RU2671278C1 - Workshop acoustic structure - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics, particularly, to broadband acoustic suppression, and can be used in all national economy industries as a means of protection from noise. Technical result is achieved by the fact that the workshop acoustic structure comprises shop framework, bearing walls with barriers in form of floor and ceiling, window and door openings, as well as single piece sound absorbers, containing a frame, in which the sound-absorbing material is located, and installed above the noisy equipment, at that, the floor is made on elastic base and includes mounting plate, that is installed on the base plate of the inter-floor overlapping with the cavities through the layers of the vibration damping material and the waterproofing material with the clearance relative to the bearing walls of the production premise, and the single-piece sound absorbers are made in the form of the silencer element consisting of a body with a hinged lid, filled with sound-absorbing material, placed into the protective shell, at that the body walls are formed by sound absorbing structure, made in the form of cylindrical perforated coaxial shells, inner and outer, between which the sound absorber is located made from at least one shaped porous sheet, wherein over its entire surface the sound-absorbing element is lined with the acoustically transparent material, and as the body sound-absorbing structure sound-absorbing material a porous sound-absorbing material is used, and the ceiling is made as the acoustic suspended one, consisting of suspended to the production building ceiling rigid frame with located inside the frame sound-absorbing structure made of sound-absorbing material wrapped in the acoustically transparent material, wherein to the frame a perforated sheet is attached, and the frame by shape is made in the form of rectangular parallelepiped, at that, the frame elements are fastened together by means of the rigidly connected to the rod brackets, to which the suspensions are attached, at that, the piece sound absorber contains rigid perforated frame, inside of which the sound-absorbing material is arranged, and the frame is made of the conical shaped lower part with a lid and the cylindrical shaped upper part, which is attached to the perforated frame lower part lid by means of a vibration-damping gasket, at that to the cylindrical perforated frame upper part an element is hinged, with the help of which the frame is attached to the desired object, wherein around the perforated frame cylindrical shape upper part at least one helical sound-absorbing element of the piece absorber is located, at that, the acoustic enclosures are made in the form of sound-absorbing elements with resonant inserts, containing smooth and perforated surfaces, between which the complex shaped sound-absorbing material layer is arranged, as well as between the perforated surface and solid areas, the resonant plates with resonant inserts are located, and inside the hollow sections additional resonant elements are located.

EFFECT: technical result is the improvement in the efficiency of acoustic suppression.

1 cl, 8 dwg, 2 tbl

Description

The invention relates to industrial acoustics.

The closest technical solution to the technical nature and the achieved result is the acoustic design of the workshop according to the patent of the Russian Federation No. 2480561, class. F01N 1/04, [prototype], comprising a frame on the ceiling of a building, walls with sound-absorbing cladding, a floor on an elastic base, piece sound absorbers.

The disadvantage of the technical solution adopted as a prototype is the relatively low noise reduction due to the relatively low coefficient of vibration damping of the floor and sound absorption coefficient of sound-absorbing cladding, as well as piece sound absorbers.

The technical result is an increase in the efficiency of sound attenuation.

This is achieved by the fact that in the acoustic structure of the workshop, containing the workshop framework, bearing walls with fences in the form of floor and ceiling, which are lined with sound-absorbing structures, window and door openings, as well as piece sound absorbers containing a frame in which sound-absorbing material is located, and installed above noisy equipment, the floor is made on an elastic base and contains a mounting plate made of concrete reinforced with vibration-damping material, which is installed on the base plate of the interfloor overlapping cavities through layers of vibration-damping material and waterproofing material with a gap relative to the bearing walls of the production room, the cavities of the base plate being filled with vibration-damping material, for example, foamed polymer, and a suspended ceiling and rocker absorbers are also used.

In FIG. 1 shows a general view of the acoustic structure of the workshop; FIG. 2 - floor structure on an elastic foundation, in FIG. 3 - design of a false ceiling, in FIG. 4 - element of a piece silencer, in FIG. 5 is a perspective view of a piece of sound absorber; FIG. 6 is a sectional view of a sound absorbing screw element of a piece absorber; FIG. 7, 8 - design options for sound-absorbing acoustic fencing.

