How To Make A Kuznetsov Oven With Your Own Hands: Diagram, Ordering With Photos And Videos, Etc

2024 Author: Bailey Albertson | [email protected]. Last modified: 2024-01-17 22:26

How to fold the Kuznetsov bell-type furnace yourself

Igor Viktorovich Kuznetsov's stoves are remembered when it comes to the economy and efficiency of heating a house. Since the 60s of the last century, our compatriot has developed and implemented dozens of projects of bell-type furnaces that use the principle of free gas movement (FGM). The popularity of these inventions is great: foreign manufacturers of heating equipment are carefully studying the experience of introducing blacksmithing furnaces. Brick ovens are constantly being improved, combined options are being developed that combine various functions - heating, cooking, baths, boilers, etc.

Content

• 1 What is a Kuznetsov oven and where is it used

  • 1.1 Advantages and disadvantages of the Kuznetsov furnace

  • 1.2 Types of "furnaces-blacksmiths"

    1.2.1 Photo gallery: shooting the Kuznetsov furnace with a thermal imager

• 2 The design of the Kuznetsov furnace, its distinctive features

• 3 Furnace designs for private low-rise construction

  3.1 Video: construction of a Kuznetsov furnace with a water boiler

• 4 Materials and tools

• 5 Preparatory work before assembling the oven

  • 5.1 One of the options for constructing a Kuznetsov furnace with your own hands
  • 5.2 Video: Kuznetsov furnace project in 3D
  • 5.3 Video: Kuznetsov furnace design in 3D (part 2)

• 6 Features of operation of bell-type furnaces

  6.1 Video: testing the Kuznetsov stove

What is a Kuznetsov oven and where is it used

Heating household stoves are divided into two types: duct and bell-type. In the duct, the movement of gases through the chimney occurs under the forced action of the draft. Passing through narrow channels inside the furnace massif, the gas gives off heat to the walls and, heating the brickwork from the inside, heats the room. But the uneven heating of the stove under the influence of increased traction wears out the masonry, cracks appear. In addition, a narrow chimney is built to a great height - this complicates work in low buildings.

Multifunctional bell-type stove with a stove bench: heats up the room faster by directing heat flows from two structures

Inside bell-type furnaces are arranged differently: with large cavities in the form of inverted bells. They are located either horizontally or vertically on top of each other. And the smoke leaves the combustion chamber due to the free flow: hot air rises, hitting the bell, lingers there for a long time, and when it gradually cools down, it descends. Due to the circulation of cold and hot streams, heat does not leave the furnace immediately, maintaining the wall temperature for a long time. In this case, the degree of heat exchange increases, since the contact time of hot gases with the heat exchanger increases. The efficiency in some models exceeds 90%.

Furnaces are used not only for heating rooms, but also in chemical production, in metallurgy for melting metals. For example, at the largest steel plant in Zaporozhye, along with blast furnaces, two bell-type furnaces are used. In the chemical industry, muffle furnaces are widely used, which in their essence are free gas movement heating systems (FGM).

The principle of operation of the muffle and bell-type furnaces is similar - combustion occurs without forced draft

Advantages and disadvantages of the Kuznetsov furnace

Bell-type furnaces are a fairly new phenomenon in construction. Heating of houses with such stoves is not widespread. More often, preference is given to the traditional Russian stove, proven for centuries. Kuznetsov's stoves cannot yet boast of such service life. On the other hand, clear advantages of the new heating system are already visible.

Advantages:

• high efficiency factor (efficiency) - up to 95% (for comparison, the efficiency of a Russian stove is in the range from 30 to 60%);
• significant savings in materials during construction: caps are voids, brick savings are up to 50%;
• shortened chimney - saves materials and work time, does not require high ceilings in the building;
• availability of various modifications (multifunctionality): the stove can be combined with a fireplace, hob, dryer, lounger, etc.
• a simple embedding mechanism for a hot water heating and hot water supply circuit;

• there are no strict design restrictions: the stove can be placed anywhere - in the corner, in the center of the room, along the wall (there are multistage structures that heat several floors simultaneously from one firebox and with one chimney);

  

  Corner location of the bell-type stove: convenient for combining the stove with a fireplace in a country house

• the foundation for the furnace is 1.5–2 times smaller;
• The "body" of the furnace heats up evenly, from the bottom up - the wear of the materials is minimal, the heat is retained much longer.

Additional advantages in operation:

• ease of maintenance: the oven is cleaned once every several years, prevention does not require special training and tools;
• any type of fuel is used - solid, liquid and gaseous;
• almost no ash and ash in the ash chamber: all fuel materials are completely (without solid residue) burned;
• minimum amount of soot in the chimney: “cold” smoke enters the chimney, and condensation, which causes corrosion of the chimney, is almost never formed;
• ease of operation: regulation of fuel combustion in the combustion chamber occurs automatically (with excessive fire, the gases from the bell go down into the furnace and slow down combustion, and with a low flame intensity, an additional stream of supply air arises, which leads to increased combustion);
• fuel economy: high efficiency of pyrolysis allows you to evenly provide the room with heat at low cost.

