Heating furnace Kuznetsov order description diagram. Kuznetsov's furnaces: advantages and disadvantages. Preparatory work before laying the furnace

11.11.2019

Among all the variety existing species furnaces of the model of I. V. Kuznetsov stand out especially. This option of stove heating for a bath, a private house, a barbecue area deserves your attention due to its undeniable advantages. Let's talk about the features of "blacksmiths" in more detail.

We briefly touched on the features of Kuznetsov's stoves when we wrote about varieties of fireplaces, Russian stoves and open hearths. Now let's pay more attention to this version of the stoves, because the "blacksmiths" heat many Russian houses and are of genuine interest. Igor Viktorovich himself pointed out that he had developed the basics of the correct design of household stoves, which were developed by I. S. Podgorodnikov on the basis of the works of Professor V. E. Grum-Grzhimailo, a Russian metallurgist scientist.

How do conventional channel ovens work? The movement of gases in them occurs under the forced action of traction. The gas gives off its heat to the brickwork, heats it from the inside, passing through narrow furnace channels. It is necessary to build a high narrow chimney, the stove warms up unevenly, the brickwork can crack. Kuznetsov's bell-type furnaces work differently - on the principle of natural, free movement of gases.

The name "bell-shaped" furnace data was not in vain: inside they have large cavities, hogs, inverted hoods, which can be located both horizontally and vertically, one above the other.

As a result, the heated smoke rises, hits the cap, the dome, lingers there, and then gradually cools down and falls. Thus, the heat is retained inside the furnace and the contact time of the hot gas with the brickwork is markedly increased.

This principle of operation can be explained by the example of a rubber glove, which is completely filled with gases, in all cavities. In the cap, which as a whole can have a different shape, convection occurs, the convective movement of gases in a natural way, according to the laws of nature.

Most often there are two-bell "blacksmiths". In the lower part of the furnace there is a chamber in which a high temperature is maintained, which ensures the end of the combustion reaction of gases that are divided into warm and cold. At the same time, hot gases are retained in the furnace, and cold gases are gradually discharged into the pipe without cooling the heat exchanger itself.

Advantages of Kuznetsov furnaces:

The efficiency reaches 93%. For comparison, for traditional Russian stoves, this figure does not exceed 70-80%;
soot in the "blacksmiths" burns out, so the stove and chimney can not be cleaned for years, which greatly facilitates their care;
the caps inside the furnace are voids, this allows you to save on brickwork, which would have to be done by equipping conventional draft channels;
the stove can be placed anywhere - in the corner, in the center of the room, against the wall. Often, "blacksmiths" heat several floors of the house, working on the same firebox;
any type of fuel can be used in Kuznetsov's furnaces;
the chimney can be made short, which also leads to material savings;
uniform heat transfer, the temperature in the house heated by the "blacksmith" fluctuates noticeably less;
the stove can be easily combined with a hob, a fireplace, a stove bench - there is a large number of modifications;
it is possible to build a supply circuit hot water and water heating;
the high efficiency of the ongoing pyrolysis allows you to save on the fuel used;
masonry lasts longer, less risk of cracking;
A valve closed at the wrong time will have practically no effect on the cooling of the furnace, because the hood is always filled with hot air, and the cold one is pressed to the bottom.

There are few cons to Kuznetsov's furnaces. Firstly, while it is difficult to find a master who is ready to take on such a project, the work of a stove-maker will cost a lot, there are some peculiarities and construction rules. Secondly, the "blacksmiths" are rather large in size, they are quite massive. However, Russian ovens cannot be called compact either.

During his activity, Kuznetsov has developed many types of furnaces that operate on the principle of free movement of gases. There are bathhouses, for home heating, outdoor (with a barbecue), fireplace, bread, cooking, mixed type.

Folding a good brick oven is hard work, and skill and art. And this art, and traditions, and principles were passed down from generation to generation. I.V. Kuznetsov not only follows traditions, but develops them and looks for new ways to solve an old problem that is very relevant today: how to get the maximum furnace performance using a minimum of fuel.

Operating principle

Kuznetsov proposed a new principle for building brick ovens. In all previously invented / designed models, hot gases move through the channels. Passing through them, they heat the brick, cool themselves. Movement is possible only if there is traction. With such a forced principle of action, the heating of the case is uneven, and this leads to the formation of cracks. A large number of bricks occupies almost the entire space, and there is nowhere to put the heat exchanger if necessary. Just put it in a firebox where it will be in contact with the flame, which is why its service life is very limited. In addition, a heat exchanger located in the combustion zone takes a significant part of the thermal energy, worsening the conditions for fuel combustion, which reduces the efficiency of the furnace and increases the amount of soot.

Kuznetsov uses a different, the principle of movement of gases in the furnace - free. The furnace consists of caps - vessels turned upside down (with or without a hole at the top - differently in different models). The hoods can be located one above the other or one after the other, but they must communicate with each other using a dry seam - a space of 2-3 cm, unfilled with a solution or a heat insulator, through which gases pass from one hood to another.

The first cap and the firebox are combined into a single space. With such a device, this is what happens. The hottest gases rise to the top. For some time they remain at the top, where they transfer part of the thermal energy to the walls, they themselves cool down. As they cool down, they sink down, and hotter ones rise in their place. With this construction, the movement of air masses occurs only due to natural physical processes.

You can visually demonstrate the process if you launch a jet of smoke into a glass turned upside down. It rises, reaches the top, then the cooled part of the smoke along the walls falls down. Noticeably the same processes, only much more complex, passing in the furnace.

The red arrows in the figure show a diagram of the movement of hot air in bell-type furnaces. The blue arrows show the movement of cold air entering the furnace. Obviously, it will not rise up, because it weighs more, but will go down and will have almost no effect on the overall temperature in the hood, which is shown in the figure on the right.

But one hood is not enough for effective heat extraction, because most furnaces have two or three arches, depending on the power. Almost the same processes take place in them as in the first one: hotter gases are at the top, heating the masonry, cold gases pass down and exit into the chimney. In the upper zone of the second vault, a heat exchanger or any other device necessary for any purpose is located. No open flames, only hot gases and very efficient heat removal: high temperature air currents constantly flow. Moreover, the heating of the coolant, stones or water in the tank does not have any effect on the combustion processes: they are separated from the furnace by a brick wall.

