Materials used in smoke exhaust pipes. Smoke exhaust ducts – how do they work? Features of installation of air ducts
Special white pipes and rotary bends for the device separate smoke removal from various gas boilers. Parts are made of aluminum alloy, painted in White color Made under high temperature with high quality powder enamel. It is equally installed for the removal of carbon monoxide and the flow of combustion air. Designed only for boilers with closed camera combustion on which it is installed various designs adapter or with pipes already present in the design.
Details for installing a split chimney 80/80:
Pipe with a diameter of 80 mm.
- Tube length 250 mm. = 300 RUR
- Tube length 500 mm. = 400 RUR
- Tube length 1000 mm. = 600 RUR
- Tube length 1500 mm. = Missing
- Tube length 2000 mm. = Missing
Bell assembly system included rubber compressor designed for high temperature exhaust gases from a wall-mounted boiler.
Bends and angles with a diameter of 80 mm.
- Bend with right angle 90 degrees = 450 rub.
- Bend with an oblique angle of 45 degrees = 450 RUR.
It is quite easy to assemble through a socket with a rubber cuff.
These are high-quality aluminum smoke removal systems for wall-mounted boilers with a closed combustion chamber, allowing them to be equipped with more than 80% of all known models of wall-mounted boilers from the world's largest manufacturers, including Electrolux, De Dietrich, Baxi, Ariston, Vaillant, Navien, Protherm and other well-known brands.
Separate smoke removal systems
How it works. Air intake and removal of fuel combustion products is carried out through two different pipes, each with a diameter of 80 mm. Due to the increased cross-section, the length of each channel can reach 20 meters. Also, due to their separate layout, such systems are ideal for apartment heating systems. To save money and space, modern houses with apartment system smoke removal systems have only one shaft - a smoke exhaust shaft, and the air intake is carried out from the facade of the building. This condition makes it impossible to use coaxial chimney in most buildings with apartment heating systems.
Protects against direct blowing of strong wind and the possibility of birds and rodents getting into the chimney system. It is installed on the carbon monoxide exhaust pipe and can also be used on the air intake. The connection takes place on the socketless part of the chimney and is fixed with a stainless steel self-tapping screw.
To make it even easier, you can purchase ready-made kits with a separate chimney, the kit will also draw air into the combustion chamber through one pipe and exhaust flue gases through the other. Pipe material is enameled aluminum (anti-corodalline) or uncoated aluminum. Typically, such systems are installed when the distance from the boiler to outer wall exceeds 5 m (the total length of the separate chimney pipes can be up to 30 m) or when separate air intake and smoke removal are necessary, for example in multi-storey buildings. The adapter included must be the one you need. heating equipment, or have the possibility of universal connection to different models gas boilers.
When a fire occurs, the greatest danger to human life is not fire and high air temperature, but smoke. Smog can provoke panic, disorient people and cause poisoning. In order to prevent such problems, smoke removal systems are installed in the premises, which can localize carbon monoxide, clean the room from fine particles dust and ash.
Smoke removal system is an important element of fire safety
The smoke removal system (SDS) is an emergency complex supply and exhaust ventilation, creating conditions for the evacuation of people in case of fire. The smoke protection system is part of the overall set of fire safety measures.
When the fire alarm is triggered, the fire ventilation is switched on. The system begins to actively remove combustion products and smoke from the source of fire, as well as prevent their spread to other areas of the room. Pressure fans direct clean air to fire exits and main exits, to flights of stairs and into elevators.
In accordance with building regulations, such installations must be installed in high-rise buildings (more than 10 floors) with fire safety class - B, rooms without natural ventilation, underground structures, prisons, hospitals and other institutions in which a large number of people are concentrated.
The smoke removal system performs the following tasks:
The fire ventilation system operates according to the laws of physics: cold air goes down in the room, and warm air rises up. Equipment for the removal of warm air will help curb the rise in temperature and reduce the negative impact of smoke on the human body.
The smoke removal system is an expensive complex, it specifications and expedient structure require special design.
Types of smoke removal systems: static or dynamic ventilation
Today, all smoke removal systems can be divided into static and dynamic complexes.
At static smoke removal an emergency shutdown of ventilation occurs. At the same time, the smoke does not “pass” to other areas of the room. This system is the most primitive and affordable. In fact, smoke removal as such does not occur; all smoke is localized in one room.
Dynamic system designed to remove smoke and fumes, as well as to influx fresh air. The operation of the complex is based on the use of fans that “pull” combustion products outside the room.
