RU2547524C1 - Kochetov(s system for acoustic protection of operator - Google Patents

Abstract

FIELD: physics, acoustics.

SUBSTANCE: invention relates to means of ensuring safe operation of operators in emergency situations, particularly at high noise levels. A system for acoustic protection of an operator, comprising an operator workstation located between acoustic shields and a suspended ceiling; in the upper area of the building, to reduce sound vibration, the operator workstation is fitted with a floor with an elastic base, wherein the operator is provided with two-stage vibration protection.

EFFECT: high efficiency of soundproofing.

2 tbl, 7 dwg

Description

The invention relates to safety equipment for operators in emergency situations, in particular at elevated noise levels.

The closest technical solution to the technical nature and the achieved result is acoustic protection according to the patent of the Russian Federation No. 2366785, 2007 [prototype] as a method of acoustic protection for the operator, which consists in the fact that the operator’s workplace is equipped with noise reduction means.

The disadvantage of the technical solution adopted as a prototype is the relatively low efficiency of sound attenuation due to the relatively low coefficient of sound absorption.

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

This is achieved by the fact that in the complex for acoustic protection of the operator, comprising the operator’s workplace located between the acoustic screens and the acoustic suspended ceiling, the operator’s workplace is equipped with a floor on an elastic base in the upper area of the room to reduce sound vibration, while the operator performs two-stage vibration protection .

Figure 1 shows a General view of the complex for acoustic protection of the operator, figure 2 - the floor structure of the premises on an elastic base, figure 3 - shock absorbing structure for installing the wall panel, figure 4 - structure of the wall sound-absorbing panel mounted on the ceiling , Fig.5 is a design of rocker sound absorbers, Fig.6 is a graph of the sound absorption efficiency of the applied panels, Fig.7 is an embodiment of a sound absorbing element in the design of a wall sound absorbing panel.

The complex for acoustic protection of the operator (Fig. 1) contains a building frame made in the form of an elastic base 1, which is the floor of the room (Fig. 2), heat and sound insulating barriers 2, rigidly connected to the columns 3, which in turn are connected to the metal structure 4, for example in the form of a farm. An acoustic suspended ceiling 5 is placed in the zone of the trusses 4 and is made in the form of rocker sound absorbers installed with a certain pitch, the lower part of which protrudes from the bottom of the trusses 4 towards the base 1. Acoustic wall panels 6 are fixed to the fences 2 (Fig. 3). On the elastic base 1 of the room installed vibroacoustic equipment 7 and 8 with different spectral characteristics of sound power levels. The operator’s workstation 15, including control panels 16 and 17 of equipment 7 and 8, is located between the acoustic screens 9 and 11, and in one of them, for example, the 9th, a soundproof inspection hatch 10 is made to control visualization of observation of the process. The building frame is closed from above with a soundproof coating 12, which also functions as a roof, in which there are vertical 13 and inclined 14 window openings in the form of vacuum soundproof glass packets.

The floor structure on an elastic base (Fig. 2) contains a mounting plate 18 made of concrete reinforced with vibration damping material, which is installed on the base plate 19 of the floor with cavities 20 through layers of vibration damping material 21 and waterproofing material 22 installed with a gap relative to the bearing walls 23 production premises. In order to ensure effective vibration isolation of the mounting plate 18, in all directions the layers of the vibration damping material 21 and the waterproofing material 22 are made with a flange that is tightly adjacent to the supporting structures of the walls 7 and the base supporting plate 19 of the floor. To increase the efficiency of sound insulation and sound absorption in the workshops located under the floor, the cavities 20 are filled with vibration damping material, for example, foamed polymer, or polyethylene, or polypropylene.

The floor structure on an elastic base works as follows. When installing vibroactive equipment 7 and 8 on plate 18, two-stage vibration protection occurs due to vibration damping inclusions in the mass of plate 18 itself, as well as due to a layer of vibration damping material 21, which can be used as: Vibrosil needle-punched mats based on silica or alumino-borosilicate fibers, material from solid vibration-damping materials, for example plastic compound, from soundproof plates based on glass staple fibers of the “Shumostop” type with a material density of 60 ÷ 80 kg / m ³ .

