The fight against noise is carried out by various methods and means:

1. Reducing the power of sound radiation of machines and aggregates;

2. Localization of sound action constructive and planning solutions;

3. Organizational and technical measures;

4. Therapeutic and prophylactic measures;

5. Application of personal protective equipment for working.

Conditionally, all means of protection against noise are divided on collective and individual.

Collective remedies:

Means reduced noise in the source;

Means that reduce the noise on the path of its distribution to the protected object.

Reducing noise in the source of occurrence is the most efficient and economical, (reduces noise by 5-10 dB):

Elimination of gaps in gear connections;

The use of global and chevron compounds as less noisy;

Widespread use, if possible, parts from plastics;

Elimination of noise in bearings;

Replacement of metal hulls on plastic;

Balancing parts (elimination of imbalance);

Elimination of bias in bearings;

Replacement of gears on clinorem;

Replacing rolling bearings on slip (15 DB), etc.

To reduce noise in reinforcement shops, it is advisable: the use of solid plastics for coating surfaces in contact with the reinforcement wire; Installing elastic materials in places of reinforcement; The use of vibration-absorbing materials in the enclosing surfaces of machines.

Technological measures to reduce noise levels in the source include: reducing the amplitude of oscillations, speed, etc.

Means and methods of collective protection that reduce the noise on the path of its distribution are divided into:

Architecturally planning;

Acoustic;

Organizational and technical.

Architectural and planning measures to reduce noise

1. From the point of view of combating noise in urban planning in the design of cities, it is necessary to clearly carry out the separation of the territory on the zones: residential and external transport, industrial, utility and external transport, in compliance with the regulations of sanitary protection zones in the development of the General Plan.

2. The correct planning of industrial premises should be carried out taking into account the isolation of the room from external noise and noisy industries. Production buildings with noisy technological processes should be placed from a leeward side with respect to other buildings and a residential settlement, and necessarily the end parties to them. (The mutual orientation of buildings is solved so that the parties to buildings with windows and doors are against the deaf sides of the buildings. The window openings of such workshops are filled with glass blocks, and the entrance is made with the vestibura and the perimeter seal.

3. The most noisy and harmful processes are recommended to be assigned to separate complexes with the provision of discontinuities between separate near objects according to sanitary standards. Indoors are also combined with noisy technologies, the number of workers exposed to noise is limited. Between buildings with noisy technology and other buildings of the enterprise must be observed (at least 100 m). Rales between workshops with noisy technology and other buildings should be labeled. The foliage of trees and shrubs serves as a good absorber of noise. New railway lines and stations should be separated from a residential building with a protective zone width of at least 200 m. When the device along the noise screens line, the minimum width of the protective zone is 50 m. The residential building should be located at a distance of at least 100 m from the edge of the carriageway of high-speed roads.

4. Noisy goals should be concentrated in one or two places and separate from such premises with ruptures or premises in which people are underwhere. In the workshops with noisy equipment, it is necessary to properly place the machines. They should be placed in such a way that the elevated noise levels were observed at the minimum area. Between the sections with different levels of noise, partitions are arranged or placed utility rooms, warehouses of raw materials, finished products, etc. For enterprises located within the city, the most noisy premises are located in the depths of the territory. Rational placement of acoustic zones, vehicle and traffic flow modes.

5. Creating noise zones.

Sound pressure levels created on the territory of residential buildings of enterprises noise (machines, equipment, etc.) are determined by the formula:

where R is the attenuation of noise at a distance R, dB;

L M1 is the level of noise intensity at a distance of 1 m from the source, dB; R is the distance from the noise source to the calculated point, m.

Determine, for example, the noise level of the engine of the ventilation unit at a distance of 100 m, if noise at a distance of 1 m from the source is 130 dB.

We get: dB.

Acoustic methods of protection against noise.These include soundproofing, sound absorption, sound-absorption (noise mild).

Soundproofing- This is the ability of structures, enclosing or separating the premises, or their elements to loosen the sound passing through them.

Soundproofing and sound insulation efficiency.

When a sound energy is met with a fencing, part of it passes through the fence, part of it is reflected, part - turns into thermal energy, part - radiating the oscillating obstacle, and the part is turns into a housing sound, propagating inside the indoor fencing.

Soundproofing the quality of the fence is characterized by a sound-permeability ratio :

(2.5.11)

where l. PR, R PR - the intensity and sound pressure of the last sound;

l. PAD, P PAD - intensity and sound pressure of the incident sound.

The soundproofing ability of the structure is higher than its superficial density. Effective soundproofing materials are: concrete, wood, dense plastics, etc.

