CN104485096B - A kind of noise reduction absorbent treatment - Google Patents

Abstract

The present invention provides a noise-reducing and sound-absorbing layer. The sound-absorbing layer includes a keel and a sound-absorbing component. The component includes a micro-perforated plate 2, a non-woven fabric 3, a two-component fiber mat 1 and backplane4. The sound-absorbing principle of the noise-reducing sound-absorbing layer couples the effects of two-component resistive sound absorption and double-layer resonant sound absorption, effectively absorbs low-frequency noise from substation transformers and high-voltage reactors, and reduces the risk of substation boundaries and sensitive points outside the station. Purpose.

Description

A noise-reducing sound-absorbing layer

technical field

The invention relates to the field of damping noise, in particular to a noise-reducing and sound-absorbing layer.

Background technique

Substation is an important power place. With the acceleration of urbanization, land resources are becoming increasingly scarce, the continuous expansion of cities and the needs of urban power grid transformation, some substations must be built in commercial and residential areas. Because noise not only pollutes the environment and endangers human health, the noise of transformers also affects the normal operation of equipment and the size of the substation's footprint, so it is necessary to reduce transformer noise.

Noise is very harmful to people. People who have been under the influence of noise for a long time often have the following symptoms: one is to affect hearing. The second is to affect study and work and interfere with sleep. The third is to affect cardiovascular function and endocrine system. This is mainly manifested in rapid heartbeat, arrhythmia, high blood pressure and so on. The fourth is to harm the central nervous system. People who have been exposed to noise for a long time will experience symptoms such as headaches, earaches, dreaminess, memory loss, and general fatigue. The fifth is to affect children's intellectual development. It has been reported that the intelligence of children in a noisy environment is 20% lower than that in a quiet environment, and noise also has an impact on the growth of the fetus.

Although transformer noise is not high-decibel strong noise, the low-frequency noise generated in most cases will cause chronic damage to the human body, making people irritable, irritable, and sometimes even lose their minds. If they are harassed for a long time, it may also cause Neurasthenia, insomnia and other nervous system diseases, if pregnant women are exposed to low-frequency noise for a long time, it will also affect the development of the fetus in the abdomen. Environmental impact assessment experts pointed out that although the impact of low-frequency noise on physiology is not as obvious as high-frequency noise, it can reach people's ear bones, make people's sympathetic nervous, and cause symptoms such as rapid heartbeat, elevated blood pressure, and endocrine disorders. Since low-frequency noise is mainly transmitted through the structure, it is easy to arouse human sensory resonance. Generally speaking, people's tolerance to low-frequency noise is relatively low. Under normal circumstances, 30 to 35 decibels is acceptable to most people, and above 35 decibels, some people will obviously feel uncomfortable conditions such as palpitation and irritability.

The main sound source equipment of the substation is the main transformer (main transformer) and the fan, the noise level of which directly determines the noise release level of the substation. The noise of the main transformer is mainly caused by the magnetostriction of the iron core during the operation of the main transformer, and the operation of the fan will also generate additional noise. In addition, the vibration of the transformer body radiates outward through the bottom plate and the wall, and the structural sound transmission and secondary vibration caused by it will also increase the noise level of the station boundary. The substation noise spectrum is wide, the frequency is mainly low frequency, and the energy is mainly distributed in the 50Hz power frequency and the multiplier frequency bands of 100Hz, 200Hz, 400Hz, and 500Hz. This type of noise has a large wavelength, slow attenuation, and strong penetrating ability to building structures. It is the key control target of substation noise reduction projects. Due to the unreasonable design of the air intake and exhaust system, walls and gates of some substations, the noise can easily spread out of the station along the ventilation ducts or through the walls and gates. Especially for residents near sensitive points of noise transmission, they are often several times more disturbed by noise than residents in other locations. Therefore, systematic substation noise control projects are often carried out for noise sources, noise transmission routes and noise sensitive points.

Sound absorption, noise reduction, sound insulation and vibration isolation are several main measures to control noise, and occupy a pivotal position in the noise reduction project of substations. At present, the design and manufacture of most noise reduction devices are based on the above four noise reduction concepts. For example, the box-in sound insulation cover designed for noise sources adopts the structure of internal suction and external partition, which is the perfect combination of sound absorption and sound insulation measures. Generally speaking, the common noise reduction, sound insulation and vibration isolation devices on the market can meet the needs of most substation noise reduction projects. However, for sound-absorbing materials and devices, since the noise energy of substations is concentrated in the low-frequency band, commonly used sound-absorbing materials such as mineral wool and polyurethane foam cannot meet the requirements. Although the low-frequency sound absorption effect of materials such as powder sintered board and foamed metal aluminum is relatively ideal, the manufacturing process of the materials is complicated and the cost is high, so it is difficult to be popularized and applied on a large scale.

