Smoke circulation systems in furnaces. Furnace chimneys (chimneys) Rough do-it-yourself brick with horizontal

Having dealt with the boilers, it's time to talk about, having considered the different designs of chimneys and the requirements for their construction.

The flue for a copper is intended for removal of products of combustion of fuel in the atmosphere. Actually, any heating boiler, if it is not electric, can only work if there is a properly made chimney.

What types of chimneys are available?

Types of chimneys for the heating system

According to the installation method, chimneys are:

• external attachments;
• double horizontal;
• internal vertical.

According to the principle of connection to boilers, chimneys are divided into:

• separate (separately for each heating boiler);
• combined (exit from, for example, two boilers is combined into one common, which leads to the street).

Now we will analyze how to properly make a chimney of each type.

Horizontal chimney

The easiest way is to make a horizontal chimney: you just need to make a hole in the wall of the boiler room to the street:

1. Horizontal chimney

Such chimneys are suitable only for boilers with forced draft.

External chimney

For such chimneys, forced draft is not needed: the exhaust gases are discharged due to natural atmospheric draft. With such a chimney device, the pipe from the boiler goes through the wall to the street, and then the chimney rises along the wall to the roof:

2. External chimney

The height of the chimney must be at least 5 m from the bottom of the boiler to the top of the chimney (see the following figure).

In the diagram, D1 and D2 are the diameters of the chimney itself and the outlet on the boiler. So these diameters should be equal and according to the standard 130 mm.

The chimney is attached to the wall with the help of additional parts (clamps and a support frame).

Internal chimney

The internal chimney immediately rises from the boiler up, passes through all the ceilings and then goes to the roof:

3. Scheme of the internal chimney

It is desirable to make the internal chimney two-layer, laying thermal insulation between the layers - to avoid fire from heating the chimney. Thermal insulation also prevents the formation of condensate inside the chimney.

Chimney in the wall of the house

The internal chimney can also be mounted in the wall of the house - inside the brickwork (see Fig. A below): from the boiler, the pipe goes into a channel inside the wall and rises to the roof through this channel.

4. A - internal chimney, made inside the brickwork; dependence of the height of the pipe on the distance to the roof ridge; B - the location of the pipe in the case of an attached boiler room.

Why insulate a chimney?

When any fuel is burned, water vapor is produced. In the chimney, the steam cools down, and at a temperature of 55 degrees and below, the steam condenses and forms water droplets. Water enters into a chemical reaction with various compounds from the exhaust gases, due to which various aggressive solutions are formed. To prevent such cooling, the chimneys are made double and insulated.

Chimney requirements

To the above, let's look at the diagrams on how chimneys are arranged.

Vertical execution. If the boiler is floor-standing and the floors are combustible, there must be a non-combustible substrate under the boiler: an asbestos sheet plus a metal sheet.

Chimney passage through a wooden wall(and in general a wall of combustible material) must have a fire seal of at least 0.5 meters around the chimney.

The next requirement is length of the horizontal section of the chimney: from the axis of the boiler to the axis of the chimney, which is outside, should be no more than 2 meters, otherwise the draft will be poor.

On the pipe section, located on the street, the pipe is two-layered and thermal insulation is laid between the layers - to prevent condensate in the pipe. But in any case, there should be a pocket at the bottom of the vertical section of the pipe for cleaning and draining condensate.

On fig. 3 a chimney that runs vertically through the floors: in this case through the ceiling and roof. The requirements are the same here. A requirement is also added: from the bottom of the boiler to the top of the pipe, a distance of at least 5 m.

Chimney diameter for gas boiler, set by the manufacturer, must be equal to the diameter of the chimney leaving the room. It happens that boilers with a smaller chimney diameter (about 80 mm), then the inner diameter of the rest of the chimney must be at least 130 mm. All these requirements must be taken into account, because if you do not do it right, you will have problems with the commissioning of gas equipment.

The following diagram (Fig. 4, A) considers the option when the chimney is embedded in the channel of the outer wall. The following requirements must be met here: there must be a cleaning hatch below the pipe entry into the wall channel. It happens that in cold weather sparrows, pigeons, etc. sit on the top of the chimney, they suffocate from carbon monoxide and fall into the chimney. Naturally, all this garbage will be collected until it clogs the entire chimney.

How high should the chimney be?

Consider how the outlet of the chimney itself can be positioned relative to the roof (Fig. 4, A, B, C).

If the pipe is at a distance of 1.5 ... 3 meters from the ridge, then the pipe is brought to the level with the ridge.

If from the pipe to the ridge is less than 1.5 meters, then the pipe should be located at least 0.5 m above the ridge.

In diagram B, the boiler room is attached to the house, while the requirements for the height of the pipe are the same as if the pipe were located on the roof.

Why is it important height of the chimney relative to the roof ridge? So that in strong winds, when air turbulence occurs, the igniter in the boiler does not blow out.

Here are the answers to basic questions about how to make a chimney.

how to make a chimney

Designs of smoke circulations and the movement of flue gases.

In some cases, when arranging heating units, it becomes necessary to install a horizontal chimney. There are several options for implementing this process: both simple and quite complex.

Horizontal chimneys are sections of the combustion products removal system, located parallel to the floor and passing between the heater and the roof outlet. There are 3 types of such structures:

1. A branch from vertical lines, which in their length should not exceed 1 m.
2. A full-fledged chimney with the presence of minimal vertical sections and a conclusion through the wall to the street. Such systems are used when the gas boiler is located close to the outer walls of the building and the installation of a vertical chimney through the ceiling is impractical. In addition, the design is necessary if it is not possible to equip a chimney in a room with a heating unit and it is necessary to carry out an output to neighboring rooms.
3. Furnace heating of the house involves heating the air due to the bricks heated during the heating process. Direct chimney will contribute to their rapid cooling. To increase the area with heat transfer and high safety of hot air, structures in the form of a snake are built.

Requirements for horizontal chimneys

The main condition for the functioning of any chimney is the presence of natural draft. To ensure it, the maximum length of horizontal sections in the entire system should not exceed 100 cm.

If there are several turns, as in the "snake" chimneys, there is a high probability of the formation of swirls and soot settling. To eliminate such shortcomings, the surface inside the system must be completely smooth, the corners are not pointed. The requirements also include the obligation to have the same section along the entire length of the structure.

Due to the difficult operating conditions, the chimney must withstand the effects of acids, condensate, mechanical stress and high temperatures, and maintain tightness for the longest possible time.

Advantages and disadvantages

The most important advantage of horizontal chimneys is the increase in heat transfer. This is especially important for stove heating or when the heaters are not powerful enough.

The negative side of the design is that the pipes of the horizontal section become clogged with soot faster, turbulence occurs if installed incorrectly, and the installation process itself is often difficult.

Whirlwinds can reduce traction. To eliminate them, the corners inside the structure are rounded off.

Rules for the installation work

Features and installation technology of a horizontal chimney allows you to do all the work yourself with basic knowledge and skills.

If we are talking about boilers with a special turbine, then everything is simple: a coaxial chimney is installed. In other cases, the horizontal section of the chimney must support natural draft. Therefore, the installation of "snake" systems is carried out strictly in accordance with the technological requirements. The design consists of several turns, in which horizontal sections alternate with short vertical ones, ensuring the complete removal of combustion products.

