Vibration of a general and local nature has a certain effect on human body. This has been proven through multiple studies and experimental tests. Therefore, there are certain acceptable vibration levels for industrial or domestic levels. It is very important to take them into account.

The maximum permissible vibration standards in the workplace are considered to be those that take into account vibrations and the amplitude of movement of household or industrial equipment for certain period work, taking into account the transfer of vibrations to other objects, surfaces and physical bodies located in the room. Sanitary standards introduce regulated sanitary standards for noise and vibration levels. This takes into account the specific operation of the equipment and its scope of application. Sanitary standards do not regulate vibration changes in self-propelled vehicles or transport, since these objects are in motion and do not have a stationary position during operation.

Vibration regulation and control of vibration changes

Hygienic standards for noise and vibration establish permissible vibration standards, which are calculated based on the design features of the element under study, as well as the nature of its use. Notes and uncertainties in vibration measurements should be addressed to the manufacturer and designer of the machine whose vibration testing has not been validated and accepted by the regulatory community. GOST indicators for vibration standards of smoke exhausters establish the efficiency, reliability and safety of equipment.

Sanitary standards for vibration of plunger pumps are needed primarily in order to calculate the maximum safe indicators for the human body, since most of the objects under study are in direct contact with a person and can harm his health if they do not function properly.

Main task all instruments and sensors for measuring vibration vibrations - measure the permissible levels of noise and vibration of equipment that is located near workplaces and has direct contact with individuals. Vibration testing should take into account the fact that human contact with a machine in production is systematic and should not contribute to the development in the body of specific occupational diseases or deformations during work, which may subsequently affect the productivity and performance of a person.

Among the most noticeable benefits of checking the permissible vibration levels of equipment, it is worth highlighting the following:

• Regular monitoring and systematic measurements of changes in vibration indicators significantly improve the work process and optimize the labor system. Since any changes in vibration indicators can affect the productivity, performance and physical health of employees.
• Hygienic standards for vibration of pipelines in production allow us to draw up a correct picture of working conditions and take measures to improve or optimize them.
• Checking indicators and establishing vibration standards in residential buildings is carried out not only at the production level, but also in the domestic sphere. Knowing the level of vibrations allows you to take a more competent approach to arranging your home life, as well as protect yourself from the possible influence of vibrations on the body.
• Local and global inspections of vibration standards at enterprises allow us to get an overall picture of the sanitary working conditions in a certain area, and take measures to improve equipment or modernize work facilities.

What do regulatory documents reflect?

Based on the results of vibration checks and calculations, the sanitary group provides regulatory documentation and a complete schedule of measurements and vibration indicators of equipment in production or in the domestic sphere. The regulatory package of documents contains the following information:

1) Complete information about the frequency analysis of equipment vibrations, taking into account the features of their design, operation and placement in a certain area in the area being tested. All measurements and indicators must be based on the regulatory framework and not exceed permissible level vibrations.
2) Integral assessment of the vibration frequency of the object being tested, taking into account the characteristics of the test, the equipment used, as well as the nature of the surfaces of the equipment being tested and the characteristics of its use.
3) Maximum permissible doses of vibrations in the tested area, taking into account the permissible limits and standards of the sanitary group.

Standard indicators provide data on the maximum permissible limits of vibration velocity and vibration acceleration of the equipment or machinery being tested. This takes into account the specifics of its functioning and interaction with individuals.

Based on the results of measurements of vibration indicators, an equivalent indicator of the vibration produced in a specific place is calculated and its relationship with the regulated framework of permissible vibrations for the human body at a certain place of work.

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Why and how is the permissible dose of vibration measured in production?

The dose of vibration is determined by calculating the square of the impact of vibration on the body over a certain period of operation of the element under study. This method calculation allows you to most effectively calculate the permissible limits of vibrations in the workplace. A qualified vibration test of a modern type is capable of analyzing equipment remotely at workplaces where the work schedule is not standardized, and a stationary test of the old type is not able to give adequate results and identify errors.