Aluminum fiber sound-absorbing board is a sound-absorbing material widely used in substation noise control. It is light in weight, good in heat dissipation, recyclable, green and environmentally friendly, and has excellent moisture resistance and durability. It can meet the service requirements of most substations. Moreover, its sound absorption characteristics can be changed by adjusting the process parameters, making it suitable for substation noise reduction. However, although the resistive sound absorption of a single aluminum fiber board is sufficient to deal with low-frequency noise, the sound-absorbing frequency band is narrow, and it cannot take into account other frequency bands with higher noise energy. The resonant sound absorption effect of the micro-perforated plate can achieve high-efficiency sound absorption for a specific frequency band. Combining aluminum fiber boards with micro-perforated boards to form a resistive and resonant composite sound-absorbing system can overcome this technical shortcoming.

Contents of the invention

In order to overcome the above-mentioned defects in the prior art, the present invention provides a noise-reducing and sound-absorbing layer, which includes a hexahedron composed of resonant sound-absorbing components, the surface of the hexahedron perpendicular to the base plane is the keel, and the plane parallel to the base plane of the hexahedron is The resonant sound-absorbing component includes an aluminum plate 2 , a non-woven fabric 3 , a bi-component fiber mat 1 and a back plate 4 arranged sequentially from the noise source toward the wall. After simulation analysis and laboratory effect verification, the invention can effectively absorb the low-frequency noise of substation transformers and high-voltage reactors, and achieve the purpose of reducing substation factory boundaries and sensitive points outside the substation.

For realizing above-mentioned purpose of the invention, the technical scheme that the present invention takes is:

A noise-reducing sound-absorbing layer. The sound-absorbing layer includes keels and sound-absorbing components. The components include a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4 arranged in sequence from the noise source to the wall.

Further, an air layer with a thickness of 20 mm to 180 mm is formed between the sound absorbing member and the base surface.

Further, an air layer with a thickness of 40 mm to 80 mm is formed between the sound absorbing member and the base surface.

Further, the length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are equal to the parallel surface of the wall respectively, and the length and width of the non-woven fabric 3 and the parallel surface of the wall are equal to the length and width of the micro-perforated plate 2 60% to 80% of the length and width.

Further, the non-woven fabric 3 is PP cotton with a thickness of 0.5mm-1.0mm.

Further, the two-component fiber mat 1 is made by blending aluminum fibers with a diameter of 20 μm to 60 μm and polyester fibers with a diameter of 30 μm to 200 μm, with an area density of 100 g/m ² to 280 g/m ² and a thickness of 20 mm to 50 mm , A bi-component fiber mat with an aluminum fiber volume fraction of 10% to 50%.

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

Aluminum fiber and polyester fiber convert sound energy into heat energy through the vibration of the air in the gap between the fibers and the vibration of the fiber itself, so as to achieve the effect of resistive sound absorption. Polyester fiber and aluminum fiber have good high-frequency and low-frequency absorption respectively. Acoustic effect, forming a layered sound-absorbing structure, the different chemical composition and structure of aluminum fiber and polyester fiber lead to the difference in their cohesive energy and viscoelastic properties, so that they have different physical properties such as skeleton strength, bending degree, etc. There are differences, and the sound absorption performance is also quite different. After blending, they are overlapped and interlaced to form a two-component fiber mat, forming a more complex two-component sound absorption system and a more complex two-component sound absorption network structure. Its refraction and reflection effect on the noise sound wave will also be strengthened when it penetrates itself, so the sound energy is absorbed in a large amount, which increases the barrier of sound energy transmission. The two-component resistive sound absorption has a wide and high-efficiency resistivity Absorbing frequency band.

The temperature gradient formed by the two-component structure ensures good heat dissipation. Polyester fibers and non-woven fabrics are organic fiber materials with low thermal conductivity. Working for a long time in a relatively closed environment will generate high heat. The aluminum structure of the component fiber microporous composite sound-absorbing panel and the bolts used for fixing have excellent thermal conductivity, and the heat dissipation system formed by the aluminum fibers in the fiber mat through direct contact with each other or the connection of polyester fibers will also accelerate heat loss. , which not only improves the safety of the product, but also promotes the process of converting sound energy into heat energy due to good heat dissipation performance, thereby enhancing the sound absorption effect.

Further, a channel composed of conical and circular parts is arranged on a plane perpendicular to the bicomponent fiber mat.

