripheral wall 131 in the axial direction, (s) A mounting portion 133 is formed at the other end of the peripheral wall 131 that is close to the nozzle portion 12 in the axial direction and is attached to the spray head 13, (t) First, second and third sound-absorbing materials 134, 135, 1 housed in the internal space 140 36, made of porous metal, extending in the axial direction of the peripheral wall 131 from the nozzle portion 12 to the end Wall 143 has the first sound-absorbing material 134 and, The third sound-absorbing material 136 and the second sound-absorbing material 135 are provided in this order. The first sound-absorbing material 134 and the second sound-absorbing material 135 are columns having axes that coincide with the axis of the surrounding wall 131. It is in that state, The third sound-absorbing material 136 is cylindrical in shape and has an axis that coincides with the axis of the peripheral wall 131. The end face of the first sound-absorbing material 134 near the nozzle portion 12 is formed on a virtual plane perpendicular to the axis of the first sound-absorbing material 134. The second sound-absorbing material 135 has an end face that is away from the nozzle portion 12, As the mounting portion 133 is attached to the spray head 13, the end face of the second sound-absorbing material 135 that is away from the nozzle portion 12 comes into contact with the end wall 143, and the end face of the first sound-absorbing material 134 that is close to the nozzle portion 12 comes into surface contact with the end face of the nozzle portion 12. These first, second, and third sound-absorbing materials 134, 135, and 136 are, It has minute voids, The fire extinguishing gas, which is ejected at high speed from the nozzle portion 12 of the spray head 13, is diffused by the first to third sound-absorbing materials 134, 135, 136 contained in the internal space 140, causing them to gradually depressurize and expand, thereby reducing the flow velocity, absorbing vibrations in the sprayed flow of the fire extinguishing gas, and is released from the through-hole 122b into the space within the fire-extinguishing target area. This is characterized by the inclusion of first, second, and third sound-absorbing materials 134, 135, 136. The present invention, as shown in Figure 15, The spray head 13 is A cylindrical portion 167 is connected to the end of the conduit 14, extends along the axis of this end, and is formed by multiple nozzle holes 16 penetrating in the thickness direction, It has an end wall portion 165 that closes one axial end of the cylindrical portion 167 that is far from the end of the conduit 14, The silencing device 17h is, (u) The first sound-absorbing material 152, Formed in a cylindrical shape, The cylindrical portion 167 of the spray head 13 is inserted through, A first sound-absorbing material 152 has an inner surface that makes surface contact with the arc-shaped end surface around the outlet end of the nozzle hole 16, which is the outer surface of the cylindrical portion 167 of the spray head 13, (v) Casing 150, (v1) A cylindrical portion 157 that extends along the axis of the cylindrical portion 167 of the injection head 13 and surrounds the first sound-absorbing material 152 at intervals in the radial direction, (v2) A casing 150 having a cylindrical portion 157 that closes near the end of the conduit 14 and a casing end wall portion 159 that is connected to the injection head 13, (w) A second sound-absorbing material 153 is formed in a cylindrical shape, arranged along the inner circumferential surface of the cylindrical portion 157, and forms an annular space 170 between itself and the outer circumferential surface of the first sound-absorbing material 152, (x) A third sound-absorbing material 156 is provided at the end of the cylindrical portion 157 of the casing 150 that is furthest from the end of the conduit 14, and releases the fire-extinguishing gas from the annular space into the space within the fire-extinguishing area. (y) These first, second and third sound-absorbing materials 152, 153, 156 are, It has minute voids, The fire extinguishing gas, which is ejected at high speed from the nozzle portion 12 of the spray head 13, is diffused and gradually depressurized and expanded to reduce its flow velocity, thereby absorbing vibrations in the spray flow of the fire extinguishing gas. The present invention The silencing devices 17b;17c;17f;17g;17h are The end face 125c of the sound-absorbing material 40;46;125;134;152 is in surface contact with the end face 12a around the outlet end of the nozzle hole 16 in the nozzle portion 12 of the spray head 13, and the sound-absorbing material 40;46;125;134;152 has fine voids. The fire extinguishing gas, which is ejected at high speed from the nozzle hole 16 of the nozzle portion 12 formed in the spray head 13, is diffused by sound-absorbing materials 40;46;125;134;152, causing it to gradually depressurize and expand, thereby reducing its flow velocity.

[0009] According to the present invention, high-pressure fire extinguishing gas supplied from a fire extinguishing gas supply source to a conduit is sprayed into the space inside the building via a spray head. Such a spray head is equipped with a sound-dampening device to prevent the generation of loud spray noise caused by the high-speed spray flow of fire extinguishing gas ejected from the nozzle of the spray head. [Effects of the Invention]

[0010] According to the present invention, since a sound-dampening device is provided on the spray head, it is possible to prevent loud spraying noises from being generated even when fire-extinguishing gas is sprayed from the nozzle of the spray head in the event of a fire. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing a fire extinguishing gas injection unit 11 provided in a gas fire extinguishing system that is one embodiment of the present invention. [Figure 2] This is an enlarged cross-sectional view of the sound-dampening device 17. [Figure 3] This is an enlarged cross-sectional view showing a sound-dampening device 17a provided in a gas fire extinguishing system according to one reference example of the present invention. [Figure 4]This is an enlarged cross-sectional view showing a sound-dampening device 17b provided in a gas fire extinguishing system of another embodiment of the present invention. [Figure 5] This is an enlarged cross-sectional view showing a sound-dampening device 17c provided in yet another embodiment of the present invention. [Figure 6] This is a cross-sectional view showing a spray head 50 of a gas fire extinguishing system, which is another reference example of the present invention. [Figure 7] Figure 6 is a cross-sectional view illustrating the effect of the injection head 50 shown. [Figure 8] This is an enlarged cross-sectional view showing a sound-dampening device 60 provided in a gas fire extinguishing system of yet another reference example of the present invention. [Figure 9] This is an enlarged cross-sectional view showing a sound-dampening device 60a provided in a gas fire extinguishing system of yet another reference example of the present invention. [Figure 10] This is an enlarged cross-sectional view showing a sound-dampening device 17d provided in a gas fire extinguishing system of yet another reference example of the present invention. [Figure 11] This graph illustrates the noise reduction effect of the noise reduction device 17d. [Figure 12] This is an enlarged cross-sectional view showing a sound-dampening device 17e provided in a gas fire extinguishing system of yet another reference example of the present invention. [Figure 13] This is an enlarged cross-sectional view showing a sound-dampening device 17f provided in yet another embodiment of the present invention. [Figure 14] This is an enlarged cross-sectional view showing a sound-dampening device 17g provided in a gas fire extinguishing system of yet another embodiment of the present invention. [Figure 15] This is an enlarged cross-sectional view showing a sound-dampening device 17h provided in yet another embodiment of the present invention. [Figure 16] This is a perspective view showing a fire extinguishing gas injection unit 1 used in a conventional gas fire extinguishing system. [Modes for carrying out the invention]

[0012] Figure 1 is a perspective view showing a fire extinguishing gas injection unit 11 provided in a gas fire extinguishing system according to one embodiment of the present invention. The gas fire extinguishing system of this embodiment is installed within a fire-extinguishing area of ​​a building and includes an injection head 13 having a nozzle unit 12 that injects high-pressure fire extinguishing gas into the space within the fire-extinguishing area, a conduit 14 to which the injection head 13 is connected and which guides the high-pressure fire extinguishing gas to the injection head 13, a fire extinguishing gas supply source 15 that supplies high-pressure inert gas to the conduit 14, and is provided in the injection head 13. The system also includes a sound-dampening device 17 that reduces the sound generated by the spraying noise of the fire extinguishing gas ejected from the nozzle hole 16 formed in the nozzle section 12.

[0013] The fire extinguishing gas is made up of inert gases such as N2 gas and CO2 gas, or active gases such as halogenated gases. By releasing such a fire extinguishing gas as a fire extinguishing agent, the O2 concentration in the area to be extinguished can be reduced, thereby extinguishing the fire.

[0014] The spray head 13 and the silencer 17 constitute the fire extinguishing gas spray unit 11. Fire extinguishing gas is supplied to the spray head 13 from a fire extinguishing gas supply source 15 via a conduit 14. The conduit 14 includes a main pipe 23 connected to the fire extinguishing gas supply source 15, a branch pipe 18 interposed in the main pipe 23, and a branch pipe 19 connected to the branch pipe 18. High-pressure fire extinguishing gas from the fire extinguishing gas supply source 15 is guided to the spray head 13 via this conduit 14. The conduit 14 is fastened to the base 20 and bracket 21 with fasteners 22 such as U-bolts, and is installed on the building structure in a state where vibration and displacement are suppressed.