The design of furnaces of different configurations and purposes is different, but they “consume” little fuel and remain hot for a long time. This is evidenced by the reviews of the owners. For example, such a stove is built in a house made of timber. At -25 ° C, they heat 5 poles each in the morning and in the evening (in total, about 18 kg of firewood is obtained per day). It is +25 o C in the house and it is not cold in the morning. At a temperature "overboard" up to -10 ° C, they heat once. So there are no questions about efficiency. If there are questions, then about the choice of the artist. After all, the parameters of its work depend on how correctly and competently the furnace is folded. And you can’t do it quickly: medium-sized and without bells and whistles - this is 2-3 weeks of work. In general, with reviews of Kuznetsov's stoves, everything is simple: people are happy. Pleasure, of course, is not cheap, but it is definitely worth it. This is claimed by all owners of such furnaces. There are no difficulties in operation, they are economical and not capricious, they give off heat for a very long time, and they heat up quickly.

Advantages of dome ovens

This principle is used in many furnaces for various purposes. There can be several caps, they can have a symmetrical or asymmetrical structure, be located side by side (horizontally) or one above the other (this option is often used to save space). This feature makes it possible to design furnaces of any type and configuration, for any premises and conditions. At the same time, the characteristics remain high: efficiency above 80% for Kuznetsov dome furnaces is almost the norm.

Any devices can be installed in the second cap: hob, heat exchanger, heater, hot water tank, bread oven, etc. There are many modifications and all have one thing in common: high efficiency, economy, uniform heating. Moreover, with a vertical arrangement of caps, the bottom is heated more intensively than the top. So in a room with such an oven is comfortable.

It should be noted that much less brick is required for the construction of such a furnace: more empty space inside. Therefore, the oven heats up faster. But, characteristically, it does not cool down faster. Everything happens exactly the opposite way: Kuznetsov dome furnaces give much smaller daily temperature fluctuations than more massive counterparts with a large number of channels. And all because the hottest part of the gases remains in the caps, and the coldest part of the gases settles down and is removed from the furnace. The oven cools down, therefore, more slowly.

Due to the fact that there are no or almost no narrow channels, the bell-type furnace has less resistance to air flow, so that the chimneys are shorter. Therefore, it is easier to build it, and the foundation is needed not so massive, although it is necessary.

After kindling and entering the operating mode, it is not necessary to regulate the operation of the furnace with the free movement of gases. The process is self-regulating. If the fuel flares up very strongly, the amount of hot gases at the top increases and squeezes the colder gases into the second cap. And the colder ones are, among other things, the air coming from the blower. With a lack of air, the flame dies out, there are fewer hot gases, they rise higher up and more air enters from below. The combustion is activated again. Therefore, although there are gate valves in Kuznetsov's two-bell furnaces, they are used extremely rarely, mainly for non-standard modes.

Automatic regulation of the combustion process leads to practically complete combustion any fuel. That is, such an oven is omnivorous and not particularly demanding on fuel conditions. When using wet fuel, it takes longer to reach normal mode, but then the process stabilizes and the resulting soot burns out. This, by the way, is another plus of dome furnaces: they need to be cleaned very rarely, since there is little ash left, and soot burns out.

Types of Kuznetsov furnaces

As mentioned above, caps can be positioned in different ways, and therefore there are a lot of options. The possibility of installing any heat exchange device in the second dome without compromising the combustion process also contributes to the presence of many different thermal units. At the same time, devices with any type of combustion can be designed according to this principle: upper, lower, pyrolysis, layered, etc. All of them have some specifics, but can be implemented. Projects posted on Kuznetsov's website for various purposes with order. They can be downloaded for personal use freely, but their republishing is not welcome.

There are Kuznetsov furnaces for two-storey houses, and they heat both levels. And there are such units with beds. Heating can be of convection type (only from the walls of the stove) or a hot water heat exchanger can be inserted inside. Then such a unit is called a boiler and denoted by CIK. Four ready-made hot-water brick boilers with a capacity of 16 kW, 17 kW, 34 kW, 64 kW are freely available on Kuznetsov's official website. They can have a built-in tank for heating water for domestic use. The boiler must be tied with metal corners, if necessary, it can be insulated, laid on top of a reinforcing mesh and plastered.

There are many more options for convection ovens. In the heating section cooking ovens without the use of OVIK fireclay bricks, there are 25 different projects. There are three options for a heating and cooking stove with a fireplace. The fireplace can be located on the side (right or left). Such options are marked OVIK BK (side fireplace), there is an option with a bench and a fireplace OVIK BK 13l. With a fireplace located at the back, the marking is OVIK ZK (rear fireplace).

Purely heating thermal units are marked with IEC. The orders in which there is a couch have the letters “lying” or “L” in the name, if there is an oven, the letter “D” is added. Heating stoves also have options with fireplaces. They are marked OIK K. There are PKIK1X calorific ovens. Separately, the category highlights ovens for greenhouses and bread ovens.

Heating furnace Kuznetsov OIK. Impressive

Russian stoves of Kuznetsov are marked with RTIK, in total there are orders of 10 models, two of which are with stove benches. They have the usual configuration of the cooking chamber, the mouth of which must have an airtight damper. If the chamber is not tight, the oven will not work normally.

In the section of stoves for a bath, Kuznetsov immediately offers a variant of the layout of the premises with an indication of the dimensions and shows how you can "enter" there suitable models. After all, the premises of the baths, as a rule, are small, and if a metal stove can be placed in it easily, then an overall brick stove is already problematic. And in this case, many factors must be taken into account: where will it be heated, where is the steam outlet and the hottest part of the furnace. And here are the ready-made options. Very convenient and worth saying a big thank you to the author! The furnaces themselves are placed in a separate category and are marked with BIC.

