Do-it-yourself brick pyrolysis oven, diagram of a wood-fired pyrolysis boiler.

Pyrolysis furnaces differ from conventional furnaces because they have a longer combustion life. Already in the very name of the furnace, the answer is contained in what is the difference between the furnaces.

The process of fuel combustion in such a furnace can be divided into two stages. The first stage is pyrolysis, that is, the decomposition of organic matter under the influence of high temperatures into solid and gaseous material. This process occurs with minimal exposure to oxygen.

At the second stage, oxygen is supplied to the resulting components at high temperature, under the influence of which complete combustion of fuel and gas occurs.

We can say that the result is a completely waste-free process in which fuel is converted into heat without leaving ash and without polluting the air.

A brick, pyrolysis boiler has a high efficiency, it saves fuel, and the exhaust gases contain a minimum amount harmful substances. A do-it-yourself brick pyrolysis oven is relatively easy to make if you have the necessary skill and knowledge.

The operation of the furnace is based on pyrolysis. The process of releasing pyrolysis gases occurs under conditions of lack of oxygen. Gases are released from the fuel at high temperatures, only subsequently they are mixed with oxygen, the process contributes to the complete combustion of the fuel and the gas itself.

Due to the design features, fuel is loaded into a brick pyrolysis furnace from above, and a secondary compartment for the “afterburning” of pyrolysis gases is provided at the bottom.

The draft in the stove is created by a smoke exhauster - a draft design; the chimney is forcedly ventilated. How does the system work? There is a lack of oxygen in the primary upper compartment, so the fuel releases pyrolysis gases, which burn out in the lower compartment.

The main material for the construction is ceramic brick. Depending on the size, on average, for a brick pyrolysis boiler you will need from three hundred to five hundred pieces.

By the way, depending on the purpose, pyrolysis furnaces may have two compartments for solid fuel.

And in some cases, secondary combustion chambers may be located higher than the combustion chamber with solid fuel. Much depends on the individual characteristics of the project, on the principles of traction, and so on.

The main thing when you install the stove long burning, strictly adhere to the scheme and comply with fire safety regulations.

To construct combustion chambers, fire-resistant bricks are required, and in order to weld a hot-water boiler, metal sheets are needed. Also, to make a stove you will need cast iron grates, combustion doors, a smoke exhauster to create draft, sensors and electrodes that measure temperature.

This means you will need tools such as a welding machine and a grinding machine.

Do-it-yourself brick pyrolysis oven

First, the foundation slab is made. It doesn’t matter what material the foundation for the stove is made of, it does not need to be connected to the foundation of the house, since these two structures can give different settlements.

The gap between the foundations of the stove and the house must be at least 5 cm. Next, this gap is filled and brickwork is carried out in accordance with the diagram.

With technology brickwork It is better to familiarize yourself with the video; it includes several work processes: installation of orders, supply of bricks and mortar, laying, reliability testing. The angles are always drawn first. Rectangular corners are lined up using a metal square.

The first few bricks are laid using a rule, and then the order is placed, verticality is given to it using a level or plumb line. When doing masonry with your own hands, it is important to take care of safety and ensure the most important thing - sealing the seams.

In order to take into account all possible flaws, you can first lay out the structure without mortar and, if everything fits, start laying bricks on the mortar. The next step is the installation of grates (cast iron grates to maintain a layer of fuel) and combustion doors.

The following is the procedure for connecting the heating system. It needs to be thought through carefully. A hot water boiler, if you have a diagram, the necessary skills and equipment, is brewed with your own hands. Of course, if there is no practice, then it is better to leave this work to specialists.

The boiler will need metal sheets and pipes of different diameters, welding machine, Bulgarian. The finished boiler is fixed in the lower chamber. Sensors are installed to regulate the pyrolysis process

Pyrolysis process

After everything is installed and connected, the system is tested. In order for the pyrolysis process to occur, the temperature must be no less than 450 and no more than 1100 degrees Celsius.