Important properties of such a furnace during operation: the bell is always filled with hot air, which does not allow cold currents to rise, pressing them to the bottom of the furnace. Therefore, an untimely closed valve has almost no effect on the cooling of the structure.

And there is only one drawback of Kuznetsov's stoves - there are few craftsmen who are able to competently and competently erect a structure. Therefore, the cost of the work is high. The best option is to entrust the laying to a certified specialist who has completed practical training at the author's seminars by Igor Kuznetsov. Their contacts can be found on the official website of the inventor.

There are also projects for private use (if you decide to build it yourself) and many models - from a stove with a dryer to a sauna that simultaneously heats a steam room with a dressing room in different modes. There are also combined versatile options for a home, a summer residence or office space. The only limitation is that you cannot replicate models on the web without reference to the source.

Training for furnace masters: here they will tell, and answer questions, and show in practice how to build a furnace yourself

Types of "blacksmith furnaces"

Furnaces are made of brick or metal.

Metal - for small rooms, temporary huts. They are smaller and warm up quickly. But they also cool down faster, since the thermal conductivity of the metal is much higher than that of the brick. There are special round metal furnaces with very high efficiency.

According to their functions, Kuznetsov furnaces are divided into the following types:

• heating;
• cooking;
• barbecue and grill;
• fireplaces;
• combined ovens.

Each type of oven is adapted for a specific purpose and solution of specific tasks.

Cooking and heating combined ovens have become popular. They not only warm the home, but are also very convenient for cooking. The presence of an oven with a stable temperature allows not only stewing and baking, but also baking bread. Ovens with a drying chamber do an excellent job with the preparation of dried mushrooms, fruits and berries. A water heating cabinet is also built into the stove, receiving warm water for domestic needs.

Multipurpose bell-type heating and cooking stove: the first bell heats the room, and the second is used as a hob or water heater

Sauna stove devices simultaneously heat the steam room, water for washing and the rest room. There is, for example, a sauna stove, combined with a fireplace, where food is cooked on glowing coals, and in the steam room you can change the mode of a wet bath to a sauna mode.

Sauna version of the Kuznetsov stove: after kindling such a stove, it is no longer necessary to regulate its operation and monitor the temperature regime - the process is self-sustaining

The most striking feature of Kuznetsov ovens is their versatility. The stove works not only on traditional fuels, but also on electricity. In this case, electric heating devices (heating elements) are located in the firebox.

Photo gallery: filming the operation of the Kuznetsov furnace with a thermal imager

A blacksmithing oven in the visible spectrum: takes up very little space, but surprises with its heating capabilities

Heat distribution at the beginning of the firebox: the top and bottom of the stove heats up almost simultaneously

Heat distribution in the middle of the firebox: the temperature balance has been established along the entire height of the side wall

Heat distribution after the end of the furnace: the temperature continues to be maintained at the same level for a long time

Kuznetsov furnace design, its distinctive features

The difference between bell-type furnaces and traction furnaces lies in the design of the heat exchanger. In the traditional version, hot gases from the firebox to the chimney pass through several chimney passages, giving off part of the heat to the brickwork along the way. The speed of their movement depends on the intensity of the flame in the combustion chamber and the draft created by the chimney. The efficiency with such a device ranges from 30 to 60%, part of the heat "flies into the pipe". The draft is regulated by means of the blower door and the stove valve. To keep the traction furnace in working order, it is necessary to regularly clean the soot from the chimney and free the ash chamber from fuel residues.

The system of channel movement of hot gases of the furnace: the gases pass under high traction pressure, not having time to completely give up their heat to densely lined brick rows

In the Kuznetsov furnace, the inner cavity is a free space called a bell. Hot gases trapped in it give off heat to the walls and, cooling down, go down.

Cold (blue arrows) and hot (red arrows) gases move along different trajectories, evenly distributed in the cavities of the domes

A “dry seam” of 2-3 cm is always left between the caps - this is a narrow hole through which the cooling gases flow from one reservoir to another. The hotter smoke moves in a different way, without actually intersecting with the colder jets. As a result, the overall heat transfer is maximized.

Variants of the vertical arrangement of the hoods: with this method of connecting the domes, the heat exchanger is placed in the upper part of the second arch, increasing the area of the heating surface

The efficiency of the furnace increases when two or more hoods are laid. Their location does not matter: in a vertical plane or horizontal. Their sizes and shapes can be different. The thickness of the heat exchange walls is usually laid out in one brick - this accelerates the transfer of heat.

