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Noise Reduction Activities

1. Architecture and planning

Functional reconstruction of the settlement;

Rational layout of the residential area - use of the protective effect of residential and public buildings close to the source of noise. At the same time, the internal layout of the building means that the living area of ​​the apartment is directed towards the quiet side of the sleeping and other rooms, and that the rooms in which the person is located - kitchens, bathrooms, stairs - are directed to the road;

To create conditions for continuous movement of vehicles by regulating traffic-free traffic (highlighting traffic intersections at different levels, underground pedestrian crossings, one-way streets);

Establishing bypass roads for public transport;

Landscaping of a residential area.

2. Technological

Modernization of vehicles (reduction of engine noise, operating equipment, etc.);

The use of engineering screens - paving the highway or railway into a recess, creating wall screens from various wall structures;

Reduce sound leakage through window openings in residential and public buildings (use of sound insulation materials - seals made of sponge rubber in the narthex of the windows, installation of windows with triple binders).

3. Administrative and organizational

State supervision of the technical condition of vehicles (monitoring compliance with maintenance requirements, mandatory regular inspection);

Monitoring the status of the road.

Test tasks

SELECT ALL RIGHT ANSWERS

1. LEARN FROM A LAND PLAN OPTION TO MAKE A PLACEMENT

1) Land

3) the presence of water and green areas

4) the nature of the soil

5) Population

2. BASIC REQUIREMENTS FOR PLANNING THE PLACEMENT ITEM

1) placement of functional areas in the region, taking into account the wind rose

2) Functional zoning of the region

3) Ensuring sufficient soil level

4) provide convenient communication routes between separate parts of the city

5) Sufficient number of tall buildings

3. THE FOLLOWING AREAS ARE PLACED IN THE CITY TERRITORY

1) Housing

2) Industrial

3) Service and storage

4) Center

5) commuter

4. TYPES OF PLANNING POPULATIONS

1) Environmental

2) Lower case

3) Mixed

4) spider web

5) Free

5. THE FOLLOWING CONDITIONS FOR PLACING THE INDUSTRIAL AREA

1) Consider the wind rose

2) Arrange a sanitary protection zone

3) take into account the land

4) to take into account the population

5) Under the city along the river

6. ACCOMMODATION IN THE HOUSING AREA

1) Residential areas

2) trade warehouses

3) Management center

4) Parking lots

5) Forest park

7. THE MOST IMPORTANT HYGIENIC FOUNDATIONS OF URBAN PLANNING IN OUR COUNTRY

1) Region for settlement state

2) restriction of growth of large and large cities

3) Possibility of landscaping

4) Functional zoning status of the city

5) Use of climate factors

8. FOREIGN AREA COMPULSORY

1) Location of industrial enterprises

2) the rest of the population

3) location of public services

4) organization of forest zone

5) placement of transport nodes

9. Determine the type of settlement development

1) Land

2) wind regime of the region

3) Population

4) the presence of green areas

5) Location of roads

10. INSUFFICIENT PERIMETRAL BUILDING

1) Difficulty in providing good conditions for insulating houses

2) difficulty in regulating the ventilation of the area

3) Ring discomfort

4) difficulty organizing the inner zone of the micro border

5) unavailability in large cities

RESPONSE STANDARDS

1. 1), 2), 3), 4)

3. 1), 2), 3), 5)

7. 1), 3), 4), 5)

9. 1), 2), 4), 5)

HYGIENE HOUSING

According to WHO experts, people spend more than 80% of their time in non-production rooms. This indicates that the quality of the indoor environment of the facility, including the home environment, can affect human health. Sanitary requirements for housing regulated by SanPiN 2.1.2.2645-10 Sanitary and epidemiological requirements for living conditions in homes and buildings; SanPiN 2.2.1./2.1.1.2585-10, modification. and add. 1 - SanPiN 2.2.1 / 2.1.1.1278-03 Hygienic requirements for natural, artificial and combined illumination of residential and public buildings.