The acoustic design of the workshop (Fig. 1) contains the workshop framework (not shown in the drawing), window 9 and door 10 openings, bearing walls 1, 2, 3, 4 with fences 5, 6: floor 6 and suspended ceiling 5 (Fig. 3 ), and the walls are lined with sound-absorbing structures (Fig. 5 and 6), and piece sound absorbers 7 and 8 (Fig. 4) contain a frame in which sound-absorbing material is located and they are installed above the noisy equipment 11.

The floor structure on an elastic base (Fig. 2) contains a mounting plate 12 made of concrete reinforced with vibration damping material, which is installed on the base plate 15 of the floor with cavities 16 through layers of vibration damping material 14 and waterproofing material 13 with a gap 17 relative to the bearing walls 1, 2, 3, 4 production facilities. In order to ensure effective vibration isolation of the mounting plate 12 in all directions, the layers of the vibration damping material 14 and the waterproofing material 13 are made with a flange that is tightly adjacent to the supporting structures of the walls 1, 2, 3, 4 and the base supporting plate 15 of the floor. To increase the efficiency of sound insulation and sound absorption in the workshops located under the floor, the cavities 16 are filled with vibration damping material, for example, foamed polymer, for example polyethylene or polypropylene, and walls 1, 2, 3, 4 are lined with sound-absorbing structures. As sound-absorbing material of sound-absorbing structures, slabs made of rockwool basalt-based mineral wool or URSA-type mineral wool or P-75 basalt wool or glass-wool lining are used, and the sound-absorbing element is acoustically lined over its entire surface transparent material (not shown in the drawing), for example, fiberglass type EZ-100 or polymer type "Poviden."

The ceiling 5 is made of acoustic suspended (Fig. 3) and consists of a rigid frame 18, made in the form of a rectangular parallelepiped with the dimensions of the parties in the plan a × b, the ratio of which lies in the optimal range of values a: b = 1: 1 ... 2: 1, suspended from the ceiling of an industrial building by means of suspensions 21 fixed to a rod 19, rigidly connected by means of brackets 20 to a frame 18. The frame is fixed to the ceiling using dowels (not shown). A perforated sheet 24 is attached to the frame, on which a layer of sound-absorbing material 22 is located through the layer of transparent acoustic material 23, and fixtures 26 are installed in the frame. When installing an acoustic ceiling, the optimum size ratios must be observed: d - from the point of suspension of the frame to any of its sides and c is the thickness of the layer of sound-absorbing material, and the ratio of these sizes should be in the optimal range of values: c: d = 0.1 ... 0.5. Perforated sheet 24 has the following perforation parameters: hole diameter 25 - 3 ÷ 7 mm, perforation percentage 10% ÷ 15%, and the shape of the hole can be made in the form of holes of a round, triangular, square, rectangular or diamond-shaped profile (shown in the drawing holes). 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 piece silencer element (Fig. 4) consists of a body 27 with a hinged cover 30 filled with sound-absorbing material 28 placed in a protective shell 29. The walls of the body 27 of each piece of sound absorber are formed by a sound-absorbing structure (not shown in the drawing) made in the form of perforated cylindrical coaxial shells of the external and internal, between which there is a sound absorber made of at least one profiled porous sheet, and in the section of the sheet in the cross section there may be triangles olny, rectangular, trapezoidal, in the form of arcs of circles, sinusoidal. The perforated coaxial shell of the body may also have a triangle, polyhedron, ellipse, and any combination of these shapes in cross section. 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 or foamed polymer, such as polyethylene or polypropylene, are used as sound-absorbing material. the element is lined with an acoustically transparent material over its entire surface (not shown in the drawing), for example, fiberglass type EZ-100 or polymer like Poviden.

A piece of sound absorber can be made of a rigid perforated frame (Fig. 5 and 6), consisting of a lower part 31 of a conical shape with a cover 32, and an upper part 34 of a cylindrical shape with an upper base 36 and a lower base 35, which is attached to the cover 32 of the lower part perforated frame by means of a vibration damping pad 38, which allows damping high-frequency vibrations transmitted from the object (not shown in the drawing). The gasket 38 may be made of vibration damping material, such as plastic compound type "Agate" or mastic VD-17.

