RU2582131C1 - Shop sound-absorbing structure - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics, particularly, to broadband acoustic suppression. Sound-absorbing construction of industrial buildings include acoustic enclosures and custom-made sound absorbers. Acoustic enclosures comprise smooth and perforated walls, between which a sound-absorbing material arranged in two layers, one of which is harder, continuous and profiled, and other is soft, discontinuous in form of discontinuous sound absorbers and placed in focus of sound reflecting surfaces of first layer. Solid shaped layer of sound-absorbing material is made from material with sound reflection factor higher than that of sound absorption. Discontinuous sound absorber located in focus of solid profiled layer is made in form of solids of revolution, for example sphere, ellipsoid, cone, truncated cone, and is fixed on perforated wall by means of pins, one end of which is rigidly fixed on perforated wall, and other is pointed and is located in body of discontinuous sound absorbers. Similar single sound dampers comprise a housing made in form of lateral closed surfaces with bottom and flap cover made of perforated sheet of stainless steel or a galvanised steel sheet with thickness of 0.7 mm with a polymer protective-decorative coating such as “Pural” with thickness of 50 mcm or “Polyester” with thickness of 25 mcm, or aluminum sheet with thickness of 1.0 mm and thickness of coating of 25 mcm. Coaxial with housing, and at an equal distance from inner surfaces hollow chamber made of a perforated sheet with surfaces congruent to surfaces of housing is placed. Between walls of housing and chamber is placed a sound absorber formed as a porous noise absorbing material, such as aluminium foam or sintered metal, or metal-foam plastic, or in form of a compressed aggregate of solid vibration-damping material such as an elastomer, polyurethane, or plastic such as “Agat”, “Antivibrit”, “Shvim”. Size of crumbs fractions is within optimal range of 0.3…2.5 mm. Other single-piece absorbers are made of a metal, pressed frame, which is attached to object, and to it is attached a body made in form of an inverted cone, in apex of which there is a hole to accommodate elastic fastening element, such as a spring with a rod on end, which is fixed on top cone of fastening element. At base of cone there is a gasket made of a vibration-damping material, through which fasteners attached to frame and by means of cone base is rigidly fixed to frame by elastic fastening element. On inner surface of cone is attached absorbing non-combustible material, for example PVC foam, fibreglass, wrapped with acoustically transparent material, for example fibreglass. AIR cavity is provided inside said cone between layer of sound absorbing material. Sound absorbing structure is also equipped with spherical acoustic absorber containing active and reactive acoustic absorbers located on a rigid frame. Frame is made of two parts, lower reactive part is made in form of a structure of spherical shape with internal congruent spherical resonant cavity, formed by rigid spherical enclosure, equidistant outer perforated spherical shell connected with top active part is made in form of a rigid perforated cylindrical shell with perforated cover and solid base. Cavity of cylindrical shell is filled with sound absorbing material. Connection of top and bottom parts of sound absorber is made by resilient damping element ensuring dampening of HF oscillations. To perforated cover of perforated cylindrical shell element is pivotally connected, using it framework is secured to required facility, for example, to ceiling of production room. Spherical resonance cavity of reactive part of frame is rigidly connected at least one sleeve with axial bore that doubles as neck of Helmholtz resonator with external perforated spherical enclosure. Space between them is filled by sound absorber. At least one spiral acoustic absorbing element in form of a cylindrical coil spring enclosing shell is mounted around perforated cylindrical shell. Screw sound-absorbing element is made as a hollow screw sound-absorbing element made up by outer and inner screw surfaces forming a cavity. Space formed by outer and inner surfaces of screw is filled with sound-absorbing material having density less than that of screw sound-absorbing element.

EFFECT: higher efficiency of noise absorption by expanding frequency range and secondary absorption of sound waves reflected from sound absorber.

1 cl, 5 dwg

Description

The invention relates to industrial acoustics, in particular to broadband sound attenuation, and can be used for sound attenuation of industrial equipment by sound absorption.

The closest technical solution to the technical nature and the achieved result is the sound-absorbing structure of the industrial building according to the patent of the Russian Federation No. 2455432 [prototype], containing the sound-absorbing devices of the production room, containing profiled and perforated walls, between which a layer of sound-absorbing material is placed, one of the walls being made smooth, and the sound-absorbing material is arranged in two layers, one of which is more rigid, made solid and profiled, and the other is soft cue, made intermittent and located under the surfaces of the first layer, and the sound-absorbing devices of the production room contain a frame, window, doorways, openings for luminaires and acoustic fences containing smooth and perforated walls and piece sound absorbers.