This video proposes a project for a furnace designed according to the principle of building furnaces proposed by Kuznetsov. The first half talks about the movement of gases and how it works, about the principles of controlling the operation of a particular model. The second commented on the masonry process. Very helpful and informative video.

For laying the body and chimney, it is recommended to use ordinary clay solid bricks. Mark M150 and above, size 250*120*65 mm. It is not difficult to calculate the number of bricks for Kuznetsov's furnaces: you need to multiply the number of rows of the model you have chosen by 0.8. This amount is enough for laying the hull (taking into account the battle and rejection). For the chimney, you need to count separately. The calculation scheme is slightly different: you know how many bricks per row, multiply by the number of rows (each one is different depending on the dimensions of the furnace and the height of the building), add 10% per battle and get the desired number.

For the fireclay core (if any), Sh-5 (230*114*40 mm) or ShB-8 (250*123*65 mm) is recommended. Its quantity is calculated according to the scheme piece by piece. The core in the Kuznetsov furnaces is not connected with the body, that is, there are no common points of contact between them. Between two parallel walls, the body and the fireclay core, there should be a gap of 5-6 mm. To make it easier to withstand, you can wrap the finished core (usually it is placed first) with ordinary packing cardboard of the appropriate thickness. Instead, for better thermal insulation of the firebox, you can lay a heat insulator, basalt cardboard, for example.

The height of the rows of masonry made of ceramic bricks does not match the height of the rows of fireclay. They do not need to be adjusted one under the other. It is important to maintain verticality and horizontality, track the angle, as well as the recommended seam width. And then everything will be as it should be. In reality, the dimensions of ceramic bricks differ from the standard 250 * 120 * 65 mm. If the deviations are not critical, they can be corrected with a seam. Therefore, when calculating furnaces and their heights, they take the height of a brick with a seam. It should be 70 mm. But you can’t make a seam more than 7 mm, so look for a brick of suitable quality and size.

Above, in places where the laying of fireclay ends, there are compensation gaps that take into account different coefficients of expansion of materials. It is imperative to observe them: the expansion of fireclay bricks is greater than that of ceramic ones, and if there is no such gap, the core will break the masonry located on top after a while due to the fact that it expands more.

The size of the gap must be calculated from the marks on the order. The drawings are labeled with height last row fireclay. Consider the height of the ceramic brick wall yourself: multiply the number of rows by the height of the row with a seam (70mm) and get the desired value. It should be 10-15 mm more than the height of the fireclay. This gap is compensatory and it must be present. The resulting void is laid with stone basalt wool (not glass wool, but one that has a use temperature above 1200 ° C).

If there are posts and inner walls inside (usually a quarter thick), bricks can be laid flat or on edge in them. There is no difference, do what is more convenient. There are places in the drawings where in one row there is a brick placed flat and on edge. In this case, it needs to be driven to size (cut).

There are also nuances in the places where furnace casting is installed. In the drawings above the firebox door, due to the features of the program, ceramic bricks are shown, but fireclay must be placed there on the edge. With a difference in height, the voids are filled with cut out plates of fireclay. A gap of 5 mm remains between the metal parts and the masonry - again, due to different thermal expansions. A suitable heat insulator is placed in this gap (with an operating temperature of 1200 ° C).

Now about the mortar: for laying the body (made of ceramic bricks), clay or clay-sand mortar is used. For laying refractory chamotte, purchased compositions (refractory mastics) are used. Kuznetsov does not recommend wetting the brick before laying. If it is necessary to do this, then only with secondary raw materials. Immediately after completion, the oven must be dried, even if you do not immediately put it into operation. If this is not done, subsequently, with the first few fireboxes, there will be a smell of waste.

Results

There are a lot of subtleties and nuances in the construction of brick ovens and this is not at all an easy task. Nevertheless, it is possible to make a Kuznetsov oven with your own hands: the orders and diagrams are provided by the author for free use. With the appropriate explanations and if there is a desire, anything can be done.

The principle of operation of Kuznetsov devices takes into account the natural properties of hot air and gases released during the combustion of fuel. Design brick stove differs in that the smoke is kept inside the stove itself. For this, a so-called hood is equipped - a combustion chamber, which is a closed dome, where the hottest air rises, displacing the cooling air through the lower side outlet.

Photo 1. Scheme of the Kuznetsov bell-type furnace, showing the features of the movement of gas flows in the device.

Air vent under the bottom of the furnace provides a constant flow of cold air. Due to the fact that hot air is kept in the stove for as long as possible, the heat transfer efficiency increases three times compared to other similar devices.

The designers also tried to achieve such results in the case of traditional stoves - for this, models with a system of chimney channels were developed. In them hot air also lingers inside the device, but the lengthening of the chimney naturally worsens the hood, so the heating efficiency does not increase much.

In the case of Kuznetsov's devices, the draft is not disturbed, and hot air is retained not by increasing the length of the channel. It happens due to the natural properties of hot gases, they rise and displace colder ones. The dimensions of this type of stove can vary depending on the required power and the area of \u200b\u200bthe room that needs to be heated. Models with one cap are usually compact and suitable for arranging a small country house.

double bell oven

The most common option for high-quality heating of a private house is the Kuznetsov device with two caps.

Its efficiency is much higher due to longer retention of hot air.

Caps made of heat-resistant bricks are located one above the other with a slight offset - the air displaced from the first cap immediately enters the second, from which it already leaves. exhaust pipe.

The size of such a stove is directly dependent on the area of \u200b\u200bthe house, even a building with an internal up to 5 cu. m. The firebox usually occupies the entire area of the base, this helps to increase the heating power of the air in the furnace.

Reference. In the design of a two-bell furnace, special valves are often installed to isolate the second bell and reduce the heat transfer of the device. It's necessary during the warmer season when high heating power is no longer required.

When using dampers, hot air from the first hood is directed directly into the chimney.

Heating and cooking version of the device

A feature of this design will be the changed location of the first cap - it is made protruding and a hob is installed in its vault most often made of cast iron.

The stove must be solid, because due to the design, the smoke is not drawn out of the hood, so it will inevitably enter the room through split burners.