Refractory bricks are used for the construction. At the same time, to organize a rotary channel, it must be cut in half. The main thing at each stage is to control the preservation of the same cross section of the air channel. The structure is built in sections. Details that will be located in the places of inversion of the air flow are rounded off by cutting and grinding corners.

At each stage of laying the rows, it is necessary to distribute the solution so that tightness is ensured. Particular attention should be paid to the installation of metal doors or knockout bricks.

Basic withdrawal methods

The layout of the pipe should be based on the output method:

1. A coaxial system is removed through the wall, followed by insulation and sealing of the pipe location.
2. When withdrawing through ceilings and roofing, a “snake” chimney is advisable. At the same time, the height of the structure is calculated so as to provide traction and eliminate turbulence (mounting methods recommend 4-6 turns).

Service

Any chimney is prone to clogging with combustion products such as soot and soot. Therefore, in addition to the external aesthetic finish, it needs constant cleaning. If a standard vertical chimney is easy to get rid of blockage, then horizontal shafts must be cleaned separately.

In the case of coaxial systems, cleaning work does not take much time and effort, because. the structure is made of stainless steel, and a strong air flow that pushes out the products of combustion prevents soot and soot from settling on the walls of the structure. To enhance the effect, chimneys are installed at a slight angle to the horizontal plane.

In brick systems of horizontal “snake” chimneys, in order to ensure the cleaning of channels from soot, metal doors are placed at the level of each horizontal section. Due to the different properties of metal and brick, in particular heating and cooling, the efficiency of the entire structure is reduced. To prevent this from happening, instead of doors, knock-out elements are often mounted - square bricks, which, if necessary, can be taken out and put back in place after cleaning work.

In the first case, access to the air duct is provided by opening and closing the product. In the second, before reaching the inner plane, it is necessary to dismantle one of the elements with little effort, and after cleaning work, install it in place, ensuring the safety of the seal. The number of such inspection holes is four, but 6 turns with access points are also allowed.

What is the difference from a coaxial chimney

In order to understand the distinguishing characteristics of horizontal chimneys from coaxial ones, one should disassemble their device and principle of operation.

The first device combines 2 pipes of different diameters: the inner one removes smoke and combustion products, and fresh air is supplied into the cavity between it and the outer wall of the outer pipe.

A prerequisite for the functioning of coaxial type chimneys is the presence of a turbine in the heating equipment, which will push out smoke and suck in oxygen. Such a system is the easiest to install, because. does not require natural traction.

Furnace chimneys (chimneys) are a system of channels inside the furnace that connect the furnace to the chimney. Furnace chimneys are designed to remove flue gases from the furnace and provide heating of the furnace walls. The heat transfer to the walls of the smoke channels occurs due to the speed of movement of gases through the furnace channels. The cross-section of chimneys (smoke circulations) must ensure the free passage of gases. Recommended sections of chimneys are 130×130 mm (half brick to half), 260×130 mm (brick to half brick), 260×260 mm (brick to brick). All turns in the stove chimneys must be rounded so that less soot settles on them. The seams of the brickwork must be completely filled so as not to create additional turbulence during the passage of gases. With a large cross section, gases passing through the chimneys will be cooled quite strongly, which will lead to the appearance of condensate at the outlet. The inner surface of the chimneys must be as smooth and even as possible in order to reduce the resistance to the movement of flue gases.
Systems of furnace chimneys (smoke circulations) are:

• channel;
• channelless;
• mixed.

In channel systems of chimneys (smoke circulations), flue gases are removed using channels. Channel chimneys are divided into:

• single-turn;
• multiturn.

Channelless furnace chimneys (smoke circulations) include a system of chambers separated by partitions.

Each chimney system has its own advantages and disadvantages. The greatest number of shortcomings has a multi-turn chimney system. In a multi-turn system, the gases must pass through the channels, making turns, which leads to resistance to their movement. To overcome the resistance, it is necessary to have good draft in the chimney. Such draft can be created by increasing the height of the chimney, which is not always feasible. Another way to get good draft is to increase the temperature of the gases at the chimney outlet, which will inevitably lead to heat loss and increased fuel consumption. A multi-turn system of furnace chimneys (chimneys) makes sense only if they are small in length. Another disadvantage of multi-turn systems is the uneven heating of the furnace in the sections of the first and last channels, and this can lead to cracking of the masonry. Therefore, the use of a multi-turn system is usually not recommended. But even such a system can be improved, which will be discussed below.

The temperature of the gases before exiting the chimney should not exceed 120 - 140°C. The high temperature of the gases (250 - 300 ° C) before entering the chimney indicates that the length of the furnace chimneys (chimneys) must be increased. The low flue gas temperature (below 120°C) indicates that the length of the chimneys must be reduced. A high outlet temperature can lead to the appearance of condensate, which, penetrating through the masonry, gradually destroys it.

Channel furnace chimneys (smoke circulations) are divided into vertical, horizontal and mixed according to their location. In the direction of movement of flue gases - to lifting and lowering.

When choosing a chimney channel system, it should be taken into account that the vertical system provides a greater heat transfer of flue gases, and the horizontal system creates better draft, which is important when the chimney is not very high.

Furnace chimneys (smoke rotations) are single-turn.

Single-turn oven chimneys have one lifting channel and one or more lowering channels connected in parallel. Flue gases from the furnace enter the lift channel, then pass into all the downcomers, and only after that they enter the chimney. Basically, the heating of the furnace walls is carried out in the downcomer channels.
A positive feature of single-turn chimneys is that their walls are heated evenly, since the temperature of the gases in all parallel downcomers is the same.
Another valuable property of single-turn chimneys is the self-regulation of draft in the downcomers. The deterioration of draft in one of the downcomer channels will lead to a decrease in the volume of gas passed through it, and as a result, to a decrease in the temperature inside the channel. But the volumetric weight of gases in this channel will increase, and heavier gases will move down faster. Therefore, the flow of gases into a less heated channel will increase. The temperature in the channel will increase, the passage of gases through all downcomers will again become uniform.
The simplest version of a single-turn furnace chimney system is a system with one lifting channel and one lowering one. But furnaces with such a chimney system have a low efficiency, as they have a small heat-receiving surface. In addition, the temperature of the gases in the first lifting channel is very high, as a result of which uneven heating of the furnace occurs, which leads to the appearance of cracks. The gas temperature at the chimney inlet can reach 200 - 220°C.

The system of chimneys (smoke circulations) with one lifting channel and several lowering channels does not have the disadvantages of a multi-turn system. But with such a system, the upper part of the furnace warms up most of all, the bottom of the furnace has a temperature much lower. The chimney system with predominantly lower heating is free from this drawback and provides heating of the bottom of the furnace. Hot gases from the furnace first go down, thereby ensuring the heating of the bottom of the furnace, then rise up. The upper part of the chimneys of such a furnace is made single-turn or in the form of a cap. Of course, the design that provides heating of the lower part of the furnace increases the amount of gas resistance, but such a chimney system is the most efficient.

Stove chimneys (smoke rotations) are multi-turn.

In multi-turn furnace chimneys, the smoke channel consists of vertical and horizontal sections connected in series. In such furnaces, flue gases during their movement overcome a large number of revolutions, which leads to soot settling in the channels. In such furnaces, a cleaning device is a prerequisite. In such a system, the gases are greatly cooled, and the draft in the furnace deteriorates. In the initial period of the furnace, the furnace smokes. Flue gas cooling can lead to condensation.