To create normal conditions in the workplace, you need to know which value you need to lower the sound pressure .. To determine the size of the sound insulation, it is necessary to measure the level of sound pressure or intensity from the source, and compare it with a regulatory value (GOST 12.1.003-83; GOST 12.1. 001-89; DSN 3.3.6-037-99). For tonal and impulse noise, as well as noise generated by air conditioning, ventilation and air heating, the LG value must be reduced to \u003d 5 dB (Fig. 2.5.3.).

When calculating the insulation of the room from external noise, it is very important to know which magnitude to lower the sound pressure. As a criterion, sound insulation is proposed:

, dB , (2.5.12)

where L 1 is the level of noise indoors, dB;

L 2 - noise level outside the room, dB.

However, formula (2.5.11.) Does not give a clear idea of \u200b\u200bwhether such a reduction in noise is effective or not, in terms of labor protection.

The choice of the necessary sound insulation is made, based on the volume of noise permissible. Insulating wall and casing must create such a sound insulation, the noise penetrating through them does not stand out on a general background. For this, noise from the source should be reduced by 3 ... 5 dB against the permissible norms:

, dB (2.5.13)

where D is the necessary size of the sound insulation, dB

L A - level from the source, dB;

LG - permissible level Noise for standards, dB.

Now, applying formula (2.5.13), we know how much dB should be reduced sound pressure. Based on the result, it is necessary to select efficient sound insulation. The insulating structure is calculated so that its soundproofing ability of the structure (R) in the DB would be equal to or would be greater than the magnitude of the necessary sound insulation, i.e. R  D.

With the frequency of fluctuations of the medium of more than 100 Hz, the efficiency of sound insulation depends on the mass of the structure ( law Mass. ).

With an increase in the mass mass M Increases insulating noise control efficiency. The sound penetrates through oscillations, and the harder, massive barrier, the harder it is to lead it to oscillation. The fender structures of noisy workshops are made by massive, thickened from dense materials or from hollow blocks, or multi-layered.

To determine the soundproofing ability of the fences, the formula is recommended:

(2.5.14.)

where  is the coefficient of sound conductivity, which is the ratio of sound energy that has passed through the design and falling on the design.

Soundproof walls and overlaps are used to insulate the noisy premises. The soundproofing ability of such fences is determined by the following formulas:

· to determine between two rooms

(2.5.15)

· for solid and monotonous fencing with a mass of construction up to 200 kg / m 2 Sound-insulating capacity is:

(2.5.16)

· the same with a mass of over 200 kg / m 2

(2.6.17)

· for dual fencing with air layer 8 ... 10 cm:

(2.5.18)

where M is the mass of the design, kg / m 2;

M 1, m 2 - the mass of the walls of the double fence, kg / m 2;

R is the soundproofing ability of the fence, dB;

L 1, L 2 is the average value of the sound pressure level in noisy and quiet rooms, dB;

S - fencing area, m 2;

A - general sound absorption in a quiet room, equal to the amount of works of all areas on their sound absorption coefficients, m 2.

If the fence itself is made of sound-absorbing material, then the amount of noise attenuation  soundproofing design is determined by the following dependency:

, (2.5.19)

where  is the sound absorption coefficient of the design material.

The soundproofing ability of the fence depends on the geometric dimensions, the number of the layers of soundproofing material, its weight, elasticity and the frequency composition of noise.

Sound insulation of single-layer fences. Single-layer are the fences (designs), if they are made of a homogeneous building material or consist of several layers of various materials with their own acoustic properties, rigidly connected throughout the surface (brick, concrete, plaster, etc.)

Soundproofing of enclosing structures depends on the occurrence of resonant phenomena. The region of resonant oscillations of fences depends on the mass and stiffness of the fence, the properties of the material. Basically, the frequency of most construction single-layer structures below 50 Hz. Therefore, at low frequencies of 20 ... 63 Hz - I range, the soundproofing of the fences is insignificant due to the large oscillations of the fence near the first frequencies of their own oscillations (sound insulation failure).

At frequencies, 2-3 times higher than the intrinsic frequency of fencing oscillations (frequency range II), sound insulation depends on the mass of the unit of the fencing area and the frequency of incident waves, and the rigidity of the fencing practically does not affect sound insulation:

, (2.5.20)

where R is sound insulation, dB;

M - mass of 1 m 2 fences, kg;

 - Sound frequency, Hz.

Doubling the mass of fencing or sound frequency leads to an increase in sound insulation by 6 dB.