Further, the conical shape and the circular shape are on the same axis, and the diameter of the circle is equal to the diameter of the conical portion.

Further, the channel is a tapered hole 5 pointing to the base surface, the diameter of the large hole of the tapered hole 5 is 20-60 mm, the diameter of the small hole is 5-10 mm, and the taper is 30°-70°. The center distance is 50mm~180mm.

Tapered holes are made in the felt by a cutting process.

Adjacent tapered holes form a structure similar to absorption wedges. Noise sound waves incident on the tapered circular holes will be reflected and absorbed by the slope multiple times, which can effectively absorb scattered sound waves and improve the sound absorption efficiency. The conical platform formed by adjacent conical holes has a cross-section that gradually increases from small to large, matching the characteristic impedance of the air. It is similar to the sound-absorbing wedge structure, which is more conducive to the absorption of sound energy. The conical holes on the felt serve as micro The resonance cavity in the micro-perforated part of the perforated plate consumes a large amount of sound energy through resonance. The two-component fiber mat combines the principles of resistive sound absorption and resonance sound absorption, and has good sound absorption performance.

Further, the thickness of the micro-perforated plate 2 is 1.0 mm to 1.5 mm, and the surface of the micro-perforated plate 2 overlaps with the non-woven fabric to have round holes evenly distributed. ～1.0mm, the perforation rate is 1%～3%.

Further, the micro-perforated plate 2 has a thickness of 1.0 mm to 1.3 mm, a hole diameter of 0.8 mm to 1.0 mm, and a perforation rate of 1% to 2%.

Further, the thickness of the back plate 4 is 1.0mm˜1.5mm.

Further, the thickness of the back plate 4 is 1.0-1.3 mm.

Further, it is fixed on the base surface with a vertical fixing member passing through the micro-perforated plate 2 , the non-woven fabric 3 , the bicomponent fiber mat 1 and the back plate 4 arranged in sequence.

Further, the fixing parts are screws and nuts.

Further, the micro-perforated board 2 is one of plywood, metal board, gypsum board or acrylic board.

Further, the back board 4 is one of plywood, metal board, gypsum board or acrylic board.

Further, the metal plate is a galvanized plate or an aluminum plate.

The back plate and the base surface form a closed air layer, forming a flat-panel resonance sound-absorbing structure. A resonant system is formed by the elasticity of the flat plate, the elasticity of the air layer and the mass of the plate, which has a greater sound absorption effect near the system resonant frequency. When the sound wave is incident on the flat plate structure, the flat plate vibrates under the excitation of the high-variable pressure of the sound wave, causing the flat plate to bend and deform, and the internal friction loss of the plate appears. At the resonant frequency, the consumption of sound energy is the largest.

The air layer formed by the back plate with sound-absorbing holes and the base surface constitutes a micro-perforated resonant sound-absorbing structure. The tapered hole perforated on the plate and behind the plate can be understood as an air layer, which can be regarded as a resonance system composed of mass and spring. When the frequency of the incident sound wave is consistent with the resonance frequency of the system, the cavity of the perforated plate generates vibration and friction, which plays the role of sound absorption.

Compared with ordinary perforated panels, the ratio of sound resistance to sound quality is greatly improved, and micro-perforated panels are good sound-absorbing materials.

According to the calculation formula of the resonance peak of the micro-perforated plate:

Where: f ₀ is the resonant frequency, Hz;

c is the speed of sound, m/s, generally 340m/s;

P is the perforation rate, that is, the percentage of perforation area in the total area;

D is the thickness of the air layer behind the perforated plate, cm;

l _k is the effective length of the neck, cm; when the hole diameter d is greater than the plate thickness t, l _k =t+0.8d;

When a porous material is pasted inside the aperture, l _k =t+1.2d.

In the case of the same cavity body, the absorption peak of the micro-perforated plate sound-absorbing structure moves to the high frequency direction with the increase of the perforation rate. When the resonance peak (that is, the frequency with the largest absorption coefficient) remains unchanged, the perforation rate increases, and the cavity depth needs to increase year-on-year. However, the compact layout of the equipment in the substation requires that the thickness of the sound-absorbing structure should not be too large.

The resonance cavity between the back panel and the wall optimizes the sound absorption effect through resonance for the main frequency band of the remaining sound energy. The absorption effect in the frequency band is very ideal. The composite system formed by the four layers combines the advantages of high low-frequency sound absorption coefficient and sound absorption frequency bandwidth, and comprehensively improves the sound absorption performance of the noise-reducing sound-absorbing layer for noise.