In a multi-turn system, the gases must pass through the channels, making turns, which leads to resistance to their movement. To overcome the resistance, it is necessary to have good draft in the chimney. Such draft can be created by increasing the height of the chimney, which is possible within certain limits. Another way to get good draft is to increase the temperature of the gases at the chimney outlet, which will inevitably lead to heat loss and increased fuel consumption. A multi-turn system of furnace chimneys makes sense only if they are small in length. Another disadvantage of multi-turn systems is the uneven heating of the furnace in the sections of the first and last channels, and this can lead to cracking of the masonry. But the biggest disadvantage of a furnace with multi-turn chimneys is that it requires a large amount of fuel to heat it, which is incommensurate with the amount of heat released. Therefore, the use of a multi-turn system without the improvements described below is generally not recommended.

How to change stoves with multi-turn horizontal chimneys (chimneys) to increase their efficiency.

In each horizontal channel, it is necessary to make suction (injection) holes with a cross section of 15 - 20 cm 2. Injection holes are made every 70 cm. The furnace will melt better, soot deposits will decrease, and a constant temperature will be maintained at the outlet of the chimneys. In more detail, the principles of operation of chimneys with injection holes are described below in the entry "Mixed system with horizontal and vertical chimneys and injection holes."

How to change stoves with multi-turn vertical chimneys

(smoke cycles) to increase their efficiency.

In the dividing walls between the vertical chimneys, it is necessary to make injection holes with a cross section of 15 - 20 cm 2, which will ensure draft in the furnace and a constant temperature of the gases at the chimney outlet.

How to change stoves with single-turn chimneys

(smoke cycles) to increase their efficiency.

It is necessary to make suction (injection) holes with a cross section of 15 - 20 cm 2 from the furnace and from the downcomer. Injection holes will contribute to a good kindling of the furnace after a long break at any time of the year. With the help of injection holes, uniform heating of the furnace walls is ensured, while overheating of the roof and ascending channel is reduced.

Furnace chimneys (smoke circulations) channelless, bell-type.

There are no smoke channels in channelless furnace chimneys. Gases from the furnace enter the chamber - the hood, rise to the roof of the furnace, disperse along the walls, heat them, and, cooling down, go down, and then go into the chimney. This system is quite simple in execution, the thermal energy of the fuel is used most fully.
The disadvantages of such a system are strong heating of the upper part of the bell, soot deposits on the walls of the bell, high temperature of the exhaust gases.
The system with two caps is more efficient. Flue gases from the furnace enter the first bell, then fall and fall into the second bell. In such a system, most of the heat is given off to the walls of the furnace, the temperature of the exhaust gases is not as high as in a system with a single hood. But the top of the furnace also overheats and soot is deposited on the walls of the furnace.

Furnace chimneys (smoke circulations), channelless, bell-type with buttresses.

Buttresses serve as additional heat accumulators on the inner surface of chimneys in a bell-type furnace. Buttresses are made in the form of vertical ribs running along the walls of the furnace and chimneys. Usually buttresses are made in a quarter of a brick. Flue gases come from the furnace into the hood, rise upwards, giving off part of the heat to the furnace walls, buttresses and the furnace roof during their movement.
The disadvantage of such a system is that a lot of soot is deposited on the inner surface of the furnace and especially on the buttresses, which can catch fire, which will lead to the destruction of the furnace.

Mixed stove chimneys (chimneys) with vertical and horizontal channels.

Flue gases from the furnace enter the horizontal channels, then go through the vertical lifting and lowering channels and then enter the pipe. The heat transfer of horizontal furnace chimneys significantly exceeds the heat transfer of vertical channels. The biggest advantage of mixed flue stoves is that they maintain a high temperature for a long time. But such furnaces have all the disadvantages of multi-turn furnaces, namely, a strong supercooling of the flue gases, due to which the draft in the furnace weakens, a large amount of soot accumulates on the walls. The low temperature of the gases at the outlet leads to the formation of condensate.

Mixed system with horizontal and vertical furnace chimneys (chimneys) and injection holes.

This system of furnace chimneys is inherently multi-turn and has several horizontal and vertical channels. Without injection holes, this system would not work at all. Consider the processes occurring in this chimney system without injection holes. When fuel burns, thrust is generated. Under the influence of draft, flue gases pass through all channels, giving off heat to the furnace array. Caps are located above the horizontal channels, into which part of the flue gases rises. During the movement, the gases cool down, giving off heat to the vertical channels and arches of the caps, become heavier and go back into the horizontal channels. In this case, the flue gases give off maximum heat to the walls of the furnace. This process takes place in every cap. But the consequence of this is a strong supercooling of the flue gases, which leads to a decrease in thrust. To enhance traction, injection holes are used to provide self-regulation of traction. Holes are made in the vault of the firebox and in horizontal channels. The process of self-regulation is as follows. With a decrease in thrust and gas temperature, a vacuum is created in the horizontal channels, hot gases are sucked in through the injection holes from the furnace and from the underlying channels, thereby increasing the temperature of the gases, while the thrust increases. Flue gases stop flowing into the injection holes when the normal temperature, pressure and speed of their movement are reached. Injection holes are made with a cross section of 15 - 20 cm 2, every 70 cm.

Furnaces with such a system d chimneys are evenly heated from bottom to top. There are no sudden temperature changes in the room. The decrease in the temperature inside the room is 2 - 4 ˚С in 12 hours, and in 24 hours 4 - 6 ˚ C. At an outside temperature of minus 10 ˚C in a well-insulated house, the stove can be fired after 36-48 hours. But in winter, stoves with such a system chimneys needs to be fired regularly.

Comparative table of various systems of furnace chimneys (smoke circulations).

• Scheme and drawings of the furnace V. A. Stroganov
• Brick heating furnace by Sergey Mikhailov (drawings)
• Author's brick oven by Sergey Mikhailov
• Author's oven-Dutch made of bricks by Sergey Mikhailov
• The simplest brick kitchen oven

Pictures and photos of the interiors of country houses rarely do without a stove. It is practically a symbol of a private dwelling. And what types of stoves exist and what are their advantages?

Scheme and drawings of the furnace V. A. Stroganov

IMAGE 1 shows a diagram of one of the most technically advanced ovens of the 19th century.

A - general traction valve, B - 1 lifting well, C - parallel well designs, D - cleaning door, D - draft suction, E - furnace door, G - grate, K - blower door, L - firebox floor, M - chamber afterburning.

This stove can be easily converted into a cooking and heating one, if the firebox is moved to the side of the stove, the stove is equipped with a stove, and the bottom of the smoke channels is lowered to the floor level.

A feature of this furnace, which was developed by V. A. Stroganov, is the presence of:

• afterburning chambers;
• technically competent distribution of the location and direction of the channels, which make it possible to obtain uniform heating of the entire area of ​​\u200b\u200bthe smoke wells of the stove;
• calibrated direct draft suction hole;
• only one cleaning door, which allows simple and easy cleaning of all wells; if there is a need, through it there is an opportunity to get rid of overturning thrust in the stove;
• grates and the hearth of the furnace furnace, which are arranged under well-thought-out slopes, which contributes to more efficient combustion of fuel residues than in stoves that have a strictly horizontal arrangement of the furnace furnace hearth and grate.