Technical documentation and regulated frameworks that establish the basis for inspection and standards for the use of this or that equipment in production must take into account the length of the working day, as well as the peculiarities of the functioning of the objects being inspected. Upon completion of the inspection, the customer is provided with complete documentation of the studies performed and data on the vibration field of the equipment in the area being tested.

The standards for vibration indicators of hand-held equipment are regulated by GOST 17770-72. The main verified indicators of this type of equipment are:

• indicators of vibration and vibration frequencies in areas of machines that are in direct contact with human hands;
• the force that an employee applies when pressing a certain area of ​​the object being tested during work;
• total weight of the machine and its individual parts, taking into account the specifics self made person with this equipment.

In the process of checking manual machines, attention is paid to the ratio of the mass of the machine and the force of a person pressing on the corresponding area during operation. When checking pneumatic drives, they check the amount of effort that a person applies while working with the equipment.

The force that a person applies when pressing individual parts of a manual machine during work is also a regulated and standardized indicator that determines the quality and efficiency of work. This force should not exceed 200N. In this case, the total weight of the machine being tested, taking into account the efforts made by a person when working with it, should not exceed 100 N.

It is also important to note that when checking vibration indicators, the heating temperature of the equipment being tested is taken into account during operation. The contact surface that comes into contact with human hands should not have a thermal conductivity higher than 0.5 W.

Why is equipment testing necessary?

Exceeding the regulated limits of thermal conductivity and vibration can be detrimental not only to the machine itself (with strong vibrations, parts break, contacts overheat, individual machine parts fail), but also to the person who is in constant contact with the equipment in working hours. Vibrations can have a destructive effect on the human body and contribute to the development of occupational diseases.

The EcoTestExpress laboratory offers a comprehensive vibration test of equipment or household appliances, which will allow you to extend the life of your equipment and maintain your health. We use only modern and high-precision equipment, which allows us to check all tested elements to the maximum extent possible. short terms. Based on the results of the inspection, the customer is provided with a complete picture of the production process and the functioning of its individual elements. All calculations and data are entered into a regulatory journal. It is also subsequently handed over to the customer for further analysis and changes to the work or household process.

You can submit a request for a vibration level assessment using the form below.

Vibrations are one of the problems of modern megacities. Moreover, every year their intensity is constantly increasing. Why is modern science so actively exploring this problem? For what reason have vibration measurements become mandatory procedures in many organizations and enterprises? The fact is that vibration is a phenomenon that causes a number of occupational diseases, which gives doctors reason to raise questions about measures to eliminate it.

Vibration concept

Vibrations are a complex oscillatory process that occurs over a wide frequency range. How does it arise? When vibrational energy is transferred from a source to a solid body. Usually vibration is understood as having a tangible effect on the human body. This refers to the frequency range from 1.6 to 1000 Hz. Sound and noise are closely related to the concept of vibration. They accompany this phenomenon at high rates of oscillatory motion.

What subject at school studies such a concept as vibration? This is a very important subject. Ensuring labor safety is one of the main problems in Russia, raised to the level of national security.

Origins

Mechanical vibrations are phenomena that occur in almost all machines, machines and tools that have unbalanced or unbalanced rotating parts that perform reciprocating and impact movements. The list of such equipment includes stamping and forging hammers, pneumatic and electric hammer drills, as well as fans, compressors, pumping units and drives.

If oscillatory movements of mechanical bodies are performed with a frequency in the range of up to 20 Hz, then they are perceived only as vibration. At high frequencies sound appears. This is vibration with noise. In this case, perception is produced not only by the vestibular apparatus of a person, but also by his hearing organs.

Vibration classification

Oscillatory movements can be transmitted in various ways. So, there is a general vibration. This is an oscillatory process transmitted to the human body through various supporting surfaces. General vibration has an adverse effect on the cardiovascular and nervous systems. In addition, it causes pathologies of the digestive tract and organs of movement.