[0015] Figure 2 is an enlarged cross-sectional view of the sound-absorbing device 17. The sound-absorbing device 17 includes a cylindrical peripheral wall 25, an end wall 26 formed perpendicular to the axis of the peripheral wall 25 at one axial end of the peripheral wall 25, a mounting portion 27 detachably connected to the injection head 13 at the other axial end of the peripheral wall 25, and a cylindrical sound-absorbing material 33 fitted and housed within the peripheral wall 25 along its inner circumferential surface. Such sound-absorbing material 33 may be, for example, constructed by stacking multiple wire meshes. Gas release holes 34 are formed on the same axis in the end wall 26.

[0016] By using the sound-dampening device 17 configured in this way, the acoustic vibrations caused by the high-speed jet stream of fire-extinguishing gas ejected from the nozzle portion 12 of the spray head 13 are absorbed by the sound-absorbing material 33 and released to the outside through the gas discharge hole 34. This makes it possible to suppress the generation of spray noise caused by the ejection of fire-extinguishing gas.

[0017] The sound-absorbing device 17 in Figure 2 includes a cylindrical peripheral wall 25, an end wall 26 formed perpendicular to the axis of the peripheral wall 25 at one axial end of the peripheral wall 25, and a mounting portion 27 formed detachably for attachment to the injection head 13 at the other axial end of the peripheral wall 25. A gas discharge hole 34 is formed in the end wall 26, penetrating the thickness direction of the end wall along the axis of the peripheral wall 25. A cylindrical sound-absorbing material 33, mounted along the inner circumferential surface of the peripheral wall 25, is housed in the internal space defined by the peripheral wall 25, the end wall 26, and the mounting portion 27.

[0018] Figure 3 is an enlarged cross-sectional view showing a sound-dampening device 17a provided in a gas fire extinguishing system of one reference example of the present invention. The same reference numerals are used for parts corresponding to the embodiments described above. The sound-dampening device 17a of this reference example includes a cylindrical peripheral wall 25, an end wall 26 formed perpendicular to the axis of the peripheral wall 25 at one axial end of the peripheral wall 25, a mounting portion 27 on which a spray head 13 is integrally formed at the other axial end of the peripheral wall 25, and an inner cylinder 29 provided in the portion 28 of the nozzle portion 12 of the spray head 13 facing downstream in the direction of spraying the fire extinguishing gas.

[0019] The inner cylinder 29 has a straight cylindrical portion 31 in which a plurality of through holes 30 are formed, and an end plate 32 formed perpendicular to the axis of the cylindrical portion 31 at one end of the cylindrical portion 31 in the axial direction.

[0020] With this sound-dampening device 17, the fire extinguishing gas ejected at high speed from the nozzle of the spray head 13 collides with the cylindrical end plate 32 of the inner cylinder 29, is released from a plurality of through holes 30 formed in the cylindrical portion 31, and then is released to the outside through the gas release holes 34 formed in the end wall 26 after passing through the space between the cylindrical portion 31 and the peripheral wall 25, thereby suppressing the generation of sound caused by the release of fire extinguishing gas.

[0021] Figure 4 is an enlarged cross-sectional view showing a silencing device 17b provided in a gas fire extinguishing system of another embodiment of the present invention. The silencing device 17b of this embodiment has a cylindrical circumferential wall 35, an end wall 36 formed perpendicular to the axis of the circumferential wall 35 at one axial end of the circumferential wall 35, and a mounting portion 37 formed at the other axial end of the circumferential wall 35 so as to be detachably attached to the spray head 13. Multiple ventilation holes 38 are formed in the end wall 36, penetrating in the thickness direction of the end wall 36.

[0022] The sound-absorbing device 17b also houses sound-absorbing material 40 in an internal space 39 defined by the peripheral wall 35, end wall 36, and mounting portion 37. This sound-absorbing material 40 may be composed of multiple layers of wire mesh.

[0023] The silencing device 17b in Figure 4 comprises (e) a cylindrical peripheral wall 35 having an axis extending along the axis of the nozzle hole 16, forming an internal space 39 that extends downstream from the outlet of the nozzle hole 16 in the direction of fire extinguishing gas injection, (f) an end wall 36 formed at one end of the peripheral wall 35 away from the nozzle portion 12 in the axial direction, which together defines the internal space 39 with the peripheral wall 35, and having a plurality of ventilation holes 38 formed in the end wall 36 that penetrate in the thickness direction of the end wall 36, and (g) the axial direction of the peripheral wall 35 (h) A mounting portion 37 formed at the other end near the nozzle portion 12 and detachably attached to the spray head 13, and (h) a sound-absorbing material 40 packed and contained in the internal space 39, the sound-absorbing material 40 having fine voids, which diffuses the fire extinguishing gas sprayed at high speed from the nozzle portion 12 of the spray head 13 in the sound-absorbing material 40 contained in the internal space 39, gradually reducing its flow velocity by depressurizing and expanding it, absorbing vibrations of the sprayed fire extinguishing gas, and releasing it from the ventilation hole 38 into the space within the fire-extinguishing target area.

[0024] In a gas fire extinguishing system equipped with a sound-dampening device 17a configured in this way, the fire extinguishing gas ejected at high speed from the nozzle portion 12 of the spray head 13 passes through the space within the peripheral wall 35, collides with the end wall 36, and is discharged to the outside through a plurality of ventilation holes 38 formed in this end wall 36. This configuration of the sound-dampening device also prevents the generation of loud noises.

[0025] Figure 5 is an enlarged cross-sectional view showing a silencing device 17c provided in a gas fire extinguishing system of yet another embodiment of the present invention. The same reference numerals are used for parts corresponding to the previously described embodiments. The silencing device 17c of this embodiment has a cylindrical circumferential wall 41, an end wall 42 formed perpendicular to the axis of the circumferential wall 41 at one axial end of the circumferential wall 41, and a mounting portion 43 formed at the other axial end of the circumferential wall 41 so as to be detachably attached to the spray head 13. Multiple ventilation holes 44 are formed in the circumferential wall 41, penetrating in the thickness direction of the circumferential wall 41.

[0026] Such a sound-absorbing device 17c contains sound-absorbing material 46 in an internal space 45 defined by the peripheral wall 41, end wall 42, and mounting portion 43. This sound-absorbing material 46 may be made up of, for example, multiple layers of wire mesh.

[0027] The silencing device 17c in Figure 5 comprises (i) a cylindrical circumferential wall 41 having an axis extending along the axis of the end of the conduit 14, forming an internal space 45 that extends perpendicularly to the axis of the circumferential wall 41 downstream from the outlet of the nozzle hole 16 in the direction of injection of the fire extinguishing gas, with a plurality of ventilation holes 44 distributed and penetrating the circumferential wall 41 in the thickness direction, (j) an end wall 42 formed perpendicularly to the axis of the circumferential wall 41 at one end of the circumferential wall 41 away from the nozzle portion 12 in the axial direction, and together with the circumferential wall 41 defining the internal space 45, and (k) the nozzle in the axial direction of the circumferential wall 41 The mounting portion 43 is formed at the other end near the nozzle portion 12 and is detachably attached to the nozzle portion 12 of the spray head 13 by the second screw; and (l) sound-absorbing material 46 is packed and contained in the internal space 45 without any gaps, having fine voids, which diffuses the fire extinguishing gas sprayed at high speed from the nozzle portion 12 of the spray head 13 within the internal space 45, gradually reducing its flow velocity by depressurizing and expanding the sound-absorbing material 46, absorbs vibrations in the spray flow of the fire extinguishing gas, and releases it from the ventilation hole 44 into the space within the fire-extinguishing target area.

[0028] In a gas fire extinguishing system equipped with the sound-dampening device 17c configured in this way, the fire extinguishing gas sprayed from the nozzle portion 12 of the spray head 13 collides with the end wall 42, attenuating its flow velocity, and is released to the outside through a plurality of ventilation holes 44 formed in the peripheral wall 41. This prevents loud noises from being generated when the fire extinguishing gas is sprayed.

[0029] Figure 6 is a cross-sectional view showing a spray head 50 of a gas fire extinguishing system of yet another reference example of the present invention, and Figure 7 is a cross-sectional view illustrating the effect of the spray head 50 shown in Figure 6. The same reference numerals are used for parts corresponding to the embodiments described above. The gas fire extinguishing system of this reference example includes a spray head 50 installed inside a building and having a nozzle section 12 that sprays high-pressure fire extinguishing gas into the space inside the building, a conduit 14 to which the spray head 50 is connected and which guides the high-pressure fire extinguishing gas to the spray head 50, and a fire extinguishing gas supply source 15 that supplies high-pressure fire extinguishing gas to the conduit 14.

[0030] The nozzle portion 12 of the spray head 50 has a nozzle hole 16 having an inner circumferential surface 52 that smoothly connects to the inner circumferential surface 51 of the branch pipe 19 of the conduit 14.