But temperature alone is not enough. You need an adjustable air supply and an additional gas combustion chamber. Another point worth paying attention to is that wet firewood is not suitable for pyrolysis heating. combined brick ovens The steam dilutes the pyrolysis gases and the furnace goes out.

By the way, for conventional brick stoves, it is also recommended to use only dry firewood. Firewood must be stored under cover for at least one year. In this case, no condensate is released during combustion and the stove will last longer.

A pyrolysis stove is a fairly effective device that does not require constant filling of the stove with firewood, but at the same time, it copes remarkably well with the task of heating heating systems. In other words, it’s every owner’s dream. And this is quite real. This oven copes with all these functions. And, besides, it can be made at home, with your own hands. Firstly, you will not have to spend huge amounts of money on purchasing a stove, and subsequently, you will save significantly on fuel.

Pyrolysis oven - device

Pyrolysis is a rather labor-intensive technological process. And, in order to have an idea of ​​what’s what, you need to understand the structure of the pyrolysis furnace. After all, not everyone, even experienced builders, can safely say that they are familiar with the processes occurring inside this device. It is good to know the pyrolysis furnace and the principle of operation - this means, subsequently, being able to make it with your own hands.

Operating principle of pyrolysis furnaces

Let's start with the fact that the operation of this unit is based on the principle where fuel is prepared with a minimum amount of oxygen. A large number of specialists involved in the manufacture of various stoves will consider such a statement to be completely crazy. Everyone knows that for the normal functioning of a standard boiler, in addition to fuel, a sufficient supply of clean air containing oxygen is necessary. Both of these components - fuel material and oxygen - guarantee the normal functionality of standard furnaces.

Pyrolysis gas is considered a new step in the use of conventional fuel, that is, firewood. What processes happen to fuel materials when they are burned? Under the influence of high temperatures, a special gas begins to be released from it. In standard stoves it comes out through the chimney pipe.

The higher the level of fuel heating with insufficient air supply, the more gas begins to be released. This process is called cracking in the oil refining industry.

Using oil pyrolysis, fuel for various cars is extracted. Also, this process can be used in the case of firewood. Only in the case of petroleum products, the refining process should take place at a temperature of 800 to 900 degrees Celsius, and for wood 500 is enough. At the same time, the wood will release substances such as charcoal, resin, acetone, vinegar, methyl alcohol.

Video about the visual design and operation of a pyrolysis furnace

Pyrolysis oven - main advantages

Advantages of pyrolysis ovens

To summarize, all these substances have the property of being flammable. This is precisely what forms the basis of the working process of pyrolysis furnaces - the combustion of gas extracted from fuel materials takes place; accordingly, another name for this type of furnace is gas generators.

These devices are endowed with unique properties - to maintain the desired temperature for a long time, even when your pyrolysis stove operates in autonomous mode.

What are the main advantages of these ovens? The most important thing is the high efficiency (from 80 percent). Secondly - Good savings on fuel consumption. Another important thing is that the efficiency can be independently adjusted. Good way recycling of rubber waste and polymers, as well as wood waste. The emissions contain practically no harmful substances: from an environmental point of view, this is a rather significant point! Soot is produced in relatively small quantities. Among other things, suitable for pyrolysis boilers various types fuel materials. At least even household garbage. Currently, special briquettes are made from household waste that can be used for these stoves.

Absolutely all long-burning pyrolysis units, even when they are made by hand, do not avoid a number of shortcomings. We believe that there is no way to hide them from consumers.

