WO1999017048A1

WO1999017048A1 - Fire-resistant sound-proof pipe

Info

Publication number: WO1999017048A1
Application number: PCT/JP1997/003538
Authority: WO
Inventors: Yasuyuki Ohira; Mitsuo Hori
Original assignee: Shishiai-Kabushikigaisha
Priority date: 1997-10-01
Filing date: 1997-10-01
Publication date: 1999-04-08
Also published as: JP4419164B2

Abstract

A fire-resistant sound-proof pipe which can be used for the piping of a water supply/drain system, an air conditioner, etc. of a building. The fire-resistant and sound-proof pipe is characterized in that a sound absorbing layer which contains an active component which increases the dipole moment value is provided between the inner pipe and a fire-resistant layer. The pipe has an unprecedented excellent sound-proof performance.

Description

TECHNICAL FIELD The present invention relates to a fireproof soundproof pipe applied to a plumbing system of a building water supply / drainage device or an air conditioner. More specifically, it relates to a fireproof soundproof tube having excellent soundproof performance. BACKGROUND ART Rigid polyvinyl chloride pipes, which have been widely used for piping and the like, are easily burned down in a fire, and have problems such as spread of fire and generation of toxic gas. In order to remedy such a problem, a fire-resistant double-layer pipe has been proposed which is provided with fire resistance by coating the periphery of a hard pipe with, for example, fiber reinforced mortar or asbestos. On the other hand, with the increasing demand for comfort in indoor environments and living spaces in recent years, noise measures have also become a major focus, and rational and reliable measures to prevent plumbing and other plumbing noise are being developed among industries. It is being done. Naturally, this concept of noise control and soundproofing among industries has spread to the above-mentioned field of fireproof double-layered pipes, and fireproofed soundproof pipes have been proposed. For example, Japanese Patent Application Publication No. 51-91051 discloses a fireproof soundproof pipe in which a foamed plastic layer is provided between a metal inner pipe and an outer pipe. However, in this fireproof soundproof tube, the sound absorbing performance (soundproofing performance) of the foamed plastic layer as the sound absorbing layer is low. To ensure sufficient performance, the gap between the inner and outer tubes must be widened and the sound absorbing layer It was necessary to increase the thickness. Therefore, the required performance is not sufficient. If sound absorption performance (soundproofing performance) that can cope with the problem is to be ensured, the diameter of the fireproof soundproof tube itself becomes too large, it does not conform to the standard, and it may lead to a situation where piping cannot be performed at the specified location. On the other hand, when trying to conform to the standard, there was no one that could satisfy both the standard-compatible thickness and sufficient soundproofing performance, such that sufficient soundproofing would not be obtained. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fireproof soundproof tube having a sufficient soundproof performance even if the thickness is small. DISCLOSURE OF THE INVENTION The present invention relates to a fireproof soundproof tube provided with a fireproof layer around an inner tube, and in the invention according to claims 1 to 6, a dipole moment between the inner tube and the fireproof layer. We have proposed a fire-resistant sound-insulating tube with a sound-absorbing layer containing an active ingredient that increases the amount, which has led to unprecedented superior sound insulation performance. The active component, which is the greatest feature of these inventions, refers to a component that dramatically increases the amount of dipole moment in the sound absorbing layer. The active component itself has a large dipole moment, or the active component. Although the dipole moment itself is small, it refers to a component in which the dipole moment in the sound absorbing layer is dramatically increased by including the active component. Also claims? In the inventions described in (1) to (11), a fireproof soundproof pipe provided with a corrugated reflection groove on the inner peripheral surface of the refractory layer or the outer peripheral surface of the inner pipe is proposed, and includes, for example, an inner pipe 2 and an outer pipe 3 shown in FIG. In a conventional soundproof tube member 11 (described in Japanese Patent Application Laid-Open No. 2-16897), which has a double-tube structure, and has a reflection-absorbing plate 4 disposed in a gap