When the frequency of forced oscillations (incident sound wave) is coincided with the frequency of fencing fluctuations (the effect of the wave coincidence), the spatial resonance of the fence is manifested, while sound insulation is sharply inspected. This happens like this: starting with some sound frequency 0,5  kr, the amplitude of the fencing oscillations increases sharply (III range).

The greatest frequency of sound (Hz), at which the wave coincidence is manifested, is called critical:

, (2.5.21)

where b is the thickness of the fence, see;

 - material density, kg / m 3;

 - Dynamic module of elasticity of fencing material, MPa.

Multilayer soundproofing fences. To enhance sound insulation and reduced mass of the fence, multilayer fences are used. For this, the space between the layers is filled with porous fibrous materials and leave an air layer with a width of 40 - 60 mm. The soundproofing capacity is influenced by the mass of the fencing layer M 1 and m 2 and the rigidity of links to, the thickness of the layer of the porous material or the air layer (Fig. 2.5.4)

The lower the elasticity of the intermediate material, the less the transmission of oscillations by the second enclosing layer, and the higher the sound insulation (practically, the double fence reduces the noise level by 60 dB).

Sound absorption. In noisy premises, the sound level is significantly increased due to its reflection from building structures and equipment. It is possible to reduce the proportion of the reflected sound by applying a special acoustic processing of the room, which consists in facing the internal surfaces with sound-absorbing materials.

When the sound energy drops, one part of the sound energy is absorbed on the surface (e), the other is reflected (E O.).

The ratio of absorbed energy to the incident - the sound absorption coefficient of this surface:

, (2.5.22)

The absorption of sound with the material is due to internal friction in the material and the transition of sound energy to heat. Depends on the thickness of the absorbing layer, the type of material and the characteristics of the sound. Sound absorbing consider materials that   .

Sound-absorbing structures are conditionally divided into three groups: porous sound-absorbing, resonant, piece (volume) sound absorbers. In construction, porous sound-absorbing materials are most often used. The designs of them are performed as a layer of the required thickness. Resonant structures are perforated screens. Conventional building materials: concrete, brick, stone, glass, are bad sound absorbers. Most effectively absorb the sound of porous, fibrous materials with low density. Sound absorption in enterprises is achieved by cladding walls and ceilings with fibrous or porous materials (P \u003d 80 ... 100 kg / m 3), fiberglass (P \u003d 17 ... 25 kg / m 3), cellular concrete slabs type "Silkor" (p \u003d 350 kg / m 3), concrete-ceramic blocks, plates from perforated panels of the brand "airline" and others. To consolidate, these materials are covered with aluminum perforated panels, fine-wired wire mesh, fiberglass, etc. Sound absorbing cladding reduces noise in rooms for 6 -10 dB.

Sound absorption of materials depends on the thickness. So, the thickness of the cotton, the wool is 400 - 800 mm, loose felt - 180 mm, dense felt - 120 mm, mineral wool - 90 mm, porous gypsum - 6 mm.

Sound-absorbing materials effectively absorb the sound of medium and high frequency. To absorb the low-frequency noise between the sound absorbing lining and the wall, create an air layer.

Frequent absorbers are often used, made in the form of bulk bodies from sound-absorbing material. They are suspended to the ceiling near noise sources. For sound absorption, various types of structures are used. Such structures consist of one or more layers of materials that are rigidly connected with each other. The sound absorption capacity of such a design depends on the coefficient of noise absorption of each layer.

In the case when the soundproofing fencing has sound-absorbing material in its design, the fence efficiency depends on the sound absorption coefficient  and sound insulation of the walls of the housing or design. To assess the effectiveness of such a design, it is necessary to know the mass of the housing walls or the design of M in kg / m 2, the frequency of oscillations in Hz and the coefficient , which represents the ratio of absorbed sound energy to the incident. The sound absorption coefficient for most porous materials on medium and high frequencies is 0.4 - 0.6. Porous sound-absorbing materials are manufactured in the form of plates and fasten directly to the wall or to the design. Grainy, porous materials are made of mineral crumbs, gravel, pembol, kaolin, slag, etc., applying cement or liquid glass as a binder. These materials are used to reduce noise in industrial premises, in corridors of public and other buildings, lobby, staircases. Sound absorbing, fibrous, porous materials are made of wood fibers, asbestos, mineral wool, glass or kapron fiber. These materials are used mainly to improve acoustic qualities in cinemas, studios, audiences, kindergartens, yawls, restaurants, etc.