Sometimes a stove is also installed above the second hood - it does not heat up so much and cannot be used for cooking, but it will be an excellent tool for drying vegetables, fruits, mushrooms and herbs. They often make a niche for storing logs and drying them before use.

With bread chamber

This option is almost the same as a standard heating and cooking stove, but additionally equipped with an oven, mounted in the space of the first cap. The chamber is usually made of cast iron or extra strong steel, lined with fireclay bricks on the inside to provide a softer heat for baking.

In addition to the bread chamber, they often install water heating tank- the area of the second cap is also suitable for this. Depending on the number of additional functions, the size of the furnace will increase, it will require large fuel costs.

Kuznetsov's stove for a bath

According to the principle of operation, the sauna stove does not differ from the options described above. But still she has several features:

built into the bottom cap of the device pallet with stones;
the device is provided water access and steam outlets;
has thicker walls for maximum heating of the stones and to avoid overheating of the room.

Furnace drawings

Photo 2. Drawing and ordering of the two-bell Kuznetsov furnace. The device is presented in one piece and in section.

Photo 3. Drawing of the Kuznetsov bell-type furnace. Also, the device is equipped with a system of chimney channels.

DIY construction, device ordering

Before undertaking work, it is necessary to correctly calculate the design of the device, For this, the following factors are taken into account:

Furnace power- depends on total area premises and the quality of its thermal insulation.
Number of caps- in Kuznetsov furnaces they are often made three or more, which significantly increases the heating efficiency, almost without requiring extra fuel consumption. Only the change in the massiveness of the device is taken into account.
The main function of the furnace- whether the device will be used only for heating or additional features will be needed: cooking, heating water.

Photo 4. Step-by-step ordering of the Kuznetsov furnace. The device is also shown in ready-made from different angles.

A common option for construction is a two-bell oven with a hob. It is functional with a fairly compact size and is well suited for placement in small spaces. country houses.

materials

A very high temperature forms inside the cap area, so only refractory brick and chamotte clay with fine sand for masonry mortar. Homemade mix is often recommended to replace ready mixes from building stores- this reduces the risk that the cap will crack during operation and lose sealing.

For display external walls and the upper tiers, ordinary ceramic bricks with a density M150 and cement mortar .

When working, we must not forget that laying ordinary and fireclay bricks in one row is excluded - they have different expansion rates and the masonry will collapse during operation.

In addition to masonry materials, you will need to purchase additional elements - metal corners, doors and hinges, latches, hob. All this is available for purchase in specialized stores. You will need reinforced wire to perform the binding of the masonry.

Instruments

For all types of work you need to prepare a set of tools in advance:

a container for preparing the solution and a shovel for mixing it;
furnace hammer-pick for breaking bricks;
grinder with cutting disc by stone;
pliers and scissors for metal for cutting wire;
trowel for applying mortar;
leveling rule;
protective gloves and goggles.

To check the correct masonry, you will also need various measuring instruments: roulette, building level, plumb lines, cords, etc.

Site preparation

construction brick oven always starts with the ground equipment. For blacksmithing suitable for a standard type foundation- depth half a meter and with sides that go beyond the perimeter of the future masonry on 10 cm. Operating procedure:

A pit is being prepared, the bottom on 15-20 cm closes the drainage - a layer of sand and crushed stone.
A wooden formwork is placed on a well-packed drainage, protruding above the surface by 20 cm
The foundation is poured concrete mix and left to dry.
After the correct laying of the foundation, a flat platform is obtained, protruding above the floor surface by 10-15 cm(depending on shrinkage).

Base surface closed waterproofing layer(roofing felt is good), then it is laid reflective layer metal industrial foil. In the case of the construction of a blacksmith, the heat from the furnace will be stronger than from conventional appliances, especially in the lower tier, so the foundation is protected from overheating.

The walls adjacent to the future location of the device are closed thermal insulation material, it is recommended to stuff a metal sheet on the floor in front of the firebox to avoid the risk of fire from falling coals. The location of the chimney is calculated in advance - it is not recommended to place it next to the roof ridge.

Masonry

After the foundation has been prepared, work begins on the construction of the device itself:

The solution is mixed in the prepared container- before starting work, the clay is soaked for two days. In addition to a shovel, the use of a construction mixer will be effective for mixing.
When laying, it is recommended each row is first laid on a dry surface to accurately determine the dimensions of the cutting of bricks. The first row of the base is made solid.
Starting from the second row the blower is laid out, and then the area of \u200b\u200bthe first cap. Hinges for the furnace door are installed as necessary. Every third row masonry is connected with wire, the cut pieces of which are laid in the solution.
Inner part furnaces laid out with fireclay bricks, outdoor- ordinary ceramic. Between these layers there is no binder solution, a small gap is left. Bricks from two rows should also not protrude, intersect with the adjacent layer.
Inside the vault of the first cap, on supports made of fireclay bricks, cast iron hob, which is hermetically fixed with a solution.
After completing the set first cap, laying out the base for the second begins with a slight offset ( to the width of the hob).
Giving all the best second cap, chimney column, valves are installed to isolate the second level in summer time of the year.

After laying out the top and installing the chimney pipe, the finished stove is left to dry, which takes at least a month. First two weeks the device is dried open windows and doors starting from the third week produce gradual heating, increasing the volume of fuel until it reaches a full bookmark.

Possible difficulties

The blacksmith masonry has some specifics, therefore In the absence of experience, mistakes are often made:

No gap is left between the walls of the firebox and the outer- fireclay brick expands when heated, so it can destroy the masonry.
No wire is used for tying masonry- due to the greater degree of heating, the walls of the furnace may crack.
No gap left when installing metal parts- also leads to the expansion of the metal with strong heating and the appearance of cracks.
Wrong warm-up disrupt the drying process of the masonry and lead to the occurrence of deformations, cracks.
Not properly insulated walls and ceilings (at the installation site of the chimney) - due to the high heating temperature, the risk of fire in the case of using a blacksmith is higher than that of a simple furnace.

Due to the very high temperatures inside the combustion chamber, most of the ash and soot burns through, reducing the frequency of cleaning.