between the inner tube and the outer tube 3 Demonstrates excellent soundproofing performance that is comparable to that of a reflection-absorbing plate (or far exceeds that in the case where a sound-absorbing layer containing an active component that increases the amount of dipole moment is provided). ing. The waveform reflection groove may be formed in a smooth curved surface such as a sine curve, or may be formed in a zigzag shape in which peaks and valleys are continuous. Further, it may have a rectangular waveform or a continuous loop-shaped cross section. By providing this wave reflection groove on the inner peripheral surface of the refractory layer or the outer surface of the inner tube, the sound from the inner tube impinges on the wall of the wave reflection groove and is irregularly reflected, repeatedly colliding in the wave reflection groove, and gradually attenuated. Will be. In particular, in the case of a wavy reflective groove having a continuous loop-shaped cross-section, once the sound has entered the groove, the sound cannot be emitted from the groove due to the small exit (opening) of the groove. Therefore, more effective damping is measured. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged sectional view showing a fireproof soundproof tube provided with a wave reflection groove on the inner peripheral surface of the fireproof layer of the present invention. FIG. 2 is an enlarged cross-sectional view showing a fireproof soundproof tube provided with a sound absorbing layer in a gap between the inner tube and the fireproof layer shown in FIG. FIG. 3 is an enlarged cross-sectional view showing a fireproof soundproof tube in which a gap is formed in a fireproof layer provided with a waveform reflection groove. FIG. 4 is an enlarged cross-sectional view showing a fireproof soundproof tube in which a sound absorbing layer is provided in a gap between an inner tube of the fireproof soundproof tube shown in FIG. 3 and a fireproof layer. FIG. 5 is an enlarged cross-sectional view showing a fireproof soundproof tube in which a sound absorbing layer is provided in a gap of the fireproof layer shown in FIG. FIG. 6 is an enlarged cross-sectional view showing a fireproof soundproof tube provided with a corrugated reflection groove on the inner peripheral surface of the inner tube of the present invention. FIG. FIG. 7 is an enlarged cross-sectional view showing a fireproof soundproof tube provided with a sound absorbing layer in a gap between the inner tube and the fireproof layer shown in FIG. FIG. 8 is an enlarged cross-sectional view showing a fireproof soundproof tube in which a gap is formed in an inner tube provided with a waveform reflection groove. FIG. 9 is an enlarged cross-sectional view showing a fireproof soundproof tube in which a sound absorbing layer is provided in a gap between an inner tube of the fireproof soundproof tube shown in FIG. 8 and a fireproof layer. FIG. 10 is an enlarged sectional view showing a fireproof soundproof tube in which a sound absorbing layer is provided in a gap of the inner tube shown in FIG. FIG. 11 is a schematic diagram showing a state of a dipole in the sound absorbing material (foam resin layer). FIG. 12 is a schematic diagram showing the state of a dipole when sound energy is applied to the sound absorbing material (foamed resin layer). FIG. 13 is a graph showing the relationship between the dielectric constant (p ') and the dielectric loss factor (d). FIG. 14 is an enlarged cross-sectional view showing a conventional soundproof tube member having a double tube structure including an inner tube and an outer tube, and having a reflection absorbing plate disposed in a gap between the inner and outer tubes. DETAILED DESCRIPTION OF THE EMBODIMENTS, refractory soundproofing tube _c present invention will be described in detail in accordance with the embodiment shown the refractory soundproof tube in the drawings of the present invention, a pipe such as plumbing device or air conditioner of a building It is applied as The fireproof soundproof tube 11 shown in FIG. 1 includes an inner tube 12, a fireproof layer 13, and a spacing member 14, which are integrally formed by extrusion. In addition, this fireproof The inner pipe 12, the refractory layer 13 and the spacing member 14 in the soundproof pipe 11 may be separately formed and then assembled. However, from the point of strength and workability, it is desirable to extrude integrally as in this embodiment. As the material of the inner tube 12, hard polyvinyl chloride—polyethylene, polypropylene, polybutene, and the like, which have been conventionally used for hard piping, can be used. As the refractory layer 13, inorganic fibers such as asbestos, glass