[0031] By using the spray head 50 configured in this way, the high-pressure fire extinguishing gas supplied from the fire extinguishing gas supply source 15 to the conduit 14 is sprayed into the space inside the building through the nozzle hole 16 of the spray head 50. At this time, the spray head 50 has a nozzle hole 16 having an inner surface 52 that smoothly connects to the inner surface 51 of the branch pipe 19 of the conduit 14, so it is possible to prevent the generation of loud spray noise caused by the high-speed spray flow of fire extinguishing gas from the nozzle portion 12 of the spray head 50, for example, the edge portion 55 facing the inlet of the nozzle hole 16, which has an inner diameter D2 smaller than the inner diameter D1 of the branch pipe 19 of the conduit 14 in the spray head 50a shown in Figure 7.

[0032] Figure 8 is an enlarged cross-sectional view showing a silencing device 60 provided in a gas fire extinguishing system of yet another reference example of the present invention. The same reference numerals are used for parts corresponding to the embodiments described above. The silencing device 60 of this reference example has a cylindrical circumferential wall 61, an attachment portion 62 formed at one axial end of the circumferential wall 61 so as to be detachably attached to a branch pipe 19, an attachment portion 63 formed at the other axial end of the circumferential wall 61 so as to be detachably attached to a spray head 13, an end wall 64 formed perpendicular to the axis of the circumferential wall 61 at the one end, and an end wall 65 formed perpendicular to the axis of the circumferential wall 61 at the other end.

[0033] The end wall 64 has at least one through-hole 66 formed through it in the thickness direction. The at least one through-hole 66 is formed in the central part 68 of the end wall 64, centered on the axis of the peripheral wall 61, and restricts the flow rate of the fire extinguishing gas supplied from the branch pipe 19. The end wall 65 has a plurality of through-holes 67 formed through it in the thickness direction. The plurality of through-holes 67 are formed in the remaining peripheral part 70 of the end wall 65, excluding the central part 69, centered on the axis of the peripheral wall 61. The end walls 64 and 65 are made of, for example, perforated metal.

[0034] With this sound-dampening device 60, the fire extinguishing gas, which is ejected at high speed from the through-holes 66 formed in the end wall 64, collides with the central part 69 of the end wall 65 within the sound-dampening device 60, attenuating its flow velocity. After being released through multiple through-holes 67 formed in the end wall 65 into the space defined by the end wall 65 and the injection head 13, it is released to the outside through the nozzle holes 16 formed in the nozzle part 12. The sound-dampening device 60 reduces the flow velocity in the through-holes 67 formed in the end wall 65 by expanding the fire extinguishing gas ejected at high speed from the through-holes 66 formed in the end wall 64 within the space inside the sound-dampening device 60, thereby suppressing the generation of sound caused by the release of fire extinguishing gas from the nozzle holes 16.

[0035] In the reference example shown in Figure 8, a through-hole 67 is not formed in the central part 69 of the end wall 65, but a through-hole 67 may be formed in the central part 69 of the end wall 65. Not forming a through-hole 67 in the central part 69 of the end wall 65 results in a higher number of through-holes than forming a through-hole 67 in the central part 69 of the end wall 65. The large amount of fire extinguishing gas sprayed at high speed from position 6 is deflected, further reducing the flow velocity, resulting in a high noise reduction effect.

[0036] Figure 9 is an enlarged cross-sectional view showing a silencing device 60a provided in a gas fire extinguishing system of yet another reference example of the present invention. The same reference numerals are used for parts corresponding to the embodiments described above. The silencing device 60a of this reference example has a cylindrical circumferential wall 61, an attachment portion 62 formed at one axial end of the circumferential wall 61 so as to be detachably attached to a branch pipe 19, an attachment portion 63 formed at the other axial end of the circumferential wall 61 so as to be detachably attached to a spray head 13, an end wall 64a formed perpendicular to the axis of the circumferential wall 61 at the one end, and an end wall 65 formed perpendicular to the axis of the circumferential wall 61 at the other end.

[0037] A guide section 72 is formed on the axis of the circumferential wall 61, facing the internal space, and has multiple nozzle holes 71 for ejecting high-pressure fire extinguishing gas supplied from the branch pipe 19 into the internal space defined by the circumferential wall 61 and the end walls 64a and 65. The multiple nozzle holes 71 of the guide section 72 are formed on an axis perpendicular to the axis of the circumferential wall 61, and are spaced at equal angles in the circumferential direction with respect to the axis of the circumferential wall 61. Multiple through holes 67 are formed in the end wall 65, penetrating in the thickness direction of the end wall 65. The multiple through holes 67 are formed in the remaining peripheral portion 70 of the end wall 65, excluding the central portion 69, with the axis of the circumferential wall 61 as the center. The end wall 65 is made of, for example, perforated metal. In the reference example shown in Figure 9, no through holes 67 are formed in the central portion 69 of the end wall 65, but through holes 67 may be formed in the central portion 69 of the end wall 65.

[0038] With this sound-dampening device 60a, the fire extinguishing gas, which is ejected at high speed from the nozzle holes 71 of the guide portion 72 formed on the end wall 64a, collides with the inner surface of the peripheral wall 61 within the sound-dampening device 60a, attenuating its flow velocity. After being released through a plurality of through holes 67 formed on the end wall 65 into the space defined by the end wall 65 and the injection head 13, it is released to the outside through the nozzle holes 16 formed on the nozzle portion 12. The sound-dampening device 60a reduces the flow velocity in the through holes 67 formed on the end wall 65 by expanding the fire extinguishing gas ejected at high speed from the nozzle holes 71 within the space inside the sound-dampening device 60, thereby suppressing the generation of sound caused by the release of fire extinguishing gas from the nozzle holes 16.

[0039] Figure 10 is an enlarged cross-sectional view showing a silencing device 17d provided in a gas fire extinguishing system of yet another reference example of the present invention. The silencing device 17d is preferably used by being attached to a spray head 13, for example, which is provided on the wall surface of a fire-extinguishing compartment.

[0040] The same reference numerals are used for parts corresponding to the embodiments described above. The silencing device 17d in this reference example includes a cylindrical circumferential wall 81, an end wall 82 formed perpendicular to the axis of the circumferential wall 81 at one axial end of the circumferential wall 81, an end wall 84 formed perpendicular to the axis of the circumferential wall 81 at the other axial end of the circumferential wall 81, having a mounting portion 83 formed to be detachably attached to the spray head 13, a barrier 85 formed perpendicular to the axis of the circumferential wall 81 between the end wall 82 and the end wall 84, a cylindrical conduit 87 that guides the fire extinguishing gas sprayed from the spray head 13 into a silencing chamber 86 which is an internal space defined by the circumferential wall 81, the end wall 82 and the barrier 85, and a cylindrical vent pipe 89 that guides the fire extinguishing gas in the silencing chamber 88, which is an internal space defined by the circumferential wall 81, the end wall 84 and the barrier 85, to the outside of the silencing device 17d.

[0041] The peripheral wall 81, end wall 82, and end wall 84 are made of, for example, sound-absorbing material. Multiple through-holes 851 are formed in the barrier 85, penetrating in the thickness direction of the barrier 85. The barrier 85 is made of, for example, perforated metal.

[0042] The conductive pipe 87 penetrates the barrier 85 and is positioned to protrude into the sound-dampening chamber 86. The conductive pipe 87 has a connecting portion 871 formed at one axial end of the conductive pipe 87, which is detachably connected to the injection head 13, and an end plate 872 formed at the other axial end of the conductive pipe 87. Peripheral wall of the conductive pipe 87 In the portion 873 of the conduction pipe 87 that protrudes into the soundproofing chamber 86, multiple through-holes 874 are formed, penetrating the circumferential wall of the conduction pipe 87 in the thickness direction. The portion 873 of the conduction pipe 87 in which the multiple through-holes 874 are formed is made of, for example, perforated metal. The ventilation pipe 89 is positioned to penetrate the barrier 85 and the end wall 82, and a wire mesh 891 is provided at the opening on the soundproofing chamber 88 side, and fire extinguishing gas is injected from the fire extinguishing gas injection port 892, which is an opening to the outside. The material of the ventilation pipe 89 is, for example, polyvinyl chloride.

[0043] With this sound-dampening device 17d, the fire extinguishing gas, which is injected at high speed into the sound-dampening chamber 86 from multiple through-holes 874 formed in the conduit 87, is released into the sound-dampening chamber 88 from multiple through-holes 851 formed in the barrier 85. The fire extinguishing gas released into the sound-dampening chamber 88 from the through-holes 851 is released to the outside of the sound-dampening device 17d via the vent pipe 89. The sound-dampening device 17d reduces the flow velocity in the vent pipe 89 by expanding the fire extinguishing gas injected at high speed from the multiple through-holes 874 in the space inside the sound-dampening chamber 86 and the space inside the sound-dampening chamber 88, thereby suppressing the generation of sound caused by the release of fire extinguishing gas from the vent pipe 89.