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Brick heating furnace by Sergey Mikhailov (drawings)

The scheme of the next furnace is shown in PICTURE 2.

A - general draft valve, B - stove, C - front view of the chimney section, D - furnace door, D - exit to the first well from the furnace (hailo), E - side view of the chimney section, G - furnace, I - stove, K - hailo, L - side view of the section of the furnace furnace.

A heating stove with horizontal chimneys is good because it does not require a clear and strict fixed marking for the exit of the chimney. In ancient times, only a senior furnace master could perform such marking. Laying the first row and laying out the foundation has never been entrusted to apprentices. The reason for this strict subordination was not a formality, but the importance of making a fatal mistake.

The main advantages of a furnace with horizontal wells:

1. It does not need an exact calculation when marking the first row.
2. It warms up evenly (the hottest parts of the stove, which allow intensive heat removal, will be located below, and the less hot ones will gradually move to the upper zone of the room that is heated).
3. It cools evenly (heat from the lower rows of the stove will gradually be transferred to the upper rows). The period of furnace cooling and intense heat transfer is the same period, which is measured in several hours. This is another advantage of a stove with horizontally located smoke channels.
4. Allows you to integrate arched dryers into the furnace masonry with absolutely no problems.

There are other auxiliary drawings and diagrams of the furnace by Sergei Mikhailov:

1. Sergey Mikhailov's stove with a built-in dryer niche in the side section shows IMAGE 3, where A is a valve, B is a cleaning door, C is a dryer, D is another cleaning door, E is hailo, E is a side view of the smoke well section.
2. Well schemes, winter and summer options, in a side section shows IMAGE 4, where A is a valve for winter, B is a valve for summer, C is high.

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Author's brick oven by Sergey Mikhailov

This stove allows the owner to heat it once a day, even in the event of prolonged frosts, up to -35 degrees Celsius. The air temperature in the room will never fall below +19 degrees Celsius.

The author's heating stove by Sergey Mikhailov is shown in IMAGE 5, where A is a valve for winter, B is a high for summer, C is the entrance to well 5, D is a valve for summer, D is a section of 2 rows, E is an entrance to well 7, F is section of the wells of the lower row, I - firebox, K - pipe, L - exit from 8 wells to 6, M - section 3 rows.

PICTURE 6 shows the author's stove-fireplace by Sergey Mikhailov, where A is an empty well design, B is the entrance to well 1, C is a lounger, G is the entrance to well 2, E is a firebox, G is a section of 1 row, I is the entrance to 3 well, K - hailo, L - section 3 rows, M - entrance to the 3rd well, H - valve, O - valve, P - lounger, P - firebox, C - section 4 rows, T - trenches, U - section numbering, Ф - side view of the vertical section.

Scheme of the well in a lateral section: A - a valve for winter, B - a valve for summer, C - hailo.

The features of this type of stove are:

1. The presence of a high (remote) lounger.
2. The absence of a stove door, which gives the stove many advantages of a fireplace with high efficiency.
3. Very good heating of the lowest layers of air in residential premises. This is important enough when there is a small child in the house. As you know, most of the time they will spend on the floor.

It is worth noting that in this oven you can bake bread well and evenly. The specified furnace can also be heated only once a day, even if it is the most severe and prolonged frosts outside.

Many authors of books about the furnace business have serious doubts about the fact that the stove, with the furnace door open, will be able to maintain heat in the house. This is due to the fact that the internal walls of the smoke well will be cooled by air that does not participate in the chemical processes of complete fuel combustion. It is worth noting that all this is quite fair, but this does not apply to this type of stove at all. This is because in its design there is no oven door. The reasons in this case are as follows:

Scheme of the heating furnace by Sergey Mikhailov: A - a valve for winter, B - hailo for summer, C - entrance to well 5, D - valve for summer, D - section 2 rows, E - entrance to well 7, G - section of wells of the lower row , I - firebox, K - pipe, L - exit from well 8 to 6, M - section 3 rows.

1. The area of ​​​​the inlet is not a fireplace, its height is 25 cm, and its width is 30 cm. Even the slightest increase in these dimensions can necessarily lead to a weakening of the overall thrust of the stove and to the fact that it starts to smoke.
2. There are no grates in the oven.
3. A high stack can significantly slow down the speed of movement of air masses, and the air that slowly passes through the furnace has time to thoroughly warm up. A characteristic feature of this furnace is that after 3 years of intensive operation it will not be possible to scrape together even 500 g of ash residues at the entrance to the first horizontal rise (where a lot of ash most often accumulates).

There are a large number of different stoves that can serve both for heating and for heating the house and cooking. Some models are quite voluminous and massive, others are compact, and for a particular room, the desired option is selected that will be most effective for a given area. In addition, any of the furnaces must be installed with the obligatory consideration of the requirements developed by specialists in accordance with SNiP 41-01-2003.

In the conditions of the modern information space, brick ovens for the home, drawings with orders can always be found on the Internet. However, it must be remembered that building this structure on your own is quite difficult, since each stove-maker has his own experience and professional secrets, which are acquired only with work experience.

Criteria for choosing a brick oven

If, nevertheless, it is decided to do such work on your own, then you need to decide on the model - with knowledge of the matter, paying attention not only to the appearance and design of the furnace, but also to its heating abilities in relation to the room that it will have to heat.

When choosing a furnace by size, it must be taken into account that its side walls give off more heat than the front and back. This factor must be taken into account when planning the installation of the stove in one place or another.

Furnaces are divided not only by functionality, but also by its form. They can be rectangular, T-shaped, with a ledge in the form of a stove bench or stove, and others.

Stoves can only be used for heating living rooms and can be installed, for example, between the living room and the bedroom, perform several functions and serve as a dividing wall between the living rooms and the kitchen.

For rooms with a small area, you should not choose too massive buildings. Although many of them are multifunctional, they will take up too much useful space that can be used for other needs.

Naturally, the location of the heated room in the house, as well as the degree of insulation of the entire building, also plays a big role.

Stove selection table depending on the heated area and the location of the rooms:

All these criteria must be predetermined, and based on them, a choice should be made in favor of one or the other model.

Types of brick ovens

As mentioned above, the design of furnaces can be different - both very difficult to build, and quite simple. The most famous of the models are "Dutch", "Swede", "Russian". Modifications named after their designers are widely popular. So, the furnaces of Bykov, Podgorodnikov, Kuznetsov and other masters are very common.

• There are heating stoves that do not have a hob and other elements, but consist only of walls in which chimney channels, fireboxes, blower and cleaning chambers pass.

• Heating and cooking stoves have in their design a stove for cooking, sometimes an oven, a hot water tank and a drying chamber.

• Another type of heating structure is a fireplace stove, which has two fireboxes in its design - a fireplace and a stove. This model can be used by heating only one of the fireboxes or both at the same time.

• There are also stoves that include the entire complex necessary for human life both in summer and in winter. Often they are equipped with a heated bed, which may well serve as the basis for the bed.

Choosing a place to install the oven

It is also important to provide for the correct installation location of the furnace. The best place is the crosshairs of the walls of the house. If it does not have a large area, then such a stove can heat all rooms at the same time. It is desirable that the structure is located near the entrance to the building, since the heat emanating from it will create a barrier to cold air coming from the front door. In addition, if the firebox door opens into the hallway, it is easier to deliver fuel to it without carrying it through the whole house.