Dynamic complexes can operate on one fan operating alternately in different directions (smoke extraction or fresh air supply), on separate air supply and air supply fans, or on a combination of two axial fans.
The choice of smoke removal scheme depends on the design features of the building and the feasibility of implementing a particular project.
Based on the type of control, SDS are divided into automatic and semi-automatic systems.
Automatic smoke removal is associated with the facility’s security system, installation automatic fire extinguishing and fire alarm.
Buildings equipped big amount equipment and engineering systems, it is advisable to arrange automatic system smoke removal. Complete system fire extinguishing and smoke removal virtually eliminates the risk of fire and fire spread, giving a signal about the slightest equipment breakdown
Elements of the smoke removal system
Smoke removal is carried out through existing ventilation shafts, inner surface which are coated with a fire retardant compound. However, the use of separate communications with special fans and air ducts is considered more effective.
The dynamic smoke removal system consists of the following main elements:
Smoke extraction fans- large heat-resistant installations of increased power. Minimum consumption air - 20,000 m3/hour. Smoke extraction fans are capable of operating at very high temperatures.
The fan pumps out smoke and combustion products from the fire site. Some fan models perform two functions alternately: supply clean air and smoke removal. Smoke extraction fans are mounted on the roof of the building.
Air boost fans create excess pressure on staircases, in elevator shafts and airlock vestibules, excluding their smoke.
No less important element smoke removal systems - fire dampers. There are four categories of fire dampers:
Smoke hatches are mounted on the roofs of buildings and automatically open when a fire occurs. Rooflights can be used as such hatches, which normal conditions perform lighting and ventilation functions.
Ventilation ducts for smoke removal(shafts) - large cross-section air ducts made of black steel. The thickness of the material must be at least 1.2 mm - this increases the resistance of smoke exhaust ducts to high temperatures. 
Automatic systems are equipped with smoke detectors that are triggered when a fire appears and send a signal to turn on fans and fire dampers.
The principle of operation of the smoke removal system
Let's consider the working cycle of the smoke removal system step by step:
- There is a fire in the room - the smoke detector is activated.
- The signal from the sensor is sent to the control station.
- System general ventilation automatically switches off and all fire suppression valves close.
- In the fire zone, a valve opens in the smoke exhaust system to remove smoke.
- The smoke exhaust fan and the air supply fan are turned on at the same time.
Important! The smoke removal system is designed to “pump out” smoke from one source of fire. That is, all smoke is removed from one grille of the system (conditionally one, since each zone may have several grilles). On other floors and areas of the room, the fire dampers of the system will be closed
Calculation of fire ventilation system
Design of a smoke removal system
The requirements for the design and maintenance of smoke removal systems are quite high, so this work must be performed by design engineers. The company’s specialists will calculate smoke removal, prepare a detailed design, install and configure equipment, and also test the system.
When calculating and developing a smoke removal scheme, take into account following parameters premises:
- building construction material;
- number of storeys of the building;
- emergency evacuation plan;
- the state of the existing ventilation system;
- smoke permeability of the room;
- the presence and location of windows in the building;
- condition and material of insulation;
- type of interior and facade finishing.
All factors that can affect the speed of spread and amount of smoke during a fire are taken into account
The smoke removal project is drawn up based on building codes and rules that clearly state the minimum requirements for fire protection system ventilation. The main document regulating the design procedure is “Calculation determination of the main parameters of smoke ventilation of buildings” dated 2008.
Regulatory documents determine the capabilities of the smoke removal system:
- maximum number of people in the room;
- area of the building served.
The company carrying out the development and installation of a smoke removal system must have a License from the Ministry of Emergency Situations of Russia to carry out activities for the installation, maintenance and repair of fire safety equipment
Nuances of smoke removal design
When developing a project and installing a smoke removal system, experts recommend taking into account a number of fundamentally important points:
- integrity of smoke-permeable structures;
- placement of fire-resistant partitions in the overall ventilation scheme;
- the ability to test the smoke removal system with “cold smoke”;
- where air ducts pass through enclosing structures, it is necessary to install fireproof valves;
- in certain regions, seismic loads must be taken into account.
The layout of air ducts is significantly influenced by the location of fire-resistant partitions. Changes in the location of such a partition may entail rearrangement of the air distribution. This is especially true if a separate air supply unit is used in each room.
Cost of fire ventilation
Development of a smoke removal project and installation of the system will cost approximately 2,000 rubles/m2. The price will depend on the complexity of the project and the equipment used.