The transition of sound energy into thermal energy (dissipation, energy dissipation) occurs in the pores of sound-absorbing material, which is a Helmholtz resonator model, where energy losses occur due to friction of the mass of air in the resonator neck, which oscillates with the excitation frequency, against the wall of the neck itself, which has view of a branched network of pores of sound-absorbing material. Moreover, needle-punched mats consist of fibers having a diameter not lower than the maximum permissible hygienic value, do not contain carcinogenic asbestos and ceramic fibers, and such harmful binders as phenol are not included in their composition. Therefore, with confidence they can be attributed to the class of heat and sound insulating materials that meet high hygienic and fire safety requirements. We add that fiberglass materials have low thermal conductivity, are not influenced by steam, oil, water, and have high temperature stability.

Acoustic wall panels 6 can be made in the form of slabs of rockwool basalt mineral wool, or URSA mineral wool, or P-75 basalt wool, or glass wool lined with glass wool, or foamed polymer, such as polyethylene or polypropylene, and the sound-absorbing element over its entire surface is lined with an acoustically transparent material, such as fiberglass type EZ-100 or polymer type "Poviden."

The complex for acoustic protection of the operator works as follows.

The operator’s workplace 15 is placed between the acoustic screens 9 and 11 and protects the operator from direct sound that is spreading from the vibroactive equipment 7 and 8. In order to increase the protection against reflected sound waves above the work area (workplace), an acoustic suspended ceiling 5 is installed, located in the upper area of the room (farm zone 4). It reduces the levels of sound waves emanating from equipment 7 and 8, due to the multiple reflection of sound waves from the rocker sound absorbers. To reduce sound vibration, the operator’s workplace is equipped with a floor on an elastic base. When installing vibroactive equipment 7 and 8 on plate 18, two-stage vibration protection occurs due to vibration damping inclusions in the mass of plate 18 itself, as well as due to a layer of vibration damping material 21, which can be used as: Vibrosil needle-punched mats based on silica or alumino-borosilicate fibers, material from solid vibration-damping materials, for example plastic compound, from soundproof plates based on glass staple fibers of the “Shumostop” type with a material density of 60 ÷ 80 kg / m ³ .

Indoors, where the area of open brick, plaster, concrete, tile, glass, metal is large, a long echo is always heard. If in such rooms there are several sources of sound (people's conversation, music, industrial noises), then direct sound is superimposed on its loud first reflections, which leads to speech illegibility and an increased noise level in the room. To reduce or correct the reverberation time of premises, sound-absorbing materials and structures (sound absorbers) are used in its decoration.

From an acoustic point of view, sound absorbers can be divided into the following groups: porous (including fibrous); porous with perforated screens; resonant; layered structures; piece or volume.

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.

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 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.

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, air is rubbed against fibers whose surface 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.

Recall that the sound absorption coefficient α is equal to the ratio of the energy of the air vibrations 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. Fibrous and porous materials are used mainly to improve acoustic performance in cinemas, theaters, concert halls, studios, and auditoriums. In addition, they are used to reduce noise in kindergartens, schools, hospitals, restaurants, offices, retail halls, lobbies, waiting rooms, industrial premises.

The operator’s workstation 15 is reliably protected both from the acoustic load on the operator and from mechanical factors of the production environment, such as, for example, shavings in the workshop or moving parts of equipment.

Sound energy from equipment 7 and 8 located in the room, passing through the perforated wall of the acoustic wall panels 6, enters the layers of sound-absorbing material (which can be either soft, such as basalt or glass fiber, or hard, such as shell rock). 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. 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, of the EZ-100 type, is located between the sound absorber and the perforated wall. In this case, the acoustic suspended ceiling 5, located in the upper zone of the room (farms zone 4), reduces the levels of sound waves emanating from equipment 7 and 8, and the operator’s workstation 15, located between the acoustic screens 9 and 11, is reliably protected as from acoustic load on the operator, and on the mechanical factors of the production environment, such as, for example, shavings floating in the workshop or moving parts of the equipment.