Owing to adopting above-mentioned technical scheme, compared with the closest prior art, the beneficial effects of the present invention include:

1. The noise-reducing sound-absorbing layer of the present invention has distinct layers and a sound-absorbing structure that takes into account both high and low frequency noise. Aluminum fibers and polyester fibers convert sound energy into heat energy through the vibration of the air in the space between the fibers and the vibration of the fiber itself, Resistive sound absorption effect is achieved. Polyester fiber and aluminum fiber have good high-frequency and low-frequency sound absorption effects respectively, forming a layered sound-absorbing structure. The different chemical composition and molecular structure of aluminum fiber and polyester fiber lead to their The difference between cohesive energy and viscoelastic properties makes them different in many physical properties such as skeleton strength and curvature, and the sound absorption performance is also quite different. After blending, they are overlapped and interlaced to form a two-component fiber mat. , forming a relatively complex two-component sound-absorbing system and a relatively complex two-component sound-absorbing network structure, which will also strengthen the refraction and reflection of the noise sound wave when it penetrates itself, and the sound energy will be absorbed in large quantities. The potential barrier for sound energy transmission is increased, and the two-component resistive sound absorption has a wide frequency band of high-efficiency resistive sound absorption, which improves the overall sound absorption performance.

2. In the noise-reducing and sound-absorbing layer of the present invention, the temperature gradient formed by the two-component structure ensures good heat dissipation. Polyester fibers and non-woven fabrics belong to organic fiber materials, which have low thermal conductivity and are long-lasting in a relatively closed environment. Working for a long time will generate high heat, and the aluminum structure of the two-component fiber microporous composite sound-absorbing panel and the bolts used for fixing have excellent thermal conductivity. The heat dissipation system formed by the connection will also accelerate the heat loss, which not only improves the safety of the product, but also promotes the process of converting sound energy into heat energy due to good heat dissipation performance, thereby enhancing the sound absorption effect.

3. In the noise-reducing and sound-absorbing layer of the present invention, the adjacent tapered holes form a structure similar to absorbing wedges, and the noise sound waves incident into the tapered circular holes will be reflected and absorbed by the slope multiple times, which can effectively absorb scattered sound waves , thus improving the sound absorption efficiency. The conical platform formed by adjacent conical holes has a cross-section that gradually increases from small to large, matching the characteristic impedance of the air. It is similar to the sound-absorbing wedge structure, which is more conducive to the absorption of sound energy. The conical holes on the felt serve as micro The resonance cavity in the micro-perforated part of the perforated plate consumes a large amount of sound energy through resonance. The two-component fiber mat combines the principles of resistive sound absorption and resonance sound absorption, and has good sound absorption performance.

4. The nonwoven fabric of the noise-reducing and sound-absorbing layer of the present invention can further consume sound energy and further optimize the sound-absorbing effect.

5. The resonance cavity of the backboard and the wall of the noise-reducing sound-absorbing layer of the present invention optimizes the sound-absorbing effect through resonance for the main frequency band of the remaining sound energy, and the sound-absorbing principle couples the two-component resistive sound-absorbing and The effect of double-layer resonance sound absorption is ideal for absorbing noise in the whole frequency range. The composite system formed by four layers combines the advantages of high low-frequency sound absorption coefficient and sound absorption frequency bandwidth, and comprehensively improves the noise reduction and sound absorption layer. sound absorption performance.

6. The noise-reducing and sound-absorbing layer in the present invention can be adjusted by adjusting the thickness, fiber diameter, and surface density of the two-component fiber mat, as well as the taper of the tapered holes and the center distance between adjacent holes, the distance between the backboard and the wall, It can effectively adjust its sound absorption frequency band, and can be applied to other situations where sound absorption for frequency bands is required.

7. The noise-reducing and sound-absorbing layer in the present invention is green and environmentally friendly, and has good serviceability. Most of the sound-absorbing panels used are all-aluminum structures, which are light, have good heat dissipation, can be recycled, and will not generate dust like rock wool , and has excellent moisture resistance, corrosion resistance and durability, and has a long service life in outdoor service.

8. The noise-reducing and sound-absorbing layer in the present invention has a simple structure, simple manufacture and low cost.