In turn, from the general vibration the following are distinguished:
- transport, which occurs when cars move on roads;
- transport and technical, the source of which are the machines and mechanisms involved in process;
- technical, arising during work stationary equipment or transmitted to areas where maintenance personnel are located, where there are no sources of vibration.

There is also local vibration. These are oscillatory movements transmitted through the hands. If a person systematically encounters such vibration, then he may develop neuritis with simultaneous loss of ability to work.

When studying workplaces, harmonic or sinusoidal vibration is released. These are oscillatory movements in which the values ​​of their main indicator change according to a sinusoidal law. This kind of vibration occurs especially often in practice.

Oscillatory movements are also distinguished by their time characteristics. So, there is constant vibration. Its frequency parameters change no more than twice during the observation period.

There is also inconsistent vibration. It is characterized by a significant change in the main parameters (more than twice).

In what subject are students given the opportunity to become more familiar with the phenomenon of vibration? This is BJD. It is taught in senior high schools.

Vibration options

The following quantities are used for characterization:
- amplitude showing the greatest deviation from the equilibrium position in meters;
- oscillation frequency, defined in Hz;
- number of oscillatory movements per second;
- vibration speed;
- period of oscillation;
- acceleration of oscillations.

Industrial vibration

Questions about reducing the level of oscillatory movements that negatively affect the human body are especially relevant at the stage of development of a technological process, which is impossible without the operation of machines, machines, etc. But, nevertheless, industrial vibration is a phenomenon that in practice cannot be avoided. It arises due to the presence of gaps, as well as surface contacts between individual mechanisms and parts. Vibration also occurs when equipment elements are unbalanced. Often, oscillatory movements increase many times due to resonance phenomena.

Conducting vibration monitoring

To control and further reduce the level of vibration in production, special vibration-measuring control and alarm equipment is used. It allows you to maintain the functionality of outdated equipment and increase the service life of new machines and mechanisms.

Everyone knows that the technological process of any industrial enterprise requires the participation large quantity fans, electric machines etc. To ensure that the equipment does not stand idle, technical services must carry out timely current or major repairs. This is possible by monitoring the vibration level, which allows timely detection of:
- rotor imbalance;
- wear of bearings;
- gear misalignment and other malfunctions and deviations.

Vibration monitoring equipment installed on the equipment issues warning signals in the event of an emergency increase in the vibration amplitude.

Impact of vibration on human health

Oscillatory movements primarily cause pathologies of the nervous system, as well as the tactile, visual and vestibular apparatus. Professional car drivers vehicles and drivers complain of ailments of the lumbosacral spine. These pathologies are the result of the systematic impact of shock and low frequency vibration arising in their workplace.

Those who are exposed to the oscillatory movements of equipment during the process cycle suffer from pain in the limbs, lower back and stomach, as well as lack of appetite. They experience insomnia, fatigue and irritability. In general, the picture of the impact of general vibration on a person is expressed in autonomic disorders, accompanied by peripheral disorders in the limbs, decreased sensitivity and vascular tone.

The impact of local oscillatory movements leads to spasms of the blood vessels of the forearms and hands. In this case, the limbs do not receive the required amount of blood. At the same time, local vibration affects bone and muscle tissue, as well as the nerve endings located in them. This leads to decreased sensitivity of the skin, deposition of salts in the joints, deformation and decreased mobility of the fingers. It is also worth mentioning that oscillatory movements performed in the range sharply reduce the tone of the capillaries, and at high frequencies vasospasm occurs.

Sometimes a worker experiences vibration in his ear. What is this phenomenon? The fact is that the frequency of oscillatory movements transmitted from operating equipment can be very different. However, at an individual enterprise there is a rather narrow range of such values. This leads to the appearance of one or another type of vibration, as well as accompanying noise. Thus, sounds can have low, medium and high frequencies.

When does vibration occur in the ear? What does this condition characterize? The fact is that sometimes the equipment creates oscillatory movements that are on par with auditory perception. As a result, noise arises, transmitted to the inner ear through the worker’s body and his bones.