The source of structural noise may be equipment operating on roofs and walls of buildings (ceiling boiler rooms, outdoor condenser units, air handling units, antenna amplifiers for cellular communication, etc.), Technical floors (ventilation and cooling equipment, pipelines and ducts, metal Internet cabinets). . inside buildings (garbage canals, elevator equipment, heating and water supply systems, sewerage, air conditioning). However, in residential buildings (power plants, engineering and technological equipment, transformer substations), in the basements of buildings (pump and lift units of separate heating units (ITP), ventilation rooms, engine rooms of refrigerators) and structural noise sources and adjacent to a residential building. apartments (washing machines, vacuum cleaners, various equipment).

Generally, after residents have contacted Rospotrebnadzor authorities, vibration and noise levels in the room are measured. If necessary, for example, a source of noise using “noisy” equipment (restaurants, cafes, shops, etc.). SN 2.2.4 / 2.1.8.562-96 Rospotrebnalzor authorities have ordered the noise source owners if excessive vibration and noise levels are exceeded according to gürültü noise in workplaces, residential buildings, public buildings and residential buildings ”. Eliminate detected health legislation violations and eliminate the need to take special measures to reduce vibration and structural noise from equipment.

How can I reduce the noise from the above equipment to avoid complaints from the residents while working? Of course, the ideal option is to provide the necessary measures at the design stage of a residential building, then the development of noise reduction measures is always possible, and its construction applications are ten times cheaper than those already built. As a rule, they design low-noise equipment when designing and remove noise as much as possible from normalized rooms. The formation of vibration isolating structures is reduced to selecting a vibration isolation scheme, selecting parameters and types of vibration isolators according to known data, selecting a floor structure on an elastic basis (if necessary) and calculating the effectiveness of this design (vibration isolation).

The situation is completely different if the building is already built and has noise sources that exceed current standards. Then, often, the noisy units are replaced with the less noisy ones and take measures for the vibration isolation and communication that leads to the units. We will then consider specific noise sources and precautions for vibration isolation of the equipment.

Noise from air conditioner

Let's give an example. After a chiller was installed on the roof of the building (from the English chiller), which was used for heating or cooling the liquid in the air conditioning system, without vibration isolation measures, the noise level infiltrating the apartment on the last floor of the capital, at 39 dBA, was higher than allowed. CH 2.2.4 / 2.1.8.562-96 to 14 dB and in the presence of the upper technical layer! When the coolant is mounted to the frame by means of a vibration isolator to the frame and rubber seals on a frame on the reinforced concrete slab (when the reinforced concrete slab is mounted on the spring vibration isolators on the roof of the building), the use of three-connection vibration insulation.

Another example The noise level entering the apartment on the last floor was 35 dBA. The apartment was placed under the ventilation unit, under the expansion chamber and under the channel on the technical floor. The noise level, which is 3-7 m away from the ventilation unit and the room in the living room, has dropped to 30-32 dBA. To further reduce noise, it is necessary to strengthen the noise vibration insulation of the air duct walls and to place a silencer on the air duct of the ventilation unit (from the side of the plant), to attach the ventilation chamber and air ducts to the ceiling by means of vibration insulation suspensions and gaskets.

Ceiling boiler room noise

In order to prevent the noise of the boiler house on the roof of the house, the base plate of the roof boiler house is installed on spring vibration isolators or a vibration isolating mat made of special material. Pumps and boilers in the boiler room are mounted to vibration isolators and soft tips are used.

Pumps in the boiler room must not be installed with the engine switched off! They must be installed so that the load from the pipelines is not transmitted to the pump housing. However, the noise level is higher than a pump with a higher power or if several pumps are installed. To reduce noise, the boiler room base plate can also be fitted with spring dampers or high-strength multilayer rubber and rubber metal vibration isolators.