The smoke removal system costs 2-3 times more than a conventional ventilation system
The cost is calculated based on the following components:
Installation and adjustment of a smoke removal system
The initial stage of installation is laying welded air ducts in the room according to the developed plan. After this, the installation of fans begins. Axial, radial or roof fans can be used.
An important stage in the installation of smoke removal is the treatment of the shafts with a special coating that protects the complex from fire. After the required level of fire resistance on the air ducts has been achieved, fire dampers are installed - they are placed in shafts running under the ceiling.
Fastening of air ducts and placement of valves is carried out in strict compliance with the requirements of the working documentation
The final stage is connecting the automation, setting up and testing the smoke removal system.
When setting up the system, it is imperative to check the operation of the valves in manual and automatic modes, calculate the actual air flow (preferably separately for each zone), and check the fan rotation speed.
During the commissioning works it is necessary to give the fan a rest - at least one hour every 30 minutes
When checking the operation of booster fans, you need to pay attention to the following parameters:
- direction of rotation of the fan blades;
- operation of fire-retarding valves (manual and automatic control);
- fan pressure measurement;
- comparison of real pressure indicators with the specified aerodynamic characteristics of the fan.
By using measuring instrument using a differential pressure gauge, it is necessary to determine the excess pressure in elevator shafts, staircases and airlock vestibules.
The pressure difference between the street and the room must be at least 20 Pa - this means that the fan pressure complies with the established standards and the smoke removal system is designed correctly
Fire ventilation maintenance
A schedule is developed for each smoke removal system. Maintenance. Instructions for scheduled maintenance are provided by the manufacturer and installer of the system.
Timely maintenance eliminates the possibility of fire ventilation failure at the most critical moment. During a system check, you can identify problems in a timely manner and eliminate them, and replace some elements of the complex with more modern equipment.
Maintenance is carried out monthly and quarterly. Once a month the following work is performed:
- examination technical condition and alarm performance;
- technical diagnostics of devices;
- checking fastenings and external assessment of the condition of valves and equipment;
- trouble-shooting.
The quarterly inspection includes the following activities:
The results of each inspection must be recorded in a journal in the prescribed form.
It's safe to say that a smoke extraction system is vital to keeping people safe during a fire. The development and configuration of the system are determined at the design stage, the equipment must be certified, and the management and maintenance of the complex must comply with the established standards of the Russian Federation.
C.O.K. N 7 | 2005 Category: HEATING AND DHW
"Regional pipe and furnace company "GALS""
Comparative analysis smoke removal systems.
Currently, autonomous heating systems are becoming increasingly widespread, which, as a rule, use boilers with low flue gas temperatures. Issues of increasing efficiency and reducing emissions harmful substances are becoming more and more relevant. Another important issue is the safety of soot fires in smoke removal systems of fireplaces and other solid fuel heat generators. As a result, the main factors of gas removal have undergone significant changes.
For modern systems smoke exhaust systems are characterized by:
more low temperature waste gases;
high content of water vapor (due to the transition to liquid or gaseous fuel);
high dew point temperature (due to high CO2 content);
wide range of flue gas temperatures due to controlled operating technology of heating systems.
In this regard, old (brick) smoke systems become unsuitable for use in modern boiler houses, since:
insufficiently rapid heating of the chimney walls leads to the formation of acid precipitation in the chimney trunk, destroying it;
the cross-section of the smoke channel is not always commensurate with that required for the system;
soot formation increases due to surface roughness.
Taking this into account, the following requirements arise for modern smoke systems:
fire resistance;
acid resistance;
tightness;
quick heating of the chimney walls;
good thermal insulation of the structure;
speed and ease of installation;
smooth channel surface.
Modular chimneys made of ceramics and of stainless steel.
By type modern chimneys are divided into:
single-circuit (non-insulated) - used as liners in a brick chimney;
double-circuit (insulated) - consist of two layers: internal and external, between which insulation is laid (layer basalt wool), allowing to reduce the formation of condensation;
combined “air-combustion products” (LAS) - used with boilers with a closed combustion chamber, the internal circuit serves to remove combustion products, and the external circuit serves to supply air to the heat generator. Modular chimneys are simple and easy to install, durable, and aesthetically pleasing, which makes them indispensable when installed with any heat generator.
Technical characteristics of materials used for the production of modular chimneys:
profiled ceramics - thickness 6–14 mm, acid-resistant, heat resistance 1500°C (restores all characteristics after soot ignition);
stainless steel AISI 316 TI (1.4571) - thickness 0.5–2 mm, acid-resistant, heat resistance 1000°C;
stainless steel AISI 316 L (1.4404) - thickness 0.4–2 mm, acid-resistant, heat resistance 1000°C;
stainless steel AISI 304 TI (1.4301) - thickness 0.5 mm, heat resistance 700°C;
mineral basalt fiber ROCKWOOL, fire resistance - 1100°C, chemically resistant, environmentally friendly, thickness 25-100mm.