In practice, the permissible level of vibration is determined. These are those meanings that do not have negative influence on the human body. These parameters depend on many factors (time of exposure, purpose of the room, etc.) and are measured by vibration amplitude, vibration velocity, vibration acceleration and frequency.

Most dangerous vibration levels

The characteristics of the negative impact of oscillatory movements on the human body are determined by the nature of their distribution with a combination of mass and elastic elements. For a person who works standing, this is the torso, pelvis and lower part of the spine. A person sitting on a chair is susceptible to negative influences upper part body and spine.

The effect of vibration on human health is determined by its frequency spectrum. Those manual mechanisms whose oscillatory movements are below 35 Hz contribute to the appearance of negative changes in the joints and musculoskeletal system.

The most dangerous vibrations close to human organs. This range is from 6 to 10 Hz. Fluctuations of this frequency also negatively affect psychological health. This frequency may well have been responsible for the deaths of many travelers in the Bermuda Triangle. At oscillation values ​​from 6 to 10 Hz, people experience a feeling of fear and danger. At the same time, sailors strive to leave their ship as quickly as possible. Prolonged exposure to vibration can lead to the death of the crew. This phenomenon is dangerous for the functioning of both individual organs and the entire organism as a whole. It disrupts the functioning of the central nervous system and metabolism.

Vibration with a large amplitude is very dangerous. It has a negative effect on bones and joints. With prolonged exposure and high intensity vibrations, such vibration provokes the development of This occupational pathology, under certain conditions, turns into a cerebral form, which is almost impossible to cure.

Elimination of oscillatory movements

How to avoid vibration in the body? What kind of activities should these be that will help maintain human health? There are two main groups similar methods. The measures of the first of them are designed to reduce vibration directly at the source of its occurrence. Such actions, carried out at the design stage, involve the use of silent equipment and correct selection its operating modes. During the construction and further operation of industrial buildings, these measures relate to measures to use technically sound equipment.

The second method of reducing vibration is to eliminate it along the propagation path. For this purpose, vibration insulation of equipment and air ducts is carried out, vibration-isolating platforms are built, and workplaces are equipped with special mats and seats. In addition, vibration along the path of its propagation can be eliminated by performing a whole range of acoustic, architectural and planning measures. Among them:
- location of vibration sources at the maximum distance from protected objects;
- appropriate placement of equipment;
- application of a vibration-isolated and rigid mounting scheme for the unit, etc.

Time protection

In order to maintain the health of a person working with manual mechanisms or equipment that transmits oscillatory movements to the body, special rest and work regimes are developed. Thus, there is a limit on the time of contact with machines and mechanisms to 1/3 of the shift. In this case, be sure to take two or three breaks of 20-30 minutes each. Moreover, free time from work during the shift is provided for conducting a variety of physiotherapeutic procedures.

Such work regimes are developed for vibration-hazardous professions and are a kind of preventive measures aimed at preserving human health.

Numerical vibration of the name

When interacting with different people, each of us behaves completely differently. Moreover, all this depends on the attitude towards the interlocutor and the current situation. We despise or respect, hate or love, we listen to their opinion or it is completely indifferent to us.

If you meet on life path If a person is reserved and taciturn, such behavior becomes typical for us. A merry fellow and joker, on the contrary, will make you laugh and will certainly lift your spirits. How can one recognize the individuality of a person that is hidden in the depths of his soul? The vibration of the name will tell you a lot. What is this? Numerological addition of the consonants of the name. Using this method, you can determine the character of relatives and spouse, friends and any person, even without knowing the date on which he was born. All you need is knowledge of the 9 numerical vibrations corresponding to the name. With their help, you can find the key to the human soul and feel like a real magician. No wonder some say that this is the vibration of my heart. Indeed, with the help of this method, a magical weapon appears in the hands of a person, which will benefit those who know its power of influence and basic meaning.

The letters of each person's name hide three meanings of his individuality. This is the number vibration:
- vowels;
- consonants;
- the sum of all letters.

Data numeric values together they give a description of the most important aspects of the personality.