[0044] [Table 1]

[0045] Table 1 shows examples of pressure and flow velocity calculations for two gas fire extinguishing systems using a silencing device 17d. In Example 1, the hole diameter of the vent pipe 89 of the silencing device 17d is 50 mm, and in Example 2, the hole diameter of the vent pipe 89 of the silencing device 17d is 80 mm. The pressure is the pressure in the silencing chamber 86, and the flow velocity (m / s) is the flow velocity at the fire extinguishing gas injection port 892 of the vent pipe 89.

[0046] When a fire extinguishing gas at 2 atmospheres is injected into an atmosphere at 1 atmosphere, the flow velocity is approximately 340 m / s, generating a loud noise. By lowering the pressure inside the sound-dampening chamber 86, the flow velocity at the fire extinguishing gas nozzle 892 can be reduced, thereby lowering the volume. In Example 1, the pressure inside the sound-dampening chamber 86 is approximately 1.5 atmospheres, and the flow velocity at the fire extinguishing gas nozzle 892 is approximately 250 m / s. In Example 2, the pressure inside the sound-dampening chamber 86 is approximately 1.1 atmospheres, and the flow velocity at the fire extinguishing gas nozzle 892 is approximately 100 m / s.

[0047] Figure 11 is a graph illustrating the sound reduction effect of the sound reduction device 17d. The vertical axis represents sound pressure (dB), and the horizontal axis represents the distance from the nozzle section 12 (m). Graph 91 shows the case without using the sound reduction device, Graph 92 shows the case of Example 1, and Graph 93 shows the case of Example 2.

[0048] At a distance of 2 m from the nozzle 12, the sound pressure is approximately 125 dB without a silencing device. In Example 1, the sound pressure drops to approximately 105 dB, and in Example 2, it drops to approximately 100 dB. Similarly, at a distance of 10 m from the nozzle 12, the sound pressure is approximately 115 dB without a silencing device. In Example 1, the sound pressure drops to approximately 96 dB, and in Example 2, it drops to approximately 92 dB. In other words, compared to the case without a silencing device, the sound pressure can be reduced by approximately 20 dB in Example 1, and by approximately 25 dB in Example 2.

[0049] Figure 12 is an enlarged cross-sectional view showing a silencing device 17e provided in a gas fire extinguishing system of yet another reference example of the present invention. The silencing device 17e is, for example, a spray device installed on the ceiling of the fire extinguishing area. It is preferably used when attached to the head 13. The same reference numerals are used for parts corresponding to the embodiments described above. The silencing device 17e of this reference example includes a cylindrical circumferential wall 81, an end wall 82 formed perpendicular to the axis of the circumferential wall 81 at one axial end of the circumferential wall 81, an end wall 84 formed perpendicular to the axis of the circumferential wall 81 at the other axial end of the circumferential wall 81, which has a mounting portion 83 formed to be detachably attached to the spray head 13, a barrier 85 formed perpendicular to the axis of the circumferential wall 81 between the end wall 82 and the end wall 84, a cylindrical conduit 87 that guides the fire extinguishing gas sprayed from the spray head 13 into a silencing chamber 86 which is an internal space defined by the circumferential wall 81, the end wall 82 and the barrier 85, and a plurality of cylindrical vents 89a that guide the fire extinguishing gas in the silencing chamber 88 which is an internal space defined by the circumferential wall 81, the end wall 84 and the barrier 85 to the outside of the silencing device 17e.

[0050] The peripheral wall 81, end wall 82, and end wall 84 are made of, for example, sound-absorbing material. Multiple through-holes 851 are formed in the barrier 85, penetrating in the thickness direction of the barrier 85. The barrier 85 is made of, for example, perforated metal.

[0051] The conduit 87 penetrates the barrier 85 and is positioned to protrude into the sound-dampening chamber 86. The conduit 87 has a connecting portion 871 formed at one axial end of the conduit 87 which is detachably connected to the injection head 13, and an end plate 872 formed at the other axial end of the conduit 87. Multiple through holes 874 are formed in the portion 873 of the circumferential wall of the conduit 87 that protrudes into the sound-dampening chamber 86, penetrating through the circumferential wall in the thickness direction of the conduit 87. The portion 873 of the conduit 87 in which the multiple through holes 874 are formed is made of, for example, perforated metal. Multiple vent pipes 89a are arranged on an axis perpendicular to the axis of the circumferential wall 81, spaced at equal angles in the circumferential direction with respect to the axis of the circumferential wall 81, and each is formed to penetrate the circumferential wall 81. Each vent pipe 89a has a fire extinguishing gas nozzle 892a, which is an opening to the outside of the silencing device 17e, and fire extinguishing gas is injected from each fire extinguishing gas nozzle 892a to the outside of the silencing device 17e. The material of the vent pipe 89a is, for example, polyvinyl chloride.

[0052] With this sound-dampening device 17e, the fire extinguishing gas, which is injected at high speed into the sound-dampening chamber 86 from multiple through-holes 874 formed in the conduit 87, is released into the sound-dampening chamber 88 from multiple through-holes 851 formed in the barrier 85. The fire extinguishing gas released into the sound-dampening chamber 88 from the through-holes 851 is released to the outside of the sound-dampening device 17e via the vent pipe 89a. The sound-dampening device 17e reduces the flow velocity in the vent pipe 89a by expanding the fire extinguishing gas injected at high speed from the multiple through-holes 874 in the space inside the sound-dampening chamber 86 and the space inside the sound-dampening chamber 88, thereby suppressing the generation of sound caused by the release of fire extinguishing gas from the vent pipe 89a.

[0053] Figure 13 is an enlarged cross-sectional view showing a silencing device 17f provided in yet another embodiment of the gas fire extinguishing system of the present invention. The same reference numerals are used for parts corresponding to the previously described embodiments. The silencing device 17f is preferably used by being attached to a spray head 13 provided on the wall surface of a fire-extinguishing compartment, for example.

[0054] The silencing device 17f of this embodiment has a cylindrical peripheral wall 121, an annular end wall 122 formed perpendicular to the axis of the peripheral wall 121 at one axial end of the peripheral wall 121, and a mounting portion 123 formed at the other axial end of the peripheral wall 121 and detachably attached to the injection head 13. The silencing device 17f has a silencing chamber 124 which is an internal space defined by the injection head 13, the peripheral wall 121, and the end wall 122. A columnar sound-absorbing material 125 is mounted and housed in this silencing chamber 124 along the inner circumferential surface of the peripheral wall 121. The peripheral wall 121, the end wall 122, and the mounting portion 123 constitute a casing 129.

[0055] The inner surface 121a of the peripheral wall 121 of the casing 129 facing the sound-absorbing chamber 124 is formed in a cylindrical shape, and the inner surface 122a of the end wall 122 facing the sound-absorbing chamber 124 is formed on a virtual plane perpendicular to the axis L121 of the peripheral wall 121. The end wall 122 has the axis L121 of the peripheral wall 121 as its central axis. The through-hole 122b, which is a line, is formed penetrating in the direction of the axis L121.

[0056] The sound-absorbing material 125 is columnar in shape, its outer surface 125a is formed in a cylindrical shape, and the end face 125b on one side and the end face 125c on the other side in the direction of the axis L125 of the sound-absorbing material 125 are formed on a virtual plane perpendicular to the axis L125. The end face 12a on the downstream side in the direction of spraying the fire extinguishing gas in the nozzle portion 12 of the spray head 13 is formed on a virtual plane perpendicular to the axis L12 of the nozzle portion 12.

[0057] In the sound-absorbing device 17f, the sound-absorbing material 125 is loaded into the space within the casing 129 from the mounting portion 123 side, in an orientation such that its axis L125 coincides with or approximately coincides with the axis L121 of the peripheral wall 121. For example, if the sound-absorbing material 125 is in the shape of a straight cylinder, it is configured to be detachable by screwing an external thread engraved on the outer circumference of the nozzle portion 12 on the downstream side in the direction of fire extinguishing gas injection into an internal thread engraved on the inner circumference of the mounting portion 123. In the sound-absorbing device 17f, the sound-absorbing material 125 is housed in the sound-absorbing chamber 124 with one end face 125b in surface contact with the inner surface 122a of the end wall 122, and the other end face 125c in surface contact with the end face 12a of the nozzle portion 12. That is, the sound-absorbing material 125 is packed tightly into the sound-absorbing chamber 124 without any gaps.

[0058] In this embodiment, the diameter of the through-hole 122b is formed to a size that allows for effective release of the fire extinguishing agent. Furthermore, the effective diameter portion of the through-hole 122b may be located not only on the end wall side but also on the periphery wall side. By providing the effective diameter portion on the periphery wall side, the effective area of ​​the single-wall side portion can be reduced, thereby allowing for miniaturization of the sound-dampening device 17f. Additionally, miniaturization of the sound-dampening device 17f can be achieved by filling the space within the casing 129 with sound-absorbing material 125 without any gaps.

