RU2550604C2 - Acoustic dissipation element for acoustic baffles, piece sound absorbers, partitions - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the industrial acoustics and can be used to reduce the noise of the machine drives, covering of industrial premises. Device comprises the perforated surfaces, between which the sound-absorbing multilayer structure is arranged. Layers of sound-reflecting and sound-absorbing materials of different densities are disposed between the perforated walls. Layers of sound-reflecting material are made of complex profile, consisting of uniformly distributed hollow tetrahedrons, located at the perforated walls. Layers of sound-reflecting material are made of heat-insulating material, capable to support the specified microclimate in the promise. Sound-absorbing element over the entire surface is covered with acoustically transparent material. Porous material or material in the form of the compressed crumbs made of solid vibration-damping materials is used as the sound-absorbing material.

EFFECT: increases efficiency of noise suppression and reliability of the design.

3 cl, 1 dwg, 1 tbl

Description

The invention relates to industrial acoustics.

The closest technical solution to the technical nature and the achieved result is a sound-absorbing element used as a facing of industrial premises, known from the RF patent No. 2463412 (prototype).

The disadvantage of the technical solution adopted as a prototype is the relatively low noise reduction due to the presence of voids between the layers, where there is no sound absorption between the layers of the sound absorber.

The technical result is an increase in the efficiency of sound attenuation and the reliability of the structure as a whole.

This is achieved by the fact that in the sound-absorbing element for acoustic screens, piece sound absorbers, partitions containing perforated surfaces, between which a multilayer sound-absorbing structure is placed, layers of sound-reflecting and sound-absorbing materials of different densities located in two layers are located between the perforated walls, and layers of sound-reflecting the material is made of a complex profile, consisting of uniformly distributed hollow tetrahedra, allowing to reflect the incident sound waves in all directions, and which are respectively located near the perforated walls, and the layers of sound-reflecting material are made of heat-insulating material that can maintain a given microclimate in the room, and rockwool basalt-based mineral wool boards are used as sound-absorbing material, or mineral wool of the URSA type, or basalt wool of the P-75 type, or glass wool with a glass wool lining, and the sound-absorbing element is lined acoustically over its entire surface a transparent material, for example, fiberglass type EZ-100 or a polymer of the type "visible", and each of the perforated walls has the following perforation parameters: hole diameter - 3 ÷ 7 mm, perforation percentage 10 ÷ 15%, and the shape of the holes can be made in in the form of holes of a round, triangular, square, rectangular or rhomboid profile, while in the case of non-circular holes, the maximum diameter of a circle inscribed in a polygon should be considered as a conditional diameter.

The drawing shows a diagram of a sound-absorbing element for acoustic screens, piece sound absorbers, partitions.

The sound-absorbing element for acoustic screens, piece sound absorbers, partitions is made in the form of symmetrically arranged perforated 1 and 6 walls, between which are layers of sound-reflecting 2 and 5 materials, as well as sound-absorbing 3 and 4 materials of different density, located in two layers, and layers of sound-reflecting material made of a complex profile, consisting of uniformly distributed hollow tetrahedra, allowing to reflect sound waves incident in all directions, and which are located respectively only perforated walls 1 and 6, and each of the perforated walls has the following perforation parameters: hole diameter - 3 ÷ 7 mm, perforation percentage 10 ÷ 15%, and the shape of the holes can be made in the form of round, triangular, square, rectangular holes or a diamond-shaped profile, while in the case of non-circular holes, the maximum diameter of the circle inscribed in the polygon should be considered as the conditional diameter.

Each of the perforated walls 1 and 6 can be made of structural materials, with a layer of soft vibration-damping material, for example, VD-17 mastic or “Gerlen-D” type material applied on their surface from one or two sides, and the ratio between the thicknesses of the material and vibration damping coating lies in the optimal range of values: 1 / (2.5 ... 3.5).

Each of the perforated walls 1 and 6 can be made of stainless steel or galvanized sheet with a thickness of 0.7 mm with a polymer protective and decorative coating of the Pural type with a thickness of 50 μm or Polyester with a thickness of 25 μm, or an aluminum sheet with a thickness of 1.0 mm and a coating thickness of 25 microns. The perforation coefficient of perforated sheets is taken to be equal to or more than 0.25.