fibers, and ceramic fibers are used, and these are combined with an inorganic binder such as cement to form a tube or a metal tube. Or a ceramic tube or a plastic tube containing a flame retardant or a flame retardant fiber. In the embodiment shown in FIG. 1, hard polyethylene was used for the inner tube 12 and the spacing member 14, and hard polyethylene containing glass fiber was used for the refractory layer 13. In addition, the fireproof soundproof pipe 11 shown in FIG. 1 has an inner pipe 12, a fireproof layer 13, and a spacing member 14 that are integrally extruded and formed. It is formed into a shape, but the thickness, length, etc. of the inner tube 12, the refractory layer 13, and the spacing member 14 are also appropriately determined in accordance with the intended use, use condition, and use location. The point that the inner pipe 12, the refractory layer 13, and the spacing member 14 are integrally extruded and formed is the same for each soundproof pipe member shown in FIGS. 2 to 10 described later. The description of this point is omitted in the description of each embodiment in FIG. In the fireproof soundproof tube 11 shown in FIG. 1, a wave reflection groove 15 is provided on the inner peripheral surface of the fireproof layer 13. The waveform reflection groove 15 in FIG. 1 has a continuous loop-shaped cross-sectional shape. For this reason, the sound from the inner tube 12 is irregularly reflected on the wall of the loop-shaped wave reflection groove 15, and repeats collision in the reflection groove 15, and is gradually attenuated. Figure 2 shows a fireproof soundproof pipe 1 1 with a sound absorbing layer 16 provided in the gap between the inner pipe 12 and the fireproof layer 13. It shows. In this embodiment, the sound absorbing layer 16 is made of a foamed resin layer. The sound absorbing layer 16 may be a fiber layer or the like in addition to the foamed resin layer. As shown in FIG. 2, by providing the sound absorbing layer 16 in the gap between the inner pipe 12 and the fireproof layer 13, the fireproof soundproof pipe 11 is caused by the irregular reflection of the sound of the waveform reflection groove 15 described above. In addition to the attenuation, the sound absorbing layer 16 absorbs the sound, so that the sound reduction is more effectively measured. The fireproof soundproof tube 11 shown in FIG. 3 has a gap 17 formed in a fireproof layer 13 provided with a wave reflection groove 16. The size and shape of the void 17 are arbitrary, and can be freely formed within a moldable range. The formation of the air gap 17 can save material, and the sound from the inner pipe 12 tends to propagate further to the outside even if the sound from the inner pipe 12 is attenuated by the irregular reflection of the waveform reflection groove 15 described above. However, the air layer formed in the gap 17 acts as an obstacle, and effective sound reduction is measured. The fireproof soundproof tube 11 shown in FIG. 4 has a sound absorbing layer 16 provided in a gap between the inner tube 12 and the fireproof layer 13 in the fireproof soundproof tube 11 shown in FIG. In this case, the sound from the inner tube 12 was first absorbed by the sound absorbing layer 16, and the sound that escaped absorption was attenuated by the irregular reflection of the waveform reflection groove 15, and was further formed in the refractory layer 13 When propagation is hindered by the air layer in the void 17, it is attenuated any time. The fireproof soundproof tube 11 shown in FIG. 5 has a form in which a sound absorbing layer 18 is formed in the void 17 of the fireproof layer 13 in the fireproof soundproof tube 11 shown in FIG. In this case, the sound from the inner tube 12 is first absorbed by the sound absorbing layer 16, and the sound that has escaped absorption is attenuated by the irregular reflection of the waveform reflection groove 15, and is further formed in the fireproof layer 13. It is attenuated as soon as it is absorbed by the sound absorbing layer in the void 17. In the fireproof soundproof tube 11 shown in FIG. 6, a wave reflection groove 15 is provided on the outer peripheral surface of the inner tube 12. The wavy reflection groove 15 in FIG. 6 has a continuous loop-shaped cross-sectional shape. You. For this reason, the sound from the inner tube 12 hits the wall of the loop-shaped wave reflection groove 15 and is irregularly reflected, and repeats collision in the reflection groove 15 to be gradually attenuated. FIG. 7 shows a fireproof soundproof pipe 11 provided with a sound absorbing layer 16 in a gap between the inner pipe 12 and the fireproof layer 13. In this embodiment, the sound absorbing layer 16 is made of a foamed resin layer.