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 the efficiency of sound absorption due to the expansion of the frequency range and the secondary absorption of sound waves reflected from the sound absorber.

This is achieved by the fact that in the sound-absorbing structure of the production building, containing profiled and perforated walls, between which a layer of sound-absorbing material is placed, one of the walls being smooth and the sound-absorbing material in two layers, one of which is more rigid, made solid and profiled and the other, soft, made intermittently and located under the surfaces of the first layer, the sound-absorbing devices of the production room contain a frame, window, doorways, etc. volumes for luminaires and acoustic fences containing smooth and perforated walls, between which sound-absorbing material is placed in two layers, one of which is more rigid, made solid and shaped, and the other is soft, made intermittent in the form of intermittent sound absorbers and located in the focus of the sound-reflecting surfaces of the first layer, a continuous profiled layer of sound-absorbing material is made of a material whose sound reflection coefficient is greater than the coefficient of sound absorption, and an intermittent sound absorber located in the focus of a continuous profiled layer is made in the form of bodies of revolution, for example a sphere, ellipsoid, cone, truncated cone, and is fixed to the perforated wall with pins, one end of which is rigidly fixed to the perforated wall, and the other made pointed and located in the body of intermittent sound absorbers.

In FIG. 1 shows a diagram of the sound-absorbing structure of an industrial building; FIG. 2 - construction of a sound-absorbing acoustic fence of the workshop; FIG. 3 is a diagram of a piece sound absorber of a prismatic shape, FIG. 4 is a schematic diagram of a piece cone-shaped sound absorber; FIG. 5 is a diagram of a spherical shaped piece of sound absorber.

The sound-absorbing structure of the production building in which the equipment 11 is located contains a workshop frame (not shown in the drawing), window 2 and 8, door 9 openings, openings 5 for luminaires, acoustic fences 1, 3, 4, 10, 12 and piece sound absorbers 6 and 7 (Fig. 1). The acoustic fence (Fig. 2) contains smooth 13 and perforated 14 walls, between which sound-absorbing material is placed, located in two layers, one of which, more rigid 15, is solid and shaped, and the other, soft 16, is made intermittent in the form intermittent sound absorbers and is located in the focus of the sound-reflecting surfaces of the first layer 15.

The continuous profiled layer 15 of sound-absorbing material is made of a material in which the reflection coefficient of sound is greater than the coefficient of sound absorption. The intermittent sound absorber 16 located in the focus of the continuous profiled layer 15 is made in the form of bodies of revolution, for example, a sphere, ellipsoid, cone, truncated cone, and is mounted on the perforated wall 14 using pins 17, one end of which is rigidly fixed to the perforated wall 14, and the other is made pointed and located in the body of intermittent sound absorbers 16. Piece sound absorbers 6 and 7 are installed above the noisiest technological equipment 11.

Each of the piece sound absorbers 7 (Fig. 3) consists of a housing made in the form of closed side surfaces 17 with a bottom 18 and a hinged lid 19 made of perforated stainless steel sheet or galvanized sheet 0.7 mm thick with a polymer protective and decorative coating Pural type with a thickness of 50 microns or Polyester with a thickness of 25 microns, or an aluminum sheet with a thickness of 1.0 mm and a coating thickness of 25 microns. Coaxial to the body, and at an equal distance from its internal surfaces, there is a hollow chamber 20 made of a perforated sheet with surfaces congruent to the surfaces of the body. Between the walls of the housing and the camera there is a sound absorber made in the form of a porous sound-absorbing material, such as foam aluminum or cermet, or metal foam, or in the form of pressed crumbs from solid vibration-damping materials, such as elastomer, polyurethane, or plastic compound such as "Agate", "Anti-vibration", " Sew ", and the size of the fractions of the crumbs lies in the optimal range of values: 0.3 ... 2.5 mm (not shown in the drawing).

Each of the piece sound absorbers 6 (Fig. 4) consists of a rigid frame 21, which is attached to the desired object (not shown in the drawing), for example, the ceiling of the industrial building, the supporting structure of the industrial equipment, and to which the housing 22 is attached, for example, metal or stamped construction , and which is made in the form of an inverted cone, and at the top of the cone there is an opening 30 for accommodating the elastic fastening element 26, for example, in the form of a spring with a rod 29 at the end, which is fixed on the top of the cone cr pezhnym element 27, for example made in the form of a nut. At the base of the cone 22 there is a gasket 25 made of a vibration-damping material, for example, agate plastic compound or VD-17 mastic, which is attached to the frame 21 by means of fasteners 24, for example in the form of screws, and is rigidly fixed to the frame 21 with the base of the cone by means of an elastic fastening element 26.