An element 40 is pivotally fixed to the upper base 36 of the upper part of the cylindrical perforated frame by means of which the frame is attached to the desired object, for example, the ceiling of the production room, the bulkhead of the ship’s cabin, the supporting structure of the production equipment, the cavities of the lower part 31 and the upper part 34 of the perforated frame are filled respectively sound-absorbing materials 33 and 37 of different densities, suppressing noise, respectively, in different frequency bands, for example at low and medium frequencies totah respectively.

Around the upper part 34 of the cylindrical shape of the perforated frame there is at least one screw sound-absorbing element 39 of the piece absorber, made in the form of a cylindrical helical spring of a dense non-combustible sound-absorbing material, for example, vinipore, or thin glass fiber wrapped in an acoustically transparent material, for example fiberglass.

The screw sound-absorbing element 39 of the piece absorber (Fig. 6) can be made in the form of a hollow screw sound-absorbing element formed by the outer 41 and inner 42 screw surfaces forming the cavity 44, while the space formed by the outer 41 and inner 42 screw surfaces, for example, circular cross-section filled with sound-absorbing material 43.

Acoustic fencing (Fig. 7) can be made in the form of rigid 45 and perforated 50 walls, between which are layers of sound-reflecting 46, 49, as well as sound-absorbing 47, 48 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, allowing to reflect sound waves incident in all directions, and which are located respectively at a rigid 45 and perforated 50 walls.

As the sound-absorbing material of the sound-absorbing material, a porous sound-absorbing material, for example, foam aluminum or cermet, or metal foam, or in the form of compressed crumbs from solid vibration-damping materials, such as elastomer, polyurethane, or plastic compound like “Agate”, “Anti-vibration”, “Shvim”, can also be used. and the size of the crumbs fractions lies in the optimal range of values: 0.3 ... 2.5 mm (not shown in the drawing). As a sound-absorbing material, a rigid porous material can also be used, for example, foam aluminum or cermets, or a shell rock with a degree of porosity in the range of optimal values: 30–45%. As a sound-absorbing material, a material in the form of crumbs from solid vibration-damping materials, for example, elastomer, or polyurethane, or plastic compound can be used, moreover, the size of the fractions of the crumb lies in the optimal range of values: 0.3 ÷ 2.5 mm (not shown in the drawing).

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.

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 Τ) 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.

Acoustic fencing (not shown in the drawing) can be made in the form of a sound-absorbing structure, which consists of: a sound-absorbing plate of the Schumanet-ECO type, 50 mm thick; gypsum fiber sheet, 12.5 mm thick; gypsum plasterboard, 12.5 mm thick; profile type Vibronet PN 100/40; gasket type Vibrostek-M in 2 layers; Vibrosil type sealant.

Sound-absorbing plate such as Schumanet-ECO or SHUMANET-BM: Sound-absorbing plate made of mineral wool. SHUMANET-BM slabs are used as an effective middle layer in the design of soundproofing frame partitions or claddings of sheets GKL / GVL, chipboard, plywood, as well as in systems of acoustic perforated screens or suspended ceilings. Composition: hydrophobized mineral wool slab based on basalt rocks. Dimensions: Plate length: 1000 mm. Plate width: 600 mm. Plate thickness: 50 mm. Physical characteristics: bulk density: 40 kg / m ³ . The number of plates in the package: 4 pcs. Amount of packaging: 2.4 m ² . Packing volume: 0.12 m3. Package weight: 5.5 kg.

Vibrostek-M is a tape packed from a soundproof fiberglass packed in a roll. Structural noise isolation is ensured by the elastic properties of the porous-fibrous structure of the material. This determines the stable physical and mechanical characteristics of the gasket under static and dynamic loads, as well as the preservation of the declared acoustic properties over a long service life. It is used as a cushioning material in building structures for the installation of a panel system, frame soundproofing partitions and cladding, as well as wooden floors and ceilings. Composition: multilayer soundproof fiberglass LB300, based on fiberglass type “C”. Vibroacoustic characteristics: dynamic modulus of elasticity Unit: 0.18 MPa at a load of 2 kPa, 0.35 MPa at a load of 5 kPa. Relative compression coefficient εd: 0.25 at a load of 2 kPa, 0.35 at a load of 5 kPa.