Main selection criteria
For chimneys of boiler houses operating on gas or diesel fuel, comparison of systems based on acid resistance and gas density is relevant. For stainless steel systems - according to the thickness and acid resistance of the material inner tube- in descending order of quality indicators: AISI 316 TI (1.4571) AISI 316 L (1.4404) AISI 304 TI (1.4301), as well as by thickness and quality of insulation. Qualitative characteristics chimney is a priority selection criterion.
Ceramic profiled pipe is comparable in acid resistance to the best steels. The use of sealants when gluing the elements of a chimney pipe allows us to ensure a high gas tightness of the system, suitable for conditions with excess pressure. The pipe manufacturing technology is also important, making it possible to make the channel even, without narrowing at the joints.
It should be noted that when operating stainless steel pipes from any manufacturer used with solid fuel heat generators, the question arises about the static stability and deformation of the chimney channel when soot ignites, and the subsequent operation of the chimney system.
In this case, ceramic pipes have an undeniable advantage, although many installers and builders avoid their use, since the time required for installation is greater than for installing a stainless steel chimney.
It is impossible not to note the importance of such a criterion as operating temperature, and, in connection with this, heat resistance smoke systems. With the advent of ceramic systems produced by Schiedel on the market in insulated chimney systems, direct competition arose between ceramics and stainless steel as materials for the production of chimneys, and the position of ceramic chimneys has strengthened significantly in Lately due to the appearance on the market of a universal UNI system comparable in price to stainless chimneys, but has advantages when operating with solid fuel heat generators.
Let's compare the main systems of chimney manufacturers
Schiedel
The Schiedel company is one of the most famous chimney companies in Europe, founded in 1946 by Senator Friedrich Schiedel in Erbach (Germany). Today, Schiedel belongs to the international concern LAFARGE and is the world's largest manufacturer of ceramic chimney systems. The company has developed many technical innovations.
The basis of the company's product line is ceramic chimney systems made of fireclay. The most versatile chimney insulated system UNI with ventilation consists of three complementary system components:
high-quality inner pipe made of fireclay with the most favorable round cross-section for flow movement, pipe connection by means of a fold for maximum stability and density;
perfectly fitted high-strength profiled insulating boards;
stone shells from lightweight concrete, exactly corresponding to the given dimensions and having an optimal cross-section of ventilation channels from an aerodynamic point of view, which protect the insulation from moisture.
Stone shells made of concrete can be equipped with multifunctional channels that serve as ventilation shafts, as well as allowing cables, antennas, engineering equipment. Specially designed smoke channel system Schiedel QUADRO not only delivers the combustion air necessary for combustion to the combustion site, but also safely removes combustion products. QUADRO system - The best decision for the removal of flue gases in an apartment building. Schiedel QUADRO - the new gas-air chimney system (internationally known as the LAS system) has the most important advantage: energy savings are achieved through the heat exchange process between gas and air.
For installing a chimney in an already built house, Schiedel recommends a chimney system KERASTAR . It provides the perfect combination of a ceramic flue duct, mineral fiber insulation and a lightweight stainless steel shell. The internal profiled pipe made of high-quality ceramics is resistant to burnout, corrosion and acids. Thanks to the connection system using stainless steel crimp clamps, simple and quick installation. The outer shell has a spectacular appearance, therefore does not require additional finishing. The use of an internal ceramic tube allows the use of solid fuel. Safe distance from flammable building structures is only 5 cm. The company gives a 30-year guarantee on the internal ceramic pipe.
For reconstruction brick channels Schiedel specialists have created a system of profiled ceramic pipes KERANOVA , which can be used both for boilers (including those with excess pressure), and for stoves or fireplaces, a special advantage of this system is the ability to insert a consumer at any level, regardless of the chimney elements. A thin profiled wall allows you to reduce the heating time of the pipe and make it comparable to stainless steel systems.
The main advantage of Schiedel ceramic chimneys is their high versatility (the ability to work with any type of fuel and any type of heating equipment, reliability, safety and durability).
The smooth, round inner surface of the fireclay pipe, high-quality insulation and the correct selection of diameters guarantee safe removal of flue gases through the roof. Chimney systems from Schiedel ceramic pipes easy to install.