A sound-absorbing non-combustible material 23 is attached to the inner surface of the cone 22, for example, vinipore, fiberglass, wrapped in an acoustically transparent material, for example fiberglass. Inside the cone between the layers of sound-absorbing material 23 there is an air cavity 28.

The spherical sound absorber (Fig. 5) contains active and reactive sound absorbers located on a rigid frame. The frame is made of two parts, while the lower, reactive part 37 is made in the form of a spherical structure with an internal congruent spherical resonant cavity 38 formed by a rigid continuous spherical shell 36, an equidistant external perforated spherical shell 34 connected to the upper, active, part 31 , which is made in the form of a rigid perforated cylindrical shell 32 with a perforated lid and a solid base, and the cavity of the cylindrical shell is filled with sound-absorbing material ohm, and the compound of upper 31 and lower 37 parts of the absorber formed by elastic-damping element 35, allowing to dampen high frequency vibrations, in this case to cover the perforated perforated cylindrical shell element is hinged, by means of which the frame is attached to a desired object, such as a ceiling of industrial premises.

The spherical resonant cavity 38 of the reactive part 37 of the frame is rigidly connected by at least one sleeve 39 with an axial hole that serves as the neck of the Helmholtz resonator, with an external perforated spherical shell 34, and the space between them is filled with a sound absorber. Around the perforated cylindrical shell 32 is located at least one screw sound-absorbing element 33, made in the form of a cylindrical helical spring, covering the shell 32.

The screw sound-absorbing element 33 can be made in the form of a hollow screw sound-absorbing element formed by the external and internal screw surfaces forming a cavity, while the space formed by the external and internal screw surfaces is filled with sound-absorbing material with a density lower than that of the screw sound-absorbing element.

Sound-absorbing structure of an industrial building works as follows.

Sound waves propagating in the production room interact as follows. Sound energy from the equipment 11 located in the room, passing through the perforated wall 14 of the acoustic fences 1, 3, 4, 10, 12, enters the layers of soft sound-absorbing material 16 (for example, made of basalt or glass fiber), which is intermittent and located under the sound-reflecting surfaces of the first layer 15. The transition of sound energy into heat (dissipation, energy dissipation) occurs in the pores of the sound absorber, which are a model of Helmholtz resonators, where energy loss occurs frictionally with the driving frequency of the oscillating mass of air located in the resonator neck, the neck of the wall itself, has the form of branched networks pore 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.

Piece sound absorbers work as follows.

Sound waves propagating in a room interact with sound-absorbing material. Sound absorption at low and medium frequencies occurs due to the acoustic effect built on the principle of Helmholtz resonators formed by air cavities. Different volumes of resonant cavities are used to suppress sound vibrations in the required sound frequency range, as a rule, large volumes for noise suppression are in the low-frequency range, and small ones are in the medium and high frequencies. The interaction of sound waves with a sound absorber leads to noise attenuation in the high frequency range, and the implementation of a sound absorber from non-combustible materials makes the design fireproof. Low-frequency sound absorption is carried out due to membrane excitation of the walls of the housing and, indirectly, the internal volumes of air in the chamber. Due to the large damping decrement, the absorption of sound energy during dissipation occurs in the material. The transition of sound energy into heat (dissipation, energy dissipation) occurs in the pores of a sound absorber, where energy losses occur due to friction of the mass of air in the resonator neck, which vibrates with the excitation frequency, against the wall of the neck itself, which has the form of a branched network of pores of a sound absorber.

Spherical sound absorber operates as follows.

Sound waves propagating at an industrial or transport facility interact with a sound-absorbing material located in a cavity formed by a rigid continuous spherical shell 36, an equidistant external perforated spherical shell 34 connected to the upper, active, part 31, as well as in the perforated cylindrical shell 32 and screw sound-absorbing element 33 of the upper 31 parts, suppressing noise at low, medium and high frequencies, respectively. The connection of the upper 31 and lower 37 parts of the frame by means of an elastic damping element 35 allows you to damp high-frequency vibrations that can be emitted by a rigid frame, which allows it to be used to reduce noise on transport objects. Sound absorption at medium and high frequencies occurs due to the acoustic effect, built on the principle of the Helmholtz resonator, formed by the air spherical cavity 38 and the neck of the resonator 39, the diameter of which is selected in the required sound frequency range for damping noise in a given frequency band, as a rule: large volumes for noise suppression in the low-frequency range, and small - in the medium and high frequencies. The interaction of sound waves with a screw sound-absorbing element 3 leads to noise attenuation in the high frequency range, and the implementation of a sound absorber from non-combustible materials makes the design fireproof.