When choosing a place, you need to take into account several more factors that are important for the operation of the furnace:

• The building must be installed in such a way that there is free access to any of its walls - this must be taken into account for unhindered control of the integrity of the walls and for cleaning the chambers.
• When erecting a furnace, it is necessary to provide for a separate foundation for it, not connected to the base of the house.
• The chimney must pass between the attic floor beams and not stumble upon them when it is raised - this is provided for when building a house, and if the stove is being built in a finished building, then before laying the foundation for it.
• For fire safety purposes, a heat-resistant flooring made of metal sheet or ceramic tiles must be placed on the floor in front of the furnace door.

Basic design of a brick oven

To know how each of the elements of the furnace works, and what it is intended for, you need to consider the basic design of the heating structure:

• The fuel chamber is designed for laying and burning fuel. It is separated from the blower chamber by a grate and connected to internal channels, through which smoke and hot gases follow through the entire furnace, redirecting to the chimney pipe.
• The blower chamber provides an adjustable air supply to the furnace and is a collector of ash from burnt fuel, therefore it requires periodic cleaning.
• An oven, a hob and a tank for heating water - these elements are built into heating and cooking stoves.
• Cleaning chambers are necessary, as soot collects in them, which crumbles from the walls of the chimney channels passing inside the furnace. With the help of them, periodic cleaning of the furnace is carried out to maintain normal traction.

• Chimney channels passing inside the furnace may have a different configuration in different models. Hot gaseous products of combustion, passing through them, heat the walls of the furnace, which give off heat to the room.
• Channels direct smoke with combustion products into a chimney located at the very top of the furnace and then going outside the building.

One of the most important conditions for the efficient operation of the furnace is good traction, which is achieved by high-quality masonry in compliance with the ordering scheme and periodic cleaning of the structure during operation. In addition, it is necessary to observe the required height of the chimney and its correct location on the roof.

Materials for building a furnace

An important issue for the long-term functioning of the furnace is the choice of high-quality materials for its masonry, so you should not save on them. To build a building you will need:

• Red refractory brick, the quantity of which is determined by the selected model. It must be remembered that this material is quite fragile, so its transportation and unloading must be carried out very carefully.
• Fireclay bricks are used for laying the combustion chamber in direct contact with the fire. It will take from 40 to 200 pieces, but the exact amount can be found in the diagram of the selected model. This type of brick is able to withstand temperatures of 1450-1500 °, it keeps heat for a long time, gradually giving it to the walls of the furnace.
• You can’t do without raising the oven without mortar for laying bricks, which is made on the basis of clay. The stove-makers are advised to use the Borovichevsky composition of the solution - it is quite plastic during the laying process and refractory during operation.
• Cast iron elements are doors for the firebox, blower and cleaning chambers, valves and a grate. If the heating and cooking stove is raised, then one or more two-burner stove, oven and water heating tank provided by the design.

• Steel wire for fixing cast iron elements in masonry.
• Asbestos cord or sheet - for laying between brick and metal parts.

Now, having become acquainted with some of the nuances of building a furnace, we can consider several models that should be available for masonry even for beginners.

Heating stove by V. Bykov

This oven is for heating purposes only as it does not include a stovetop or oven. However, despite this, it is quite popular for houses with a small area, as it is compact - it takes up little space, but at the same time it is able to heat even three rooms.

The size of the building is 510 × 1400 mm, while its height without a chimney is 2150 mm. If we take the size in bricks, then it is 2 × 5½ bricks.

The stove is quite simple in laying, as it does not have complex internal configurations. In appearance, it generally resembles a thick wall, so the designer himself called it a "thick warm wall." Heat transfer from the entire structure is 2400 kcal/h, but at the same time, 920 kcal/h fall on the side walls, and only 280 kcal/h on its front and back parts. The cross section of the flue duct is 130 × 260 mm.

Due to its small width, the stove fits perfectly between two rooms, opening into a third room, for example, into a hallway, and is not only a separator for two rooms, but also a source of heat for them.

The whole design of this model is conditionally divided into two compartments - this is the upper gas outlet and the lower one is the furnace. In the lower part there are two channels - ascending and descending. They help heat the furnace part of the furnace and equalize the temperature throughout the building, preventing it from overheating.

The upper part of the furnace is made in the form of a cap divided into five vertical, descending and ascending channels, which are overlapped by ⅔ of bricks laid horizontally in the masonry. They create a kind of sieve that delays the release of heat directly into the pipe. The walls of the channels not only direct the heated air in the right direction, but also significantly increase the internal surface area of ​​​​the furnace. These factors increase the efficiency of the heating structure, which leads to greater heat transfer. It is also facilitated by a valve installed in the upper part of the building, which regulates the exit of warm air into the pipe.

For this oven model you will need the following materials:

• Red refractory brick - 407 pcs.
• White fireclay brick SHA-8 - 197 pcs.
• Furnace door 210×250 mm - 1 pc.
• Cleaning doors 140×140 mm - 2 pcs.
• Grate 250×252 mm -1 pc.
• Chimney damper 130×250 mm -1 pc.
• Metal sheet for flooring in front of the firebox, size 500 × 700 mm - 1 pc., ceramic tiles can be laid instead of the sheet.

Bykov furnace ordering

The laying of the furnace takes place on the foundation prepared for it, which should have a size larger than the base of the furnace by 100 ÷ 120 mm in each direction. The height of the foundation must be two rows of masonry below the finished floor. Before laying, it is laid with a layer of waterproofing - roofing material.