Six boxes with Internet equipment were installed in one of the three cellular companies in one of the residential houses on the roof above the apartment. The landlady was harassed by noise and vibration. The woman woke up at night and could not sleep until morning. In the afternoon, the sounds decreased, but the headache remained the feeling of complete deterioration. The mistress of the “bad apartment adı did not immediately find the sound source. Apparently, this "vacation" was arranged for him by the management company and allowed the mobile operator to set up three Internet providers at once on the roof of a residential building.

However, you can feel noise and vibration even with a ventilation system operating inside the unit when installing amplifiers on the upper floors, lofts and technical floors of the apartments. Often, the fan becomes a source of sound and vibration in the amplifier. To prevent the vibration of a metal cabinet from being transmitted by a locking device, the latter must be installed on the vibration isolators.

Floating floors without special vibration isolators are recommended for use only with equipment with an operating frequency of at least 45-50 Hz. These are usually small machines where vibration isolation can be achieved by other means. At such low frequencies, the efficiency in an elastic base is small, so they are used only with other types of vibration isolators.

It is forbidden to design the elevator engine room floor as a continuation of the ceiling of the living room upstairs. Such a situation was identified by the complaint of the inhabitants of Moscow's apartments. Excessive noise during operation of the elevator was 15 dBA and no effective measures were taken to separate a single plate - the floor in the engine room and the ceiling that served as the ceiling of the room.

In one of the capital's residential buildings, during the measurements, the noise level entering the apartment from the elevator unit in the basement to the apartment in the basement exceeds the permissible levels for the night. Turns out the pipelines went under the living room. It is understood that the equipment of the elevator unit is installed considering the vibration isolation coming from the building support structures, the pipelines are thermo-sound insulated. What is the reason? The truth is that the elevator nodes should not be attached to the wall, the continuation of which is the wall of the living room. If the mines have pipelines of sewage and water supply systems, the first one should not be adjacent to rooms that require noise protection.

Currently booster systems (pumps) are as economical, efficient and quiet as possible. They play the role of pressure booster stations in water supply systems. Hydrophore plants create the required water pressure in high buildings, low pressure residential areas, industrial production processes, ie where the existing pressure is insufficient. The compact design significantly reduces installation space, operating costs and capital investment by enabling both the equipment of the facilities under construction and the modernization of existing facilities. The amplifier unit is very profitable compared to analogs. Tenants and inhabitants of lower floors often complain about the sound and vibration of working pumps. When using a support unit, there is no such problem.

The present regulations prohibit the placement of a roof boiler room on the ceiling of residential buildings (since the ceiling cannot be the basis for the boiler room) and adjacent to these buildings. It is forbidden to establish roof boiler rooms in dormitory buildings of recreation facilities and sanatoriums, in the buildings of children's schools and preschool institutions, in the medical buildings of polyclinics and in hospitals that stay in hospitals for 24 hours. When installing equipment on the ceiling and ceiling, it is recommended that it be located as far away from protected objects as possible.


Noise from Internet equipment

According to the recommendations regarding the design, communication and transmission of the information systems, it is recommended to install antenna antennas for cellular communication in a metal cabinet with a locking device in the attic technology. upholstery of the upper floors or stairwells. Paragraph 5.18 of these recommendations states that if home risers need to be installed on different floors of multi-storey buildings, they should be placed in metal cabinets at a height of more than 2 m from the base of the cabinet to the floor, in the immediate vicinity of the riser below the ceiling.

Output - vibration isolators and "moving" floors

For ventilation, cooling equipment on the technical floors of residential buildings, in hotels, multifunctional complexes or near noise-regulated rooms where people are constantly staying, you can install the units on a concrete slab to factory vibration isolators. In a technical room, this plate springs onto a vibrating insulating layer or a "sliding" floor (additional concrete plate to a vibrating insulating layer). It should be noted that the fans of the external condenser units being manufactured are equipped with vibration isolators only at the customer's request.