Fire safety certificate from VNIIPO RF for ceramic systems. Certificate of conformity to GOST of the Russian Federation. Sanitary and epidemiological certificate for Schiedel products.
Raab
Raab Joseph Raab GmbH & Cie. KG has a history of more than a century - from its creation in 1898 to the present day. Today at production program German manufacturer includes:
single-walled, double-walled flue ducts made of mirror stainless steel with diameters from 80 to 600 mm and a patented Alkon connection system;
noise-absorbing devices;
thermal exhaust gas valves;
flow limiters and combustion air supply valves for all types of heating boilers, block thermal power plants, furnaces with exhaust gas temperatures up to 600°C using gas, diesel and solid fuels.
Raab flue gas exhaust systems are designed for use with: boiler installations; condensing boiler installations; BTES; emergency power generators; on bakery ovens.
Operating modes of Raab flue gas exhaust systems: with overpressure; under discharge.
The main characteristics of Raab flue gas exhaust systems include:
1. Gas density - up to 5000 Pa;
2. The sealing area is 20 times larger than normal joint.
The vertical section is a self-compacting system. In the horizontal section, the elements are pulled together with special clamps;
3. Heat resistance - up to 600°C;
4. Metal seal. There are no seals from artificial materials(rubber, caoutchouc, etc.), which, as a rule, are much less heat-resistant. Thermal insulation 30 mm made of non-flammable mineral fiber.
5. Speed of installation. There is no need to secure all connections with static clamps - each element is inserted separately, a plastic cover is placed on top, and 3-4 light blows are applied with a hammer in the direction of the joint, as a result of which the conical surfaces of the elements are pressed tightly against each other.
6. Corrosion resistance. All elements of the flue are made of acid-resistant stainless steel grades 1.4404 and 1.4571 made in Germany. Each element has a capillary stopper. Continuous thermal insulation guarantees the absence of temperature changes.
7. Internal diameters of the gas duct are from 80 to 1200 mm.
Fire safety certificate for insulated gas flue DW Alkon. Fire safety certificate for single-wall flue EW/FU. Sanitary and epidemiological certificate for Raab products.
Bofill
Spanish company F.F. Bofill has hundreds of years of experience in the production of chimney pipes. The plant is located in Barcelona, products are supplied only to Spain and Russia. In Russia, the company's chimneys have already been successfully used long time. The plant's products supplied to the Russian market can be divided into four main categories:
1. Double-walled chimneys
The inner wall of the pipe is made of AISI 316 stainless steel with a thickness of 0.4 mm, and all components are made of AISI 304 stainless steel with a thickness of 0.5 mm. The insulating insulation is made from dense basalt fiber ROCKWOOL 30 mm thick. Working temperature double-walled chimney - 500°C. Short-term heating of pipes up to 700–750°C is possible. System double-circuit chimneys retains all performance characteristics at temperatures up to 500°C. The double-circuit chimney system retains all performance characteristics at temperatures environment down to –50°C. Recommended for use both indoors and outdoors.
2. Single-wall chimneys
Also made of AISI 304 stainless steel, 0.5 mm thick. Working temperature single wall chimney - up to 450°C. Recommended as an insert into a brick chimney and as part of a chimney located indoors exclusively for gas fuel.
3. Enameled chimneys
Enameled pipes made of carbon steel, coated with heat-resistant glaze. Operating temperature - 900°C. Recommended for solid fuel boilers and fireplaces as an indoor connection line.
4. Flexible flues
On the Russian market, the most widely used flexible gas duct is Lisflex, made of AISI 316 stainless steel. They are used in chimneys of strongly curved structures, or as inserts in a brick chimney. Chimneys from F.F. Bofill have proven themselves on the Russian market as one of the cheapest and easiest to install.
The main disadvantage of F.F. pipes Bofill, both single-walled and insulated - narrowing of the pipes at the joint and the absence of single-walled elements made of AISI 316 steel, which limits the use of combined systems (single/double-layer) for diesel fuel boilers.
Baltvent
Baltvent LLC, Kaliningrad, specializes in the manufacture of attachmentsinsulated chimneys, as well as inserts For brick chimneys. The plant's equipment was manufactured by leading companies in Western Europe (Germany, Sweden, Austria). The material of the inner pipe is acid-resistant steel AISI 316 L, 0.5–1.5 mm thick. The diameters of pipes produced by the plant are 80–1000 mm.
Mineral wool with galvanized mesh, chemically resistant and environmentally friendly, is used as insulation in double-circuit chimneys. A special technology for expanding the sockets made it possible to produce an internal channel without narrowing it to an almost ideal shape.