The sound absorbing layer 16 may be a fiber layer or the like in addition to the foamed resin layer. As shown in FIG. 7, by providing the sound absorbing layer 16 in the gap between the inner pipe 12 and the fireproof layer 13, the fireproof soundproof pipe 11 is caused by the irregular reflection of the sound of the above-described waveform reflection groove 15. In addition to the attenuation, the sound absorbing layer 16 absorbs the sound, so that the sound reduction is more effectively measured. The fireproof soundproof tube 11 shown in FIG. 8 has a gap 19 formed in an inner tube 12 provided with a waveform reflection groove 16. The size and shape of the void 19 are arbitrary, and can be freely formed within a moldable range. The formation of the air gap 19 can save material, and the sound from the inner tube 12 tends to propagate to the outside, whereas the air layer formed in the air gap 17 Since it becomes an obstacle, effective sound reduction can be measured in combination with the attenuation caused by the irregular reflection of the waveform reflection groove 15 described above. The fireproof soundproof pipe 11 shown in FIG. 9 has a sound absorption layer 16 provided in the gap between the inner pipe 12 and the fireproof layer 13 in the fireproof soundproof pipe 11 shown in FIG. In this case, the sound from the inner pipe 12 is first prevented from propagating by the air layer in the gap 19 formed in the inner pipe 12, and is attenuated by the irregular reflection of the waveform reflection groove 15, and the sound is further absorbed. It will be absorbed by layer 16. The fireproof soundproof pipe 11 shown in FIG. 10 is a form in which the sound absorbing layer 20 is formed in the gap 19 of the inner pipe 12 in the fireproof soundproof pipe 11 shown in FIG. 9. In this case, the sound from the inner tube 12 is first absorbed by the sound absorbing layer 20 provided in the inner tube 12, and the sound that has escaped absorption is attenuated by the irregular reflection of the waveform reflection groove 15. Absorbed by sound absorbing layer 1 6 Will be. The sound absorbing layers 16, 18, 20 (foamed resin layers) shown in the forms shown in FIGS. 2, 4, 5, 5, 7, 9, and 10 are made of urethane, chloroprene, and styrene. Using resins conventionally used as polymer materials for foam molding, such as butadiene copolymer, polyethylene, polypropylene, ethylene vinyl acetate, and styrene, based on one or more of these resins It is foamed by adding a foaming agent and a catalyst to the mixture. The sound absorbing layers 16, 18, 20 (foamed resin layers) shown in the above figures are made of polyurethane and foamed by adding a foaming agent, a catalyst and the like to this resin. The sound absorbing layers 16, 18, 20 (foamed resin layer) shown in each figure contain an active ingredient that increases the amount of dipole moment in the sound absorbing layer (foamed resin layer). As described above, the active component is a component that dramatically increases the amount of dipole moment in the sound absorbing layer (foamed resin layer), and the active component itself has a large dipole moment amount, or is an active component. Although the amount of dipole moment of the component itself is small, it refers to a component in which the amount of dipole moment in the sound-absorbing layer (foamed resin layer) dramatically increases due to the inclusion of the active component. Here, the relationship between the sound absorbing property of the sound absorbing layer (foamed resin layer) and the amount of dipole moment will be described. It is generally known that when sound energy is applied to a sound absorbing material having a foamed structure, the sound passes through the bubbles while colliding, and is consumed as frictional heat at this time, and its attenuation is measured. (If a fiber layer is provided as the sound absorbing layer, the sound passes through the fiber surface or the fiber gap while colliding, and is consumed as frictional heat at this time, and the sound is attenuated.) Have proposed a theory that there are different attenuation mechanisms from the above-mentioned sound energy attenuation mechanism, and that they cooperate to attenuate sound energy. That is, when sound collides with the sound absorbing material (foamed resin layer), vibration is generated. This and Then, as shown in FIG. 11, displacement occurs in the dipole 22 existing inside the sound absorbing material (foamed resin layer) 21. Displacement of the dipole 22 means that each dipole 22 in the sound absorbing material (foam resin layer) 21 rotates or shifts in phase. It can be said that the arrangement state of the dipoles 22 inside the sound absorbing material (foam resin layer) 21 before sound energy is applied as shown in FIG. 11 is stable. However, as shown in FIG. 12, when sound energy is applied to the sound absorbing material (foamed resin layer) 21, displacement occurs in the dipole 22 existing inside the sound absorbing material (foamed resin layer) 21. Each dipole 22 inside the sound absorbing material (foam resin layer) 21 will be placed in an unstable state, and each dipole 22 will return to the stable state shown in FIG. At this time, energy is consumed. It is thought that the sound absorption effect is generated through the generation of frictional heat on the surface of the sound absorbing material (foamed resin layer), the displacement of the dipole inside the sound absorbing material (foamed resin layer), and the energy consumption due to the dipole restoring action. It is done. Due to the mechanism by which the above-described sound absorbing effect occurs, as the amount of the dipole moment inside the sound absorbing material (foamed resin layer) 21 shown in FIGS. 11 and 12 increases, the sound absorbing material (foamed resin layer) increases. It is considered that the sound absorbing performance of 21 is also high. From this, the amount of the dipole moment in the sound-absorbing layer (foamed