The screed of the floating floor must be carefully insulated from the floorboard and walls, since the formation of small bridges between them can greatly impair the vibration isolation properties. With this in mind, measures have been taken to prevent concrete from penetrating into the elastic layer while forming a "sliding" floor. Where the "floating" floor touches the walls, there shall be a waterproof seam made of non-hardening material.

Noise from the gutter

The trash can is a potential source of daytime noise. Most often occurs during the disposal of household waste containing soft and hard objects, including bottles and cans. The garbage chute body is generally made of pipes with a nominal diameter of about 400 mm. The complaint of noise from the trash can include not only the apartment occupants adjacent to the trunk and the trash room of the rooms, but also apartments on all floors of the staircase (even the houses of the P-44 series) where the trunk passes adjacent to the apartment. The maximum noise level that enters the apartment when hit by gutter and drain glass containers can reach 58 dBA.

In order to reduce noise, you must comply with the requirements of the norms and not design the trash trunk body near the settlements. The body of the garbage chute should not be in contact with the walls surrounding residential or office buildings with standard sound levels.

The most common measures to reduce the noise of garbage channels are:

The garbage collection rooms have a “floating taban base;
with the agreement of all residents of the entrance apartments, garbage chute, baby carriage trash rooms, a concierge room, etc. (or eliminated). (The positive point is, in addition to noise, the elimination of odors, the possibility of the emergence of mice and insects, the possibility of fire, dirt, etc.);
the loading valve bucket is mounted with framed rubber or magnetic seals;
The decorative coatings of the body of the garbage gutter are separated from the building structures of the building by sound-proof gaskets, with heat and sound protection properties from the building materials.

Today, many construction companies offer various designs to increase their services, sound insulation of walls and promise complete silence. In fact, it should be noted that no structures can eliminate structural noise from floors, ceilings and walls when disposed of in solid waste trash.

Noise from Elevators

The noise and vibration sources during the operation of the elevator are the units in the elevator shaft and in the engine room. The first includes car and counterweight shoes (especially when passing rail connections) sliding along the rails, switches and car and shaft door openers, and the second includes lifting cranes, control panels and transformers. The noise of the elevator entering the office and living areas is the sum of the air and structural components.

SP 51.13330.2011 “Protection against noise. The updated version of SNiP 23-03-2003 says that the elevator shaft is optimally located between the stairs in the stairwells (paragraph 11.8). For architectural solutions of residential buildings, it is necessary to ensure that rooms (corridors, halls, sanitary facilities, kitchens) that do not require further protection against vibration and noise are adjacent to the built-in elevator shaft. Regardless of the layout, all elevator spaces must be self-supporting and have an independent foundation.

Mines should be separated from the rest of the building structure with an acoustic seam of 40-50 mm or with vibration-proof seals. As a material of the elastic layer, plates made of mineral wool on a glass fiber or basalt base and various polymer foamed roll materials are proposed.

To protect against the structural noise of the elevator installation, the drive motor with crane and gearbox as a rule fitted to a single common frame is vibration-insulated from the support surface. The modern drive units of the elevators are equipped with suitable vibration isolators located under the metal frames where cranes, motors and gearboxes are mounted and therefore no additional vibration isolation of the drive unit is required. It is also recommended to install a two-stage (two-link) vibration isolation system by installing a support frame via vibration isolators on a reinforced concrete slab separated from the floor by vibration isolators.

The operation of elevator cranes mounted on two-stage vibration isolation systems has shown that the noise levels from them do not exceed the normative values ​​in the nearest residential areas (over several walls). For practical purposes, you must ensure that the vibration isolation is not violated by any rigid bridge between the supporting surface and the metal frame. However, the operation of other elevator installation elements (control panels, transformers, cabin and counterweight shoes, etc.) may accompany noise above standard values.