9. The noise-reducing and sound-absorbing layer in the present invention is easy to install and disassemble.

Description of drawings

Fig. 1 is a cross-sectional view of a noise-reducing sound-absorbing layer;

Fig. 2 is a cross-sectional view of a resonant sound-absorbing component;

Fig. 3 is the comparison of the sound absorption properties of the noise-reducing sound-absorbing layer and the aluminum fiberboard in Example 1

Figure 4 is a comparison of the sound absorption properties of the noise reduction and sound absorption layer and the aluminum fiberboard in Example 2

Figure 5 is a comparison of the sound absorption properties of the noise reduction and sound absorption layer and the aluminum fiberboard in Example 3

Figure 6 is a comparison of the sound absorption properties of the noise reduction and sound absorption layer and the aluminum fiberboard in Example 4

Figure 7 is a comparison of the sound absorption properties of the noise-reducing sound-absorbing layer and the aluminum fiberboard in Example 5

Figure 8 is a comparison of the sound absorption properties of the noise-reducing sound-absorbing layer and the aluminum fiberboard in Example 6

Figure 9 is a comparison of the sound absorption performance of the noise reduction sound absorption layer and the aluminum fiberboard in Example 7

1-two-component fiber mat, 2-micro-perforated plate, 3-non-woven fabric, 4-back plate, 5-tapered hole, 6-bolt, 7-keel.

Detailed ways

Below in conjunction with example the present invention is described in detail.

Example 1:

As shown in Figure 1, the noise-reducing sound-absorbing layer of the present invention, the sound-absorbing layer comprises a hexahedron composed of resonant sound-absorbing components, the surface of the hexahedron perpendicular to the base surface is the keel, and the surface of the hexahedron parallel to the base surface is the resonant sound-absorbing component , The resonant sound-absorbing component includes a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4, which are sequentially arranged from the noise source to the wall.

The thickness of the air layer formed by the back plate 4 and the base surface is 180mm.

The length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are respectively equal to the parallel surface of the wall, and the length of the non-woven fabric 3 and the parallel surface of the wall is 60% of the length of the micro-perforated plate 2, The width is 60% of the micro-perforated plate 2.

The non-woven fabric 3 is pure PP cotton with a thickness of 0.5mm.

The two-component fiber mat 1 is made by blending aluminum fibers and polyester fibers, with an area density of 100g/m ² , a thickness of 20mm, a diameter of aluminum fibers of 50 μm, a diameter of polyester fibers of 30 μm, and a volume fraction of aluminum fibers of 20%.

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

Two-component fiber mat 1 is provided with a tapered hole 5, the diameter of the large hole of the tapered hole 5 is 20mm, the diameter of the small hole is 5mm, and the taper is 30°. The large hole is opened in the direction close to the non-woven fabric 3, and the adjacent cone The hole center distance is 50mm.

Tapered holes are made in the felt by a cutting process.

The micro-perforated plate 2 is an aluminum plate with a thickness of 1.2 mm. The surface of the micro-perforated plate 2 overlaps with the non-woven fabric and has round holes evenly distributed. The round holes correspond to the large holes of the bicomponent fiber mat 1. The rate is 1%.

The back plate 4 is an aluminum plate with a thickness of 1.0mm.

The micro-perforated plate 2, the non-woven fabric 3, the bicomponent fiber mat 1 and the back plate 4 are stacked in sequence, and the screws and nuts pass through the micro-perforated plate 2, the bi-component fiber mat 1 and the back plate 4 to fix the four layers.

Example 2

As shown in Figure 1, the noise-reducing sound-absorbing layer of the present invention, the sound-absorbing layer comprises a hexahedron composed of resonant sound-absorbing components, the surface of the hexahedron perpendicular to the base surface is the keel, and the surface of the hexahedron parallel to the base surface is the resonant sound-absorbing component , The resonant sound-absorbing component includes a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4, which are sequentially arranged from the noise source to the wall.

The thickness of the air layer formed by the back plate 4 and the base surface is 40mm.

The length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are respectively equal to the parallel surface of the wall, and the length of the non-woven fabric 3 and the parallel surface of the wall is 80% of the length of the micro-perforated plate 2, The width is 80% of the micro-perforated plate 2.

The non-woven fabric 3 is pure PP cotton with a thickness of 1.0mm.

The two-component fiber mat 1 is made by blending aluminum fibers and polyester fibers, with an area density of 150g/m ² , a thickness of 30mm, a diameter of aluminum fibers of 55 μm, a diameter of polyester fibers of 40 μm, and a volume fraction of aluminum fibers of 30%.

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

Two-component fiber mat 1 is provided with a tapered hole 5, the diameter of the large hole of the tapered hole 5 is 30mm, the diameter of the small hole is 6mm, and the taper is 40°. The large hole is opened in the direction close to the non-woven fabric 3, and the adjacent cone The center distance of the shaped holes is 55mm.

Tapered holes are made in the felt by a cutting process.

The micro-perforated plate 2 is an aluminum plate with a thickness of 1.5 mm. The surface of the micro-perforated plate 2 overlaps with the non-woven fabric and there are round holes evenly distributed. The round holes correspond to the large holes of the bicomponent fiber mat 1. The rate is 2%.