Reducing the sound pressure level in acoustically processed room can be determined by dependence:

, (2.5.23)

where b 2 and b 1 are permanent premises before and after its acoustic processing, determine the SNIP II-12-77,

, (2.5.24)

where in 1000 is a permanent room on the medium-meter frequency of 1000Hz, m 2, determined depending on the volume of the room;

 - the frequency factor defined by reference tables (varies from 0.5 to 6, depending on the size of the room and the sound frequency). Maximum sound absorption can be obtained by cladding at least 60% of the room area.

Particular isolation of jobs can be performed using screens. The shielding method is used when other methods are ineffective or unacceptable from a feasibility study point. The screen is an obstacle to the propagation of air noise, which occurs a sound shadow (Fig. 2.5.3.). The material for the manufacture of screens are steel or aluminum plates with a thickness of 1 ... 3 mm, covered with noise source sound-absorbing material. The acoustic efficiency of the screen depends on its shape, sizes, location relative to the source of noise and the workplace. Efficiency k e screen

where,  - frequency; h - screen height; R is the distance from the screen to the workplace; l. - screen width; D - distance from the screen to the source of noise.

The screenshot sound-absorption efficiency depends on the distance between the source and the calculation point ( l.) To length (a), width (B) and height (H) of the room. Efficient screen work will be provided with l./ A, l./ B, l./ H less than 0.5. With the value of equal to 1, the application of the screen is little effectively. Efficiency can be increased by increasing the size of the screen and approaching it as close as possible to the noise source. The English company "AcoustikeBS" has developed a noise absorbing screen for industrial buildings. It can be used as a temporary partition for insulation of rooms.

To combat noise, suspended or piece sound absorbers, cubic or conical shapes, made of perforated plywood, plastics, metal filled with porous sound-absorbing material are used. Sound absorption efficiency is estimated sound absorption area. One of the directions of sound insulation is the use of soundproofing cabins, allowing remotely controlling production. It is recommended to use typical stationary reinforced concrete cabins for the bathroom in residential buildings as soundproofing cabins. They are installed directly on the floor on rubber shock absorbers. Inside, the sound-absorbing slabs and produce double glazing. When designing industrial premises, it must be remembered that the noise level decreases with an increase in the size of the room. However, the height (h) of the room has great importance for sound absorption than its volume. With the distance between the noise source and the calculation point ( l.) to the height of the room (H) equal l./ H \u003d 0.5, sound absorption is 2 ... 4 dB; for l./ H \u003d 2 ... 10 dB; for l./ H \u003d 6 ... 12 dB.

Fig.2.5.1. Soundproofing:

1 - soundproofing fencing; 2 - soundproofing cabins and control panels; 3 - soundproofing covers; 4 - acoustic screens; ISH - noise source

To reduce the noise created by the inlet systems and the release of exhaust gases of internal combustion engines, ventilation plants, compressors, and the like, apply silencers of noise. They are absorption, reactive and combined (fig. 2.5.2).

Absorption silencers reduce noise by 5 - 15 dB due to the absorption of sound energy with sound-absorbing materials, which are lined with their inner surface. They can be tubular, lamellar, cellular, on-screen. The latter are installed at the outlet of the gas to the atmosphere or at the inlet to the channel. Jet silencers reduce the noise in resonant chambers at 28 - 30 dB (Fig. 2.5.3.)

Organizational and technical measures to reduce noise.A decrease in noise through organizational and technical measures is carried out by changing technological processes, a remote control device and automatic control, timely carrying out planning and preventive repair repairs, the introduction of rational labor and recreation regimes.

Individual protection against noise.In cases where technical means cannot reduce the noise and vibration to permissible limits, individual means of protection apply. To reduce the noise of DSN 3.3.6-037-99, it recommends applying individual means of protection according to GOST 12.1.003-88; For ultrasound (GOST 12.1.001-89). Individual protection against noise must have the following main properties:

reduce the noise level to permissible limits at all spectrum frequencies;

do not exert excessive pressure on the ear shell;

do not reduce the perception of speech;

do not drain the sound signals of danger;

save hygienic requirements.

Individual means of protection of hearing organs include internal and outer anti-influenza (antifons), anti-checose helmets.

The protozoa from the internal anti-free funds are wata, march, sponge, etc., inserted into the auditory canal. WATT reduces noise by 3 - 14 dB in the frequency band from 100 to 6000 Hz; Wat with wax - up to 30 dB. Safety sleeves are used (ear inserts "earplugs"), tightly closing the auditory channel and reduce noise by 20 dB (Fig. 2.5.4.).