resin layer) increases to 3 times or 10 times under the same conditions by blending the above-mentioned active ingredient. Therefore, the energy consumption due to the dipole restoring effect when the energy is transferred is also increased drastically, and it is thought that the sound absorption performance far exceeds the expected. Examples of the active ingredient that induces such an effect include compounds containing a mercaptobenzothiazyl group such as N, N-dicyclohexylbenzothiazyl-1-sulfenamide, 2-mercaptobenzothiazole and dibenzothiazyl sulfide; 2-{2 'one hydroxy 3'-(3 ", 4", 5 ", 6" tetrahydroftarimidemethyl) one 5 '—methylphenyl} benzotriazole, 2 _ {2 Xy-5'-methylphenyl} benzotriazole, 2- {2'-hydroxy-3'-t-butyl-5'-methylphenyl} 1-5-chlorobenzotriazole, 2- {2'-hydroxy 3 ', 5' —Di-tert-butylphenyl} -1-5-Chemical compound having a benzotriazole group such as benzotriazole or ethyl 2-cyano-1,3,3-diphenylacrylate And one or more compounds selected from compounds having a diphenyl acrylate group such as The compounding amount of the active ingredient is preferably from 100 to 200 parts by weight based on 100 parts by weight of the polymer constituting the sound absorbing layer (foamed resin layer). This is because if the amount of the active ingredient is out of the above range, no drastic improvement in sound absorption due to the incorporation of the active ingredient will be observed. As described above, the sound-absorbing layer (foamed resin layer) containing the active ingredient dramatically increases the amount of dipole moment, thereby exhibiting excellent sound energy absorbing performance (sound absorbing properties). However, the amount of dipole moment in this sound absorbing layer (foamed resin layer) is expressed as the difference in dielectric constant ε ') between A and B shown in Fig. 13. In other words, the larger the difference between the dielectric constants (£ ′) between 示す and Β shown in FIG. 13 is, the larger the amount of the dipole moment is. FIG. 13 is a graph showing the relationship between the dielectric constant (£ ') and the dielectric loss factor (£ 〃). As shown in this graph, there is a relationship between the dielectric constant (£ ') and the dielectric loss factor (£ 〃) such that the dielectric loss factor (e〃) = the dielectric constant (£') X the dielectric loss tangent (tancS) Holds. Through research on sound-absorbing materials, the inventor has found that the higher the dielectric loss ratio here, the higher the energy absorption performance (sound absorption). It was done. Based on this finding, the dielectric loss factor (£ 〃) of the above sound absorbing layer (foamed resin layer) was examined. When the dielectric loss factor at a frequency of 110 Hz was 50 or more, the sound absorbing layer (Foamed resin layer) was found to have excellent energy absorption performance (sound absorption). The fire-resistant sound-insulating pipe of the present invention is freely provided as long as the water supply and drainage noise can be more effectively reduced, such as a vibration damping layer, a sound insulation layer, and a vibration insulation layer outside and / or inside the above sound absorbing layer. It can be used additionally. In this case, it is desirable that the additionally used damping layer, sound insulation layer and vibration damping layer contain an active ingredient that increases the dipole moment. In this way, by appropriately determining the type and stacking order of each layer, the thickness of each layer, the number of layers, and the like according to the use and use state of the fireproof soundproof tube, the most suitable for the use and use state can be obtained. A fireproof soundproof tube can be created. As the above-mentioned vibration damping layer, for example, a layer obtained by mixing rubber with the above vinyl chloride resin can be used. In this case, the rubber includes acrylonitrile-butene-diene rubber (NBR), styrene-butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), isoprene rubber (IR) and the like. The compounding of the rubber is for obtaining good viscoelastic properties at room temperature, and the compounding amount is preferably 10 to 80% by weight. If the amount is more or less than this range, sufficient viscoelastic properties at room temperature cannot be obtained. The damping layer can be filled with a filler to improve the damping properties. As the filler, the same one as exemplified in the description of the foamed resin layer can be used. The vibration-proof layer is mainly made of rubber-based materials such as acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), and isoprene rubber (IR). And those obtained by blending a resin with these rubber-based materials. The vibration-proofing layer may be filled with a filler such as carbon black or calcium carbonate, if necessary (for adjusting the hardness). Examples of the sound insulating layer include acetic acid obtained by random copolymerization or block copolymerization with at least one kind of monomer copolymerizable with vinyl chloride monomer in addition to a resin polymerized with vinyl chloride alone. Vinyl chloride copolymer resins such as vinyl-vinyl chloride copolymer, ethylene-vinyl chloride copolymer, vinylidene chloride-vinyl chloride copolymer, or resins that can be graft-copolymerized with vinyl chloride monomer In addition to vinyl chloride-based resins such as ethylene monoacetate-vinyl chloride graft copolymer and polyurethane-vinyl chloride graft copolymer obtained by graft copolymerization, calcium carbonate , Talc, magnesium oxide, alumina, titanium oxide, barite, iron oxide, zinc oxide, graphite, etc. Filled ones can be mentioned. In this case, the filling amount of the filler is preferably 50 to 95% by weight, as in the case of the foamed resin layer described above. It should be noted that the scope of the present invention is defined in “Claims”, and all changes and modes included in the scope can be adopted.