[0059] The sound-absorbing material 125 is made of porous metal with continuous columnar voids. By installing such sound-absorbing material 125 immediately after the nozzle hole 16, the sound-absorbing device 17f can gradually depressurize and expand the fire extinguishing gas supplied from the branch pipe 19 side, thereby reducing its flow velocity. This makes it possible to suppress the generation of spray noise caused by the spraying of the fire extinguishing gas.

[0060] In detail, since the sound-absorbing material 125 is packed tightly into the sound-absorbing chamber 124, the fire extinguishing gas released from the nozzle hole 16 can be directly introduced into the porous metal sound-absorbing material 125, and the fire extinguishing gas that has entered the porous metal can be directly released from the perforations 122b. By directly introducing the fire extinguishing gas released from the nozzle hole 16 into the sound-absorbing material 125 in this way, the fire extinguishing gas enters the sound-absorbing material 125 before it over-expands immediately after being released from the nozzle hole 16 and generates a shock wave, causing it to rapidly decelerate and diffuse. Therefore, the generation of strong turbulence accompanied by a shock wave is prevented, and noise is suppressed.

[0061] Furthermore, because the fire extinguishing gas diffuses through the fine voids in the sound-absorbing material 125, the fire extinguishing gas released from the sound-absorbing material 125 through the perforations 122b to the outside has reduced flow velocity, so it does not generate large shock waves, and this also suppresses noise. In this way, compared to the case where there is a gap between the end face 12a of the nozzle section 12 and the end face 125c of the sound-absorbing material 125, the rapid decompression and expansion of the fire extinguishing gas can be suppressed. Moreover, compared to the case where there is a gap between the inner surface 122a of the end wall 111 and the end face 125b of the sound-absorbing material 125, the rapid decompression and expansion of the fire extinguishing gas can be suppressed.

[0062] Thus, the sound-dampening device 17f of this embodiment can gradually reduce the pressure and expand of the fire extinguishing gas using the porous metal sound-absorbing material 125, thereby lowering its flow velocity and suppressing the generation of spray noise caused by the spraying of the fire extinguishing gas. Furthermore, since the sound-dampening device 17f is configured to suppress the rapid pressure and expansion of the fire extinguishing gas, it can suppress the generation of noise caused by rapid pressure and expansion.

[0063] In Figure 13, the nozzle hole 16 has a nozzle hole axis L12 that extends along the conduit axis at the end of the conduit 14, and the cross section of the nozzle hole 16 perpendicular to the nozzle hole axis L12 is uniform along the nozzle hole axis L12. The end face 12a around the outlet end of the nozzle hole 16 where the nozzle hole 16 opens in the nozzle portion 12 of the spray head 13 is formed on a virtual plane perpendicular to the nozzle hole axis L12. The sound-dampening device 17f comprises: (m) a cylindrical circumferential wall 121 having a circumferential wall axis L121 extending along the nozzle hole axis L12, forming an internal space 124 that extends downstream from the outlet of the nozzle hole 16 in the direction of fire extinguishing gas injection; (n) an end wall 122 formed in connection with one end of the circumferential wall 121 away from the nozzle portion 12 in the direction of the circumferential wall axis L121, defining the internal space 124 together with the circumferential wall 121, with a through hole 122b formed penetrating in the direction of the circumferential wall axis L121; (o) a mounting portion 123 formed at the other end of the circumferential wall 121 near the nozzle portion 12 in the direction of the circumferential wall axis L121, and attached to the injection head 13; and (p) a sound-absorbing material 125 that is packed and contained in the internal space 124 without any gaps, made of a porous material, and having a sound-absorbing material axis L125 that coincides with the circumferential wall axis L121. The sound-absorbing material 125 is columnar in shape and has one end face 125b that is away from the nozzle portion 12 and the other end face 125c that is close to the nozzle portion 12. The other end face 125c that is close to the nozzle portion 12 is formed on a virtual plane perpendicular to the axis L125 of the sound-absorbing material, and the mounting portion 123 is attached to the spray head 13 so that the one end face 125b is supported by the end wall 122, and the other end face 125c and the end face 12a of the nozzle portion 12 are in surface contact and have fine gaps, and the sound-absorbing material 125 contains the sound-absorbing material 125 which diffuses the fire extinguishing gas sprayed at high speed from the nozzle portion 12 of the spray head 13 in the sound-absorbing material 125 contained in the internal space 124, causing it to gradually depressurize and expand to reduce its flow velocity, absorb vibrations in the spray flow of fire extinguishing gas, and releases it into the space within the fire-extinguishing target area through the through hole 122b.

[0064] Figure 14 is an enlarged cross-sectional view showing a silencing device 17g provided in a gas fire extinguishing system of yet another embodiment of the present invention. The same reference numerals are used for parts corresponding to the previously described embodiments. In this embodiment, the silencing device 17g is attached, for example, to a spray head 13 provided on the wall surface of a fire-extinguishing compartment.

[0065] The silencing device 17g of this embodiment has a cylindrical peripheral wall 131, an end wall 132 formed perpendicular to the axis of the peripheral wall 131 at the other axial end of the peripheral wall 131, and a mounting portion 133 formed in connection with the end wall 132 and detachably attached to the injection head 13. An internal thread is engraved on the inner circumferential surface of one axial end of the peripheral wall 131. The silencing device 17g has a silencing chamber 140, which is an internal space defined by the peripheral wall 131, the end wall 132, and the injection head 13.

[0066] The sound-absorbing chamber 140 houses a columnar first sound-absorbing material 134 provided at one end in the axial direction, a columnar second sound-absorbing material 135 provided at the other end in the axial direction, a cylindrical third sound-absorbing material 136 provided between the first sound-absorbing material 134 and the second sound-absorbing material 135, an annular end plate 141 supporting the first sound-absorbing material 134, an annular spacer 142, and a nut 143.

[0067] The first sound-absorbing material 134 and the second sound-absorbing material 135 are made of flat, columnar porous metal. The first sound-absorbing material 134 is mounted and housed along the inner circumferential surface at one axial end of the peripheral wall 131, and is provided in contact with one surface of the end wall 132 facing the sound-absorbing chamber 140 and one axial end of the spray head 13.

[0068] An annular end plate 141 having a through hole 141a is provided on the axial end side of the first sound-absorbing material 134. The end plate 141 is provided in contact with the first sound-absorbing material 134 and restricts the movement of the first sound-absorbing material 134 toward the axial end side. A third sound-absorbing material 136 is provided on the axial end side of the end plate 141. In this embodiment, the third sound-absorbing material 136 is the aforementioned sound-absorbing material The third sound-absorbing material 136 is made of the same material as the sound-absorbing material 33 of the sound device 17. Alternatively, the third sound-absorbing material 136 may be made of a porous metal. The third sound-absorbing material 136 is mounted and housed along the inner surface of the peripheral wall 131.

[0069] An annular spacer 142 having a through hole 142a is provided at one end of the third sound-absorbing material 136 in the axial direction. The spacer 142 is provided in contact with the second sound-absorbing material 135 and maintains the distance between the third sound-absorbing material 136 and the second sound-absorbing material 135.

[0070] A second sound-absorbing material 135 is provided on one end of the spacer 142 in the axial direction. In this embodiment, the second sound-absorbing material 135 is formed in the same shape as the first sound-absorbing material 134, but it may be formed in a different shape from the first sound-absorbing material 134. The second sound-absorbing material 135 is mounted and housed along the inner circumferential surface of the peripheral wall 131.

[0071] A nut 143 is provided on one end of the second sound-absorbing material 135 in the axial direction. The nut 143 has external threads on its outer circumference and is tightened by screwing it into internal threads on the inner circumference of the open end of the peripheral wall 131, thereby supporting the second sound-absorbing material 135 while pressing it toward the other end in the axial direction. This restricts the displacement of each sound-absorbing material 134, 135, 136, as well as the end plate 141 and spacer 142 toward the one end in the axial direction.