There is also a sound vibration of the name, because life is a continuous movement. That is why it has its own vibration. Each name has its own vibration. Throughout life, its meaning is gradually transferred to the owner. Scientists believe that the lower threshold of such vibrations is at the level of 35,000 vibrations per second, and the upper threshold is at the level of 130,000/sec. Those people who have the highest coefficient are resistant to various types of infections. They also have high levels of moral attitudes.

Vibration

What is vibration?

Vibration is the vibration of solids or particles with a frequency of less than 20 Hz, which is perceived by a person through touch.

Why is prolonged exposure to vibration harmful to humans?

Vibrations in excess of permissible sanitary standards have a harmful effect on the nervous and cardiovascular systems. Workers who are exposed to harmful effects vibrations, become ill with vibration disease, the main symptoms of which are neurovascular disorders of the fingers, which manifests itself in increased sensitivity to cooling of the hands (numbness, blueness or paleness), the appearance of pain in the joints of the hands and fingers, as well as headaches, increased fatigue and irritability.

What can be a source of harmful vibrations in agriculture?

A machine operator working on a tractor or other agricultural machine may be exposed to the harmful effects of vibrations. Hand-held electric or pneumatic tools used to repair agricultural machinery can also create vibrations that are harmful to the worker. These are the most common sources of vibration.

What are the maximum permissible sanitary standards for vibration?

The standards limiting vibrations when working with machinery and equipment and in the workplace are given in Table 8.

Table 8. Limiting vibration standards

Frequency, Hz	Vibrotool		Workplace
		vibrational speed, cm/s	vibration speed level, dB	vibrational speed, cm/s
			—	—

At frequencies up to 11 Hz, the following oscillatory displacements are normalized for workplaces:

Frequency, Hz	1	2	3	4	5	6	7	8	9	10	11
Displacements, mm	0,6	0,5	0,4	0,2	0,1	0,08	0,07	0,05	0,045	0,04	0,035

Who gives permission to work with a tool whose vibration exceeds sanitary standards?

The enterprise administration must obtain such permission from the local sanitary and epidemiological service authorities.

It is prohibited to work with machines whose vibration levels are more than 4 times (more than 12 dB) higher than sanitary standards.

How is vibration measured?

Vibration meters and vibrographs are used to measure vibrations in workplaces. various models. The most common noise and vibration meter is ISHV-1. Instrument vibration is also measured using sound level meters.

How are machine vibration parameters determined?

The vibration parameters of machines are determined according to technical documentation for new machines, and for operating ones - according to actual measurements carried out at least once a year, as well as after repairs for all types of machines, and for manual ones - at least twice a year.

What is the permissible contact time for a worker with a vibrating tool or in the workplace with a machine that does not meet the requirements of sanitary standards?

The contact time of workers in this case depends on the amount of excess of permissible levels of sanitary standards and corresponds to the following values ​​(Table 9).

Table 9. Allowable contact time for workers with vibrating tools that do not meet sanitary standards

Excess of permissible vibration velocity levels in octave frequency bands relative to sanitary standards, dB	Allowable total vibration activity per work shift, min
	manual machines	workplace
Up to 3 (1.41 times)
Up to 6 (2 times)
Up to 9 (2.8 times)
Up to 12 (4 times)

To eliminate the influence of harmful vibrations on a worker, it is necessary to maintain the ratio of the duration of exposure to vibration and the performance of other operations not related to it, at least 1:2. For example, if the sanitary standards for vibration of a manual machine exceed 9 dB, it is advisable to establish a procedure for operating the machine for 10 minutes with periods of other types of work for 20 minutes each, that is, 10 + 20 + 10 + 20 + 10 + 20 + 10 = 100 minutes. During the rest of the working time (480-100 = 380 min) work not related to vibration should be carried out.

What are the requirements for vibrating equipment?

Vibrating equipment includes powered tools, mechanisms, manual controls, devices or workpieces, during operation of which vibrations occur that exceed 20% of the maximum permissible sapitary standards.