Outdoor anti-free tools include antifons that cover the ear shell. Some constructs of contractions provide noise reduction up to 30 dB at frequencies of about 50 Hz and up to 40 dB at frequencies of 2000 Hz. Antifons are tired by a person. Currently, antifons have been developed, having a selective ability, i.e. Protecting hearing organs from the penetration of the unwanted frequency sound and transmitting sounds of a certain frequency. Recently, the use of anti-noshemny PSH-00 headphones, Casque Anti-National SCNCII-2. They are very effective means With high-frequency noise, however, it should be borne in mind that they are not very easy to use and can only be applied temporarily. With noise level, more than 120 dB headphones and liners do not give the necessary tolerance of noise.

The means and methods of protection against noise are divided into collective and individual protective equipment (GOST 12.1.029-80).

Facilities collective protectionin relation to the source of the excitation of noise are divided:

• on funds that reduce the noise in the source of its occurrence;
• Means that reduce the noise on the path of its propagation from the source to the protected object.

Noise reduction issues in the source of its occurrence are solved at the stages of design and manufacturing machines, mechanisms, aggregates and other products. In technical tasks, restrictions on this parameter are indicated on the design, they are controlled at all stages of work, up to the launch into mass production. This includes all types of ground, air and water transport, construction vehicles, industrial equipment, household appliances, etc. One of the ways to solve this problem is to improve technological processes, replacing them for more perfect and silent.

The means and methods of collective protection against noise on the path of its distribution depending on the method of implementation are divided:

• on acoustic agents;
• architectural and planning solutions;
• Organizational and technical measures.

TO acoustic means Protection includes soundproofing, sound absorption, vibration insulation and damping, noise silencers.

Any obstacle on the path of propagation of sound (noise) has the ability to absorb, reflect and refracting the sound wave. This property is used when choosing the materials of walls, partitions, floors and floors of buildings and structures at the stages of their design. For example, a more dense and homogeneous material has a greater absorption capacity, less dense - reflective. In construction, single, double and multilayer partitions consisting of several layers of materials with different acoustic characteristics are widely used for sound insulation. This is plasterboard, mineral fiber, foamed polystyrene, organic glass, leaf steel, facing tiles, etc. Each of them is characterized by its sound absorption coefficient.

From these materials, soundproofing casing of centrifugal fans and other noise sources, soundproofing cabins, sound screens, etc.

The sound absorption coefficient of the material is the attitude of the sound energy absorbed to them. Acoustic characteristics along with the material produces a manufacturer.

Essence architectural and planning solutions The protection against noise in the residential sector and the environment is to develop at the stages of the district planning and the master plan for the development of the territory of scientifically based decisions on the placement of objects, methods and means of their protection against noise. Main directions: a) an increase in the distance to noise sources, the creation of protective screens - noise absorbers, including frosting along the transport highways; b) The use of low noise drainage asphalt, facade facing buildings with sound-absorbing materials from motorways and railway tracks.

Hospitals, sanatoriums, holiday homes, children's preschool and educational institutions, hotels, guesthouses are located in accordance with the general plan in zones remote from transport highways and industrial facilities in compliance with sanitary and hygiene requirements. Forest parks create favorable conditions for protection against noise.

Organizational and technical methods Noise protection include:

• use of low-noise technological processes;
• equipping noisy machines with remote control and automatic control;
• introduction of low noise machines and technologies;
• The use of rational labor regimes and recreation workers in noisy enterprises.

To funds individual protectionthe noise includes antiseum:

• Headphones covering ear sink outside;
• liners overlapping the outer hearing pass;
• helmets and helmets;
• Suits (with sound pressure\u003e 125-130 dB).

The noise above the painful threshold finds workarounds of impact on the body through the bone of the musculoskeletal system and the skull. Thus, sound pressure is perceived not only by hearing organs, but also by the whole organism as a sound-conducting material or substance.

Studies have shown that SIZ is only protected from irritating noise and ensure the prevention of various functional disorders and disorders. They do not solve the problem of protection against noise as a whole. It must be solved by comprehensively measurable.

The fight against industrial noise is comprehensively and includes the following measures:

· Technological;

· Sanitary-technical;

· Medical and prophylactic.

The classification of means and methods of protection against noise is given in

GOST 12.1.029-80 SSBT "Funds and methods are sewn from noise. Classification ", SNIP II-12-77" Noise Protection "that provide for noise protection the following construction and acoustic methods :

a) sound insulation of enclosing structures, sealing
windows, doors, gates, etc., the device for soundproofed cabin for
personnel; shelter sources of noise into casing;

b) installation indoors on the path of noise spread sound
absorbing structures and screens;

c) the use of aerodynamic noise in engines
internal combustion and compressors; Sound-absorbing cladding B.
airways of ventilation systems;

d) creating noise protection zones in various locations
People using screens and green plantings.