ordering	Description of works
	According to this scheme, two zero rows are presented, which are below the level of the finished floor. Each row will require 22 red bricks.
	Masonry, located on the same level with the finishing floor, as well as a metal sheet mounted in front of the firebox. The floor surface around the stove is lined with heat-resistant ceramic tiles.
	1 row - a blower chamber is formed. At the entrance to it, a hewn brick is installed, which facilitates the selection of combustion waste. For laying this row, 21 bricks are needed.
	2nd row - when laying it, the blower door is installed and the chamber itself continues to form. For laying this row, 20 bricks are required.
	3rd row - the blower chamber continues to form. The wire attached to the ears of the door is embedded in the seams of the masonry. For a row, you will need 19 whole bricks and 2 ⅓ bricks, which are stacked near the installed door.
	4 row - the front part of the blower chamber is blocked with bricks together with the installed door. At the rear of the structure, the base of the swivel well begins to form. This row will take 12 whole, 6 in ¾ and 2 in ½ bricks.
	5th row - the base of the fuel chamber is formed from fireclay bricks above the blower chamber. Hewn bricks are laid in the front and rear parts of the base, along which the combustion waste will slide into the ash-blowing chamber through the grate installed on the same row. A gap of 5 mm must be left between it and the bricks. The fuel chamber door is mounted on the same row. It will take 17 whole and two ⅓ bricks.
	6 row - the walls of the fuel chamber begin to form, the chimney well continues to lay out. 11 pieces of fireclay bricks are used.
	7 row - the chimney well is divided in two by two bricks. The bricks above the well must be hewn. As a result of masonry, the base of two vertical channels is formed - ascending and descending. In this row, 11 whole, 2 in ½ and 4 fireclay bricks cut obliquely across the entire width were used.
	8 row is laid according to the scheme, repeating the previous one, the only difference is the direction of the brick. A row will take 15 bricks.
	9th row - the door of the fuel chamber is blocked with two bricks. This row will require 16 fireclay bricks. The back of the oven is placed according to the scheme.
	10 row - bricks are laid according to the scheme in compliance with their direction. This row needs 16 bricks.
	11 row - a brick on the back wall of the furnace and at the entrance to the drop-down channel must be hewn from above, otherwise the work is carried out according to the scheme. A row will require 12 whole, 2 in ½ and 4 in ¾ fireclay bricks.
	12 row - there is a combination of a falling chimney channel and a fuel chamber. For a row, you need 13 whole and 2 in ½ fireclay bricks.
	The 13th row is laid, according to the presented scheme, and it uses 10 whole, 2 in ½ and 4 in ¾ fireclay bricks.
	The 14th row also fits according to the scheme, it will take 10 whole and 6 in ¾ bricks.
	15 row - using prepared bricks, ¾ in size, a narrowing of the fuel chamber, combined with a descending channel, is arranged. The total number of bricks used is 7 whole and 14 pieces in ¾.
	16 row - the combined descending channel and the fuel chamber are completely blocked with bricks. This and the next row divide the structure into two parts - the upper gas-air and the lower fuel. For a row, 17 whole, 4 in ¾ and 2 in ½ bricks are used.
	17th row is laid out of red brick. An opening of the ascending channel is left in it, along its edges hewn obliquely bricks are mounted. Used 14 whole, 6 in ¾ and 2 in ½ bricks.
	18 row - a horizontal channel of the furnace is formed, it is the basis for mounting five channels that will go vertically. The cleaning chamber door is installed on the same row. For a row, you need 8 whole, 2 - ½, 2 - ¼ and 4 in ¾ bricks.
	19 row - the formation of the first vertical channel, the upper part of the building, is underway. It will be a continuation of the ascending channel of the lower furnace part of the furnace. The bricks that form this channel must be cut obliquely from below. Used 11 whole and 4 in ¾ bricks.
	20 row - the second vertical channel begins to form in the same way as the first. Half a brick is mounted between the first and second channels. This part in this row and in the subsequent ones has a dual purpose - it is the basis for the next row and forms windows in the masonry for heat exchange with the walls and maintaining normal traction. In a row, 7 whole, 3 in ½ and 8 in ¾ bricks are used.
	21 row - the third, fourth and fifth channels are formed in it. Bricks placed at the base of the walls dividing the channels are pressed together from below, as in previous cases. For a row, you need 11 whole, 5 in ½ and 4 in ¾ bricks.
	The 22nd row is placed according to the scheme in compliance with the formation of channels. For a row, you need 11 whole and 4 pieces of ½ and ¾ bricks, for a total of 17 pieces.
	The 23rd row is also laid according to the scheme and for it you need to prepare 12 whole, 4 in ½ and 4 in ¾ bricks.
	24 row - on this row, the laying of the wall between the second and first vertical channels is completed. The upper brick in the wall is hemmed from the two upper sides obliquely. For a row, you need 9 whole, 3 in ½ and 8 in ¾ bricks. A total of 18 bricks need to be used, some of which split in two.
	25th row - it completes the laying of the walls between the second and third vertical channels. The upper brick in the wall from above is pressed together on both sides. For masonry, you need 10 whole, 4 in ¾ and 5 in ½ bricks.
	26th row - completion of the wall masonry between the third and fourth vertical channels. The upper brick of the wall is also pressed on both sides. You need to prepare 10 whole, 4 in ¾ and 4 in ½ bricks.
	27th row - work is proceeding according to the scheme, and it requires 9 whole, 4 in ¾ and 4 in ½ bricks.
	28 row - it uses bricks made in ¾ of a solid brick - they form a horizontal channel for flue gases, which is called a cap. For a row, 4 whole ones are used, 14 pieces - ¾, 4 hewn obliquely over the entire thickness.
	29 row - in it, the channel formed in the previous row is completely blocked, with the exception of the opening left for the chimney pipe. For its masonry, 17 whole, 4 - ¾ and 2- ½ bricks will be required.
	30 row is also laid out solid, according to the scheme, except for the opening for the chimney. It uses 6 whole and 20 in ¾ bricks.
	31 rows are laid out according to the scheme and 17 whole, 4 in ¾ and 2 in ½ bricks are prepared for it.
	32 row - the first row of the chimney begins to be laid out, for it you will need 5 whole bricks.

Stove-fireplace "Swede" A. Ryazankin

Quite popular, due to its efficiency, the heating and cooking stove of the "Swede" type. Its design contributes to the rapid heating of the premises and allows not only to heat the house, but also to cook dinner.

The appearance of the "Swede" Ryazankin

Such an oven is usually installed between the kitchen and the living area of ​​the house, positioning it so that the hob and oven are turned towards the kitchen. In some Swede designs, a fireplace is provided on the side intended for heating the living room or bedroom. It is this option that is worth considering, since it is perfect for both a spacious and a small building, and, as you know, many owners of private houses dream of a fireplace in one of their living rooms.

This stove model is heated with wood, has a size of 1020 × 890 mm around the perimeter and 2170 mm in height, excluding the pipe. At the same time, it is necessary to provide for the fact that the fireplace portal will protrude 130 mm beyond the building. The foundation must be larger than the size of the base of the furnace and be 1040 × 1020. The power of the Swede reaches 3000 kcal / h.

For the construction of this model of the furnace, the following materials will be required:

• Red brick, excluding pipe laying - 714 pcs.
• Blower door 140×140 mm - 1 pc.
• Door for combustion chamber 210×250 mm - 1 pc.
• Door for cleaning chambers 140×140 mm - 8 pcs.
• Oven 450×360×300 mm - 1 pc.
• Two-burner cast-iron stove 410 × 710 mm - 1 pc.
• Grate 200×300 mm - 1 pc.
• Chimney damper 130×250 mm - 3 pcs.
• Steel corner 50×50×5×1020 mm - 2 pcs.
• Steel strip 50×5×920 mm - 3 pcs.
• Steel strip 50×5×530 mm - 2 pcs.
• Steel strip 50×5×480 mm - 2 pcs.
• Fireplace grate, you can make it yourself from reinforcing bars.
• Metal sheet for flooring in front of the firebox 500 × 700 mm - 1 pc.
• Asbestos sheet or cord for laying between metal elements and masonry bricks.

Furnace masonry

The presented diagrams show in detail the location of all the cast-iron elements of the fireplace stove, and the description of the masonry will help to avoid mistakes at some rather complex stages of work.

Experienced master masons recommend laying the entire oven dry to begin with, that is, without mortar, adhering to the scheme and understanding the configuration of each of the rows. This process is especially important for beginners who are barely familiar with the work of the stove.

Another trick of experienced craftsmen is the preliminary adjustment and laying of each of the rows without mortar during work. Any row is first laid out, and, if necessary, individual bricks are cut or hemmed, and then they are laid on the mortar.

This approach will slow down the work somewhat, but will allow it to be done much better, without errors that could negatively affect the creation of normal traction.

When performing masonry, you need to keep at hand not only the diagram of each of the rows, but also a sectional drawing of the furnace. It will also help - it will allow you to present all the channels passing inside and the design of the furnaces.