Only equipment, tools, mechanisms or devices that are in good working order, within the limits of permissible wear and tear, should be allowed for operation.

After repair, equipment and machines that generate vibrations are checked for vibration compliance with sanitary standards before being put into operation.

It is prohibited to use vibrating equipment in modes other than those specified in the nameplate if the resulting vibrations transmitted to the workers’ hands and pressing forces exceed sanitary permissible standards.

What are the requirements for operating personnel of vibrating equipment?

Persons at least 18 years of age who have completed training are allowed to work with vibrating equipment. medical examination who have the appropriate qualifications and have passed the technical minimum according to the rules for safe performance of work.

It is prohibited to allow persons suffering from cardiovascular diseases, an active form of tuberculosis, peptic ulcer disease, vegetative-endocrine disorders, functional disorders of the peripheral and central nervous system, mental illness, diseases of the musculoskeletal system, diseases of the middle and inner ear, chronic liver diseases.

When working with vibrating equipment that meets the requirements of sanitary standards, the total time of contact with vibrating surfaces should not exceed 2/3 of the working day. Under this working regime, if other factors of working conditions comply with sanitary standards, the lunch break should be at least 40 minutes and two regulated breaks are established for active rest, industrial gymnastics and physical prophylactic procedures: 20 minutes 1...2 hours after the start of the shift and 20...30 minutes 2 hours after the lunch break.

Overtime work with vibrating equipment is prohibited.

Work with vibrating equipment is carried out, as a rule, in heated rooms with an air temperature of at least 16°, with a humidity of 40...60% and a movement speed of no more than 0.3 m/s.

When working in the cold season in unheated rooms or in the open air, for periodic heating, workers must create heated rooms with an air temperature of 22 ° C at a speed of no more than 0.3 m/s and a humidity of 40...60%.

Local heating is provided at workplaces. Those working with power tools are provided with individual vibration protection equipment.

All workers involved in work with vibrating equipment undergo periodic examinations once a year with the participation of doctors: a therapist, a neurologist, an otolaryngologist, and, if indicated, other specialists.

Workers who show even initial signs of vibration disease are transferred to work that is not associated with exposure to vibration and noise.

To prevent vibration disease, it is recommended to periodically use workers in other operations that do not involve exposure to vibration. For this purpose, complex teams are being introduced at repair enterprises, where its members, when performing production processes alternate jobs.

Lecture 10

PRODUCTION VIBRATION

Lecture outline:

1. Classification of industrial vibrations.

2. Impact of vibration on human health.

3. Standardization of industrial vibrations.

4. Ways to reduce industrial vibration.

Classification of industrial vibrations

Vibration is small mechanical vibrations that occur in elastic bodies under the influence variable forces. All types of equipment that have moving components, transport, create mechanical vibrations. The increase in speed and power of technology has led to a sharp increase in vibration levels.

A person feels vibration in the range from fractions to 1000 Hz. Vibration more high frequency perceived as a thermal sensation

The impact of vibration on humans is classified:

According to the method of vibration transmission to a person,

According to the direction of vibration.

According to the time characteristics of vibration.

According to the method of transmission of vibrations to a person, a distinction is made between general, transmitted through supporting surfaces to the entire body, and local, transmitted to the hands or feet of a person.

According to the direction of action, vibrations are subdivided in accordance with the direction of the orthogonal coordinate axes X o, Y o, Z o for general vibration and X l, Y l, Z l for local vibration.

According to the time characteristics, they are distinguished constant vibration(the monitored parameter changes no more than 2 times during the observation period) and unstable vibration.

Basic vibration parameters: oscillation amplitude (m) - the magnitude of the greatest deviation of the oscillating point from the equilibrium position, oscillation period (s) - the time between two successively identical states of the system, frequency (Hz), associated with the period by a known ratio, vibration velocity (m/s) , vibration acceleration (m 2 /s)

Impact of vibration on human health.