Today, the plant is the first in Russia to begin manufacturing pipes with a diameter of over 1000 mm. A wide range of diameters and thicknesses of the internal contour pipe have made this brand one of the most widespread of domestically produced chimneys. For the first time, the stock program includes oval pipes and components for the rehabilitation of brick chimneys. Baltvent chimneys also attract buyers inexpensive price and ease of installation.
Certificate of conformity. Fire safety certificate for insulated flue. Fire safety certificate for single-wall flue. Sanitary and epidemiological certificate for Baltvent products.
Rosinox
Another Russian company successfully moving into the market is Rosinox. The company is based in Klin, Moscow region.
The Rosinox company produces chimneys made of AISI 304, AISI 316 L stainless steel using imported equipment and imported raw materials.
Rosinox chimneys are divided into series insulated - “Thermo” and non-insulated - “Mono”. Laying of an insulated chimney - made of non-combustible basalt fiber high density.
High quality socket connections make the installation of these chimneys easy and reliable. The advantages are comparable to chimneys from Baltvent companies.
Certificate of conformity. Fire safety certificate for insulated flue. Fire safety certificate for single-wall flue. Sanitary and epidemiological certificate for Rosinox products.
Trankol
The Trankol plant has solid experience in the production of stainless steel pipes and components for chimneys. In terms of its product line, it is most comparable to F.F. Bofill, but has a seam seam, which undoubtedly limits its use in systems with high excess pressure, although the fit tolerances of both insulated and single-circuit pipes are much better than those of F.F. Bofill. The main products are pipes for large and medium power boiler houses. On gas fuel, diameters are 300–500 mm. Issued single-wall maintenance system and insulated TD. Trankol is one of the first Russian companies to develop an AutoCAD catalog for design.
Certificate of conformity. Fire safety certificate. Sanitary and epidemiological certificate for Trankol products.
Fire retardant coating is used to prevent fire from entering the ventilation system and the subsequent spread of combustion products throughout the building.
Ventilation surrounding any building (from a small apartment to a huge factory) can spread combustion products in a matter of minutes, aggravating the situation. To help localize the source of fire, use fire protection systems air ducts
Which premises need protection first?
Premises in which it is necessary to install fire protection for air ducts are, first of all:
- Warehouses for fuel, lubricants and flammable materials.
- Places with large crowds of people: office buildings, business centers, residential apartment buildings, shopping centers.
- Buildings with high temperatures: baths, saunas, boiler rooms.
The ventilation system, which carries air through the floors, has several compartments with valves and upholstered in fire-resistant materials. In this way, isolation of each individual room is achieved.
Covering with insulating materials is required ventilation pipes, air conditioning and smoke removal systems. The latter are made to remove smoke from the building, so they need increased protection.
Why do you need fire protection for air ducts?
According to statistics, during a fire, the greatest harm to people is caused by smoke, not fire.
Since air conditioning and ventilation are an integral part of any room, they become extremely dangerous during a fire, as they quickly spread smoke. Fire protection for blowers is designed primarily to delay the time of combustion products entering the ventilation.
Its second goal is to isolate the fire so that it “suffocates” without receiving the necessary oxygen. The third is smoke removal, removal of flammable gases from the room.
The material covering the outside of the ventilation ducts foams during excessive heating, thereby creating additional thermal insulation. Fire-retardant plaster, impregnation for fabric coverings, and special paint are common. These materials are designed to protect finishing materials from fire, which tend to ignite easily and emit toxic smoke.
Rules and regulations for the operation of fire protection for air ducts
The set of rules established by the legislative act SP 7.13130 of 2013 on fire safety technology regulates the installation of ventilation, heating and air conditioning systems.
When laying ventilation systems Only non-flammable insulating and facing materials"A" class. Inside one fire compartment you can use low-flammable materials of class “B”. “B1” - semi-fire-resistant materials are allowed for use in air ducts that do not pass:
- through ceilings (including suspended ceilings) and walls;
- in corridors and escape routes.
According to these rules, the ventilation system in addition to fire protective coating must have: air valves, fire dampers. According to technical fire safety standards, fire protection must withstand heating during the evacuation time. For each individual case a certain time interval is calculated.
Materials must be certified according to fire resistance standards. The fire resistance of a structure is determined by the time from the onset of excessive heating to the moment of destruction of the surface. The fire protection material must withstand temperatures up to 1000º, given the average fire temperature in the room is 850º.