So, the laying is done as follows:

Ordering - from 1 to 6 row

• The first, continuous row of the furnace is laid on top of laid on ready ruberoid foundation. It is very important to lay out the row perfectly evenly and correctly, since the quality of the masonry of the entire structure will depend on it. Therefore, first it is worth marking the roofing material with a ruler, square and chalk, drawing on it the shape of the base of the furnace, observing the dimensions. Then, relying on the scheme and observing the brick laying configuration, the first row is assembled dry, and then - laying on the mortar.
• 2 row. Metal elements are laid in it, consisting of pieces of reinforcement, on which the fireplace grate will later be fixed by welding, or this decorative element is completely leveled. The rest of the laying is carried out according to the scheme.
• 3 row. At this stage, the doors of the first cleaning and blowing chamber are mounted, previously wrapped with asbestos rope or lined with asbestos pieces. To fix the doors in place, a wire is used, which is threaded into special eyelets of a cast-iron frame. Further, the wire is placed in the seams of the masonry, where it is fixed with mortar and pressed against the top row of bricks. Temporarily, until the final fixing, the doors are supported on both sides with bricks.

• 4 row. The work is proceeding according to the scheme, but the series is notable for the fact that the doors on both sides are fixed with masonry, which must be brought out perfectly evenly. The seams in this area can be two to three millimeters wider due to the wire embedded in them.
• It is recommended to lay out the 5th row using fireclay fire-resistant bricks, as well as all the walls of the combustion chamber. On the same row, a grate and an oven box are mounted, which are wrapped or lined with asbestos in order to avoid premature burnout.

• 6 row. On this row, a furnace door is installed, wrapped with an asbestos cord, and with pieces of wire fixed in it.

• 7 row. The masonry is carried out according to the scheme, a steel strip is mounted above the laid out walls of the fireplace, which will serve as a support for the next row of masonry. It is laid flat or in the form of a semi-arch, giving it the desired shape in advance.
• 8 and 9 rows are laid out according to the presented scheme.
• 10 row. The front wall of the furnace is being strengthened, since a cast-iron hob will be mounted in this part of the building. A steel corner is fixed to the wall with the help of two wire hooks, then pieces of asbestos sheet are laid on the place of installation of the plate, and the plate itself is installed. In the same row, the door of another cleaning chamber is fixed.
• 11 and 12 rows are laid out according to the scheme without installing metal elements. On the twelfth row there is an overlap of the cleaning chamber door.

Ordering - from 13 to 24 row

• From 13 to 15 rows are laid according to the developed scheme, strictly adhering to the brick laying configuration.
• 16 row. The device of the walls of the chamber is being completed, located above the cooking stove, which is covered with metal strips. They will serve as the basis for laying bricks for the next row.
• 17 and 18 rows are stacked according to the scheme.
• 19 row. At this stage, two more cleaning chambers are mounted, which are fixed in the same way as the previous ones.
• 20, as well as 21 rows are placed according to the scheme.
• 22 row. Two more doors of the cleaning chambers are being installed.
• 23 row. The laying goes according to the scheme.
• 24 row. A chimney valve is being installed, the frame of which is installed on the solution.

• 25 row. Next to the first, on the adjacent chimney channel, a second chimney valve is mounted.
• 26 row. The cleaning chamber door is being installed.
• From 27 to 30 rows are laid out according to the scheme.
• 31 row. At this stage, the third, last chimney valve is installed.
• 32-33 rows. In this area of ​​\u200b\u200bthe design, there is a transition to laying out a pipe that rises to the ceiling.

When wiring a pipe through an attic floor, it is necessary to isolate combustible materials of construction from it. To do this, a metal box is arranged around the chimney with sides 100 ÷ 120 mm higher than the thickness of the ceiling. This "difference" remains in the attic.

If the walls of the furnace will not be covered with decorative material, then when laying bricks, the still wet mortar in the seams is embroidered with a special tool, that is, it is given a neat convex or concave shape.

The Swede oven can be supplemented with a warm stove bench. This one is shown in the video.

Furnace chimneys (chimneys) are a system of channels inside the furnace that connect the furnace to the chimney. Furnace chimneys are designed to remove flue gases from the furnace and provide heating of the furnace walls. The heat transfer to the walls of the smoke channels occurs due to the speed of movement of gases through the furnace channels. The cross-section of chimneys (smoke circulations) must ensure the free passage of gases. Recommended sections of chimneys are 130×130 mm (half brick to half), 260×130 mm (brick to half brick), 260×260 mm (brick to brick). All turns in the stove chimneys must be rounded so that less soot settles on them. The seams of the brickwork must be completely filled so as not to create additional turbulence during the passage of gases. With a large cross section, gases passing through the chimneys will be cooled quite strongly, which will lead to the appearance of condensate at the outlet. The inner surface of the chimneys must be as smooth and even as possible in order to reduce the resistance to the movement of flue gases.
Systems of furnace chimneys (smoke circulations) are:

• channel;
• channelless;
• mixed.

In channel systems of chimneys (smoke circulations), flue gases are removed using channels. Channel chimneys are divided into:

• single-turn;
• multiturn.

Channelless furnace chimneys (smoke circulations) include a system of chambers separated by partitions.

Each chimney system has its own advantages and disadvantages. The greatest number of shortcomings has a multi-turn chimney system. In a multi-turn system, the gases must pass through the channels, making turns, which leads to resistance to their movement. To overcome the resistance, it is necessary to have good draft in the chimney. Such draft can be created by increasing the height of the chimney, which is not always feasible. Another way to get good draft is to increase the temperature of the gases at the chimney outlet, which will inevitably lead to heat loss and increased fuel consumption. A multi-turn system of furnace chimneys (chimneys) makes sense only if they are small in length. Another disadvantage of multi-turn systems is the uneven heating of the furnace in the sections of the first and last channels, and this can lead to cracking of the masonry. Therefore, the use of a multi-turn system is usually not recommended. But even such a system can be improved, which will be discussed below.

The temperature of the gases before exiting the chimney should not exceed 120-140°C. The high temperature of the gases (250 - 300 ° C) before entering the chimney indicates that the length of the furnace chimneys (smoke cycles) must be increased. The low flue gas temperature (below 120°C) indicates that the length of the chimneys must be reduced. A high outlet temperature can lead to the appearance of condensate, which, penetrating through the masonry, gradually destroys it.

Channel furnace chimneys (smoke circulations) are divided into vertical, horizontal and mixed according to their location. In the direction of movement of flue gases - to lifting and lowering.

When choosing a chimney channel system, it should be taken into account that the vertical system provides a greater heat transfer of flue gases, and the horizontal system creates better draft, which is important when the chimney is not very high.

Furnace chimneys (smoke rotations) are single-turn.

Single-turn oven chimneys have one lifting channel and one or more lowering channels connected in parallel. Flue gases from the furnace enter the lift channel, then pass into all the downcomers, and only after that they enter the chimney. Basically, the heating of the furnace walls is carried out in the downcomer channels.
A positive feature of single-turn chimneys is that their walls are heated evenly, since the temperature of the gases in all parallel downcomers is the same.
Another valuable property of single-turn chimneys is the self-regulation of draft in the downcomers. The deterioration of draft in one of the downcomer channels will lead to a decrease in the volume of gas passed through it, and as a result, to a decrease in the temperature inside the channel. But the volumetric weight of gases in this channel will increase, and heavier gases will move down faster. Therefore, the flow of gases into a less heated channel will increase. The temperature in the channel will increase, the passage of gases through all downcomers will again become uniform.
The simplest version of a single-turn furnace chimney system is a system with one lifting channel and one lowering one. But furnaces with such a chimney system have a low efficiency, as they have a small heat-receiving surface. In addition, the temperature of the gases in the first lifting channel is very high, as a result of which uneven heating of the furnace occurs, which leads to the appearance of cracks. The gas temperature at the chimney inlet can reach 200 - 220°C.