[0072] In Figure 14, the end face around the outlet end of the nozzle hole 16, where the nozzle hole 16 opens in the nozzle portion 12 of the spray head 13, is formed on a virtual plane perpendicular to the axis of the nozzle hole 16. The sound-absorbing device 17g comprises (q) a cylindrical peripheral wall 131 having an axis extending along the axis of the nozzle hole 16, forming an internal space 140 that extends downstream from the outlet of the nozzle hole 16 in the direction of fire extinguishing gas injection; (r) an end wall 143 formed at one end of the peripheral wall 131 away from the nozzle portion 12 in the axial direction, which together defines the internal space 140 with the peripheral wall 131, and which has through holes penetrating the peripheral wall 131 in the axial direction; (s) an attachment portion 133 formed at the other end of the peripheral wall 131 closer to the nozzle portion 12 in the axial direction, which is attached to the injection head 13; and (t) first, second, and third sound-absorbing materials 134, 135 housed in the internal space 140. ,136, made of porous metal, and in the axial direction of the peripheral wall 131, from the nozzle portion 12 to the end wall 143, a first sound-absorbing material 134, a third sound-absorbing material 136, and a second sound-absorbing material 135 are arranged. They are arranged in this order, and the first sound-absorbing material 134 and the second sound-absorbing material 135 coincide with the axis of the peripheral wall 131. The first sound-absorbing material 134 is cylindrical with an axis that coincides with the axis of the peripheral wall 131, the end face of the first sound-absorbing material 134 near the nozzle portion 12 is formed on a virtual plane perpendicular to the axis of the first sound-absorbing material 134, the second sound-absorbing material 135 has an end face that is away from the nozzle portion 12, and the mounting portion 133 is attached to the spray head 13 so that the end face of the second sound-absorbing material 135 that is away from the nozzle portion 12 and the end wall 143 come into contact, and the first sound-absorbing material 134 comes into contact with the nozzle portion 12 The first, second, and third sound-absorbing materials 134, 135, and 136 are in surface contact with the end face of the nozzle portion 12, and these first, second, and third sound-absorbing materials 134, 135, and 136 have fine voids, and the first to third sound-absorbing materials 134, 135, and 136 housed in the internal space 140 diffuse the fire extinguishing gas sprayed at high speed from the nozzle portion 12 of the spray head 13, gradually depressurizing and expanding to reduce its flow velocity, absorbing vibrations in the sprayed flow of fire extinguishing gas, and releasing it from the through-hole 122b into the space within the fire-extinguishing target area.

[0073] According to this embodiment, the sound-absorbing device 17g is provided with three sound-absorbing materials. By providing the first sound-absorbing material 134 immediately after the nozzle hole 16, the sound-absorbing device 17g can gradually depressurize and expand the fire extinguishing gas supplied from the branch pipe 19 side, thereby reducing its flow velocity. Furthermore, since the third sound-absorbing material 136 is provided, the third sound-absorbing material 136 absorbs acoustic vibrations caused by the spray flow of the fire extinguishing gas, thereby suppressing the generation of spray noise caused by the spray of the fire extinguishing gas. Furthermore, since the second sound-absorbing material 135 is provided, the fire extinguishing gas that has passed through the third sound-absorbing material 136 The gas pressure can be further reduced, lowering its flow velocity. This further suppresses the generation of spray noise caused by the injection of fire extinguishing gas.

[0074] Figure 15 is an enlarged cross-sectional view showing a silencing device 17h provided in a gas fire extinguishing system of yet another embodiment of the present invention. The same reference numerals are used for parts corresponding to the previously described embodiments. In this embodiment, the silencing device 17h is attached, for example, to a branch pipe 19 provided on the wall surface of a fire-extinguishing compartment via a spray head 13.

[0075] The silencing device 17h of this embodiment includes a spray head 13, a bottomed cylindrical casing 150, a nut 151 screwed into the opening of the casing 150, a cylindrical first sound-absorbing material 152 attached to the spray head 13, a cylindrical second sound-absorbing material 153 housed in the casing 150 and arranged along the inner circumferential surface of the casing 150, an annular first clamping piece 154 attached to the base end of the spray head 13 inside the casing 150, a disc-shaped second clamping piece 155 provided on the opening side inside the casing 150 in contact with the end face of the spray head 13, and a disc-shaped third sound-absorbing material 156 held in a state supported by the opening of the casing 150 by the nut 151.

[0076] The casing 150 has a straight cylindrical section 157, a flange section 158 that protrudes perpendicularly radially outward from one axial end of the cylindrical section 157, and an annular end wall section 159 that extends radially inward from the other axial end of the cylindrical section 157. External threads 160 are engraved on the outer circumference of the flange section 158. An insertion hole 161 is formed in the end wall section 159 on its central axis, into which the base end of the injection nozzle 13 fits. Such a casing 150 is made of metal. The first to third sound-absorbing materials 152, 153, and 156 are made of porous metal similar to that described above.

[0077] The nut 151 has a straight cylindrical portion 162 and a flange portion 163 that protrudes radially inward from one axial end of the cylindrical portion 162. An internal thread 164 is engraved on the inner circumferential surface of the other axial end of the cylindrical portion 162 and is screwed onto the external thread 160 of the casing 150. Such a nut 151 is made of metal, and when tightened while screwed onto the external thread 160 of the casing 150, the peripheral edge of the third sound-absorbing material 156 is clamped between the flange portion 158 of the casing 150 and the flange portion 163 of the nut 151, the second clamping piece 155 is clamped between the third sound-absorbing material 156 and the end wall portion 165 of the spray head 13, and the second sound-absorbing material 153 is prevented from coming out of the casing 150.

[0078] The spray head 13 has a engagement portion 166 into which a tightening tool such as a wrench is engaged, a cylindrical portion 167 axially connected to the engagement portion 166, and an end wall portion 165 that closes one axial end of the cylindrical portion 167. Nozzle holes 16 are formed in the cylindrical portion 157 at circumferential intervals, for example every 90°, penetrating in the thickness direction. An external thread 168 is engraved on the base of the cylindrical portion 167 near the engagement portion 166. An internal thread 169 engraved on the inner circumference of the first clamping piece 154 is screwed into this external thread 168, and the end wall portion 159 of the casing 150 is clamped by the second clamping portion 155 and the engagement portion 166, thereby fixing the spray head 13 to the casing 150 on the same axis. As described above, the first sound-absorbing material 152 is held in place by the first and second clamping pieces 154 and 155 from both sides in the axial direction while attached to the spray head 13, that is, while attached to the cylindrical portion 12 within the casing 150. In such a sound-absorbing device 17h, an annular space 170 is formed between the first sound-absorbing material 152 and the second sound-absorbing material 153, extending from the end wall portion 159 of the casing 150 to the third sound-absorbing material 156.

[0079] The high-pressure fire extinguishing gas supplied from the branch pipe 19 to the spray head 13 is injected into the first sound-absorbing material 152 from each nozzle hole 16 of the spray head 13, and the shock wave rapidly diffuses and decelerates, thereby preventing the generation of strong disturbances accompanied by shock waves and reducing noise. The fire extinguishing gas discharged from 2 into space 170 penetrates the second sound-absorbing material 153, where it is rapidly diffused and decelerated, similar to the first sound-absorbing material 152, and reflected from the inner surface of the cylindrical portion 150, heading towards the third sound-absorbing material 156. The fire extinguishing gas that penetrates the third sound-absorbing material 156, similar to the first and second sound-absorbing materials 152 and 153 described above, diffuses and stalls before it can rapidly expand, thereby further reducing noise and significantly reducing the spray noise caused by the ejection of the fire extinguishing gas.

[0080] In Figure 15, the spray head 13 is connected to the end of the conduit 14 and extends along the axis of this end, having a cylindrical portion 167 through which a plurality of nozzle holes 16 penetrate in the thickness direction, and an end wall portion 165 that closes one end of the cylindrical portion 167 in the axial direction away from the end of the conduit 14. The silencing device 17h is (u) a first sound-absorbing material 152, which is formed in a cylindrical shape, through which the cylindrical portion 167 of the spray head 13 is inserted, and has an inner surface that makes surface contact with the arc-shaped end surface around the outlet end of the nozzle hole 16, which is the outer surface of the cylindrical portion 167 of the spray head 13, and (v) a casing 150, which (v1) extends along the axis of the cylindrical portion 167 of the spray head 13 and surrounds the first sound-absorbing material 152 at intervals in the radial direction, and (v2) the end of the conduit 14 The casing 150 includes (w) a casing end wall portion 159 that closes the cylindrical portion 157 near the nozzle portion 13 and is connected to the spray head 13, (w) a second sound-absorbing material 153 that is formed in a cylindrical shape and arranged along the inner circumferential surface of the cylindrical portion 157, forming an annular space 170 between itself and the outer circumferential surface of the first sound-absorbing material 152, and (x) a third sound-absorbing material 156 that is arranged at the end of the cylindrical portion 157 of the casing 150 that is farther from the end of the conduit 14, and releases the fire-extinguishing gas from the annular space into the space within the fire-extinguishing area, and (y) these first, second and third sound-absorbing materials 152, 153 and 156 have fine voids, which diffuse the fire-extinguishing gas sprayed at high speed from the nozzle portion 12 of the spray head 13, gradually depressurizing and expanding it to reduce its flow velocity and absorb vibrations in the spray flow of the fire-extinguishing gas.

