RU2528353C1 - Kochetov's noise absorbing panel - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: in noise absorbing panel, containing frame and noise absorbing insert located in its internal hollow, the frame is made as a parallelepiped formed by front and back walls. Noise absorbing insert is made as perforated plates, between which the symmetrically located layers of sound reflecting material are located, between which the layers of sound-absorbing materials of various density located in two layers. The layers of sound reflecting material are made from complex profile composed of evenly distributed hollow tetrahedrons, allowing to reflect acoustical surges incident in all directions. The layers are located at perforated plates.

EFFECT: improvement of efficiency of noise absorption at the expense of expansion of the frequent range.

4 cl, 2 dwg

Description

The invention relates to industrial acoustics, in particular to broadband sound attenuation, and can be used in all industries, in particular: in construction (architectural panels and screens; cladding of buildings and premises; sound absorbing panels for elevator shafts; sound absorbing shields and screens along roads ), in transport engineering (noise-attenuating inserts in doors and bodywork; lining of car hoods; sound-absorbing shields for subway tunnels), in the aviation and space industry (noise insulation ia engine covers; sound insulation of aircraft cabin) and other industries.

The closest technical solution to the technical nature and the achieved result is a sound-absorbing panel according to the patent of the Russian Federation No. 2323793, class. F01N 1/04, (prototype) comprising a frame and a sound-absorbing insert located in its internal cavity.

The disadvantage of the prototype is the relatively low efficiency of sound attenuation due to the partial reflection of sound waves from the sound absorber, as well as the relatively narrow (exceptionally high frequencies) range of sound attenuation.

The technical result is an increase in sound absorption efficiency due to the expansion of the frequency range, simplification and universality of installation and improvement of operational properties through the use of promising sound-absorbing and protective-decorative materials.

This is achieved by the fact that in the noise-absorbing panel containing the frame and the sound-absorbing insert located in its inner cavity, the frame is made in the form of a parallelepiped formed by the front and rear walls, each of which has a U-shape, with side ribs, and there is a slit on the walls perforation made in the form of rectangles and arranged in rows with row widths b ₁ and b ₂ and distance between them h ₁ and h ₂ , and adjacent rows are offset, and the number of slots in one row is even and odd in the other, the perforation coefficient is taken to be equal to or more than 0.25, and a sound-absorbing insert is placed between the front and rear walls of the frame, and the panel walls are fixed to each other from above and below by vibration damping covers, which can be made with cells and have a U-shape, while the front and the back wall of the frame can be made of stainless steel or galvanized sheet with a thickness of 0.7 mm with a protective and decorative polymer coating of the type “Pural” 50 μm thick or “Polyester” 25 μm thick or of aluminum sheet hydrochloric 1.0 mm and coated with 25 microns thick, and the ratio of height h to width carcass b in the optimum values concerning: h / b = 1.0 ÷ 2.0; and the ratio of the thickness s 'of the frame assembly to its width b is in the optimal ratio of values: s' / b = 0.1 ÷ 0.15; and the ratio of the thickness s of the sound-absorbing material to the thickness s 'of the frame assembly is in the optimal ratio of values: s / s' = 0.4 ÷ 1.0, and the sound-absorbing insert is made in the form of perforated plates between which layers of sound-reflecting material are symmetrically located, and in the center between the layers of sound-reflecting material there are layers of sound-absorbing materials of different density, arranged in two layers, and the layers of sound-reflecting material are made of a complex profile consisting of uniformly distributed hollow tetrahedrons Allowing reflect incident in all directions the sound waves, and which are located respectively at the perforated plates, the perforated plate can be made of plastic, such as caproic, or metal mesh with small mesh.

In Fig.1 shows a General view of the sound absorbing panel in disassembled form, Fig.2 shows a diagram of a noise absorbing insert.

The noise-absorbing panel (Fig. 1) contains a frame that is made in the form of a parallelepiped formed by the front 1 and rear 2 walls, each of which has a U-shape, with side ribs 6, and there is a slotted perforation 7 and 8 on the walls made in in the form of rectangles and arranged in rows with row widths b ₁ and b ₂ and distance between them h ₁ and h ₂ , the adjacent rows being offset, and the number of slots in one row is even and odd in the other. The perforation coefficient is taken to be equal to or more than 0.25. Between the front 1 and rear 2 walls of the panel there is a sound-absorbing insert 3 inscribed in the frame of the panel and located in its inner cavity. The walls of the panel 1 and 2 are fixed to each other by vibration damping covers 4 and 5, which can be made with cells 9 and have a U-shaped shape. Vibration dampers 4 and 5 fasten the frame, respectively, from above and from below, making it a single unit, i.e. the frame with a sound-absorbing insert 3 inside is a sound-absorbing panel as an assembly unit (not shown in the drawing).