The system of chimneys (smoke circulations) with one lifting channel and several lowering channels does not have the disadvantages of a multi-turn system. But with such a system, the upper part of the furnace warms up most of all, the bottom of the furnace has a temperature much lower. The chimney system with predominantly lower heating is free from this drawback and provides heating of the bottom of the furnace. Hot gases from the furnace first go down, thereby ensuring the heating of the bottom of the furnace, then rise up. The upper part of the chimneys of such a furnace is made single-turn or in the form of a cap. Of course, the design that provides heating of the lower part of the furnace increases the amount of gas resistance, but such a chimney system is the most efficient.

Stove chimneys (smoke rotations) are multi-turn.

In multi-turn furnace chimneys, the smoke channel consists of vertical and horizontal sections connected in series. In such furnaces, flue gases during their movement overcome a large number of revolutions, which leads to soot settling in the channels. In such furnaces, a cleaning device is a prerequisite. In such a system, the gases are greatly cooled, and the draft in the furnace deteriorates. In the initial period of the furnace, the furnace smokes. Flue gas cooling can lead to condensation.

In a multi-turn system, the gases must pass through the channels, making turns, which leads to resistance to their movement. To overcome the resistance, it is necessary to have good draft in the chimney. Such draft can be created by increasing the height of the chimney, which is possible within certain limits. Another way to get good draft is to increase the temperature of the gases at the chimney outlet, which will inevitably lead to heat loss and increased fuel consumption. A multi-turn system of furnace chimneys makes sense only if they are small in length. Another disadvantage of multi-turn systems is the uneven heating of the furnace in the sections of the first and last channels, and this can lead to cracking of the masonry. But the biggest disadvantage of a furnace with multi-turn chimneys is that it requires a large amount of fuel to heat it, which is incommensurate with the amount of heat released. Therefore, the use of a multi-turn system without the improvements described below is generally not recommended.

How to change stoves with multi-turn horizontal chimneys (chimneys) to increase their efficiency.

In each horizontal channel, it is necessary to make suction (injection) holes with a cross section of 15 - 20 cm 2. Injection holes are made every 70 cm. The furnace will melt better, soot deposits will decrease, and a constant temperature will be maintained at the outlet of the chimneys. In more detail, the principles of operation of chimneys with injection holes are described below in the entry "Mixed system with horizontal and vertical chimneys and injection holes."

How to change stoves with multi-turn vertical chimneys

(smoke cycles) to increase their efficiency.

In the dividing walls between the vertical chimneys, it is necessary to make injection holes with a cross section of 15 - 20 cm 2, which will ensure draft in the furnace and a constant temperature of the gases at the chimney outlet.

How to change stoves with single-turn chimneys

(smoke cycles) to increase their efficiency.

It is necessary to make suction (injection) holes with a cross section of 15 - 20 cm 2 from the furnace and from the downcomer. Injection holes will contribute to a good kindling of the furnace after a long break at any time of the year. With the help of injection holes, uniform heating of the furnace walls is ensured, while overheating of the roof and ascending channel is reduced.

Furnace chimneys (smoke circulations) channelless, bell-type.

There are no smoke channels in channelless furnace chimneys. Gases from the furnace enter the chamber - the hood, rise to the roof of the furnace, disperse along the walls, heat them, and, cooling down, go down, and then go into the chimney. This system is quite simple in execution, the thermal energy of the fuel is used most fully.
The disadvantages of such a system are strong heating of the upper part of the bell, soot deposits on the walls of the bell, high temperature of the exhaust gases.
The system with two caps is more efficient. Flue gases from the furnace enter the first bell, then fall and fall into the second bell. In such a system, most of the heat is given off to the walls of the furnace, the temperature of the exhaust gases is not as high as in a system with a single hood. But the top of the furnace also overheats and soot is deposited on the walls of the furnace.

Furnace chimneys (smoke circulations), channelless, bell-type with buttresses.

Buttresses serve as additional heat accumulators on the inner surface of chimneys in a bell-type furnace. Buttresses are made in the form of vertical ribs running along the walls of the furnace and chimneys. Usually buttresses are made in a quarter of a brick. Flue gases come from the furnace into the hood, rise upwards, giving off part of the heat to the furnace walls, buttresses and the furnace roof during their movement.
The disadvantage of such a system is that a lot of soot is deposited on the inner surface of the furnace and especially on the buttresses, which can catch fire, which will lead to the destruction of the furnace.

Mixed stove chimneys (chimneys) with vertical and horizontal channels.

Flue gases from the furnace enter the horizontal channels, then go through the vertical lifting and lowering channels and then enter the pipe. The heat transfer of horizontal furnace chimneys significantly exceeds the heat transfer of vertical channels. The biggest advantage of mixed flue stoves is that they maintain a high temperature for a long time. But such furnaces have all the disadvantages of multi-turn furnaces, namely, a strong supercooling of the flue gases, due to which the draft in the furnace weakens, a large amount of soot accumulates on the walls. The low temperature of the gases at the outlet leads to the formation of condensate.

Mixed system with horizontal and vertical furnace chimneys (chimneys) and injection holes.

This system of furnace chimneys is inherently multi-turn and has several horizontal and vertical channels. Without injection holes, this system would not work at all. Consider the processes occurring in this chimney system without injection holes. When fuel burns, thrust is generated. Under the influence of draft, flue gases pass through all channels, giving off heat to the furnace array. Caps are located above the horizontal channels, into which part of the flue gases rises. During the movement, the gases cool down, giving off heat to the vertical channels and arches of the caps, become heavier and go back into the horizontal channels. In this case, the flue gases give off maximum heat to the walls of the furnace. This process takes place in every cap. But the consequence of this is a strong supercooling of the flue gases, which leads to a decrease in thrust. To enhance traction, injection holes are used to provide self-regulation of traction. Holes are made in the vault of the firebox and in horizontal channels. The process of self-regulation is as follows. With a decrease in thrust and gas temperature, a vacuum is created in the horizontal channels, hot gases are sucked in through the injection holes from the furnace and from the underlying channels, thereby increasing the temperature of the gases, while the thrust increases. Flue gases cease to flow into the injection holes when the normal temperature, pressure and speed of their movement are reached. Injection holes are made with a cross section of 15 - 20 cm 2, every 70 cm.

Furnaces with such a system d chimneys are evenly heated from bottom to top. There are no sudden temperature changes in the room. The decrease in the temperature inside the room is 2 - 4 ˚С in 12 hours, and in 24 hours 4 - 6 ˚ C. At an outside temperature of minus 10 ˚C in a well-insulated house, the stove can be fired after 36-48 hours. But in winter, stoves with such a system chimneys needs to be fired regularly.

Comparative table of various systems of furnace chimneys (smoke circulations).