[0081] In the embodiment shown in Figure 15, the spray head 13 is configured to spray fire extinguishing gas radially outward by forming a plurality of spray nozzles 16 perpendicular to its axis in the cylindrical portion 12. However, in yet another embodiment of the present invention, the spray head 13 may be configured to have nozzle holes 16 inclined toward the opening of the casing 150 in the cylindrical portion so that the gas that has permeated the first sound-absorbing material 152 is discharged directly toward the third sound-absorbing material 156, thereby achieving a similar effect.

[0082] The present invention can be implemented in the following embodiments. (1) A spray head having a nozzle section that sprays high-pressure fire extinguishing gas into space, A spray head is connected, and a conduit is provided to guide high-pressure fire extinguishing gas to the spray head. A fire extinguishing gas supply source that supplies high-pressure fire extinguishing gas to the conduit, A gas fire extinguishing system characterized by including a sound-dampening device provided in the spray head for attenuating the sound produced by the discharge of fire extinguishing gas from the nozzle.

[0083] (2) The sound-dampening device includes a cylindrical peripheral wall, an end wall formed perpendicular to the axis of the peripheral wall at one end in the axial direction of the peripheral wall, and a mounting portion formed at the other end in the axial direction of the peripheral wall so as to be detachably attached to the spray head. A gas fire extinguishing system characterized in that multiple ventilation holes are formed in the surrounding wall, penetrating the wall in the thickness direction. The sound-dampening device has a peripheral wall, an end wall, and a mounting section, and is detachably attached to the spray head by the mounting section. With the sound-dampening device configured in this way, the fire extinguishing gas sprayed from the nozzle of the spray head collides with the end wall and is then released to the outside through multiple perforations formed in the peripheral wall, thereby suppressing the generation of loud spray noise.

[0084] (3) The sound-dampening device includes a cylindrical peripheral wall, an end wall formed perpendicular to the axis of the peripheral wall at one end in the axial direction of the peripheral wall, and a mounting portion formed at the other end in the axial direction of the peripheral wall so as to be detachable from the spray head, wherein the end wall is characterized by having a plurality of ventilation holes formed through it in the thickness direction of the end wall. A gas fire extinguishing system.

[0085] The sound-dampening device includes a peripheral wall, an end wall, and a mounting section, and is detachably attached to the spray head by the mounting section. The fire extinguishing gas, ejected at high speed from the nozzle of the spray head, passes through the space within the peripheral wall, collides with the end wall, and is then released to the outside through multiple perforations formed in this end plate. This configuration of the sound-dampening device also prevents the generation of loud spray noise when the fire extinguishing gas is sprayed.

[0086] (4) A gas fire extinguishing system characterized in that sound-absorbing material is contained in the internal space defined by the surrounding walls, end walls and mounting parts.

[0087] Since sound-absorbing material is housed in the internal space defined by the peripheral wall, end wall, and mounting portion of the sound-absorbing device, vibrations of the fire extinguishing gas spray are absorbed by this sound-absorbing material, thereby further preventing the generation of spray noise.

[0088] (5) The sound-dampening device includes a cylindrical peripheral wall, an end wall formed perpendicular to the axis of the peripheral wall at one end of the peripheral wall in the axial direction, a mounting portion integrally formed with a spray head at the other end of the peripheral wall in the axial direction, and an inner cylinder provided in the nozzle portion of the spray head facing downstream in the direction of spraying the fire extinguishing gas. The end wall has gas release holes that penetrate in the direction of its thickness. A gas fire extinguishing system characterized in that the inner cylinder has a cylindrical portion in which a plurality of through holes are formed, and an end plate formed perpendicular to the axis of the cylindrical portion at one end of the cylindrical portion in the axial direction.

[0089] The fire extinguishing gas, ejected at high speed from the nozzle of the spray head, collides with the cylindrical end plate of the inner cylinder, is released through multiple perforations formed in the cylindrical section, and then further discharged to the outside through gas release holes formed in the end wall via the space between the cylindrical section and the peripheral wall. This prevents the generation of spray noise when the fire extinguishing gas is released.

[0090] (6) A spray head having a nozzle section for spraying high-pressure fire extinguishing gas into space, A spray head is connected, and a conduit is provided to guide high-pressure fire extinguishing gas to the spray head. It includes a fire extinguishing gas supply source that supplies high-pressure fire extinguishing gas to the conduit, A gas fire extinguishing system characterized in that the nozzle portion of the spray head has a nozzle hole having an inner surface that smoothly connects to the inner surface of the conduit.

[0091] High-pressure fire extinguishing gas supplied from a fire extinguishing gas source to a conduit is sprayed into a space such as inside a building via a spray head. Since such a spray head has nozzle holes with an inner surface that smoothly connects to the inner surface of the conduit, it is prevented from generating loud spray noises caused by the high-speed spray flow of fire extinguishing gas ejected from the nozzle part of the spray head.

[0092] (7) A spray head having a nozzle section for spraying high-pressure fire extinguishing gas into space, A spray head is connected, and a conduit is provided to guide high-pressure fire extinguishing gas to the spray head. A fire extinguishing gas supply source that supplies high-pressure fire extinguishing gas to the conduit, A gas fire extinguishing system characterized by including a sound-dampening device provided between the spray head and the conduit, which attenuates the sound caused by the discharge of fire extinguishing gas from the nozzle.

[0093] High-pressure fire extinguishing gas supplied from a fire extinguishing gas source into a conduit is sprayed into the space inside the building via a spray head. A sound-dampening device is installed between the spray head and the conduit to prevent the generation of loud spray noise caused by the high-speed spray of fire extinguishing gas from the nozzle of the spray head.

[0094] (8) The silencing device includes a cylindrical circumferential wall, a first mounting portion formed at one axial end of the circumferential wall so as to be detachable from the conduit, a second mounting portion formed at the other axial end of the circumferential wall so as to be detachable from the injection head, a first end wall formed perpendicular to the axis of the circumferential wall at the one end, and a second end wall formed perpendicular to the axis of the circumferential wall at the other end. At least one through-hole is formed in the first end wall, centered on the axis of the peripheral wall, in the central part of the first end wall, penetrating in the thickness direction of the first end wall. A gas fire extinguishing system characterized in that a plurality of through-holes are formed in the second end wall, penetrating through the second end wall in the thickness direction.

[0095] The silencing device has a peripheral wall, first and second end walls, and first and second mounting parts, and is detachably attached between the spray head and the conduit by the first and second mounting parts. The fire extinguishing gas supplied from the conduit and sprayed at high speed from through holes formed in the first end wall collides with the center of the second end wall within the silencing device, and is then released through multiple through holes formed in the second end wall into the space defined by the second end wall and the spray head, before being released to the outside from the spray head. The silencing device reduces the flow velocity at the through holes formed in the second end wall by expanding the fire extinguishing gas sprayed at high speed from the through holes formed in the first end wall within the space inside the silencing device, thereby suppressing the generation of sound caused by the release of fire extinguishing gas from the spray head.

[0096] (9) The silencing device includes a cylindrical circumferential wall, a first mounting portion formed at one axial end of the circumferential wall so as to be detachable from the conduit, a second mounting portion formed at the other axial end of the circumferential wall so as to be detachable from the injection head, a first end wall formed perpendicular to the axis of the circumferential wall at the one end, and a second end wall formed perpendicular to the axis of the circumferential wall at the other end, The first end wall has a guide section formed on the axis of the circumferential wall facing the internal space, which ejects high-pressure fire extinguishing gas supplied from the conduit into the internal space defined by the circumferential wall, the first end wall, and the second end wall. The multiple nozzle holes are formed on an axis perpendicular to the axis of the circumferential wall, spaced at equal angles in the circumferential direction with respect to the axis of the circumferential wall. A gas fire extinguishing system characterized in that a plurality of through-holes are formed in the second end wall, penetrating through the second end wall in the thickness direction.

[0097] The silencing device has a peripheral wall, first and second end walls, and first and second mounting parts, and is detachably attached between the spray head and the conduit by the first and second mounting parts. The fire extinguishing gas supplied from the conduit and sprayed at high speed from the nozzle holes of the guide part formed in the first end wall collides with the inner surface of the peripheral wall within the silencing device, is then released through a plurality of through holes formed in the second end wall into the space defined by the second end wall and the spray head, and is then released to the outside from the spray head. The silencing device reduces the flow velocity at the through holes formed in the second end wall by expanding the fire extinguishing gas sprayed at high speed from the nozzle holes of the guide part formed in the first end wall within the space inside the silencing device, thereby suppressing the generation of sound caused by the release of fire extinguishing gas from the spray head.