When installing the sound-absorbing structure of the load-bearing walls, the VIBROSTEK-M tape gasket is used, which is laid in two layers at the places of their support on the floor (not shown in the drawing), as well as at the places where the panels come in contact with the side walls and the ceiling, and also use a Vibrosil type sealant. and as vibration-isolating wall mounts, a shock-absorbing device (not shown) of the VIBROFLEX type is used, and microporous polyurethane wall mounts are used for mounting to vertical enclosing structures elastomer type EP (not shown in the drawing).

When installing the sound-absorbing structure of load-bearing walls, the VIBROSTEK-M tape laying is laid in two layers at the places of their support on the floor, as well as at the places where the panels come in contact with the side walls and the ceiling. When mounting frame partitions and claddings, the VIBROSTEK-M material is used between the frame profiles (fasteners) and the supporting building structures. VIBROSTEK-M material tapes are also used in the places where the cladding sheets of the partition (cladding) are adjacent to other building structures.

Vibrosil type sealant: VIBROSIL one-component vibration-isolating silicone sealant is intended for sealing joints and joints in special soundproof structures. Sealant provides high vibration isolation of joints between building structures. Reduces the spread of structural noise over them and, thereby, increases their own sound insulation. It is used to fill joints in the construction of soundproof (floating) floors, panel systems, frame soundproofing partitions and claddings. Composition: sealant is made on the basis of silicone resins and silicon-containing modifying additives.

Vibro-insulating wall mounts VIBROFLEX is a shock-absorbing device for solving problems of reducing noise and transmitting vibrations in rooms of any type and purpose. For mounting to vertical enclosing structures, wall versions of EP type fasteners have been developed. Composition: the design is based on the unique Sylomer material - it is a microporous polyurethane elastomer specially developed for solving problems of sound and vibration isolation.

The acoustic design of the workshop is as follows.

Sound energy from the equipment 11 located in the room falls on the layers of sound-absorbing material of sound-absorbing structures, which are lined with load-bearing walls 1, 2, 3, 4 with fences 5, 6 (floor 6 and ceiling 5), as well as piece sound absorbers 7 and 8, containing a framework in which sound-absorbing material is located and which are installed above noisy equipment 11. 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 the losses energies occur due to friction, fluctuating with the frequency of excitation, the mass of air located in the cavity of the resonator against the walls of the mouth itself, having the form of a branched network of pores of a sound absorber. The perforation coefficient of the perforated wall is taken to be equal to or more than 0.25. To prevent the eruption of a soft sound absorber, a fiberglass fabric, for example, type EZ-100, is located between the sound absorber and the perforated wall.

Suspension of the suspended acoustic ceiling is carried out on the suspensions 21, which are attached to the ceiling using dowels, and the other end is fixed to the frame 18 through the rod 19 and the brackets 20.

When installing vibroactive equipment on the plate 12, two-stage vibration protection occurs due to vibration damping inclusions in the mass of the plate 12, as well as due to the layer of vibration damping material 14, which can be used as: Vibrosil needle-punched mats based on silica or alumino-borosilicate fiber , material from solid vibration damping materials, for example, plastic, from soundproof plates based on glass staple fibers of the “Shumostop” type with a material density of 60 ÷ 80 kg / m ³ .

Sound energy from the equipment 11 located in the room, passing through the perforated wall 50 (Fig. 7) of the acoustic fences 1, 2, 3, 4, of the industrial building falls on the layers of sound-reflecting material of a complex profile, consisting of uniformly distributed hollow tetrahedrons that allow reflecting the incident sound waves in all directions, and which are located respectively at the rigid 45 and perforated 50 walls, and then onto layers 47, 48 of soft sound-absorbing material of different densities located in two layers (for example ep made of basalt or glass fibers). 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. The perforation coefficient of the perforated wall is taken to be equal to or more than 0.25. To prevent the eruption of a soft sound absorber, a fiberglass fabric, for example, type EZ-100, is located between the sound absorber and the perforated wall.