The back plate 4 is an aluminum plate with a thickness of 1.5mm.

The micro-perforated plate 2, the non-woven fabric 3, the bicomponent fiber mat 1 and the back plate 4 are stacked in sequence, and the screws and nuts pass through the micro-perforated plate 2, the bi-component fiber mat 1 and the back plate 4 to fix the four layers.

Example 3

A noise-reducing and sound-absorbing layer includes a keel and a sound-absorbing component, and the component includes a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4 arranged in sequence from the noise source to the wall.

An air layer with a thickness of 100 mm is formed between the sound-absorbing member and the base surface.

The length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are respectively equal to the parallel surface of the wall, and the length and width of the non-woven fabric 3 and the parallel surface of the wall are equal to the length and width of the micro-perforated plate 2. 70% of the width.

The non-woven fabric 3 is polypropylene fiber cotton with a thickness of 0.6 mm.

Two-component fiber mat 1 is a two-component fiber mat with an area density of 200g/m ² , a thickness of 25mm, and a volume fraction of aluminum fibers of 35%, which is processed by blending aluminum fibers with a diameter of 40 μm and polyester fibers with a diameter of 40 μm. .

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

The cross-section of the bicomponent fiber mat is convex and concave. The concave shape is a tapered hole 5 pointing to the base surface. The large hole diameter of the tapered hole 5 is 60mm, the small hole diameter is 10mm, the taper is 70°, and the center distance between adjacent tapered holes is 110mm.

Tapered holes are made in the felt by a cutting process.

The micro-perforated plate 2 is a galvanized plate with a thickness of 1.4 mm. The surface of the micro-perforated plate 2 overlaps with the non-woven fabric and has round holes evenly distributed. The round holes correspond to the large holes of the two-component fiber mat 1, and the diameter of the holes is 1.0 mm. , the perforation rate is 3%.

The back plate 4 is a galvanized plate with a thickness of 1.3mm.

Fix on the base surface with screws and nuts that are vertical and pass through the micro-perforated plate 2, non-woven fabric 3, bicomponent fiber mat 1 and back plate 4 arranged in sequence.

Example 4

A noise-reducing and sound-absorbing layer includes a keel and a sound-absorbing component, and the component includes a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4 arranged in sequence from the noise source to the wall.

An air layer with a thickness of 120 mm is formed between the sound-absorbing member and the base surface.

The length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are respectively equal to the parallel surface of the wall, and the length and width of the non-woven fabric 3 and the parallel surface of the wall are equal to the length and width of the micro-perforated plate 2. 75% of the width.

The non-woven fabric 3 is pure PP cotton with a thickness of 0.7mm.

Two-component fiber mat 1 is a two-component fiber mat with an area density of 230g/m ² , a thickness of 50mm, and a volume fraction of aluminum fibers of 25%, which is processed by blending aluminum fibers with a diameter of 55 μm and polyester fibers with a diameter of 180 μm. .

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

The cross-section of the bicomponent fiber mat is convex and concave. The concave shape is a tapered hole 5 pointing to the base surface. The large hole diameter of the tapered hole 5 is 50mm, the small hole diameter is 9mm, the taper is 60°, and the center distance between adjacent tapered holes is 90mm.

Tapered holes are made in the felt by a cutting process.

The micro-perforated plate 2 is plywood with a thickness of 1.5mm. The surface of the micro-perforated plate 2 overlaps with the non-woven fabric and has round holes evenly distributed. The round holes correspond to the large holes of the two-component fiber mat 1. The rate is 2.5%.

The backboard 4 is plywood with a thickness of 1.3mm.

Fix on the base surface with screws and nuts that are vertical and pass through the micro-perforated plate 2, non-woven fabric 3, bicomponent fiber mat 1 and back plate 4 arranged in sequence.

Example 5

A noise-reducing and sound-absorbing layer includes a keel and a sound-absorbing component, and the component includes a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4 arranged in sequence from the noise source to the wall.

An air layer with a thickness of 80 mm is formed between the sound-absorbing member and the base surface.

The length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are respectively equal to the parallel surface of the wall, and the length and width of the non-woven fabric 3 and the parallel surface of the wall are equal to the length and width of the micro-perforated plate 2. 65% of the width.

The non-woven fabric 3 is pure PP cotton with a thickness of 0.8 mm.

Two-component fiber mat 1 is a two-component fiber mat with an area density of 250g/m2, a thickness of 40mm, and an aluminum fiber volume fraction of 40% by blending aluminum fibers with a diameter of 60 μm and polyester fibers with a diameter of 100 μm.