The weakening of noise is achieved by using under the gender of elastic gaskets without tough communication with the supporting structures of buildings, installation of equipment on shock absorbers or special foundations. Sound absorption tools are widely used - mineral wool, felt plates, perforated cardboard, fiberboard, fiberglass, and active and jet silencers (Fig. 4).

Silencersaerodynamic noise is absorption, reactive (reflex) and combined. In the absorption silencers, the noise attenuation occurs in the pores of the sound-absorbing material.

Fig. 4. Silencers of noise:

a - absorption tubular type; b - absorption cellular type;

g - absorption screen type; D - reactive chamber type; e - resonant;

f - combined type;

1 - perforated tubes; 2 - sound absorbing

material; 3 - fiberglass; 4 - expansion chamber; 5 - resonant camera

The principle of operation of jet silencers is based on the effect of sound reflection as a result of the formation of a "wave plug" in the elements of the muffler. In combination silencers, both absorption and sound reflection occurs.

Soundproofingis one of the most efficient and common reduction methods production noise On the path of its distribution. With the help of soundproof devices (Fig. 5) it is easy to reduce the noise level by 30 - 40 dB. Effective soundproofing materials are metals, concrete, wood, dense plastics, etc.

Fig. 5. Soundproofing schemes: A - soundproofing partition; b - soundproofing casing;

in - soundproofing screen; A - zone of increased noise; B - protected zone;

1 - noise sources; 2 - soundproofing partition; 3 - soundproofing casing; 4 - soundproofing; 5 - acoustic screen

To reduce noise indoors, sound-absorbing materials are applied to the inner surfaces, and space-cutters are placed indoors.

Sound absorbing devices are porous, porous fibrous, with a screen, membrane, layered, resonant and volumetric. The effectiveness of the use of various sound-absorbing devices is determined as a result of acoustic calculation, taking into account the requirements of SNiP II-12-77. To achieve the maximum effect, it is recommended to sneak at least 60% of the total area of \u200b\u200bthe enclosing surfaces, and the volume (piece) sound absorbers are located as close as possible to the noise source.

Reduce the adverse effects of noise on the workers maybe shorting the time of their stay in noisy shops, rationally distributed time and recreation time, etc. The working hours of adolescents under noise is regulated: for them it is necessary to arrange a mandatory 10 - 15-minute breaks, during which they should relax in specially isolated rooms outside the noise effect. Such breaks are arranged for adolescents working for the first year, every 50 minutes - 1% of work, for the second year - after 1.5 hours, the third year - after 2 hours of operation.

Zones with sound level or equivalent sound level above 80 dBA should be indicated by safety signs.

The main sources of vibration (mechanical) noise of machines and mechanisms are gears, bearings, constructive metal elements, etc. Reducing the noise of gears can be increased by the accuracy of their processing and assembly, the replacement of the gear material, the use of conical, osostic and chevron gears. Reduce the noise of machines can be used by high-speed steel for a cutter, lubricating and cooling fluids, replacing metal parts of plastic machines, etc.

To reduce aerodynamic noise use special noiseless elements with curvilinear channels. Reduce aerodynamic noise can be improved by the aerodynamic characteristics of the machines. Additionally, sound insulation and silencers are used.

Acoustic treatmentmandatory in noisy shops of engineering plants, shops of weaving factories, machine halls of machine-tools and computing centers.

New noise reduction method is method "Anti-Commission"(equal in magnitude and opposite by the phase of sound). As a result of the interference of the main sound and the "anti-community" in some places of the noisy room, you can create silence zones. In a place where it is necessary to reduce the noise, the microphone is installed, the signal from which is enhanced and emitted in a certain way with the speakers. A complex of electrocouples for interference noise suppression has already been developed.

Application of personal protective equipmentit is advisable from noise in cases where collective protection tools and other means do not provide noise reduction to permissible levels.

PPE makes it possible to reduce the level of perceived sound by 0 - 45 dB, with the most significant fracture of noise observed in the high frequency area that are most dangerous to humans.

The means of individual sewn from noise are divided into antioxide headphones, covering the ear shell outside; antioxide liners overlapping an outer hearing pass or adjacent to it; antinoise helmets and helmets; Antinemic costumes. Antically liners are made of solid, elastic and fibrous materials. They are one-time and multiple use. Anti-shit helmets cover the entire head, they are used at very high noise levels in combination with headphones, as well as anti-co-costumes.