As the material of the sound-reflecting layers 2, 5, a material based on aluminum-containing alloys can be used, followed by filling them with titanium hydride or air with a density in the range of 0.5 ... 0.9 kg / m ³ with the following strength properties: compressive strength in the range of 5 ... 10 MPa, bending strength in the range of 10 ... 20 MPa, for example foam aluminum.

As the material of the sound-reflecting layers 2, 5, sound-proofing plates based on glass staple fiber of the “Shumostop” type with a material density of 60 ÷ 80 kg / m ³ can be used.

To reduce or correct the reverberation time of premises, sound-absorbing materials and structures (sound absorbers) are used in its decoration.

Porous sound absorbers are made in the form of plates that are attached to the enclosing surfaces directly or on the basis of light and porous mineral piece materials - pumice, vermiculite, kaolin, slag, etc. with cement or other binder. Such materials are strong enough and can be used to reduce noise in corridors, foyers, staircases of public and industrial buildings.

Table Material, object 125 250 500 1000 2000 4000 Unpainted concrete 0.01 0.012 0.016 0.019 0.023 0.035 Painted concrete 0.009 0.011 0.014 0.016 0.017 0.018 Marble 0.01 0.01 0.01 0.013 0.015 0.017 Brick unpainted 0.024 0.025 0.031 0.042 0.049 0.07 Painted brick 0.012 0.013 0.017 0.02 0.023 0.025 Gypsum plaster 0.02 0.026 0.04 0.062 0.058 0.028 Lime plaster 0.024 0.046 0.06 0.085 0.043 0.056 Fiberboard (MDF), 12 mm 0.22 0.3 0.34 0.32 0.41 0.42 Gypsum panel 10 mm to 100 mm from the wall 0.41 0.28 0.15 0.06 0.05 0.02 Parquet floor 0.04 0.04 0.07 0.06 0.06 0.07 Boardwalk Floor 0.2 0.15 0.12 0.1 0.08 0.07 Metlakh tile 0.01 0.01 0.02 0.02 0.02 0.03 Glazed Window Bindings 0.35 0.25 0.18 0.12 0.07 0.04 Lacquered Doors 0.03 0.02 0.05 0.04 0.04 0.04 Wool carpet 9 mm thick for concrete 0.02 0.08 0.21 0.26 0.27 0.37

The raw materials for their production are wood fibers, mineral wool, glass wool, synthetic fibers. The surface of the fibrous absorbers is treated with special porous paints that allow air to pass through (for example, Acutex T) or coated with breathable fabrics or non-woven materials, such as Lutrasil.

Currently, fibrous sound absorbers are the most common in construction practice. They not only proved to be the most effective from an acoustic point of view in a wide frequency range, but also meet the increased requirements for room design.

In fibrous absorbers, the dissipation of the energy of air vibrations and its transformation into heat occurs at several physical levels. Firstly, due to the viscosity of the air, and there is a lot of it in the interfiber space, the oscillation of air particles inside the absorber leads to friction. In addition, there is air friction on the fibers, the surface of which is also large. Thirdly, the fibers rub against each other and, finally, energy dissipation occurs due to the friction of the crystals of the fibers themselves. This explains that at medium and high frequencies the sound absorption coefficient of fibrous materials is in the range of 0.4 ... 1.0. The sound absorption coefficient α is equal to the ratio of the energy of the air vibration not reflected (absorbed inside and passed through) from the surface to the total energy acting on the surface. Sound absorption coefficients for most building materials are shown in table 1.

As sound-absorbing material of layers 3 and 4, rockwool-type mineral wool or URSA-type mineral wool, or P-75-type basalt wool or glass wool lined with glass wool, or foamed polymer, such as polyethylene or polypropylene. The surface of the fibrous sound absorbers is treated with special porous paints that allow air to pass through (for example, Acutex T), or covered with breathable fabrics or non-woven materials, such as Lutrasil.

Each of the perforated walls 1 and 6 can be made of solid, decorative vibration-damping materials, for example, plastic compounds such as Agate, Anti-Vibrate, Shvim, and the inner surface of the perforated surface facing the sound-absorbing structure is lined with an acoustically transparent material, for example fiberglass type EZ-100 or polymer type "poviden", or non-woven materials, such as "lutrasil."