The front 1 and rear 2 walls of the frame can be made of stainless steel or galvanized sheet with a thickness of 0.7 mm with a protective and decorative polymer coating such as Pural 50 μm thick or Polyester 25 μm thick or from an aluminum sheet 1.0 mm thick and with a coating thickness of 25 microns. Moreover, the ratio of the height h of the frame to its width b (complete, not shown) is in the optimal ratio of values: h / b = 1.0 ÷ 2.0; and the ratio of the thickness s 'of the frame assembly to its width b is in the optimal ratio of values: s' / b = 0.1 ÷ 0.15; and the ratio of the thickness s of the sound-absorbing material to the thickness s 'of the frame assembly is in the optimal ratio of values: s / s' = 0.4 ÷ 1.0.

Sound-absorbing insert 3 (Fig. 2) is made in the form of perforated 10 and 15 plates, between which layers 11 and 14 of sound-reflecting material are symmetrically located, and in the center, between layers 11 and 14 of sound-reflecting material, there are layers 12 and 13 of sound-absorbing materials of different densities located in two layers, and the layers of sound-reflecting material are made of a complex profile, consisting of uniformly distributed hollow tetrahedra, which allow reflecting sound waves incident in all directions, and which are located respectively but for perforated plates 10 and 15, the perforated plate can be made of plastic, for example, nylon, or a fine mesh metal mesh.

As the material of the sound-reflecting layers 11, 14, a material based on aluminum-containing alloys can be used with their subsequent filling 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 11.14, sound-insulating boards based on glass staple fiber of the “Shumostop” type with a material density of 60 ÷ 80 kg / m ³ can be used.

As sound absorbing material, slabs made of rockwool basalt mineral wool or URSA mineral wool or P-75 basalt wool or glass wool lined with glass wool are used as sound absorbing material, and the sound-absorbing element is lined with acoustically transparent material over its entire surface , for example, fiberglass type EZ-100 or polymer type "poviden."

The sound-absorbing panel 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 2 of the frame and the perforated plates 10 and 15 of the noise-absorbing insert 3 falls on layers 11 and 14 of a sound-reflecting material of a complex profile, consisting of uniformly distributed hollow tetrahedra, allowing to reflect sound waves incident in all directions, which then fall on layers 12 and 13 of soft sound-absorbing material of different density, located in two layers (for example Making a basalt or glass fibers). 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 the 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 excitation frequency against the wall of the neck itself, which has the form branched network of pore sound absorbers. In addition, there is air friction on 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 technical solution proposed by the authors is an effective means to combat noise in the production halls of various sectors of the national economy, as well as mobile vehicles, and a means of protecting the environment from noise.

Claims (4)

1. The sound-absorbing panel containing the frame and a sound-absorbing insert located in its internal cavity, the frame is made in the form of a parallelepiped formed by the front and rear walls, each of which is U-shaped, with side ribs, and there is a slotted perforation on the walls made in the form of rectangles and located in rows with row widths b ₁ and b ₂ and the distance between them h ₁ and h ₂ , and adjacent rows are offset, and the number of slots in one row is even and odd in the other, the perforation coefficient is taken to be equal to or more than 0.25, and a sound-absorbing insert is placed between the front and rear walls of the frame, and the panel walls are fixed to each other from above and below by vibration damping covers, which can be made with cells and have a U-shape, while the front and rear walls the frame can be made of stainless steel or galvanized sheet with a thickness of 0.7 mm with a protective and decorative polymer coating of 50 μm thick or Polyester 25 μm thick or from an aluminum sheet with a thickness of 1.0 mm and coated with t lschinoy 25 microns, wherein the ratio of the height h carcass to its width b is in the optimum ratio values: h / b = 1.0 ÷ 2.0; and the ratio of the thickness s 'of the frame assembly to its width b is in the optimal ratio of values: s' / b = 0.1 ÷ 0.15; and the ratio of the thickness s of the sound-absorbing material to the thickness s 'of the frame assembly is in the optimal ratio of values: s / s' = 0.4 ÷ 1.0, characterized in that the sound-absorbing insert is made in the form of perforated plates, between which the layers of sound-reflecting are symmetrically located material, and in the center, between the layers of sound-reflecting material there are layers of sound-absorbing materials of different densities, arranged in two layers, and the layers of sound-reflecting material are 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 near the perforated plates, and the perforated plate can be made of plastic, for example, kapron, or a metal mesh with a small cell. 2. The sound-absorbing panel according to claim 1, characterized in that as the material of the sound-reflecting layers, 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 s 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. 3. The noise absorption panel according to claim 1. characterized in that as the material of the sound-reflecting layers can be applied sound-insulating boards based on glass staple fiber type "Shumostop" with a density of material equal to 60 ÷ 80 kg / m ³ . 4. The soundproofing panel according to claim 1. characterized in that as sound-absorbing material, slabs made of rockwool basalt type mineral wool or URSA type mineral wool or P-75 basalt wool or glass wool lined with glass wool are used as sound absorbing material, the sound-absorbing element along its entire surface lined with an acoustically transparent material, such as fiberglass type EZ-100 or polymer type "poviden."

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