General vibration is more dangerous than local vibration, as it causes shaking of the entire body. Initially, headaches, sleep disturbances, and fatigue appear. With prolonged exposure to vibration, vibration disease develops: the activity of the nervous system, blood vessels, organs of vision, hearing, and vestibular apparatus is disrupted, dizziness, drowsiness, stomach diseases occur (since under the influence of vibration the secretion of gastric juice increases), and destructive damage to the joints occurs.

General vibration is especially dangerous when the frequencies coincide external influences with the natural vibration frequencies of human organs (resonance phenomenon), because the vibration amplitudes increase sharply and there may be mechanical damage to these organs. For abdominal organs and chest natural frequencies lie in the range of 6-9 Hz, for the head - 25-30 Hz, for the eyes - 60-90 Hz.

General vibration with a frequency of less than 0.7 Hz does not lead to vibration sickness. The consequence of such vibration is seasickness, caused by disruption of the normal activity of the vestibular apparatus.

Electric train drivers, drivers of earth-moving and agricultural machinery, operators of pumping and compressor stations, and power plants are exposed to general vibration.

Local vibration causes a deterioration in the blood supply to the hands and, as a result, salt deposition, deformation and decreased mobility of the joints. The wrist, elbow and shoulder joints suffer the most, but in addition, the entire body is affected: pain appears in the heart and lower back. Those working with hand-held power tools are exposed to local vibration. When exposed to low-frequency vibration, the disease occurs after 8-10 years, when exposed to high-frequency vibration (above 125 Hz) - after 5 or less years.

Standardization of industrial vibrations

There are hygienic and technical standardization of vibrations. Hygienic standards - limit the vibration parameters of workplaces and the surface of contact with the hands of workers, based on physiological requirements that exclude the possibility of vibration disease. Technical – limit vibration parameters not only taking into account the specified requirements, but also based on what is currently achievable for of this type vibration level equipment.

Hygienic standards for vibration load at workplaces are established in GOST 12.1.012-90 “SSBT. Vibration safety. General requirements", sanitary standards SN 2.2.4/2.1.8.556 - 96 "Industrial vibration, vibration in residential and public buildings." The documents establish the classification of vibrations, methods of hygienic assessment, standardized parameters and their valid values, labor regimes for persons in vibration-hazardous professions, requirements for ensuring vibration safety and vibration characteristics of machines.

In the hygienic assessment of vibrations, the normalized parameters are the root mean square values ​​of vibration velocity or vibration acceleration. But, since absolute values vibration velocities vary over a very wide range; in practice, a logarithmic vibration velocity level is used:

L v =20lg V/ V o (dB)

where V is the measured value of vibration velocity, m/s,

V o =5 *10 -8 m/s – the lowest value of vibration velocity that a person begins to feel.

The vibration frequency spectrum is divided into octave bands with geometric mean frequencies:

For general vibration 1,2,4,8,16, 31,5.63.

For local 1,2,4,8,16, 31.5, 63,125,250,500,1000.

Vibration affecting a person is normalized separately in each octave band separately for general and local vibration.

General vibration is normalized taking into account the properties of the source of its occurrence and is divided into categories:

Category 1 - transport vibration affecting the operator at the workplace of self-propelled and trailed machines and vehicles when they move across the terrain, agricultural background and roads, including during their construction;

Category 2 - transport and technological vibration affecting the human operator at the workplace of machines with limited mobility when moving them along specially prepared surfaces of production premises, industrial sites and mine workings;

The normalized parameters of vibration load are the root mean square values ​​of vibration velocity and their logarithmic levels for local vibrations in octave frequency bands, for general vibration in octave or third octave bands

Hygienic vibration standards according to GOST 10.1.012-90

Table 8.1.

Type of vibration	Permissible level of vibration velocity, dB, in octave bands with geometric mean frequencies, Hz
						31,5
General transport:
vertical								-	-	-	-
horizontal								-	-	-	-
Transport and technological "								-	-	-	-
Technological	_							-	-	-	-
In production areas where there are no machines that generate vibration	_							-	-	-	-
In office premises, health centers, design bureaus, laboratories								-	-	-	-
Local vibration			-

The reason for the excitation of vibrations is the unbalanced force effects arising during the operation of the machine. Their sources in the compressor installation are: poor balancing of rotors, wear of bearings, uneven gas flow.