Noise from substations on ground floors

It is forbidden to install transformer substations in designed, newly built and reconstructed residential buildings. This SP 54.13330.2011 “Finance multi-apartment buildings. SNiP 31-1-2003 ”updated” (paragraph 4.10). In the basement, in the basement, on the 1st and 2nd floors of buildings, appendices of magnetic resonance imaging and built-in substations, cabinets are not permitted (paragraph 4.10).

MGSN 2.04-97 Handbook 7.4. As stated in the paragraph ası Designing protection against noise and vibration of engineering equipment in residential and public buildings ”, transformers of transformer substations built into buildings are sources of vibration that cause structural noise to spread to buildings. 100 Hz frequency.

To protect this noise from dwellings and other rooms with standard noise levels, the following conditions must be observed:

the buildings of the built-in substations must not come into contact with noise-protected buildings;
built-in substations must be located on ground floors or in the basements of buildings;
the transformers must be installed in properly designed vibration isolators;
electrical panels with electromagnetic communication devices and electrically driven separately mounted oil circuit breakers must be mounted on rubber vibration isolators (air separators do not require vibration isolation);
internal transformer The ventilation devices in the substation shall have a silencer.

Another way to reduce noise from the internal transformer transformer is to treat the ceiling and interior walls with a sound-absorbing liner.

Today, built-in substations connected to residential buildings using dry transformers have ”exceptional” placement situations. Acoustic calculations have been made in the projects of these built-in substations, which show that there will be no increased structural noise adjacent to the transformer locations when taking the following measures:

double \ u200b \ u200bflexing device;
use of sound-absorbing coating;
installation of transformers, cabinets and panels in vibration isolators;
installation of silencers in ventilation holes.

And not all of these measures, as a rule, give a hundred percent reduction in vibration and structural noise. After commissioning the substation in a building on the second floor, the noise from the transformers can disturb and disturb the inhabitants of the house by closing not only adjacent apartments but also the entire entrance. Please note that the internal transformer substations must be protected against electromagnetic radiation (a special grounded material grid to reduce the radiation level of the electrical component and steel sheet for magnetic).

Noises from shop, restaurant or cafe work in a residential building

Elevators, elevators, conveyors, car movements, refrigeration compressors in built-in stores and catering establishments on the ground floor generate structural noise from the building structures. Sounds from the movement of mechanical elevators and elevators of high-rise buildings are heard on all floors up to the tenth floor.

Sanitary and epidemiological requirements for commercial organizations and the circulation of food raw materials and food products değişiklik (amendment and addition) states that commercial establishments in residential or other buildings are not allowed to equip machinery. Compartments, forklifts, cold rooms (below) are right next to the living rooms (Section 5.1). Therefore, for example, in one of the Moscow apartments, structural sound was emitted from the wall adjacent to the apartment, from the commercial floor of the store. According to residents' complaints about the daytime noise in the shop on the ground floor, a number of measures were taken to improve the sound insulation of the adjacent wall. The wall cladding and thickness increase with the sound-absorbing material provided a negligible noise reduction effect. Worktops, refrigerated cabinets, car wheels and so on. - with vibration isolation of all technological equipment of the store. - Drilling sound levels in an apartment have dropped to an acceptable level at night.

In another store, while the trams were moving for customers without vibration isolation, the noise level in the second floor apartment was 48 dBA, which was 3 dBA higher than the standard (45 dBA for maximum noise). After applying tires to the car wheels, the sound level in the apartment decreased by 6 dBA. In 2015, SES magazine spoke in detail about noise reduction measures in stores, cafes and restaurants on or near the ground floors of residential buildings.

Noise from connected boiler rooms, basement pumps and pipes

The attached boiler rooms are used for the heat supply of public, household, industrial, administrative and residential buildings. Equipment of boiler rooms (pumps and pipelines, ventilation units, air ducts, gas boilers, etc.) must be vibration-insulated using vibration bases and soft inserts. The ventilation units are equipped with silencers.