One of the advantages of blacksmithing is the ability to choose any currently available solid fuel : firewood, dry pieces of peat, sawdust.

With small changes in the design, it is possible to install a heating system with gas or electricity. It is possible to connect the stove to a water circuit, which will allow high-quality heating of remote rooms. The undoubted advantage will be relatively low cost of materials, the ability to perform all stages of work independently.

Despite the current abundance of various heating appliances and systems, brick ovens are in no hurry to “give ground”. Many owners under construction country houses When planning a heating system, they also provide a place for this traditional heating facility, which, in any case, can both heat and help with cooking.

Moreover, in this area there is a constant development, search interesting solutions, development of new models with improved performance. A striking example of this are the so-called bell-type furnaces. And the most popular of the bell-type furnaces are the designs of the Russian engineer I.V. Kuznetsova. Since the distant 1962, he has been improving existing designs and developing new versions of them. As a result, about 150 models appeared, which have different dimensions and are designed for heating various areas.

Kuznetsov's stoves are very popular. Therefore, to meet the needs of interested readers, the topic of this publication will be a do-it-yourself bell-type furnace - Video instruction+ ordering. One of the multifunctional options for such furnaces will be presented, which has a design that is quite affordable for self-construction.

Kuznetsov's bell-type furnaces

General principles of bell-type furnaces

Furnaces designed by I.V. Kuznetsov, are distinguished by high efficiency of their work. And besides, they have a very aesthetic appearance, which is able to complement and harmoniously fit into the interior design, made in any style.

In common parlance, this engineer's designs are often referred to as "caps" or "blacksmiths". Their well-deserved popularity is explained by the fact that they compare favorably with other furnaces with their efficiency and increased heat transfer. Almost all Kuznetsov furnaces have an efficiency approaching 80÷85%, while this indicator of a traditional Russian furnace does not exceed 60%, despite its large mass and impressive linear dimensions.

This high performance was achieved thanks to the successful located internal channels of the furnace, along which the movement of heated gas flows is carried out. Almost all previously used furnace schemes have a channel system for the removal of heated gases, which, in principle, is a long labyrinth. Hot air, moving through such a labyrinth, gives off heat to the brick and cools quickly. Without well-organized draft in such structures, the outflow of combustion products from the combustion chamber slows down or stops, so smoke often begins to enter the premises (for example, when strong wind on the street).

In Kuznetsov's designs, the principles of free movement of gases operate, so heat exchange in them is carried out in a different way. Caps-vaults, which are equipped inside the furnace, gradually take heat from hot streams. The cooled gases do not immediately go into the chimney, but slowly fall down the hood and only from there rush into the chimney pipe, and new streams of hot air take their place in the upper part of the hood. This happens as long as there is heat in the furnace furnace.

This process can be traced visually by conducting an experiment with hot smoke launched into an inverted glass - it first rises up, touches the bottom of the container, heats it, and then, distributing along the walls, descends to its lower part, thus covering the entire space of the glass with heat.

Of course, Kuznetsov furnaces have a more complex design, but the main thing is that the processes of gas movement occur naturally. Thanks to this, it is possible to achieve high heat transfer and serious savings in solid fuel.

Separately, it must be said about the thrust created in such a furnace. It is formed not only due to the chimney, but also for the reason that the high temperature of the gases that rise under the arch of the hood contributes to the creation of rarefaction of the air. In connection with such phenomena, draft in bell-type furnaces is also formed naturally, without requiring the construction of a high chimney, which, for example, cannot be dispensed with when building and.

Furnace prices

bell-type furnace

It should be noted that bell-type furnaces are divided into Various types in terms of their functionality, like conventional canal structures. So, they are divided into the following "classes":

Heating. Designed for space heating only. This option, by the way, is chosen the least often, since usually the owners of private houses prefer multifunctional structures, because they are more practical.
with one or two burner hob. This design will work both for heating and for heating water, cooking or heating food. In a word, she will help out the owners of the house in any situation.
, whose purpose is clear from the name.
Multifunctional designs, including not only a hob, but also an oven, drying chamber, hot water tank or circuit, as well as a heated bench.

Moreover, if you choose a stove with a wide entrance to the furnace and install a glazed door in it, then the stove can also be used as a fireplace

As you can see, the range of bell-type furnaces is quite large. There is an opportunity to choose the option that is ideal both in terms of functionality, and in terms of its dimensions, and in terms of thermal power for a specific area of \u200b\u200bthe house.

The obvious advantages of bell-type furnaces

The advantages of bell-type furnace designs include the following points:

During the construction of bell structures, much less brick and, as a result, a mortar for its masonry. Yes, and the masonry itself is much easier to perform, since you do not have to display long labyrinths of channels to move gas flows.
Due to the smaller amount of material used, the stove is lighter, and this, in turn, means that the foundation for it may not be as massive as for channel stoves.
Combustion in this design is more intense, so there are practically no solid particles left in the combustion products. As a positive consequence, there will be much less plaque on the walls of the chimney, and therefore it will be possible to clean it less often.
As mentioned above, the part of the chimney that rises above the roof may be smaller than that of channel structures where the pipe must have a height of at least five meters.
The unpretentiousness of the cap design in maintenance. The presence of narrow channels in channel furnaces requires their frequent cleaning, as they quickly become overgrown with soot. Their narrowing significantly reduces draft, which can lead to the reverse flow of combustion products that begin to enter the premises.
In this bell design, sufficient space is created for the installation of water heat exchangers. The heated water can be used for household needs or put into a heating circuit, which will bring heat to other rooms in the house.
There is a rapid heating of the structure, and hence the heated premises.
Such furnaces are characterized by uniform heating of all walls and their high heat transfer.

The design and principle of operation of the bell-type furnace

Kuznetsov's furnaces can be single or double bell. The second option is more common, since its efficiency is much higher. The most simple circuit such a furnace is shown in the diagram.