According to GOST 12.1.003-83 in the development of technological processes, design, manufacturing and operation of machines, industrial buildings and structures, as well as the organization of jobs, all necessary measures should be taken to reduce noise affecting a person to values \u200b\u200bnot exceeding permissible.

Noise protection should be ensured by the development of noise-safe techniques, the use of funds and methods of collective protection, including construction and acoustic, the use of personal protective equipment.

First of all, the collective protection means should be used. In relation to the source of noise excitement, collective means of protection are divided into funds that reduce the noise in the source of its occurrence, and the means that reduce the noise on the path of its propagation from the source to the protected object.

The reduction of noise in the source is carried out by improving the design of the machine or change the technological process. Means that reduce the noise in the source of its occurrence depending on the nature of the noise formation are divided into funds that reduce the noise of mechanical origin, aerodynamic and hydrodynamic origin electromagnetic Origin.

Methods and means of collective protection depending on the method of implementation are divided into construction and acoustic, architectural and planning and organizational and technical and include:

• - change of the emitting of noise radiation;
• - rational planning of enterprises and industrial premises;
• - acoustic processing of premises;
• - Application of sound insulation.

The architectural and planning solutions also includes the creation of sanitary protection zones around enterprises. As the distance from the source increases the noise level decreases. Therefore, the creation of the sanitary and protective zone of the required width is the most simple way providing sanitary and hygienic standards around enterprises.

The choice of the width of the sanitary protection zone depends on the installed equipment, for example, the width of the sanitary and protective zone around the large TPP can be several kilometers. For objects located within the city, the creation of such a sanitary and protective zone is sometimes an intractable task. Reduced the width of the sanitary and protective area can be reduced by noise on its distribution paths.

The means of individual protection (PPE) are used in the event that other methods provide a permissible noise level in the workplace.

The principle of operation of the SIZ is to protect the most sensitive channel of the effect of noise on the human body - ear. The use of PPE makes it possible to prevent disorder not only hearing organs, but also nervous system From the action of excessive stimulus.

Most effective PPE, as a rule, in the field of high frequencies.

PPE includes anti-liners (earplugs), headphones, helmets and helmets, special costumes.

Noise is a totality of sound waves of different frequencies.

Noise is one of the side-harmful phenomena for a person. With him, a person meets everywhere: at home, on the street, at work, most often, working in production. In most, noise creates dangerous working conditions for humans.

In fact, noise is a sound that becomes often unfavorable for a person.

Sound vibrations can cause a sense of discomfort, lead to violation of the body and various professional diseases. Therefore, noise protection should occupy one of the first places among the action to protect its body and the prevention of diseases. If you want to measure the noise level or spend other studies () you can contact our laboratory.

Further, the article will consider various methods and means of protection against noise. This will be useful to know everyone. After reading, think about whether these methods of protection against noise and vibration are performed on your workplace?

The impact of noise and vibration per person. Methods and means of protection against noise

Noise has a negative effect on the human body. With prolonged influence, it causes discomfort. With a longer exposure, noise is capable of influence the nervous and cardiovascular system of a person. The optimal level of sound oscillations for a person is 40-50 decibels in day and night. If these indicators exceed the norm, then a person loses performance, attention weakens, disorders appear in work digestive systemThere are changes in blood pressure indicators.

In addition, if a person is regularly exposed to noise, it may lead to a deterioration or loss of hearing. Therefore, on some types of production, hearing loss is a professional disease. Noise over 90 dB and may be fatal for humans. Therefore, it is very important to take measures to protect against noise at work and at home, as well as to control the noise in your home.

Influence of vibration on internal organs leads to tissue breaks. In addition, the impact of mechanical oscillations can be initiated by the manifestation of the so-called marine disease. In order to avoid such phenomena, the means of individual protection against noise and vibration should be applied. An example, you can use professional shoes on a compacted rubber sole, rubber gloves and liners.

Types of noise and vibrations and various ways of protection against noise

Distinguish such types of vibration depending on the contact of a person with a vibrating tool:

• Common;
• Local.

There are such types of noise:

• Shock;
• Mechanical;
• Gas and hydrodynamic.

Methods of protection against noise and vibration

There are various means of protection against noise and vibration. To ensure safety, various methods of protection are applied not only in production, but also in everyday life. Noise protection is a mandatory production event that an employer should provide.

In order not to harm human well-being, various ways of protection against noise are used. They are classified as follows. :

1. Collective means of protection against noise;

Individual protection means.