Mounts the pumps in the basements, lift units (ITP), ventilation units, refrigerators, vibration isolation equipment at the specified vibration bases. Pipelines and air ducts are vibration-insulated from smoke structures because the dominant noise in the above apartments may be the noise transmitted to the building envelope through the vibration of pipelines and equipment foundations, not the basic noise from equipment in the basement. It is forbidden to arrange built-in boiler room in the houses.

In piping systems connected to the pump, flexible ends - rubber fabric hoses or rubber fabric hoses reinforced with metal spirals must be used. If there are pipe sections between the flexible end and the pump, the sections must be secured to the ceilings and walls of the room with vibration-proof supports, suspensions or shock-absorbing gaskets. The flexible tips must be located at the closest distance to the pumping unit, both in the suction line and in the discharge line.

In order to reduce the vibration and noise levels in residential buildings from the operation of heat supply systems, it is necessary to isolate the distribution pipelines from the building structures where they pass through the support structures (entering and leaving buildings). The clearance between the pipeline and the foundation at the inlet and outlet must be at least 30 mm.

It is also recommended to establish a regulation mechanism for the rotational frequency of the electric motor in ITP, which is built-in pumping. This measure will have a tangible effect if a pump with a power reserve is selected or if maximum power operation is required only during peak hours.

Which pumps are very important in water supply systems. Multi-pump, cantilever and cantilever monobloc units are used to increase the pressure of the fluid flow and to circulate for a long time during the supply of cold and hot water in industrial and residential buildings, but have some disadvantages. To install such a unit, it is necessary to provide a great basis for reducing the vibration level. Aggregates produce increased noise. For the normal operation of such equipment, it is necessary to install a drainage system to drain water that begins to leak through seals that need regular replacement and monitoring over time. When worn, the oil enters the pumped water which is unacceptable to sanitary standards. Operation of the unit requires systematic technical control and trained service personnel.

Noise from washing machines, vacuum cleaners and refrigerators

The noise generated by the operation of neighbors - washing machines, vacuum cleaners, refrigerators and construction tools during repair is temporary and is not subject to standardization and restrictions during use. Vibration isolation and ease of service control of these units are carried out by the owners.

An interesting example of the refrigerator's self-vibration isolation was given by one of the Internet users. In particular, he was concerned about the strong “vibrations buzdolabı of the refrigerator compressor when it was turned off, so he put several layers of polyethylene foam under the four legs of the unit. The result - the vibration became almost unnoticeable, but the noise increased, that is, the energy conservation law remained the law: if before the sound was created before the "shock absorbers" and went to the neighbor on the baseplate, then after creating the shock absorbers, half of the energy entered the "air" of the room refrigerator where.

Ph.D. LV Rodionov, head of research support department; PhD SA Gafurov, Senior Researcher; Ph.D. VS Melentiev, Senior Researcher; PhD AS Gvozdev, FGAOU VO Samara National Research University, Academician SP Koroleva ", Samara

In order to provide hot water and heating to modern apartment buildings (MKD), roof boilers are sometimes involved in projects. In some cases, this solution is cost effective. In this case, most of the time, proper vibration insulation is not provided during the installation of the boilers on the foundations. As a result, the residents of the upper floors are constantly exposed to noise.

According to the health standards in force in Russia, the sound pressure level in residential areas should not exceed 40 dBA - day and night 30 dBA - at night (dBA - acoustic decibel, unit of measurement of noise level taking into account human sound perception. - Ed.).

The experts at the Institute of Mechanical Acoustics at Samara State Aviation University (IAM at SSAU) measured the sound pressure level in the living room of the apartment under the roof boiler room. The source of the noise turned out to be exactly ceiling boiler room equipment. Although this room was separated from the roof boiler room with a technical floor, it was recorded that daily sanitary standards were exceeded at both the equivalent level and the octave frequency of 63 Hz (Figure 1).

Measurements were made during the day. At night, the boiler room operating mode remains virtually unchanged and the background noise level may be lower. Since the “problem ortaya appeared to be present throughout the day, it was decided not to take measurements at night.