The use of perlite phosphogel sheets, asbestos cement, gypsum fiber, plasterboard, basalt slabs, special spraying and fire retardant paint coating increases the maximum fire resistance time to 240 minutes. According to the standards, this time cannot be less than 150 minutes.
Methods and materials for protection
Now let’s look at what means can be used for fire protection:
- Basalt protection.
- Fire retardant paint.
- Sprayed material.
Below we will consider each option in more detail.
Balsat fire protection for air ducts
Basalt is a substance of volcanic origin, including impurities of iron, calcium, magnesium and 47% silicon dioxide. It is thanks to silica that basalt is widely used as fire protection. When exposed to high temperatures, the material does not lose its shape, solid properties and does not emit hazardous substances.
Basalt fiber, which is used to insulate pipes from fires, is created from the original rock without the participation of foreign additives that reduce its natural properties.
The most popular and reliable brands are:
- Rockwool (Wired Mat) . Hydrophobized heat-insulating boards, light and rigid, are available in rolls. Size of 1 roll: 800x600x50 mm.
- Pro-Vent. Roll dimensions: 10000x1000-1200x20-80. There are options for one-sided lining: foil, reinforced foil, glass, basalt, silicon fabric, metal mesh.
- TIZOL. Roll sizes: 1000-1200x500-600x40-200. Covered with fiberglass and foil. Price on average from 326 rubles/m².
- Buffalo. Roll size: 6000x1000x20-80. The material can be lined with basalt, silicon, glass, aluminum foil, metal mesh. Price from 200 rub/m².
- MBF. Maximum roll length 31000x1000-1500x5-20. The material has a foil coating. Price from 320 rub/m².
Advantages of using basalt fire protection:
- comparative cheapness;
- high degree of protection;
- non-toxic;
- non-flammability.
The main disadvantage is requirement for additional fasteners. As a rule, metal brackets are used for this, which are destroyed at high temperatures, causing the insulation to simply fall off the ventilation duct. It is safest to glue rolls of basalt protection using fire-resistant adhesives.
Other disadvantages include: comparative difficulty of installation, heavier structure.
Installation is carried out in several stages:
- Surface preparation. Cleaning, leveling, drying, removing rust and unevenness.
- Application of adhesive. One layer is enough for fire resistance of 30-150 minutes, for longer a second layer is needed.
- The material is glued in strips. Material consumption per 1 m² is 1.1 m². When installing double protection, the layers are offset from each other and the consumption is 2.05 m².
- If glue is not used, the roll is unwound over the entire surface of the pipe and secured with metal brackets.
For basalt rolls, the fire resistance limit is 180 minutes with a thickness of 70 mm. The greater the thickness, the higher the protection, and vice versa. Options with foil increase resistance to heat energy. Use together with paint or sprayers provides comprehensive and most reliable protection..
Application of rolled basalt fire protection (video)
Fire retardant paint
During strong heating, when exposed to temperatures in the region of 100º, such paint foams, forming new layers of carbon fire protection and additional thermal insulation.
Popular brands:
- Thermal barrier. Paint consumption for minimum protection of 45 minutes – from 0.95 kg/m² depending on thickness metal structure(the thicker the duct, the less paint is required).
- Kedr-Met-V. Consumption averages 1 kg/m².
- Ecofire. Average consumption: 1.11 kg/m².
- CROZ. Average consumption: 1.37 kg/m².
Pros of fire retardant paint:
- ease of application;
- speed of repair after a fire;
- the structure is not heavier.
The first disadvantage is that the thickness and integrity of the coating must be constantly monitored, since the paint peels off over time, falls off, and runs off. Paints on water based may not have time to foam if the fire is of the carbon type (if the temperature rises sharply in the first five minutes). In this case, the paint is ineffective, and the possibility of this type of fire should be considered in advance.
Water-based paint is applied by spraying or brushes. It provides protection for 120 minutes with a thickness of 0.8 mm. The more paint is applied, the higher the fire resistance time.
The more paint is applied to a surface, the more often it needs to be revised and checked for integrity.
The result of using fire retardant paint for wood (video)
Sprayed fire retardant material
A composition applied by spraying for fire protection of surfaces. It is created from mineral microfibrous substances, an inorganic binder and additives with a very high fire resistance limit (2-3 hours).
Famous brands:
- POLINOR;
- Thermal spray;
- Corundum.
They are used to quickly remove combustion products from premises, ensure the possibility of effective fire extinguishing and clear escape routes for the removal of people.