The following sound absorbing material options are available:

- as a sound-absorbing material used sheet soundproofing material, which is made on the basis of magnesia binder with reinforcing fiberglass or fiberglass.

- Polyester is used as a sound-absorbing material.

- as a sound-absorbing material used a porous sound-absorbing ceramic material having a bulk density of 500 ÷ 1000 kg / m ³ and consisting of 100 wt. parts of perlite with a grain diameter of 0.1 ÷ 8.0 mm, 80 ÷ 250 wt. parts of one of the sintering materials selected from the group including fly ash, slag, quartz, lava, stones or clay as the main material, 5 ÷ 30 wt. parts of the inorganic binder, and after sintering the mixture, the perlite particles form interconnected holes between their contacting surfaces so that the inner pores are interconnected.

Piece sound absorber works as follows.

Sound waves propagating at industrial or transport facilities interact with sound-absorbing material 33 and 37 of different densities, which suppress noise in different frequency bands, for example, at low and medium frequencies, respectively. Sound absorption at medium and high frequencies occurs due to the acoustic effect built on the principle of Helmholtz resonators formed by air cavities of a perforated frame. Different volumes of resonant cavities: the lower part 31 are conical in shape and the upper part 34 are cylindrical, serve to suppress sound vibrations in the required sound frequency range, usually large volumes to suppress noise in the low-frequency range, and small ones in the medium and high frequencies. The interaction of sound waves with a screw sound-absorbing element 39 leads to noise attenuation in the high frequency range, and the implementation of a sound absorber from non-combustible materials makes the design fireproof.

In FIG. 8 shows a design variant of a sound-absorbing acoustic fence with resonant inserts, which contains a smooth 51 and perforated 52 surfaces, between which is a layer of sound-absorbing material of complex shape, which is an alternation of solid sections 53 and hollow sections 55, and the hollow sections 55 are formed by prismatic surfaces having a section parallel to the plane of the drawing the shape of a parallelogram, the inner surfaces of which have a gear structure 56, or wavy, and whether a surface with spherical surfaces (not shown in the drawing). Cavities 54 formed by smooth 51 and perforated 52 surfaces, between which a layer of sound-absorbing material of complex shape is located, are filled with a sound absorber. In this case, the tops of the teeth are turned inward to the prismatic surfaces, and the edges of the prismatic surfaces are fixed respectively on smooth 51 and perforated 52 walls. Cavities 57 of hollow sections 55 formed by prismatic surfaces are filled with construction foam. Between a smooth 51 surface and solid sections 53 of a layer of sound-absorbing material of complex shape, as well as between a perforated 12 surface and solid sections 13, there are resonant plates 58 and 59 with resonant inserts 60, which serve as the neck of Helmholtz resonators.

Sound-absorbing fence with resonant inserts works as follows.

Sound energy, passing through a layer of a perforated surface 52 and a combined sound-absorbing layer of a complex shape, decreases, since the transition of sound energy into thermal energy (dissipation, energy dissipation) occurs, i.e. in the pores of the sound absorber, which are the Helmholtz resonator model, there are energy losses due to friction, which fluctuates with the excitation frequency of the mass of air in the resonator neck against the walls of the neck itself, which has the form of an extensive network of micropores of the sound absorber. Between a smooth 51 surface and solid sections 53 of a layer of sound-absorbing material of complex shape, as well as between a perforated 12 surface and solid sections 53, there are resonant plates 58 and 59 with resonant inserts 60, which serve as the neck of Helmholtz resonators.

The resonant holes 60 (inserts) located in the resonant plates 58 and 59 serve as the necks of the Helmholtz resonators, the frequency band of the damping of sound energy of which is determined by the diameter and number of resonant holes 60.

It is possible that inside the hollow sections 55, the inner surfaces of which have a toothed structure 56, additional resonant elements 61 are arranged, made in the form of spherical shells, the inner surface of which is connected by the resonant inserts 62 with cavities located between the perforated 52 surface and the solid sections 53 sound-absorbing element.