Figure 1 . Sound pressure in the apartment compared to sanitary standards.
Localization of noise and vibration source

In order to determine the ”problematic” frequency more accurately, sound pressure level measurements were made in the different operating modes of the equipment in the apartment, boiler room and technical floor.

The most characteristic equipment operating mode in which a tone frequency appears in the low frequency zone is the simultaneous operation of three boilers (Figure 2). It is known that the frequency of boiler operation operations (internal combustion) is quite low and is in the range of 30-70 Hz.

Fig. 2 Sound pressure in various rooms during operation of three boilers simultaneously

Fig. Figure 2 shows that 50 Hz frequency prevails in all measured spectra. Thus, the main contribution to the spectrum of sound pressure levels in the studied rooms is made by the boilers.

The background noise level in the apartment does not change much when the boiler equipment is switched on (except for the frequency of 50 Hz), so it can be concluded that the sound insulation of the two floors separating the boiler room from the living rooms is sufficient to reduce the air noise level produced by the boiler equipment to sanitary standards. Therefore, you should look for other (not direct) noise propagation paths (vibration). Due to structural noise, a high sound pressure level at 50 Hz is likely.

In order to determine the source of structural noise in residential buildings and also to determine the ways of propagating vibration, vibration acceleration measurements were also performed in the boiler room, technical floor and also in the residential buildings of the upper floor.

The measurements were performed in the operating modes of the various boiler equipment. Sec. Figure 3 shows the vibration acceleration spectrum for a mode in which all three boilers operate.

Based on the measurement results, the following results are drawn:

- sanitary standards are not met in the top floor apartment under the boiler room;

- Increasing noise source in residential buildings is the combustion process in boilers. The dominant harmonic frequency in the noise and vibration spectra is 50 Hz.

- the lack of proper vibration insulation from the foundation causes the structural noise to be transferred to the floor and walls of the boiler room. Vibration is propagated both by the supports of the boilers as well as by the pipes which are transmitted to the walls and also to the floor; where there are hard ties.

- measures should be developed to combat noise and vibration along the spreading paths from the boiler.

a) b)
c)

Figure 3 . Vibration acceleration spectrum: a - at the bottom of the boiler room, at the bottom of the boiler room; b - on the support of the boiler's exhaust pipe and on the ground near the exhaust pipe of the boiler; c - On the wall of the boiler room, on the wall of the technical floor and in the residential area of ​​the apartment.
Development of vibration protection system

Based on a preliminary analysis of the mass distribution of the gas boiler structure and equipment, BMT-120 and VMT-60 cable vibration isolators with nominal load on a vibration isolator (VI) of 120 and 60 kg respectively were selected for the project. The vibration isolator circuit is shown in FIG. 4.

Figure 4 3D model of the cable vibration isolator of the VMT product line.


Fig. 5 Schematics for securing vibration isolators: a) support; b) hang; c) lateral.

Three options have been developed to fix the vibration isolators: support, suspension and side (Figure 5).

The calculations showed that the lateral installation scheme could be implemented using 33 economically unsuitable VMT-120 vibration isolators (for each boiler). In addition, very serious welding work is expected.

When applying the suspension scheme, the entire structure becomes more complex, because the large and very long corners must be welded to the boiler frame, which will be welded to several profiles (to provide the required mounting surface).

In addition, the technology of attaching the boiler frame VI to these slides is complex (it is not appropriate to install VI, it is difficult to position and center the boiler, etc.). Another disadvantage of such a scheme is the free movement of the vessel in the lateral direction (oscillation in the transverse plane on VI). The number of VMT-120 vibration isolators for this circuit is 14.

The frequency of the vibration protection system (VZS) is approximately 8.2 Hz.

The third, most promising and technologically simpler option is a standard reference circuit. 18 BMT-120 will require vibration isolator.