The firebox is located in front of the furnace. The diagram shows the exit of heated air from it - a smooth red arrow pointing up.
Further, the heated air from the furnace enters the lower hood, separated from the firebox by a non-continuous partition. Entering the lower hood, hot air rises to its ceiling. Then, cooling down, it gradually descends to its bottom, where below, in back wall cap there is an opening leading to the channel connecting the lower cap with the upper one.
Passing through the connecting channel, the still warm air rises again to the ceiling, but already in the upper hood. There, hot gases cool down and begin to descend to the ceiling separating the lower and upper hoods. Going down and passing along the floor, hot air enters the hole, which directs the already very cool gases into the chimney.
A valve is installed in the upper front part of the fuel chamber, called "winter-summer". It is designed to direct hot air from the furnace directly into the chimney - this is necessary in the summer, when only hob. If this, as well as the valves located above (blocking the chimney) are in the open state, the combustion products, having found an easy way out, will not go into the pipe through the caps, but will go into it directly. In winter, the lower valve closes, and the upper one opens halfway, and hot air, passing through the entire structure of the furnace, heats its walls and, having already cooled down, given off heat, goes into the pipe.

If it is planned to mount it in a bell structure, then it is best to install it in the upper part of the lower hood. Such a location will not affect the combustion mode of the fuel, as well as the thermal equilibrium of the furnace.

Calculation of a bell-type furnace

In order for the stove to justify the hopes placed on it, its parameters must correspond to the real indicators of the room (or several rooms) to be heated. For the correct selection of the design of the furnace, the first thing to do is to determine the volume of the room that is planned to be heated, as well as calculate the possible heat loss. The dimensions of the furnace walls involved in direct heat exchange are also taken into account, also taking into account a number of important nuances.

These calculations are quite cumbersome, and require some experience and some knowledge to carry out. Therefore, they often proceed from common “constants”: for a well-insulated house with a conventional firebox, one can proceed from an indicator of 0.5 kW per square meter room area. But in case severe frosts it is better to lay also an operating margin - focus on the value of 0.76 kW / m².

If there is no experience in such calculations, then it is recommended to use ready-made projects in which the developers already indicate the power of the device and the area for which this furnace is designed. Moreover, today a large number of models are offered that have different linear dimensions and are designed for heating any reasonable area.

And for inquisitive readers who still wish to carry out an independent calculation of the necessary furnace, a special article will be published on our portal with a detailed description of the calculation algorithm and the necessary reference and tabular data.

Construction of a bell-type furnace

Preparatory work before laying the furnace

The list of preparatory work can include all those actions that will be listed and described in this section.

Choosing a model and location for installing a stove in a house

Before choosing the design and size of the furnace, you need to determine the place of its installation in the house and the approximate area that can be allocated for it.

In this case, the location of the chimney pipe must be taken into account, since it must pass through the attic floor between its beams, at a distance of at least 150 mm from them. Of course, the location of the roof rafters is also taken into account - the requirements are the same there.

Brick prices

Foundation for the installation of the furnace

Further, for the construction of the furnace, you will need to prepare a reliable foundation. If the furnace is being built together with the house, then it must be remembered that the foundation of the building must be separated from the base furnace building. Otherwise, due to possible shrinkage, the skew of one foundation can pull the structure of another along with it.

In the event that it is decided to build a stove in an already built house with a wooden floor, part of the plank flooring will have to be dismantled. The foundation must be wider and longer than the base of the furnace by 50 ÷ 80 mm on each side. If the house is built on a slab concrete foundation, and the furnace design is relatively small, then it can be installed on the common foundation of the house. But this is usually stipulated by the developers of the heating facility.

To equip the foundation, it will be necessary to dig a pit, the depth of which will depend from distance from floor to ground. AT total the height of the foundation (taking into account all the layers of the structure) should be 500 ÷ 700 mm. If the floor is raised high above the ground, then formwork must be built to the height of this distance, since the foundation must extend to the height of the finished floor.

It will be necessary to fix the waterproofing material on the formwork walls, since it will have to be completely filled with concrete mortar. The layer scheme presented above is completely suitable for the foundation, except for the upper concrete layer located in the ground, which will serve as a natural formwork for it.

If the foundation is almost completely sunk into the ground, then after installing waterproofing along its walls, a sand cushion of 150 mm is poured into the bottom of the pit, which must be well compacted. Broken bricks, large gravel and stones are laid on top of the sand - they must also be compacted as far as possible. This layer should be 150÷200 mm.

Prices for crushed stone

Crushed stone of the middle fraction is poured on top of the stone. After that, a formwork rises around the pit to pour a concrete layer into it, which is recommended to be reinforced by laying it in a solution metal mesh with cells 50×50 mm. Dynamic loads are not expected, so it is quite possible to use concrete with brand strength M 200 (approximate proportions of the components: PC 400 cement - 1 part, building sand - 1.9 parts, gravel or small gravel - 3.6 parts).

To determine the exact amount of ingredients needed to prepare the required amount of concrete for pouring the furnace foundation, you can use the calculator below.

Today, many are wondering how and what is the best way to heat your home if there is no gas. Firewood and coal are among the most affordable types of fuel. Therefore, the right decision here would be to build a heating stove, and even better, add a cooking function to it for cooking. There are a lot of design options both in form and in principles of operation.

In this article I will introduce you to the features of the Kuznetsov furnace, its advantages and step by step diagram erection of such a unit independently.

The furnaces of the engineer Kuznetsov have been known not only at home, but throughout the world since the 60s of the last century.

Moreover, the relevance of developments half a century ago has not become less at all, but on the contrary, Kuznetsov's furnaces are becoming more and more popular.

The purpose of modernizing the old design of the Russian stove with a not so significant change in its internal device was the creation of a heating unit with more high efficiency while saving fuel.

Bell-type furnaces are one of the most common and in terms of characteristics they are in no way inferior to channel furnaces.

This oven is latest development in the conservative field: installation and design of furnaces. This stove is fundamentally different new method use of hot gas.

In a standard type design, the movement of cold and hot gas occurs due to the draft of air, which enters through the ash pan.

The bell-type furnace is very similar in principle to the work rocket ovens, where hot gases move not under the influence of thrust chimney, but due to the gravity of the gases themselves.