The range of human vibration sensitivity is from 1 to 12000 Hz with the greatest sensitivity from 200 to 250 Hz.

Vibration standards are defined in SNiP 2.2.4/2.1.8.566-96 “Vibration. General safety requirements.” The permissible vibration level at the operator's workplace is 0.2 dB. The root mean square value of the vibration velocity is no more than 2 mm/s.

The vibration safety of a machine is assessed based on monitoring its vibration characteristics. The normalized parameters of the vibration characteristic are the root-mean-square value of the vibration velocity or the corresponding logarithmic level (dB) and the level of vibration acceleration (dB) - for local vibration in the octave frequency band, and for general vibration in the octave or one-third octave band.

To ensure that the impact of vibration does not worsen the well-being of the worker and does not lead to the appearance of vibration disease, it is necessary to comply with the maximum permissible level of vibration (MAL). MPL is the level of a factor that, when working daily (except weekends), but not more than 40 hours a week during the entire working period, should not cause diseases or health problems. Compliance with vibration limits does not exclude health problems in hypersensitive people.

To reduce vibration, the following parts and work are provided in the design of the compressor unit:

Dynamic balancing of rotors over the entire operating range on a stand with a vacuum chamber;

Application of AMP bearings;

Application of vibration damping.

Vibration can be combated both at the source of its occurrence and along the path of its propagation. To reduce vibrations in the machine itself, it is necessary to use materials that have a high internal resistance. To combat vibration in accordance with GOST 12.1.012-90 “Vibration safety. General requirements", the installation is placed on a block foundation, which should not be connected to the foundation of the room. The mass of the foundation for the compressor is selected in such a way that the amplitude of vibrations of the base of the foundation does not exceed 0.1-0.2 mm, which corresponds to permissible norm according to “Vibration standards. General requirements."

To protect a person from vibration, it is necessary to limit the vibration parameters of workplaces and the surface of contact with the hands of workers, based on physiological requirements that exclude the possibility of vibration disease. Hygienic standards for vibration are responsible for this, which are established for the duration work shift 8 o'clock.

Standardized parameters:

The root mean square value of the vibration velocity or the corresponding logarithmic level - , determined by the formula:

Where - speed threshold value.

The level of vibration acceleration - , determined by the formula:

Where - acceleration threshold value.

The values ​​of speed and acceleration are determined by the formulas:

where a – displacement, m, f – vibration frequency:

Where - operating frequency rotor rotation.

Hygienic standards have been established (vibration velocity level) for process vibration that occurs when working in a production facility with vibration sources (category 3, technical type– a) (when operating stationary machines) in the octave range with a geometric mean frequency value of 1000 Hz should not exceed 109 dB. Such a high permissible value of the vibration velocity level was chosen because the installation is located in an underground bunker, where personnel enter several times a year for maintenance. installation maintenance.

Reasons causing noise during operation of a compressor unit:

The flow of gas in the flow part of the compressor causes aerodynamic noise, which arises due to flow heterogeneity and the formation of vortices;

Gas flow in compressor pipes and pipelines;

Rotating impeller blades and other rotating parts.

The nature of the noise is broadband with a continuous spectrum more than one octave wide.

According to the time characteristics, there is a constant sound level, which changes during a shift by no more than 5 dB when measured on the time characteristic of a “slow” sound level meter according to GOST 17187-81 “Sound Level Meters. General Technical Requirements and Test Methods”.

Noise should not exceed its maximum limits. The standards establish sound pressure limits in octave bands, as well as sound levels depending on:

1. type of work;

2. duration of noise exposure per shift;

3. the nature of the noise spectrum.

The maximum permissible noise level (MAL) is the level of a factor that, during daily (except weekends) work, but not more than 40 hours a week during the entire working period, should not cause diseases or health problems.