Disadvantages of pyrolysis ovens

One of the disadvantages of pyrolysis furnaces is their overall design

The disadvantages include the following:

• quite high price. It is conditioned at great expense to purchase a suitable boiler for the stove. Therefore, this minus can be corrected into a plus if you take on making the boiler yourself;
• the need for continuous energy supply. In order for the work to be carried out correctly, connect the pyrolysis oven to the electrical network;
• The variation of the heating system presented to your attention is too selective in terms of fuel materials. It should be noted that only dry wood is applicable here. In cases where fuel materials contain a large percentage of moisture, the pyrolysis process is not feasible;
• Quite a large design. If you do not have a home with large area, then it is better to opt for a slightly different heating system, or build a mini pyrolysis oven with your own hands.

Most likely, this is where the list of shortcomings ends. As you can see, they are not that significant. Provide everything that is necessary for the installation and normal functioning of devices such as pyrolysis combustion furnaces, and be sure that it will not only suit you, but will prove its advantages over time!

Operating principle of a pyrolysis furnace

Fuel materials are loaded into the solid fuel conversion chamber and ignited. The process of producing gas from the fuel begins. Primary air is supplied to the chamber, and under the influence of excess pressure, gas begins to flow into the lower compartment, where afterburning occurs. Secondary air enters this compartment, and the resulting mixture continues to burn under the influence of high temperatures. Water, already heated, enters the heating system from the water jacket of the boiler. At the same time, return flow begins to flow into the jacket. The coolant that is used is also a coolant for the boiler. For the correct operation of a pyrolysis furnace, strict adherence to the proportions of the mixture of oxygen and fuel is necessary.

Drawings of pyrolysis furnaces

Drawing of a square pyrolysis furnace

So, making pyrolysis ovens with your own hands is not a question. But, we note right away that for the construction of such units it is not enough to have only excellent skills in carrying out welding work or to have drawings of a pyrolysis furnace in hand (by the way, on our website it is possible to download drawings of a pyrolysis furnace for free). To carry out this process, you need to stock up quality materials, which, we note, are often not cheap. And, first of all, these requirements apply to metal. We will need excellent quality alloy steel. Proper electronics are also a must. Unless, of course, your plans include maintaining a furnace worker who continuously monitors the operation of the boiler.

You can download detailed description materials and photos and detailed drawings of a pyrolysis furnace, using which you can easily create such a furnace with your own hands

Homemade long-burning pyrolysis stoves made from trash - is it possible, but is it worth it? Some will argue that they have seen pyrolysis combustion furnaces made from scrap materials - it is very convenient, and, moreover, cheap and, they say, they work great. It is so, if you do not take into account one small nuance. Such “models” are a good example of a mini pyrolysis oven with your own hands and can show us the principle of operation of this device. But there is no point in talking about using such a pyrolysis stove for general heating of a building.

Pyrolysis oven from a gas cylinder or barrel - a budget option

To make such a unit, you can undoubtedly take what is at hand, for example, as an option - a pyrolysis furnace from a gas cylinder or from an old metal barrel, pieces of pipes and other various metal trash. But, do not discount the fact that the processes that will occur inside the device are very complex and require compliance with specific rules in order for it to function correctly. Of course, as an option, you can install manual air supply regulators and thereby ensure more or less stable operation of the pyrolysis furnace. But it’s unlikely that your plans include spending all your time next to this device.

There is no point in unregulated pyrolysis; therefore, it is imperative to install an electronic filling that regulates the fuel combustion process. Otherwise, your pyrolysis stove will be a primitive potbelly stove. High temperatures (up to 1100 degrees Celsius) resulting from the combustion of the resulting gases imply the use of certain materials that protect the furnace from burning out.

How a pyrolysis oven from a gas cylinder functions can be viewed in the video:

Homemade long-burning pyrolysis furnaces

To make your own stove, you must use exclusively high quality metal, its cross-section must be no less than 8 millimeters, otherwise it can quickly burn out. It is also necessary to have the appropriate drawings (you can take a ready-made option, for example, the Lachinyan pyrolysis furnace, the drawings of which are provided above). Welding work should only be carried out at a professional level. If you do not have the necessary skills and abilities, it is better to entrust this matter to specialists.