Sound-absorbing element operates as follows.

Sound energy from equipment located in the room, or another object that emits intense noise, passing through the perforated walls 1 and 6 falls on layers 2 and 5 of sound-reflecting material of a complex profile, consisting of uniformly distributed hollow tetrahedrons, which allow reflecting sound waves incident in all directions waves, which are located respectively at the perforated walls 1 and 6, and then falls on layers 3 and 4 of soft sound-absorbing material of different densities located in two layers (for example, made of basalt or glass fiber). In fibrous absorbers, the dissipation of the energy of air vibrations and its transformation into heat occurs at several physical levels. Firstly, due to the viscosity of the air, and there is a lot of it in the interfiber space, the oscillation of air particles inside the absorber leads to friction. The transition of sound energy into thermal energy (dissipation, energy dissipation) occurs in the pores of a sound absorber, which are the Helmholtz resonator model, where energy losses occur due to friction of the mass of air in the resonator neck oscillating with the frequency of excitation on the neck wall, which has the form of a branched sound absorber pore network. In addition, there is air friction on the fibers, the surface of which is also large. Thirdly, the fibers rub against each other and, finally, energy dissipation occurs due to the friction of the crystals of the fibers themselves. This explains that at medium and high frequencies the sound absorption coefficient of fibrous materials is in the range of 0.4 ... 1.0.

Claims (3)

1. A sound-absorbing element for acoustic screens, piece sound absorbers, partitions, containing perforated surfaces, between which a multilayer sound-absorbing structure is placed, layers of sound-reflecting and sound-absorbing materials of different densities located in two layers are located between the perforated walls, and the layers of sound-reflecting material are made of a complex profile consisting of uniformly distributed hollow tetrahedra, allowing reflecting falling in all directions uk waves, which are located respectively near the perforated walls, and the layers of sound-reflecting material are made of heat-insulating material that can maintain a given microclimate in the room, and rockwool basalt-based mineral wool boards are used as sound-absorbing material, and the sound-absorbing element throughout it is lined with an acoustically transparent material, for example, fiberglass type E3-100 or a polymer of the type "visible". and each of the perforated walls has the following perforation parameters: hole diameter 3–7 mm, perforation percentage 10–15%, or a porous noise-absorbing material is used as sound-absorbing material, or material in the form of pressed crumbs from solid vibration-damping materials, or agate plastic compound "," Anti-Vibrate "," Shvim ", and also porous mineral piece materials, for example pumice, vermiculite, kaolin, slag with cement or another binder, or synthetic fibers, and the surface in oknistyh porous absorbers treated with special paints, air-permeable, e.g., type Akutex T or coated breathable woven or nonwoven materials, such lutrasilom. 2. A sound-absorbing element for acoustic screens, piece sound absorbers, partitions according to claim 1, characterized in that the material based on aluminum-containing alloys is used as a sound-reflecting material, followed by filling them with titanium hydride or air with a density in the range of 0.5 ... 0.9 kg / m ³ with the following strength properties: compressive strength in the range of 5 ... 10 MPa, bending strength in the range of 10 ... 20 MPa, for example foam aluminum, or sound-proofing boards based on glass staple fiber of the Shumostop type with a tight the material capacity equal to 60 ÷ 80 kg / m ³ . 3. A sound-absorbing element for acoustic screens, piece sound absorbers, partitions according to claim 1, characterized in that each perforated wall can be made of structural materials, with a layer of soft vibration-damping material applied to their surface, for example, VD- mastic 17, or material of the type "Gerlen-D", while the ratio between the thicknesses of the material and the vibration damping coating lies in the optimal range of values: 1 / (2.5 ... 3.5), or stainless steel, or a galvanized sheet with a thickness of 0, 7 mm with a polymeric protective and decorative coating of the Pural type with a thickness of 50 μm, or Polyester with a thickness of 25 μm, or an aluminum sheet with a thickness of 1.0 mm and a coating thickness of 25 μm, or from solid, decorative vibration-damping materials, such as plastic compound like Agate ”,“ Anti-Vibrate ”,“ Shvim ”, moreover, the inner surface of the perforated surface facing the sound-absorbing structure is lined with an acoustically transparent non-woven material, for example Lutrasil.

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