RU2500860C1 - Method of operator's acoustic protection - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method of acoustic protection includes equipping of an operator's workplace by noise reduction facilities. The operator's workplace is located between acoustic screens for protection against direct sound. For protection against reflected sound waves an acoustic suspended ceiling is installed above the working zone arranged in the upper zone of the room. To reduce the sound vibration, the operator's workplace is equipped with a floor on an elastic base, at the same time the double-cascade vibration protection of the operator is realised. A link sound absorber comprises a stiff frame suspended at hooks on ropes to a ceiling of a production building with a sound-absorbing material wrapped with a meshed caproic fabric and arranged inside the frame. An expanded steel sheet is fixed to the frame. The frame is made in shape of a rectangular parallelepiped with dimensions of ribs d×h×b, the ratio of which is in the optimum interval of values d:h:b=2:1:0.5 or a cube with the rib dimension k×L, where min L=100 mm; k - coefficient of proportionality, lying within the limits from 1 to 10 with the pitch of 2. In all schemes of suspension the optimal ratios of dimensions shall be observed: m - from the point of frame suspension on a guide to the ceiling and c - distance between axes of adjacent frames. The ratio of these dimensions shall be in the optimum interval of values: m:c=1:1…0.5:1. A wall sound-absorbing panel is installed on the slab, and it consists of a sound-absorbing board of shumanet-ECO (50 mm); a gypsum board sheet 12.5 mm; a gypsum board sheet 12.5 mm; a profile of Vibronet type PN 100/40; a gasket of Vibrostek-M type (2 layers); a sealant of Vibrosil type.

EFFECT: invention makes it possible to increase efficiency of noise damping.

4 cl, 6 dwg

Description

The invention relates to industrial acoustics, in particular to broadband sound attenuation, and can be used in all sectors of the economy as a means of protection against noise.

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 way of acoustic protection for the operator, namely 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 sound attenuation efficiency by increasing the sound absorption coefficient by increasing the sound absorption surfaces while maintaining the overall dimensions of the room.

This is achieved by the fact that in the method of acoustic protection, namely, that the operator’s workplace is equipped with noise reduction means, the operator’s workplace is placed between the acoustic screens, and thereby protect the operator from direct sound that is spreading from vibroactive equipment, and in order to increase efficiency To protect against reflected sound waves, an acoustic suspended ceiling is installed above the working area located in the upper area of the room and to reduce sound vibration, the operator’s workplace they floor with an elastic base, and a two-stage vibration protection of the operator is carried out.

Figure 1 shows a General view of the device 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 a wall panel, figure 4 - structure of a 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.

A device for acoustic protection of the operator of a production room (Fig. 1) comprises a building frame made in the form of an elastic base 1, which is the floor of a building (Fig. 2), of heat and sound insulating barriers 2, rigidly connected to columns 3, which in turn are connected to a 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, on 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 closely 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 the vibroactive equipment 7 and 8 on the plate 18, two-stage vibration protection occurs, due to vibration damping inclusions in the mass of the plate 18, as well as due to the layer of vibration-damping material 21, which can be used: needle-punched mats of the type “Vibrosil” based on silica or aluminum-borosilicate fiber, a material made of solid vibration-damping materials, for example, plastic, from soundproofing plates based on glass staple fiber 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 oscillating with the excitation frequency against the neck wall itself, having the form branched pore network 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.

The 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 acoustic protection method of the operator is 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 effectiveness of protection against reflected sound waves above the work area (workplace), an acoustic suspended ceiling is installed 5, located in the upper zone 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 the vibroactive equipment 7 and 8 on the plate 18, two-stage vibration protection occurs, due to vibration damping inclusions in the mass of the plate 18, as well as due to the layer of vibration-damping material 21, which can be used: needle-punched mats of the type “Vibrosil” based on silica or aluminum-borosilicate fiber, a material made of solid vibration-damping materials, for example, plastic, from soundproofing plates based on glass staple fiber 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, slags, 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 0.034 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 O.os 0.07 Metlakh tile 0.01 0.01 0.02 0.02 0.02 0.03 Glazed Window Bindings 0.35 0.25 0.18 0.12 0.07 0.04 Lacquered Doors 0,03 0.02 0.05 0.04 0.04 0.04 Wool carpet 9 mm thick for concrete 0.02 0.08 0.21 0.26 0.27 0.37