The estimated frequency of VZS is 4.3 Hz. In addition, the design of VI (a portion of the cable rings arranged at an angle) and their competent placement along the circumference (FIG. 6) allow in this diagram to sense the lateral load such that the vertical load for each load is about 60 kgf. each VI is about 160 kgf.


Fig. 6 Placement of the vibration isolators in the frame with reference circuit.
Design of vibration protection system

Based on the data of the static tests and the dynamic calculation of the VI parameters, a vibration protection system was developed for the boiler room of a residential building (Figure 7).

The purpose of vibration protection includes three boilers of the same design 1 mounted on concrete foundations with metal screeds; pipe system 2 for cold supply and removal of heated water and removal of combustion products; pipe system for gas supply to boilers 3.

The created vibration protection system includes the external vibration protection supports of the boilers 2 designed to support 4 pipelines; inner vibration protection belt of boilers 5 designed to isolate the vibration of boilers from the floor; External vibration protection supports 6 for gas pipes 3.


Figure 7 Overview of the boiler room with vibration protection system.

The main design parameters of vibration protection system:

1. The height of the power frames of the boilers is 2 cm (where the mounting tolerance is minus 5 mm).

2. Number of vibration isolators in each boiler: 19 BMT-120 (on the inner belt 18 carrying the weight of the boiler and 1 on the external support to damp the vibrations of the water pipe) and 2 VMT-60 vibration isolator for external supports, vibration protection of the gas pipeline.

3. The “support” type loading circuit works for compression and provides good vibration isolation. The natural frequency of the system is in the range of 5.1-7.9 Hz providing effective vibration protection in the region above 10 Hz.

4. The damping coefficient of the vibration protection system is 0.4-0.5, which provides a gain in a resonance of not more than 2.6 (the amplitude of the oscillations is more than 1 mm with an input signal amplitude of 0.4 mm) it is not).

5. There are nine seats for similar types of vibration isolators to adjust the horizontal position of the U-shaped profiles on the U-shaped profiles of the boilers. Only five nominally installed.

During installation, it is possible to place the vibration isolators in any order from the nine locations provided to achieve a combination of the center of mass of the boiler and the center of rigidity of the vibration protection system.

6. Advantages of improved vibration protection system: ease of design and installation, insignificant amounts of boilers rising from the ground, good damping characteristics of the system, possibility of adjustment.
Effect of using vibration protection system developed

With the introduction of the improved vibration protection system, the sound pressure level in the residential buildings of the upper floors has decreased to an acceptable level (Figure 8). Measurements were made at night.

From the graph in the figure. Figure 8 shows that health standards in the living room are met in the normalized frequency range and equivalent volume.

From the improved vibration protection system, the efficiency for measurements in a living room at a frequency of 50 Hz is 26.5 dB and 15 dBA for the equivalent sound level (Figure 9).


Figure 8 . Vibration protection system was developed by considering sound pressure according to sanitary standards in the apartment .


Fig. 9 Sound pressure in one-third octave frequency bands in residential buildings when three boilers operate simultaneously.
Result

The created vibration protection system allows you to protect a house equipped with a roof boiler from the vibrations created by the operation of gas boilers, while at the same time providing the piping system for gas equipment as well as a normal vibration operating mode that increases service life and reduces the likelihood of an accident.

The main advantages of the improved vibration protection system are the simplicity of design and installation, low cost compared to other types of vibration isolators, resistance to temperature and pollution, a small amount of boiler rising from the floor, good damping properties and adjustment capability of the system.

The vibration resistant system prevents structural noise from spreading from the equipment of the roof boiler house to the building structure, thereby reducing the sound pressure level in the houses to an acceptable level.


8AXX
SHARPER IMAGE Ultimate Sleep White Noise Sound Machine for Adults and Baby, Portable Relaxing Music and Nature Sounds Therapy, Aids Sleeping, Stress and Anxiety Relief [New 2019 USB Version]