[0098] (10) The silencing device includes a cylindrical circumferential wall, a first end wall formed perpendicular to the axis of the circumferential wall at one axial end of the circumferential wall, a second end wall formed perpendicular to the axis of the circumferential wall at the other axial end of the circumferential wall, having a mounting portion formed to be detachably attached to the spray head, a barrier formed perpendicular to the axis of the circumferential wall between the first end wall and the second end wall, a cylindrical conductive pipe that guides the fire extinguishing gas sprayed from the spray head into a first silencing chamber which is an internal space defined by the circumferential wall, the first end wall and the barrier, and a cylindrical vent pipe that guides the fire extinguishing gas in the second silencing chamber which is an internal space defined by the circumferential wall, the second end wall and the barrier to the outside. The barrier has multiple through-holes formed that penetrate through the thickness of the barrier. A gas fire extinguishing system characterized in that a connecting portion is formed at one axial end of the conductive pipe, which is detachably connected to a spray head, an end plate is formed at the other axial end of the conductive pipe, a plurality of through holes are formed in the portion of the peripheral wall of the conductive pipe that protrudes into the first sound-dampening chamber, penetrating the peripheral wall of the conductive pipe in the thickness direction, and a vent pipe is arranged to penetrate the barrier and the first end wall.

[0099] The sound-dampening device includes a peripheral wall, a first barrier, and a second end wall and barrier having a mounting portion, and is detachably attached to the spray head by the mounting portion. Fire extinguishing gas, injected at high speed into the first sound-dampening chamber through a plurality of perforations formed in a conduit pipe connected to the spray head by a connecting portion, is discharged into the second sound-dampening chamber through a plurality of perforations formed in the barrier. The fire extinguishing gas discharged into the second sound-dampening chamber is discharged to the outside of the sound-dampening device via a vent pipe. The sound-dampening device reduces the flow velocity in the vent pipe by expanding the fire extinguishing gas injected at high speed through the plurality of perforations formed in the conduit pipe in the space inside the first sound-dampening chamber and the space inside the second sound-dampening chamber, thereby suppressing the generation of sound caused by the discharge of fire extinguishing gas from the vent pipe.

[0100] (11) The silencing device includes a cylindrical circumferential wall, a first end wall formed perpendicular to the axis of the circumferential wall at one axial end of the circumferential wall, a second end wall formed perpendicular to the axis of the circumferential wall at the other axial end of the circumferential wall, having a mounting portion formed to be detachably attached to the spray head, a barrier formed perpendicular to the axis of the circumferential wall between the first end wall and the second end wall, a cylindrical conduit that guides the fire extinguishing gas sprayed from the spray head into a first silencing chamber which is an internal space defined by the circumferential wall, the first end wall and the barrier, and a plurality of cylindrical vents that guide the fire extinguishing gas in the second silencing chamber which is an internal space defined by the circumferential wall, the second end wall and the barrier to the outside. The barrier has multiple through-holes formed that penetrate through the thickness of the barrier. The conductive pipe has a connecting portion formed at one end in the axial direction of the conductive pipe, which is detachably connected to the spray head, and an end plate formed at the other end in the axial direction of the conductive pipe. Multiple through holes are formed in the portion of the peripheral wall of the conductive pipe that protrudes into the first sound-dampening chamber, penetrating in the thickness direction of the peripheral wall of the conductive pipe. A gas fire extinguishing system characterized in that multiple vent pipes are arranged on an axis perpendicular to the axis of the peripheral wall, spaced at equal angles in the circumferential direction with respect to the axis of the peripheral wall, and each vent pipe penetrates the peripheral wall.

[0101] The sound-dampening device includes a peripheral wall, a first barrier, and a second end wall and barrier having a mounting portion, and is detachably attached to the spray head by the mounting portion. Fire extinguishing gas, injected at high speed into the first sound-dampening chamber through a plurality of perforations formed in a conduit pipe connected to the spray head by a connecting portion, is discharged into the second sound-dampening chamber through a plurality of perforations formed in the barrier. The fire extinguishing gas discharged into the second sound-dampening chamber is discharged to the outside of the sound-dampening device via a vent pipe. The sound-dampening device reduces the flow velocity in the vent pipe by expanding the fire extinguishing gas injected at high speed through the plurality of perforations formed in the conduit pipe in the space inside the first sound-dampening chamber and the space inside the second sound-dampening chamber, thereby suppressing the generation of sound caused by the discharge of fire extinguishing gas from the vent pipe.

[0102] (12) A gas fire extinguishing system characterized in that the sound-dampening device includes a cylindrical peripheral wall, an end wall formed perpendicular to the axis of the peripheral wall at one end of the peripheral wall in the axial direction, a mounting portion formed to be detachably attached to the spray head, and a sound-absorbing material made of porous metal housed in an internal space defined by the peripheral wall, the end wall, and the spray head.

[0103] The sound-absorbing material consists of a porous metal and is housed within an internal space. By placing such a sound-absorbing material immediately after the nozzle opening, the fire extinguishing gas supplied from the branch pipe can be gradually depressurized and expanded, reducing its flow velocity. This suppresses the generation of spray noise caused by the ejection of the fire extinguishing gas.

[0104] (13) A gas fire extinguishing system characterized in that the sound-absorbing device includes a first sound-absorbing material provided at one end of the peripheral wall in the axial direction and a second sound-absorbing material provided at the other end in the axial direction.

[0105] The sound-absorbing material includes a first sound-absorbing material provided at one axial end of the peripheral wall and a second sound-absorbing material provided at the other axial end. Therefore, the fire extinguishing gas supplied from the branch pipe side immediately after the nozzle hole is gradually depressurized and expanded by the first sound-absorbing material, thereby reducing its flow velocity, and immediately before spraying The second sound-absorbing material further depressurizes and expands the fire extinguishing gas, thereby reducing its flow velocity. This further suppresses the generation of spray noise caused by the ejection of the fire extinguishing gas.

[0106] (14) A gas fire extinguishing system characterized in that the sound-absorbing device further includes a third sound-absorbing material provided between the first sound-absorbing material and the second sound-absorbing material.

[0107] A third sound-absorbing material is provided between the first and second sound-absorbing materials. This third sound-absorbing material absorbs acoustic vibrations caused by the spray flow of the fire extinguishing gas, thereby suppressing the generation of spray noise caused by the spraying of the fire extinguishing gas.

[0108] Furthermore, since the spray head has nozzle holes with inner surfaces that smoothly connect to the inner surface of the conduit, it is possible to prevent loud spraying noises from being generated even when fire extinguishing gas is sprayed from the nozzle part of the spray nozzle in the event of a fire.

[0109] Furthermore, since a sound-dampening device is installed between the spray head and the conduit, it is possible to prevent loud spraying noises from being generated even when fire-extinguishing gas is sprayed from the nozzle part of the spray nozzle in the event of a fire. [Explanation of Symbols]

[0110] 11 Gas injection unit 12 Nozzle section 13, 50, 50a spray head 14 Conduit 15. Source of fire extinguishing gas 16,71 Nozzle holes 17,17a~17h,60,60a Silencer 18 Branch pipe 19 Branch pipe 20 bases 21 Brackets 22 Fasteners 23 Master 25,35,41,61,81 Peripheral wall 26,36,42,64,64a,65,82,84 End wall 27,37,43,62,63,83,123 Mounting parts 28. The part facing the downstream side in the injection direction. 29 Inner cylinder 30,66,67,851,874 through-pores 31 Cylindrical section 32,872 end plate 33 Sound-absorbing material 34 Gas release holes 38,44 Ventilation holes 39,45 Interior space 40, 46 Sound-absorbing material 51,52 Inner surface 55 Edge section 72 Guide section 85 Barrier 86,88 Soundproof room 87 Conductive pipes 89, 89a Vent pipes 125 Sound-absorbing material 134 First sound-absorbing material 135. Second sound-absorbing material 136 Third sound-absorbing material 871 Connecting part 891 Wire mesh 892,892a Fire extinguishing gas nozzle D1,D2 Inner diameter

Claims

1. By spraying high-pressure fire extinguishing gas into the space within the fire-fighting area of ​​the building, the O ２ A firefighting method that extinguishes a fire by reducing its concentration, The fire extinguishing gas is discharged through a branch pipe, a spray head screwed onto the outside of the branch pipe, a nozzle hole in the spray head, and a sound-absorbing material made of porous metal located immediately after the nozzle hole, in this order. Within the sound-absorbing material, the fire extinguishing gas gradually depressurizes and expands, reducing its flow velocity, thereby suppressing the generation of spray noise caused by the spraying of the fire extinguishing gas. The sound-absorbing material has a cylindrical peripheral wall, and is formed perpendicular to the axis of the peripheral wall at one end of the peripheral wall in the axial direction. It has end walls that are made If the direction of the fire extinguishing gas flowing through the branch pipe is defined as the first direction, and the direction opposite to the first direction is defined as the second direction, then high-pressure fire extinguishing gas is injected along the first direction toward the space within the fire-fighting target area of ​​the building, while high-pressure fire extinguishing gas is not injected in the second direction. ２ A firefighting method that reduces the concentration of the substance.

2. The fire extinguishing method for reducing O2 concentration according to Claim 1, wherein the sound-absorbing material made of porous metal is packed tightly into a sound-dampening chamber.

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