Claims (1)

The acoustic structure of the workshop, comprising the workshop framework, bearing walls with fences in the form of floor and ceiling, which are lined with sound-absorbing structures, window and door openings, as well as piece sound absorbers containing a frame in which sound-absorbing material is located and installed above noisy equipment, while the floor is made on an elastic base and contains a mounting plate made of concrete reinforced with vibration damping material, which is installed on the base plate of the floor with the floor through layers of vibration-damping material and waterproofing material with a gap relative to the bearing walls of the production room, and piece sound absorbers are made in the form of an element of a silencer, consisting of a body with a hinged lid filled with sound-absorbing material placed in a protective shell, while the walls of the body are formed by a sound-absorbing structure, made in the form of cylindrical perforated coaxial shells - external and internal, between which there is a sound absorber, made of at least one profiled porous sheet, and the profile of the sheet in cross section may be triangular, rectangular, trapezoidal, in the form of circular arcs, sinusoidal, moreover, slabs made of mineral wool based on basalt, or mineral wool, or basalt are used as sound-absorbing material. cotton wool, or glass wool, and the sound-absorbing element is lined with an acoustically transparent material over its entire surface, for example, fiberglass type EZ-100 or a polymer of the “visible” type, and The sound-absorbing material of the sound-absorbing material of the sound-absorbing structure of the body uses a porous sound-absorbing material, for example, foam aluminum, or cermet, or metal foam, or material in the form of pressed crumbs of solid vibration-damping materials, such as elastomer, polyurethane, and the ceiling is made of an acoustic suspended one consisting of a rigid frame the ceiling of a production building, with a sound-absorbing structure made of sound-absorbing material located inside the frame wrapped in an acoustically transparent material, and a perforated sheet is attached to the frame, and the frame is made in the form of a rectangular parallelepiped with side dimensions in the plan a × b, the ratio of which lies in the optimal range of values a: b = 1: 1 ... 2: 1, as well as optimal aspect ratios c: d = 0.1 ... 0.5; where d is the distance from the suspension point of the frame to any of its sides; c is the thickness of the layer of sound-absorbing material, while the frame elements are fastened together by brackets rigidly connected to the bar to which the suspensions are attached, and the perforated sheet has the following perforation parameters: perforation diameter 3 ... 7 mm, perforation percentage 10% ... 15%, moreover, fixtures are installed in the frame, characterized in that the piece sound absorber contains a rigid perforated frame, within which a sound-absorbing material is placed, and the frame is made of the lower part of the conical shape with a lid and an upper part Part of a cylindrical shape, which is attached to the cover of the lower part of the perforated frame by means of a vibration damping pad, which allows damping high-frequency vibrations, while the upper part of the cylindrical perforated frame is pivotally fixed by means of which the frame is attached to the desired object, for example, the ceiling of the production room, and the cavity of the lower and the upper parts of the perforated frame are filled with sound-absorbing materials of various densities, and around the upper part of the qi at least one screw sound-absorbing element of the piece absorber made in the form of a cylindrical coil spring from a dense non-combustible sound-absorbing material, and a screw sound-absorbing element of the piece absorber is made in the form of a hollow screw sound-absorbing element formed by the external and internal helical surfaces that form the floor while the space formed by the outer and inner screw surfaces is filled with sound with acoustic material, while acoustic fencing is made in the form of sound-absorbing elements with resonant inserts containing smooth and perforated surfaces, between which there is a layer of sound-absorbing material of complex shape, which is an alternation of solid sections and hollow sections, and the hollow sections are formed by prismatic surfaces having a section the shape of a parallelogram, the inner surfaces of which have a gear structure, with the tops of the teeth facing inward prismatic surfaces, and the edges of the prismatic surfaces are mounted respectively on the smooth and perforated walls, and the cavities of the hollow sections formed by the prismatic surfaces are filled with a sound absorber, and resonant resonance between the smooth surface and the solid sections of the layer of sound-absorbing material, as well as between the perforated surface and the solid sections plates with resonant inserts that serve as the necks of Helmholtz resonators, and inside is empty telyh portions, inner surfaces of which have a toothed structure arranged additional resonance elements formed in a shape of spherical shells, the inner surface of which inserts coupled resonant cavities, arranged between the perforated and solid portions of the surface of sound-absorbing element.

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