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

The cross-section of the bicomponent fiber mat is convex and concave. The concave shape is a tapered hole 5 pointing to the base surface. The large hole diameter of the tapered hole 5 is 55mm, the small hole diameter is 8mm, the taper is 65°, and the center distance between adjacent tapered holes is 120mm.

Tapered holes are made in the felt by a cutting process.

The micro-perforated plate 2 is an aluminum plate with a thickness of 1.0mm. The surface of the micro-perforated plate 2 overlaps with the non-woven fabric and there are round holes evenly distributed. The round holes correspond to the large holes of the bicomponent fiber mat 1. The rate is 2%.

The back plate 4 is an aluminum plate with a thickness of 1.2mm.

Fix on the base surface with screws and nuts that are vertical and pass through the micro-perforated plate 2, non-woven fabric 3, bicomponent fiber mat 1 and back plate 4 arranged in sequence.

Example 6

A noise-reducing and sound-absorbing layer includes a keel and a sound-absorbing component, and the component includes a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4 arranged in sequence from the noise source to the wall.

An air layer with a thickness of 40 mm is formed between the sound-absorbing member and the base surface.

The length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are respectively equal to the parallel surface of the wall, and the length and width of the non-woven fabric 3 and the parallel surface of the wall are equal to the length and width of the micro-perforated plate 2. 65% of the width.

The non-woven fabric 3 is pure PP cotton with a thickness of 0.8mm.

Two-component fiber mat 1 is a two-component fiber mat with an area density of 270g/m2, a thickness of 30mm, and an aluminum fiber volume fraction of 45% by blending aluminum fibers with a diameter of 60 μm and polyester fibers with a diameter of 200 μm.

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

The cross-section of the bicomponent fiber mat is convex and concave. The concave shape is a tapered hole 5 pointing to the base surface. The large hole diameter of the tapered hole 5 is 60mm, the small hole diameter is 8mm, the taper is 65°, and the center distance between adjacent tapered holes is 160mm.

Tapered holes are made in the felt by a cutting process.

The micro-perforated plate 2 is an aluminum plate with a thickness of 1.3 mm. The surface of the micro-perforated plate 2 overlaps with the non-woven fabric and has round holes evenly distributed. The round holes correspond to the large holes of the bicomponent fiber mat 1. The rate is 2%.

The back plate 4 is an aluminum plate with a thickness of 1.5 mm.

Fix on the base surface with screws and nuts that are vertical and pass through the micro-perforated plate 2, non-woven fabric 3, bicomponent fiber mat 1 and back plate 4 arranged in sequence.

Example 7

A noise-reducing and sound-absorbing layer includes a keel and a sound-absorbing component, and the component includes a micro-perforated plate 2, a non-woven fabric 3, a bicomponent fiber mat 1 and a back plate 4 arranged in sequence from the noise source to the wall.

An air layer with a thickness of 20 mm is formed between the sound-absorbing member and the base surface.

The length and width of the micro-perforated plate 2, the two-component fiber mat 1 and the back plate 4 are respectively equal to the parallel surface of the wall, and the length and width of the non-woven fabric 3 and the parallel surface of the wall are equal to the length and width of the micro-perforated plate 2. 65% of the width.

The non-woven fabric 3 is pure PP cotton with a thickness of 0.8mm.

Two-component fiber mat 1 is a two-component fiber mat with an area density of 280g/m2, a thickness of 30mm, and an aluminum fiber volume fraction of 50% by blending aluminum fibers with a diameter of 40 μm and polyester fibers with a diameter of 180 μm.

Aluminum fibers and polyester fibers are blended together and processed through a felting process.

The cross-section of the bicomponent fiber mat is convex and concave. The concave shape is a tapered hole 5 pointing to the base surface. The large hole diameter of the tapered hole 5 is 60mm, the small hole diameter is 8mm, the taper is 65°, and the center distance between adjacent tapered holes is 180mm.

Tapered holes are made in the felt by a cutting process.

The micro-perforated plate 2 is an aluminum plate with a thickness of 1.0mm. The surface of the micro-perforated plate 2 overlaps with the non-woven fabric and there are round holes evenly distributed. The round holes correspond to the large holes of the bicomponent fiber mat 1. The rate is 2%.

The back plate 4 is an aluminum plate with a thickness of 1.5mm.

Fix on the base surface with screws and nuts that are vertical and pass through the micro-perforated plate 2, non-woven fabric 3, bicomponent fiber mat 1 and back plate 4 arranged in sequence.