Advantages and disadvantages of the furnace

Advantages:

- high efficiency of 75-85% (efficiency);
- fuel burns at high temperatures;
- the stove runs on all types of solid fuels - wood, hard and brown coal, briquettes, etc.;
- ease of maintenance, no need to clean long channels (low soot formation);
- durability of the furnace;
- aesthetic, original appearance;
- high efficiency, multifunctionality;
- profitability;
- long-term heat retention;
- the shape and design of stoves may vary depending on the purpose;

combining the Kuznetsov stove and water heating at home is not difficult and is often used in practice.

A tubular heat exchanger is installed inside the furnace and connected to the heating circuit pipeline. The main plus is that the heat engineering and heat transfer of the furnace during modernization remain unchanged, without the slightest decrease in efficiency;

the design of the blacksmith allows you to arrange low chimneys, and there is no reduction in thrust. This fact is somewhat surprising to those who first get acquainted with the design and operation of these furnaces;

The features of the internal design of Kuznetsov's furnaces make it possible to install the unit in almost any room of any size, regardless of what the room is intended for.

Both in kitchens and in common rooms, the stove looks solid and aesthetically pleasing, and organically fits into many interiors;

the most interesting and unusual feature of blacksmithing in the context of a house oven: you can not close the view. This most important part of the furnace and one of the conditions for safe everyday operation is needed for the Kuznetsov furnace only if an emergency occurs.

The fact is that when the process of fuel combustion comes to an end and cooling begins, the thrust in the furnace channels is redistributed spontaneously, “automatically”.

It was the bell-type stoves that became the basis for the creation of many household, heating and cooking stoves of a new type, which give a much better effect with less fuel consumption.

What can be said about the shortcomings of the furnace.

Technically, they are not, but something still needs to be taken into account.

The Kuznetsov furnace cannot have massive walls - this would nullify many of its advantages. But at the same time, it is subjected to rather high thermal loads.

Therefore, this unit must be carefully calculated and verified at the development stage and just as carefully, with scrupulous observance of all technology requirements, built. At the slightest deviation from the technical regulations, the blacksmithing will turn out to be very short-lived.

The principle of operation of the furnace

It is based on the principle of free movement of gases. For air to circulate in a conventional furnace, external energy is required, that is, the creation of forced draft in the pipe.

When gases are in a closed space, in the presence of a constant source of heat, they are separated under their own weight - cold ones settle down, hot ones rise up. At the same time, in the area of high temperatures, the pressure rises, and where it is cold, it drops and energy is generated.

It turns out that turbulent motion occurs automatically due to the laws of physics. This means that if convection flows are correctly directed, then thermal energy will be transferred by the masses of gas themselves.

With electrical heat supply, no draft pipe is required. If the stove is heated with wood, then invariably the combustion product must go outside.

Thanks to a cunning design, it accumulates at the last stage of its journey, as if under a hood. There it burns out again, giving up its heat to the end, and then it is discharged into the street in the form of useless gas, without cooling the system. Such furnaces are also called bell-type.

The fundamental feature of the gas filling of the cavities is that, no matter how many compartments the furnace has, they are all filled with gas evenly and the same physical processes occur in all. It is impossible to create something similar with the help of traction, the principle of countercurrent (widely used in Europe) or other convective methods.

That is why such stoves are an innovation in the stove heating system.

They regulate themselves and, no matter what configuration they are given, they always work according to a natural principle.

The principle of the furnace device is quite simple: the lower tier and the firebox (it is also called the hearth) are combined into a single space - a cap, inside which hot gases move freely.

The hottest, lighter gases move to the top of the bell, while the “heavy” cold gases are located at the bottom. And between them circulate gases having an intermediate temperature.

The heated air is kept in the furnace for a long time, transferring heat to the walls of the hood, and the cooled air is discharged through a special passage into the chimney. The combustion temperature in the hood is very high. The efficiency of such a stove is three times higher than that of a traditional Russian stove.

Varieties of Kuznetsov furnaces

According to the functions performed, Kuznetsov's brick kilns can be divided into several main groups:

Fireplaces.
Grills and BBQ.
Combined structures, complexes.
Perhaps the most popular are Kuznetsov's heating and cooking stoves. They will warm the house and will not leave you hungry.

Kuznetsov also has such projects.

Before you start building, make sure that this is exactly the option that you want to see in your home.

Such furnaces imply the presence of a convenient ledge with a cast-iron surface, with the possibility of partially opening holes to increase the temperature. It is also possible to make a door for a cauldron, like old Russian stoves.

The layout of heating and cooking stoves requires its own approach and individual drawings.

Bell-type furnaces can be erected in almost any room. It can be an apartment, a residential building, an outbuilding or a bathhouse. For example, for a bath, a bell-type stove will be an ideal replacement for a conventional standard stove.

By building this stove for a bath, you can solve several problems at once. This design is able to heat several rooms: a sink and a steam room, as well as a rest room. In addition, it is very convenient to heat water on the stove, creating steam in the required amount in parallel.

The house can be equipped with two-bell heating using a stove, this installation is very functional. Before building such a structure, it is necessary to carefully study the project.

A system that burns raw fuel must be organized by the most optimal way. The furnace must always be maintained at the correct temperature, otherwise the gases that form after combustion can be transformed into harmful soot and tar waste.

Do-it-yourself Kuznetsov oven

The construction of a blacksmith requires not so much skills as the availability of good schemes and drawings, as well as the utmost care. Not even a stove-maker, but a masterful householder can master this task.

It will be easier for those who already have the precious experience of bricklaying, then the only thing you will need to do is quietly and peacefully lay the rows, following the pattern.

Having decided to build a furnace according to one of Kuznetsov's orders with your own hands, get ready for careful and scrupulous work.

On the diagrams, which can be easily found on the Internet, you will see a graphic representation of each row, however, before starting laying, you need to get acquainted with the features of the technique, in particular:

selection and pre-treatment of bricks;
purchase of metal parts (plates, dampers, doors, valves);
determining the most suitable location;
preparation of the base and foundation;
the possibility of equipping a chimney, etc.