An advantage of the invention is the versatility of its application for various production facilities having a wide variety of noise characteristics. At the same time, it should be noted the relative ease of setting up a piece of sound absorber for the required frequency range of noise reduction and its economically feasible efficiency (meaning reducing noise to sanitary standards). In addition, the implementation of the sound absorber of non-combustible materials makes the design fireproof.

Claims (1)

The sound-absorbing structure of the industrial building, including acoustic barriers and piece sound absorbers, while the acoustic barriers contain smooth and perforated walls, between which there is a sound-absorbing material located in two layers, one of which is more rigid, made solid and profiled, and the other is soft, made intermittent in the form of intermittent sound absorbers and located in the focus of the sound-reflecting surfaces of the first layer, a solid profiled layer of sound-absorbing material The ala is made of a material in which the sound reflection coefficient is greater than the sound absorption coefficient, and the intermittent sound absorber located at the focus of a continuous profiled layer is made in the form of bodies of revolution, for example, a sphere, ellipsoid, cone, truncated cone, and is mounted on a perforated wall with pins, one end of which is rigidly fixed to the perforated wall, and the other is made pointed and located in the body of intermittent sound absorbers, one piece sound absorbers contain a housing made in the form of closed lateral surfaces with a bottom and a hinged lid made of perforated stainless steel sheet or 0.7 mm thick galvanized sheet with a protective and decorative polymer coating of the Pural type 50 μm thick or Polyester 25 μm thick, or an aluminum sheet 1.0 mm thick and a coating thickness of 25 μm, and a hollow chamber made of a perforated sheet with surfaces congruent to the surfaces of the body is placed coaxially with the body and at an equal distance from its internal surfaces, while between the walls a pus and a camera there is a sound absorber made in the form of a porous sound-absorbing material, such as foam aluminum or cermet, or metal foam, or in the form of pressed crumbs from solid vibration-damping materials, such as elastomer, polyurethane or plastic compound such as Agate, Anti-Vibrate, Shvim, moreover, the size of the fractions of the crumb lies in the optimal range of values of 0.3 ... 2.5 mm, other piece sound absorbers are made in the form of a metal die-welded frame, which is attached to the object, and a body is attached to it made in the form of an inverted cone, at the top of which there is a hole for placing an elastic fastening element, for example, in the form of a spring with a rod at the end, which is fixed on the top of the cone by a fastening element, and at the base of the cone there is a gasket made of vibration damping material, which is fastened by means of fasteners attached to the frame and using the base of the cone is rigidly fixed to the frame by means of an elastic fastening element, and sound-absorbing is attached to the inner surface of the cone non-combustible material, for example, vinipore, fiberglass, wrapped in an acoustically transparent material, for example fiberglass, while inside the cone between the layers of sound-absorbing material there is an air cavity, and is also equipped with a spherical sound absorber containing active and reactive sound absorbers placed on a rigid frame, the frame is made of two parts, while the lower, reactive, part is made in the form of a spherical shape with an internal congruent spherical resonant cavity formed solid rigid spherical shell, an equidistant external perforated spherical shell connected to the upper, active part, which is made in the form of a rigid perforated cylindrical shell with a perforated cover and a solid base, and the cavity of the cylindrical shell is filled with sound-absorbing material, and the connection of the upper and lower parts of the sound absorber made by means of an elastically damping element, which allows damping high-frequency vibrations, while being perforated to An element is pivotally fixed to the aperture of the perforated cylindrical shell by means of which the frame is attached to the desired object, for example, the ceiling of the production room, and the spherical resonance cavity of the reactive part of the frame is rigidly connected by at least one sleeve with an axial hole that serves as the neck of the Helmholtz resonator to the external perforated spherical shell, and the space between them is filled with a sound absorber, while around the perforated cylindrical shell is located, on at least one screw sound-absorbing element made in the form of a cylindrical screw spring spanning the shell, and the screw sound-absorbing element is made in the form of a hollow screw sound-absorbing element formed by the external and internal screw surfaces forming a cavity, while the space formed by the external and internal screw surfaces, filled with sound-absorbing material with a density lower than that of a screw sound-absorbing element.

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