Furnace projects for private low-rise construction

About 150 projects of bell-type furnaces have already been created and brought to life. All of them have stood the test of time and work successfully. Kuznetsov's team of like-minded people continues to develop new options, improving the existing ones. His website contains complete information with detailed descriptions and recommendations for the manufacture of furnaces.

Models are indexed and abbreviated. For example, OVIK stands for Igor Kuznetsov's heating and cooking stove. OIC is simply "heating", etc. Each project is accompanied by step-by-step instructions and visual order, performed in the AutoCAD program

Combined model of a stove with a fireplace: the location of the fireplace on the stove is selected based on the layout of the room - a side fireplace, a rear fireplace and a side fireplace with a stove bench

There is no need to do calculations and calculations: the site provides accurate measurements and descriptions of finished projects. If necessary, you can contact Kuznetsov and discuss the design conditions with the formulation of a specific problem.

The vertically positioned hoods allow you to build a narrow oven if the room is very small

The stove can be installed in any house: a new building or an already built one. But construction in a finished house will be more expensive, since you will have to partially disassemble the roof to remove the chimney. It is better to schedule work for a warm time. To choose the right place for installing the stove, you should remember that the closer it is to the center of the room, the more even the heating will be. At the same time, the stove is located closer to the front door - it is more convenient to bring in fuel.

Video: building a Kuznetsov furnace with a water boiler

The rounded dome furnace works with the greatest heat output. But if we are talking about a small room and the radius of the furnace circumference is less than 2 m, complications arise with the installation of furnace casting - furnace doors, cleaning pockets, etc. Metal parts designed for flat planes are not placed in semicircular shapes: gaps and cracks will appear, which is unacceptable.

A schematic representation of the functioning of the furnace with horizontal cuts-orders helps to better understand the specifics of laying out bricks

An experienced craftsman with an assistant lays out the bell-type oven in 2-3 weeks (depending on the complexity of the model). The process is unhurried, requires great care, fitting of all parts must be careful, with measurements. A beginner will need more time, and this must be prepared before starting work.

Materials and tools

To independently perform work on installing the furnace, you will need:

1. Bricks of two types: solid red (grades not lower than M150) and heat-resistant fireclay (ШБ-8).

   

   Fireclay and red creepers differ in their properties: fireclay bricks are heat-resistant, but more fragile, and red bricks retain moisture well and are mainly used as facing

   You can count their number with an accuracy of one, if you carefully study the order. But as practice has shown, 3-4% of the total amount should always be in stock (in case of marriage and brick breaks).

2. Sand and cement in a ratio of 3 to 1, or ready-made dry mix, packaged in bags of 25-30 kg. For 500 bricks - about 0.2 m ^{3 of} dry mix.

   

   The composition of the mixture made in the factory: natural red clay, quartz sand, molding sand

3. Cast iron - firebox and ash chamber doors, cleaning hole doors, grate, furnace valves, views.

   

   Cast iron stove valves are made to order according to the exact dimensions so that there are no gaps allowing air to pass through

4. Wire for tying brickwork (about 5–7 m), up to 2.5 mm in diameter. The dressing is carried out every 2 rows along the outer contour.

5. Two steel corners to cover the combustion chamber.

   

   The length of the corner is determined depending on the design of the firebox

6. Reinforcement mesh for the foundation.

   

   The thickness of the metal bar and the cell size are determined depending on the load on the foundation

Of the tools required:

1. Mason's trowel, hammer, trowel, jointing.

   

   The mason's tool should always be kept with you, so as not to be distracted every time while working in search of what you need at the moment

2. Buckets or other containers for mixing the solution.

   

   Preparation of mortar for masonry is a responsible matter: the better the mortar is mixed, the more reliable the masonry seams will be

3. Measuring instruments: hydraulic or laser level, plumb line, square, tape measure.

   

   All devices greatly facilitate the process of building a furnace, and it is important to learn how to use them correctly.

4. From a power tool, a grinder and an electric drill with a mixing attachment will be of great help.

Preparatory work before assembling the oven

The most important stage before the construction of the furnace is the laying of the foundation. It is necessary to approach its device with all responsibility, because an incorrectly poured foundation can nullify all the work - a sagging furnace will eventually crack and fall apart.

An example of a foundation device made of silicate bricks with the names of the materials used and markings

In order for the foundation to comply with the requirements of the standards, its linear dimensions must exceed the dimensions of the furnace base by 10-15 cm

The procedure for laying the foundation for the furnace is as follows:

1. A pit is dug in the ground to a depth of at least 0.9 m (to the depth of soil freezing in the cold season). The edges of the pit should be as straight and vertical as possible - this will prevent unnecessary consumption of cement slurry.
2. At the bottom of the pit, clean sand is poured to a height of at least 15 cm. Builders call this a pillow. Shrinkage time of the pillow is 2-3 days.
3. The formwork is knocked out of boards and improvised material. The height of the upper point of the formwork should coincide with the floor level in the house (minus 2 bricks, i.e. approximately 13 cm).
4. Fittings are mounted. It can be a metal mesh with a cell of 50 mm and a bar thickness of 5 mm and more. The mesh should not lie at the bottom of the pit, but should be located inside the foundation. The best place is for concrete to exit from the soil to the outside.