Figure 4 presents the design of the wall sound-absorbing panel mounted on the ceiling, which consists of: 24 - sound-absorbing plate of the Schumanet-ECO type (50 mm); 25 - sheet gypsum fiber 12.5 mm; 26 - gypsum plasterboard sheet 12.5 mm; 27 - profile type Vibronet PN 100/40; 28 - gasket type Vibrostek-M (2 layers); 29 - sealant type Vibrosil.

Sound-absorbing plate like Schumanet-ECO or SHUMANET-BM Sound-absorbing plate from 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 . The volume of the packaging: 0.12 m ^3. Package weight: 5.5 kg.

Table 1 Acoustic Test Results Purity, Hz one hundred 125 160 200 250 320 400 500 630 SHUMANET-BM slabs without slope 0.14 0.26 0.40 0.56 0.67 0.82 1.00 1.00 1.00 SHUMANET-BM plates with a slope of 50 mm from a hard surface 0.45 0.54 0.68 0.76 0.92 0.96 0.99 1.00 1.00 frequency Hz 800 1000 1250 1600 2000 2500 3200 4000 5000 SHUMANET-BM plates without rel 1.00 1.00 1.00 1.00 0.99 0.99 0.93 0.90 0.90 SHUMANET-BM plates with a slope of 50 mm from a hard surface 1.00 1.00 0.98 0.95 0.90 0.88 0.85 0.83 0.80

Vibrostek-M is a tape packed from a soundproof fiberglass packed in a roll. The isolation of structural noise 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.

VIBROSTEK-M is used as a cushioning material in building structures during 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 sandwich panels, the VIBROSTEK-M strip gasket is laid in two layers at the points 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, a one-component vibration-isolating silicone sealant, is designed to seal joints and joints in special soundproof structures. The 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 (Fig. 3) 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. Scope: wall mounts are used for soundproofing wall cladding, vibration isolation of pipelines of engineering networks, ventilation ducts, suspended engineering equipment and other vibration-emitting units. 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 sound-absorbing element (Fig. 7) as an option in the design of the wall sound-absorbing panel is made in the form of rigid 30 and perforated 35 walls, between which are layers of sound-reflecting 31 and 34 materials, as well as sound-absorbing 32 and 33 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 tetrahedrons, which allow reflecting sound waves incident in all directions, and which are respectively located in a rigidly 30 and perforated 35 walls, and the perforated wall has the following perforation parameters: hole diameter 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 shape in this case, in the case of non-circular holes, the maximum diameter of the circle inscribed in the polygon should be considered as the conditional diameter.

The perforated wall 35 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 one or both sides of the surface, and the ratio between the thicknesses of the material and the vibration-damping coating lies in optimal range of values: 1 / (2.5 ... 3.5).

Perforated wall 35 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 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 31, 34, 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 31, 34, sound-proofing plates based on glass noise staple fiber of the “Shumostop” type with a material density of 60 ÷ 80 kg / m ³ can be used.

Sound-absorbing element operates as follows. Sound energy from equipment located in the room, or another object that emits intense noise from the object, passing through the perforated wall 35, enters the layers 31 and 34 of the sound-reflecting material of a complex profile, consisting of uniformly distributed hollow tetrahedrons, allowing to reflect sound waves incident in all directions, and which are located respectively at the rigid 30 and perforated 35 walls, and then onto the layers 32 and 33 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.