Such tasks are characterized by high responsibility, since people’s lives and the safety of valuable property or equipment are at stake. Therefore, the requirements for the air channels through which smoke and gases generated during a fire are exhausted are quite strict. The equipment must ensure full performance of its functions and exclude the possibility of failures or malfunctions. The quality, characteristics or other parameters of smoke removal systems are regulated by SNiP, since operating conditions require strict standardization of all elements and components.
Which includes smoke removal means, performs a responsible and vital important role. The operating conditions for smoke exhaust ducts are complex and contain an abundance of negative factors:
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Heat
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Presence of aggressive combustion products
An additional factor that has a negative impact on the performance of the system is low load - most of the time the fire duct is idle, which creates the possibility of foreign objects appearing inside the ducts. To effectively remove, redistribute or cut off flows, specialized air ducts are used, the material and coating of which ensure the specified performance at high temperatures (fire resistance determined by SNiP).
From a design point of view, smoke exhaust ducts are no different from conventional ones ventilation ducts, but complex and harsh operating conditions place increased demands on the level of tightness - all channels are installed in the “P” (tight) or “N” (normal) design - for buildings with a low level of fire hazard or low possibility of smoke.
In addition, taking into account the responsibility and complexity of the operating conditions of the system, the requirements for the material have been increased - welded air ducts made of galvanized or low-carbon steel with a thickness of 0.9 to 3 mm are used (thickness is taken based on the conditions of welding work).
Air ducts made of black steel have a special coating that serves as protection against corrosion and increases the resistance of the material when exposed to high temperatures (fire protection). Welding is carried out using the electric contact method; air ducts made of carbon steel are most suitable for this method of joining materials and provide the greatest density. The parts are connected to each other using flanges.
Expert opinion
Heating and ventilation engineer RSV
Fedorov Maxim Olegovich
Attention! For rooms with a low degree of fire hazard, channels made of galvanized steel with a seam connection can be used.
Types and characteristics
According to the sectional shape there are:
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Round. Represent a pipe round section. They are considered more efficient and economical, and provide tighter installation. According to SNiP, when performing design work should first of all be considered round types channels.
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Rectangular. Less economical, have low aerodynamic performance and more high level noise. At the same time, they visually look more compact and fit better into the volume of rooms or corridors.
The most common air ducts are made of black steel - if they have all the necessary characteristics, they are cheaper, which is an important argument in the conditions of a large industrial enterprise. In addition, the operating conditions of smoke protection systems most often do not imply constant operation. Air ducts made of carbon steel, having a high strength welded joint, are able to provide the required density of the smoke exhaust channel, which eliminates leakage of combustion products.
Fire protection is a coating that reduces the destructive effects of high temperatures on the material. According to SNiP requirements, the surface of air ducts must have a coating that is resistant to the transported medium.
In the event of a fire, the temperature of the exhaust gases can reach high values, therefore, the condition for the operation of ducts designed for rooms with a high degree of fire danger is the ability to withstand a temperature of 600°C for 0.75 hours (45 minutes). In addition to coating, they are used various materials, laid on the outside of the box, which protect the material from external aggressive influences. determined by the level of danger of the premises, as well as the composition of flammable substances present nearby.
Shaped products
Shaped products for smoke exhaust ducts perform the same functions as for all conventional systems - they provide the ability to connect, change direction and branch ventilation ducts. The following elements apply:
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Retraction. Changes the direction of the channel. Can be made in several options, from 15° to 90°.
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Stub. Hermetically closes the end part of the channel.
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Tee. An element for connecting one air duct to another. Installed in a channel gap, there are options for connecting rectangular with round or rectangular lines in all variants.
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Transition. Carries out longitudinal connection of channels having different diameter or side dimensions.
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Cross. Combines transverse threads of air ducts into one network.
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Duck. An element connecting channels that do not coincide with each other along the longitudinal axis. Basically, it is made to order, since everything is provided in advance possible options connection is not possible.
All shaped elements are made in both round and rectangular designs (or in combination with one another). For smoke exhaust systems, shaped elements are subject to the same requirements as straight air ducts - in terms of material and manufacturing method and the presence of a protective coating. The connections of the elements are made with a high degree of density, for which a special fire-resistant sealant is used.
Smoke removal ducts are one of the most critical elements. Difficult working conditions, high temperatures and the aggressive effects of combustion products can quickly damage unsuitable equipment. In addition, most of the time the equipment is idle, which can negatively affect its operation in critical situations. High technical requirements and great responsibility of the system require accurate calculations, the right choice and strict compliance with the requirements of SNiP in relation to all parameters of air ducts of smoke removal systems.
How it works?