Fireclay refractory bricks (Sh-5, ShB-8) are recognized as the best material for the internal laying of "blacksmiths", and ceramics (M-150) for external design.

For amplification brick walls use metal elements (rebar, wire).

In order for the furnace to function with maximum heat output, experienced craftsmen hone not only their skills, but every brick - literally. They polish every detail, which is why projects made by professionals look flawless.

The main purpose of any stove is heating, its location must be chosen to provide heat in the most efficient way.

Kuznetsov's furnace are infrared heaters, which provide the most heat by direct radiation.

Thus, maximum power is achieved with the correct positioning.

Therefore, the center of the room is always right choice. A wise decision is to place it as a functional space divider, such as a kitchen and living room or living room and bedroom.

Try to avoid placing the stove masonry next to outer wall or, even worse, place it in a niche in the outer wall (a typical place for conventional fireplaces) if you want to keep the heat indoors.

The choice of a stove of one type or another and its location in the house, in addition to the preferences of the owner, depends on the purpose of the stove, the size of the house and the level of its thermal insulation, the number and size of windows.

In addition, for normal operation and repair, access to the stove must be free from all sides, that is, none of the sides of the stove should simultaneously enter into any of the external walls of the house.

To complete the construction process, you need to stock up on a bayonet and shovel, as well as the following materials:

sand (3 parts), cement (1 part) and water for mortar preparation;
reinforcing rod of medium section;
polyethylene film;
board for the construction of formwork.

Construction stages:

1. After making the foundation, you need to take care of preparing the mortar for laying the furnace. For the construction of a brick oven, not cement is used, but clay. And not any, but only the one that lies at a depth of at least 2 meters. The clay is sieved and washed out, preparing a solution of the desired viscosity.
2. After the concrete foundation has completely hardened, you can proceed to the brickwork. The Kuznetsov furnace is correctly lined up only if the order proposed by the inventor is followed.
3. Before starting masonry, it is worth considering the location of the chimney pipe inside the room and outside on the roof, which must meet certain requirements. Recall that any Kuznetsov furnace has ready-made drawings, in accordance with which construction work is carried out.
4. Fireclay fire-resistant bricks are used for laying the first two rows. To connect the bricks, a special masonry mortar is prepared. It is not recommended to use a mixture prepared for arranging the foundation.
5. After completing the laying of the 1st row, the corners are checked, each of which should be 90 degrees. From the 2nd row, the arrangement of chimney channels begins.
6. To improve the heat output of the device, it is recommended to install 4 cleaning channels for the channels - in the back, in the blower and on the sides. The sizes of cleanings are chosen individually. At this stage, the horizontalness of all surfaces is checked using a corner.
7. From the 2nd row, an ashpit and a blower are formed. These working chambers are designed to clean the ash and create the necessary draft for combustion. Brickwork performed in a checkerboard pattern with a seam 6 mm thick. To fix the bricks, a solution based on refractory clay is used.
8. Next, partitions are installed for internal compartments, a wall is formed between the blower and the working part of the furnace.
9. When laying the 5th row, a grate is installed, the thickness of which is determined by the degree of loading of the chamber with fuel.
10. Until the 16th row, laying is carried out similarly to the previous rows.
11. From the 17th row, a cap is installed, after which you can begin to equip the second chamber located above the first. It will be the second cap. At this stage, the cap is overlapped, and on the 21st row, passages are arranged that are directed along internal walls on both sides.
12. The work is carried out in accordance with the proposed order until the 26th row, after which top part the cap is securely closed with brickwork.

24 hours after the completion of the masonry, a test run of the stove can be carried out with the addition of a small amount of fuel material. This will check finished structure for tightness and the absence of gaps between the bricks.
If even minor deficiencies are found, they must be eliminated immediately.

The firebox is made of fireclay bricks, and the body of the furnace is made of ceramic, which means that when heated and cooled, they behave differently. Therefore, the firebox itself must be floating; for this purpose, a special dry seam is made around it.

This is done so that different physical characteristics the laying of fireclay and ceramic bricks did not break during operation.
"Dry joint": between fireclay and ceramic bricks, masonry mortar must be removed, and mineral cardboard must be inserted into the resulting void.

It is necessary to strictly observe one more rule - the protrusions of fireclay masonry should not enter the recesses of ceramic masonry, and vice versa. Thus, we get a completely independent firebox.

Features of the operation of the furnace

The first is the automatic fuel combustion mode.

In a conventional stove, when kindling, it is recommended to open the blower to the maximum width in order to create more draft in the stove. Then, as the fire in the furnace intensifies, the door is gradually covered so that the temperature of the flame decreases somewhat, and the heat is transferred to a greater extent into the room.

In bell-type furnaces, manipulations with doors and furnace valves do not make sense. The intensity of combustion is regulated by the ratio of the volume of the caps and the combustion chamber. This happens automatically, you just need to kindle a fire and lay the required amount of firewood or other fuel.

The second thing that pleasantly strikes is the absence of the need for daily cleaning of the ash pan.

Any combustible material burns completely in the furnace, without a solid residue. Almost no soot is formed on the walls of the furnace: as a result of pyrolysis, carbon is oxidized to the state of carbon monoxide (and partially carbon dioxide) gas.

A chimney valve that is not tightly closed will not lead to a cooling of the furnace: hot gases will be in the dome until they give up all thermal energy bricks.

In summer mode, the Kuznetsov stove turns from a heating and cooking oven into a cooking one. To do this, it is enough to open a special valve (it is called the valve of the summer run), after which the flue gases will enter the chimney directly, bypassing the caps. Accordingly, only the hob will be heated.

The temperature inside the cooking chamber can be regulated by a damper installed on the exhaust channel extending from it. By closing the valve and the door of the chamber, it can easily be turned into an oven. For ease of use, shelves for baking sheets can be fixed in the walls.

If you need to quickly warm up the room or dry out, the door of the cooking chamber is opened. At the same time, the temperature on the burners remains high enough for cooking.