The composite rocker sound absorber (Fig. 5) consists of at least two parts of a rigid frame, pulled together by clamps and suspended by hooks on rails (not shown in the drawing) or directly attached to the ceiling of a production building. Inside the frame is a sound-absorbing material wrapped in a mesh nylon fabric or fiberglass. In some cases, expanded glass sheet (not shown) may be attached over the glass fabric 3 to the frame. The frame can be made in the form of a rectangular parallelepiped with dimensions of edges d × h × b, the ratio of which lies in the optimal range of values d × h × b = 2: 1: 0.5, or a cube with the size of the edge k × L, where min L = 100 mm; k is the coefficient of proportionality, lying in the range from 1 to 10 in steps of 2. Inside the wings, cavities can be made that are not filled with sound-absorbing material. For all suspension schemes, optimum size ratios must be observed: m - from the point of suspension of the frame on the guide to the ceiling and c - the distance between the axes of adjacent frames, and the ratio of these sizes should be in the optimal range of values: m: c = 1: 1 ... 0, 5: 1. The filling is carried out with a sound-absorbing non-combustible material (for example, vinipore, fiberglass) with a protective layer of fiberglass, preventing the sound absorber from falling out.

Rocker piece absorber works as follows.

Sound waves propagating in the production room interact with cavities filled with sound absorber. Sound absorption at low and medium frequencies occurs due to the acoustic effect constructed on the principle of Helmholtz resonators formed by cavities. Different volumes of resonant cavities are used to suppress sound vibrations in the required sound frequency range, as a rule large volumes to suppress noise in the low-frequency range, and small ones in the medium and high frequencies.

The proposed method of acoustic protection is an effective way to combat industrial noise.

Claims (1)

The complex for acoustic protection of the operator, containing the operator’s workplace equipped with noise reduction means, the operator’s workplace is located between the acoustic screens that protect the operator from direct sound propagating from vibroactive equipment, and an acoustic suspended ceiling located in the upper area of the room is installed above the working area, and to reduce sound vibration, the operator’s workplace is equipped with a floor on an elastic base, which carries out two-stage vibration protection of the operator, as well as A rocker sound absorber is included, which consists of a rigid frame suspended by hooks on cables to the building ceiling with sound-absorbing material inside the frame wrapped in mesh nylon fabric, and expanded metal steel sheet attached to the frame, and SHUMANET B boards are used as sound-absorbing material. as an effective middle layer in the design of soundproofing frame partitions or facings made of sheets GKL / GVL, chipboard, plywood, as well as in acoustic perforated acoustic systems for installation of sandwich panels, use the VIBROSTEK-M strip gasket, which is laid in two layers at the places of their support on the floor, as well as at the places where the panels come into contact with the side walls and the ceiling, use Vibrosil type sealant: one-component vibration isolating silicone sealant for sealing joints and joints in special soundproofing structures, and as vibration-isolating wall mounts - VIBROFLEX - a shock-absorbing device for solving problems to reduce the level of noise and vibration transmission in rooms of any type and purpose, and for mounting to vertical enclosing structures, wall mounts of the EP type are used - microporous polyurethane elastomer, especially for solving problems of sound and vibration isolation, characterized in that sound absorbing panel is used in the design of the wall sound-absorbing panel an element containing smooth and perforated surfaces, between which a multilayer sound-absorbing structure is placed, which is made in the form of rigid and perforated steel nock, between which are layers of sound-reflecting and 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 tetrahedrons, which allow reflecting sound waves incident in all directions, and which are respectively located in the rigid and perforated walls, and the layers of sound-reflecting material are made of heat-insulating material that can maintain a given microclimate in , and as sound-absorbing material, slabs made of rockwool basalt-based 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, and the sound-absorbing element is lined over its entire surface with an acoustically transparent material, for example, E3-100 fiberglass or “visible” polymer, and the perforated wall has the following perforation parameters: hole diameter - 3 ÷ 7 mm, perforation percentage - 10% ÷ 15%, and according to the shape of the hole I can be in the form of round holes, triangular, square, rectangular or rhombic profile, wherein in the case of non-circular holes as the nominal size should be regarded as the maximum diameter of the polygon circumference fits into.

Images