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

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

In fibrous absorbers, the dissipation of the energy of air vibrations and its transformation into heat occurs at several physical levels. Firstly, due to the viscosity of the air, and there is a lot of it in the interfiber space, the oscillation of air particles inside the absorber leads to friction. In addition, there is air friction on 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.

Recall that the sound absorption coefficient a 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 the equipment.

Sound energy from the equipment 7 and 8 located in the room, passing through the perforated wall of the acoustic wall panels 6, falls on the layers of sound-absorbing material (which can be either soft, for example from basalt or glass fiber, or hard, for example, shell rock). 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. At the same time, 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 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 type Schumanet-ECO (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 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 . 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.

Table 1 Acoustic Test Results frequency Hz one hundred 125 160 200 250 320 400 500 630 SHUMANET-BM plates without rel 0.14 0.26 0.40 0.56 0.67 0.82 1.00 1.00 1.00 SHUMANET-BM plates with a ratio 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 ratio 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 packaged in a roll of soundproof fiberglass. Insulation 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. 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 a unique material. Sylomer is a microporous polyurethane elastomer specially developed for solving problems of sound and vibration isolation.

The composite rocker 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 the dimensions of the 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, ranging from 1 to 10 in steps of 2. Inside the wings, cavities not filled with sound-absorbing material can be made. For all suspension schemes, the 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 sound 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 (4)

1. The method of acoustic protection of the operator, which consists in the fact that the operator’s workplace is equipped with noise reduction means, while the operator’s workplace is located between the acoustic screens and thereby protect the operator from direct sound that is spreading from vibroactive equipment, and in order to increase the protection against reflected sound waves, an acoustic suspended ceiling is installed above the working area located in the upper area of the room, and to reduce the sound vibration, I equip the operator’s workplace a floor on an elastic base, in this case, a two-stage vibration protection of the operator is carried out, and the rocker absorber consists of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with a sound-absorbing material located inside the frame wrapped in mesh nylon fabric, and an expanded metal sheet is attached to the frame and the frame is made in the form of a rectangular parallelepiped with dimensions of d × h × b ribs, the ratio of which lies in the optimal range of d: h: b = 2: 1: 0.5 or cube s Dimensions rib k × L, where L = 100 min mm; k is a proportionality coefficient ranging from 1 to 10 in increments of 2, and for all suspension schemes, the optimal size ratios must be observed: m - from the point of suspension of the frame on the guide to the ceiling and c is 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, characterized in that they use the design of a wall sound-absorbing panel mounted on the ceiling, which consists of a sound-absorbing plate of the Schumanet-ECO type (50 mm); gypsum sheet 12.5 mm; gypsum plasterboard sheet 12.5 mm; profile type Vibronet PN 100/40; gaskets like Vibrostek-M (2 layers); Vibrosil type sealant. 2. The method of acoustic protection of the operator according to claim 1, characterized in that the SHUMANET-BM boards are used as an effective middle layer in the designs of soundproofing frame partitions or claddings from sheets GKL / GVL, chipboard, plywood, as well as in systems of acoustic perforated screens or false ceilings. 3. The operator’s acoustic protection method according to claim 1, characterized in that when installing the 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 ceiling . 4. The operator’s acoustic protection method according to claim 1, characterized in that the Vibrosil type sealant is used during installation: a one-component vibration-isolating silicone sealant for sealing joints and joints in special soundproof structures, and VIBROFLEX as vibration-isolating wall mounts — a shock-absorbing device for solving problems reduce noise and transmit vibration in rooms of any type and purpose, and for mounting to vertical enclosing structures use wall options for mounting ty na EP - microporous polyurethane elastomer, especially for solving problems of sound and vibration isolation.

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