5. Concrete solution is poured. The composition may include gravel and heavy mineral additives. A good practical addition would be a water repellent, which prevents moisture absorption into the foundation during operation. After pouring, the upper surface is leveled in a horizontal plane and all large defects are immediately eliminated by smoothing with a trowel or spatula.

   

   Concrete mixed with a water repellent agent has water-repellent properties, which improves the quality and properties of the foundation

The time for complete drying of the foundation is considered from 20 to 30 days, depending on weather conditions. But you can start installing the furnace in a week, when the solution grasps and turns to stone. The ideal option for foundation shrinkage is one year (a full cycle of freezing and thawing of the soil).

One of the options for constructing a Kuznetsov furnace with your own hands

Before starting laying, pay attention to the following important points:

• a waterproofing layer is laid between the foundation and the first rows of the furnace. It can be roofing material or foil isothermal film (with the foil facing up to reflect heat energy);
• making changes to the order is highly undesirable. This can lead to improper operation of the oven later. Kuznetsov's author's projects have been tested in practice, which guarantees the quality and service life of the furnaces. The only exception is solid overlap rows, which can be modified for aesthetic purposes;
• for the front masonry, bricks are selected without chips, cracks and other noticeable defects;
• cutting bricks is done with a grinder. The edges and planes must remain smooth and even: a torn shape is unacceptable.

Below is the order of the bell-type furnace I. Kuznetsov with comments and recommendations.

An example of the ordering of a bell-type furnace: a strict order of laying out the rows will ensure the reliability and longevity of the entire structure

1. The first and second levels are laid out with fireclay heat-resistant bricks. In this case, an oven bonding solution is used. The refractory layer will prevent heat energy from leaving the foundation.
2. The chimneys are equipped with four cleaning doors (standard sizes) for ease of maintenance.
3. The grate is placed on the 5th level. At the same time, partitions are laid between the blower, the firebox and the bell.
4. Starting from row 5 to row 14, a fireclay brick combustion chamber is laid out. It is important to remember that a compensation gap must be left between the fireclay and red masonry bricks. This will save the oven from damage caused by thermal expansion of the materials.

5. The installation of the firebox and ashtray doors is carried out using an asbestos seal.

   

   An asbestos sealant for the cracks in the combustion chamber allows you to retain heat between the metal and the brickwork

6. In rows 17 and 18, the cap overlaps have a solid plane (except for the chimney openings).
7. In row 21, there are two aisles that run along the inner wall.
8. In the 28, 29 and 30 rows, deviations in the installation of floors are allowed if you need to arrange an unusual appearance. With a low ceiling, fireproof cuts are made in this place.
9. As it is laid out, it is necessary to lining the inner surface of the brickwork (the joints are smoothed out with a solution with the addition of a heat-resistant material).

The firebox is overlapped with two metal support corners. Sizes are selected according to the load, the length of the arm starts from 45 mm.

The thermal gap between the fireclay bricks of the furnace and the furnace body protects the brick from destruction during furnace heating

Following the exact instructions of the ordering, fold the furnace-blacksmithing by the forces of any man who knows how to handle a stone and mortar. The main thing is to observe the vertical and horizontal projections of the structure.

Even a woman can cope with such work: building a stove with her own hands is interesting and exciting

After finishing the laying, the stove should be checked and control kindling carried out. The intensity of the first firebox should not be high. Smooth heating of the body evenly dries the cement slurry in all directions, from the ash chamber to the exit of the chimney outside.

Video: Kuznetsov furnace project in 3D

Video: Kuznetsov furnace project in 3D (part 2)

Features of operation of bell-type furnaces

The first is the automatic mode of fuel combustion.

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

An ordinary stove requires constant attention to itself, and "as a reward" also stains its owner and the space around it

In bell-type furnaces, manipulation of doors and stove valves is meaningless. The intensity of combustion is regulated by the ratio of the volume of the hoods and the combustion chamber. This happens automatically, you just need to light a fire and lay the required amount of wood 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.

Video: testing the Kuznetsov stove

The chimney damper, not tightly closed, will not lead to cooling of the furnace: hot gases will remain in the dome until they give up all the thermal energy to the bricks.

So, the construction of Kuznetsov's bell-type furnace is available to everyone. However, if the self-laying of the stove is in doubt, it is better to seek help from professionals. Their participation will not only reduce the construction time, but also serve as a guarantee in the further operation of the furnace unit.