With the noise-reducing and sound-absorbing layers in Examples 1 to 7, according to the national standard GBT20247-2006 "Acoustic Reverberation Room Sound Absorption Measurement", the sound absorption coefficient (SAC curve) of the above-mentioned materials was measured, and compared with the same surface density, aluminum The aluminum fiber sound-absorbing panels with fiber diameter and back cavity thickness are compared, and the results are shown in Figures 3-9.

The main sound-absorbing frequency of the noise-reducing sound-absorbing layer is concentrated between 100-200Hz, and its low-frequency sound-absorbing performance is excellent, and the sound absorption coefficient can reach up to 0.97; the main sound-absorbing frequency of the aluminum fiberboard is also concentrated in the same low-frequency range, but the absorption The sound effect is not as good as the noise reduction and sound absorption layer. In the range of 250-1600Hz, as the frequency increases, the sound absorption coefficient curve of the composite panel generally shows a downward trend, but there are also 1-2 peaks, and the sound absorption coefficient can reach up to 0.65 (Example 7, 900Hz); The sound absorption performance of fiberboard decreases with the increase of frequency. Although there are slight fluctuations in some frequency bands, it is still inferior to the noise reduction and sound absorption layer on the whole. It can be seen that by adjusting the appropriate process parameters, the high-efficiency sound-absorbing frequency band of the noise-reducing sound-absorbing layer can be widened, which not only ensures its low-frequency sound-absorbing performance, but also enhances its sound-absorbing effect in the high-frequency band.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.

Claims (8)

1. A noise-reducing sound-absorbing layer, said sound-absorbing layer comprising a keel and a sound-absorbing member, characterized in that: said member comprises a micro-perforated plate 2, a non-woven fabric 3, a double-layered plate arranged successively by the noise source to the wall direction Component fiber mat 1 and back plate 4; An air layer with a thickness of 20 mm to 180 mm is formed between the sound-absorbing member and the base surface; An air layer with a thickness of 40 mm to 80 mm is formed between the sound-absorbing member and the base surface; The non-woven fabric 3 is pure PP cotton with a thickness of 0.5 mm to 1.0 mm; The two-component fiber mat 1 is processed by blending aluminum fibers with a diameter of ²⁰ μm to 60 μm and polyester fibers with a diameter of 30 μm to 200 μm. Bi-component fiber mat with a fraction of 10% to 50%; The channel is a tapered hole 5 pointing to the base surface. The diameter of the large hole of the tapered hole 5 is 20-60mm, the diameter of the small hole is 5-10mm, and the taper is 30°-70°. The center of the adjacent tapered hole The distance is 50mm ~ 180mm; Conical and circular tunnels are arranged on a plane perpendicular to the bicomponent fiber mat; The micro-perforated plate 2 has a thickness of 1.0 mm to 1.5 mm, and round holes are evenly distributed on the surface of the micro-perforated plate 2 overlapping with the non-woven fabric. 0.5~1.0mm, the perforation rate is 1%~3%; The micro-perforated plate 2 has a thickness of 1.0 mm to 1.3 mm, an aperture of 0.8 mm to 1.0 mm, and a perforation rate of 1% to 2%; The thickness of the back plate 4 is 1.0 mm to 1.5 mm; The thickness of the back plate 4 is 1.0-1.3mm. 2. A noise-reducing and sound-absorbing layer as claimed in claim 1, characterized in that: the length and width of the micro-perforated plate 2, the bicomponent fiber mat 1 and the back plate 4 parallel to the wall are respectively equal , the length and width of the non-woven fabric 3 parallel to the wall are 60% to 80% of the length and width of the micro-perforated plate 2 . 3. A noise-reducing and sound-absorbing layer according to claim 1, wherein the conical shape and the circular shape are on the same axis, and the diameter of the circle is equal to the diameter of the conical portion. 4. A kind of noise-reducing and sound-absorbing layer as claimed in claim 1, characterized in that: said micro-perforated plate 2, non-woven fabric 3, bicomponent fiber mat 1 and The fixing part of the back plate 4 is fixed on the base surface. 5. A noise-reducing and sound-absorbing layer according to claim 1, characterized in that: the fixing parts are screws and nuts. 6. A noise-reducing and sound-absorbing layer according to claim 1, characterized in that: the micro-perforated board 2 is one of plywood, metal board, gypsum board or acrylic board. 7. A noise-reducing and sound-absorbing layer according to claim 1, wherein the backboard 4 is one of plywood, metal board, gypsum board or acrylic board. 8. A noise-reducing and sound-absorbing layer according to claim 6 or 7, characterized in that: the metal plate is a galvanized plate or an aluminum plate.