Design of a homemade long-burning pyrolysis furnace

The furnace body can also be made of pipe. The pipe for preparing the pyrolysis furnace must be of large diameter and, for the best, the gas exchange chamber must be at the top. The first thing to do is to cut out a not too large area where the grate will be located. This section will later act as an independent part.

The resulting gap should be joined using rectangular strips to provide rigidity at the back, and at the front for the fire door.

Then, we take another blank from the pipe and cut out special parts from it that will be needed for the design of the ash compartment. A compartment for the gas-air chamber is welded to the part that is located on top. Then the structure of the firebox compartment should be welded. This will later be the door.

Then we begin to assemble the grate, repeating the lower parts of the stove for fasteners. Then we mount it in the design position. Now, finally, we install the front and back walls and perform the final assembly.

This unit can heat a room quite well. small sizes, For example, country house or a sauna steam room for a very short period of time.

DIY brick pyrolysis oven

A very large number of craftsmen often wonder: is there a way to build a pyrolysis oven out of brick? An answer that gives quite a lot of hope - of course, and even without any difficulties! But it is necessary to approach the solution of this issue wisely and with full responsibility.

Brick pyrolysis oven options

Let's consider the process of building a brick kiln. Before you start installation work, an appropriate diagram of the future unit should be developed and, of course, all the necessary calculations must be performed. The best option is to take a ready-made scheme (for example, Belyaev’s scheme).

Ceramic bricks are laid along the perimeter of the future building. The partitions inside the stove are made of special bricks called fireclay. After you have assembled this structure and activated the fan, feel free to start using it.

It is imperative to take into account the time factor - how long each fuel material will burn. You need to know this so as not to miss the moment of timely adding firewood to the stove. Pressed briquettes are ideal as fuel.

The most important step, after launching a pyrolysis brick stove, is calculating its efficiency. No special effort is required here - you just need to pay attention to the specific smell of smoke that comes out of the chimney. If the presence of carbon monoxide elements is not observed in it, then the efficiency is quite high.

Construction of a brick pyrolysis furnace

Ready-made pyrolysis oven

Ready-made stoves designed for heating greenhouses can use wood whose moisture content reaches 55 percent. As for the duration of combustion, such structures can withstand up to three days in the stove maintenance mode and up to 30 hours in intensive mode!

Long-burning pyrolysis furnaces

Don't forget that the rules fire safety no one has canceled them and stick to them when you build a brick pyrolysis oven with your own hands! Violation of certain fire safety rules may cause damage not only to your property, but also pose a danger to your life and health and to all members of your family.

The best thing to do would be to put the boiler in some kind of separate room or in non-residential premises. To make a stone pyrolysis stove, it is necessary to make an additional base of concrete or brick. Use thick sheets of metal for additional protection of the combustion chamber.

The most important advantage of this design is the fact that the coolant in it can be air, not water. What does this give? Not too little, not too much – it saves you from unwanted freezing of pipes in winter period. Therefore, you will not need to bother with draining the system.

A necessary condition for the construction of a stove is its location from the walls no less than 200 millimeters. Also make sure that your boiler room is sufficiently ventilated.

Building a brick pyrolysis oven with your own hands will significantly save your family money. This is ensured by economical consumption of fuel materials.

Scheme of a pyrolysis furnace

If the idea of ​​​​creating a pyrolysis furnace for a home or any other building does not leave you, and you definitely want to do it yourself, then stock up on the following building materials and equipment (tools):

• Steel sheets - parameters - 6 * 1.5 meters, thickness - at least 4 millimeters.
• A fan whose power must be at least 300W.
• A pair of doors - for the combustion chamber and for the ash chamber.
• Electric drill.
• Grinder + 2 circles of different sizes (large and small).
• Metal pipes - diameter - 3.2; 5.7; 15.9 millimeters.
• Sensor showing temperature.
• Profile pipes – diameter – 80*40.
• Welding electrodes.
• PROK – fuel synthesizers.
• Welding machine.
• Lever type thermostat.
• Brick – fireclay, as well as ceramic.
• Cast iron grates, at least three pieces.