Claims

Scope of word blue

1. A fireproof soundproof tube provided with a fireproof layer around the inner tube, wherein a sound absorbing layer containing an active ingredient that increases the amount of dipole moment is provided between the inner tube and the fireproof layer. Features a fireproof soundproof tube.

2. The fireproof soundproof tube according to claim 1, wherein the sound absorbing layer is a foamed resin layer.

3. The fireproof soundproof tube _{c according} to claim 1, wherein the sound absorbing layer is a fiber layer.

4. The active ingredient is a compound containing a mercaptobenzothiazyl group such as N, N-dicyclohexylbenzothiazyl-2-sulfenamide, 2-mercaptobenzothiazole, dibenzothiazylsulfide, etc., 2- { 2 '—Hide mouth 3'-(3 ", 4" _} 5,6 tetrahide mouth rimidemethyl) 1 5'—Methylphenyl} Venzotriazole, 2— {2'—High Droxy 5 '—methyl phenyl} benzotriazole, 2- {2' —hydric oxy 3 '— t-butyl -1 5' —methyl phenyl} — 5 _chloro benzotriazole, 2 — {2 '-Hydrox xy-l 3', 5 '-G-t-butylphenyl} -l- 5-Methyl-benzobenzotriazole or other compound having a benzotriazoyl group, or ethyl 2-cyano — 3, 3 —Different creatures Refractory soundproofing pipe according to any one of claims 1 to 3, characterized in that one or more selected from among of compounds having Ruakurireto group.

5. The method according to any one of claims 1 to 4, wherein the active ingredient is blended in a proportion of 10 to 200 parts by weight to 100 parts by weight of the polymer constituting the sound absorbing layer. The described fireproof soundproof tube.

6. A sound insulation layer, a vibration suppression layer or a vibration insulation layer is provided outside or inside the sound absorption layer The fire-resistant soundproof tube according to claim 1, wherein:

7. A fireproof soundproofing tube provided with a fireproof layer around the inner tube, wherein a wave reflection groove is provided on the inner peripheral surface of the fireproof layer or the outer peripheral surface of the inner tube.

8. The fireproof soundproof tube according to claim 7, wherein a sound absorbing layer containing an active ingredient for increasing a dipole moment is provided between the inner tube and the fireproof layer.

9. The fireproof soundproof tube according to claim 7 or 8, wherein a gap is formed in the fireproof layer or the inner tube provided with the wave reflection groove.

10. The fireproof soundproof tube according to claim 9, wherein a sound absorbing layer containing an active component that increases the amount of dipole moment is provided in the gap.

11. The fireproof soundproof tube according to claim 8, wherein a sound insulation layer, a vibration suppression layer, or a vibration insulation layer is provided outside or inside the sound absorption layer.