• Reduction of noise on the way of its expansion;
• Noise reduction directly in the source;
• Medical and preventive actions;
• Organizational and technical (the use of less noisy technological processes and machines, equipping noisy machines with means of remote control and automatic control, consumption of expedient labor and recreation modes of workers in noisy enterprises, etc.);
• Architectural and planning measures regarding noise reduction are envisaged at the stage of designing industrial structures. An example is the location of noisy machines in a separate room, the use of noise reduction materials.

Ways to protect against noise that reduce it on the dispersion paths are:

• acoustic;
• architectural and planning (the formation of noise-proof zones, expedient placement of equipment of workplaces, expedient acoustic solutions of planning planning and general plans of objects, etc.).

Reducing noise on the path of dispersion is achieved in certain methods:

• removal from the source for certain distances;
• change the direction of noise expansion.

Order a free consultation of the environmentalist

Individual protection against noise

For individual restrictions and protection against noise at production, traffic jams, headphones, plugs, liners and helmets are most often used. If you want to measure the noise level or carry out other studies (for example, the study of radiation) must be applying to EcotestExpress.

Among all the means inserts are the cheapest, affordable and practical. They are inserted into the ear canal, without giving a sound wave to pass in the ear. Depending on the material of the inserts are tough and soft.

Advantages. Inserts do not make it difficult to wear hats and glasses.

Disadvantages. Perhaps irritation of the auditory canal. Multiple operation of the inserts requires a thorough medical examination.

So, the means of individual protection against noise. All familiar headphones may be so. They carefully cover the ear shell and hold sound waves, not letting go to the ear.

Advantages. Convenience, small weight, actively reduce the noise, mostly high-frequency part of the spectrum.

Anti-shine helmets are used in production to protect those operating from high levels noise. Such sounds penetrate not only through the hearing pass, but through bone fabric. Helmets are recommended when exposed to noise more than 120 dB. Other means of personal protection against noise are not able to provide the necessary protection humorcraft At such a frequency.

Protection against noise and vibration in production

Protection against noise at production is carried out comprehensively. There are also collective, and individual protection measures. Individual means of noise are used when collective protection methods cannot reduce the noise level to the permitted indicators.

Protection against noise and vibration in production is the responsibility of the employer. The level of such sound oscillations is governed by the appropriate regulatory acts, the observance of which should follow the sanitary and epidemiological service. The employer can save time and money, and to hold, which includes a number of different studies.

There are also therapeutic and prophylactic methods for protection against noise. These include advanced and regularly repetitive medical examinations, the use of rational labor and recreation regimes for people working on the "loud" production. Noise is a dangerous working condition, so it is not allowed to work in the workshops and in production.

If possible, use noise protection measures, arriving on a noisy street and at home. It will help you to keep health, it is better to relax, improve performance. Remember that the methods and means of protection against noise are different, even the simplest and inexpensive will be able to protect you from the impact of a harmful sound level.

In order to measure the level of noise at production, you can contact our EcotestExpress laboratory, where all the studies will spend only in one day and, if necessary, provide research results as soon as possible.

How to protect yourself from external street noise?

Many worries the problem of street noise, but not everyone knows how to protect himself and their relatives from his negative impact. What are the main sources of so-called external noise exist?

The main sources of street noise are various vehicles, noise of roads, railway transport, car alarms, aircraft noise, cry and laughter of playing children, manufacturing enterprises, proximity of stadium location, etc. They can be listed for a very long time, since each street has its own characteristics that in one way or another affect the outer noise.

You can list the following main quarterly noises:

• Various vehicles on narrow streets, entry in parking and parking;
• Mandatory ventilation of large objects (plants, supermarkets, other industrial enterprises), as well as air conditioning on large objects;
• Household courtyards and warehouses of stores, supermarkets, restaurants and cafes;
• Central places of thermal points;
• Sports grounds;
• Construction and repair work, etc.

Unfortunately, the sound insulation of the outer walls, as well as all doors and windows can not be clearly regulated. Ways to protect against noise are chosen in accordance with the necessary calculations. But let's go about everything in order.

Before proceeding with the so-called acoustic calculation in the building, the first thing is determined by the foresown noise level from possible street sources (or the available noise level is measured). The sound may be in the range from 63 to 8000 Hz. These limits are likely octave levels of different sound power.

After the consultation and selection of further actions should be made to protect the dwelling from external noise. Soundproofing work will not and should not stop until the noise level in the room will not be within acceptable limits.

In cases where it is planned to build a private house in places where the noise level exceeds the allowable one must ensure that all the rules of sound insulation are taken into account, and all the necessary calculations are made.

In order not to worry about how true the data obtained and in the residential premises, you can contact our independent EcotestExpress laboratory to accurately study the noise level, as well as further recommendations for improving the current situation.