The quantity and, accordingly, the size of the materials varies depending on the direct purpose of the homemade brick pyrolysis stove: will it be intended for the home, or for the sauna, or for some other room.

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Before every owner country house The question arises about choosing a heating system.

The main selection criterion is the energy resource, as well as the cost of construction and maintenance of the system. An alternative option today is. Every year the popularity of such structures is growing rapidly.

The peculiarity of the pyrolysis furnace is that it runs on solid fuel, which is recognized as the most economical energy resource today. These stoves are a suitable option for heating a country or private home. In addition, you can easily build a pyrolysis oven with your own hands.

Operating principle and advantages

According to the principle of operation, such furnaces resemble a dry distillation boiler. The thermal energy released during fuel combustion is used to heat the air.

Solid fuel is ignited and closed in the furnace. In this case, a fan is put into operation, as a result of which combustion occurs with a minimum amount of oxygen.

This leads to the breakdown of fuel into wood coke and pyrolysis gas. When combined with oxygen, the gas begins to burn intensely, resulting in the release of a large amount of thermal energy. It will be enough for both heating the room and heating water.

The advantages of a pyrolysis oven include:

• high efficiency, which is expressed in control of the strength and duration of combustion;
• fuel economy;
• use of wood industry waste as fuel;
• absence of harmful substances in combustion products.

All these advantages explain the growing popularity of modern pyrolysis furnaces. The main advantage of the design is that it can be manufactured with my own hands. The main thing is to have a drawing of such a furnace and certain materials on hand. Every master will be able to decorate and heat his home with the help of such a stove.

Scheme and components

The design of the stove is quite simple. It consists of two combustion chambers. With the help of these chambers, pyrolysis is supported during the combustion process.

The first chamber is used to load solid fuel; it closes tightly, which prevents oxygen from entering the combustion zone.

When fuel burns without oxygen, pyrolysis gas is released, which is transferred to the next chamber. This is where the gas is burned. To improve the combustion process, secondary gas is introduced into the second chamber.

A traditional oven consists of the following functional elements and components:

• gasification chambers;
• metal grate;
• chambers in which fuel is burned;
• air supply systems.

When assembling a pyrolysis furnace with your own hands, it is worth considering the presence of all structural elements. If the system is missing at least one of the listed components and chambers, then the oven will not work as it should.

Self-assembly options

Pyrolysis ovens are quite expensive, so many owners are thinking about how to make one with their own hands.

Homemade structures can be made from various materials, such as gas cylinder, tin cans, barrels, bricks and much more.

Depending on the material of production, all furnaces are divided into:

• stone;
• metal.

Stone or brick ovens are used extremely rarely. This is due to the fact that its construction will require a lot of investment and time.

Of course, recently such designs have undergone some modifications, which has significantly increased their efficiency. As for metal stoves, they are especially popular. The fact is that they can be made even from an old gas cylinder or barrel.

• furnace operating on treated oil;
• Kuznetsov furnace;
• Lachinyanka;
• Bubafonya.

The principle of operation of all these structures is the same - afterburning the gas that is released from the fuel. But, when choosing a design, it is worth considering some features of each type.

Thus, it is undesirable to use stoves that run on waste oil in bathhouses and other residential premises. They are ideal for heating garages and other non-residential premises.

Of course, it is worth considering that small furnaces running on waste oil are highly productive. You only need a cup of oil to get the job done.

Made of brick

To build a brick stove you will need:

Having such materials and tools at hand, you can build a stove with your own hands. Of course, we should not forget about some nuances on which the strength and efficiency of the heating structure will depend.

If you have chosen a brick kiln, the construction process will look like this:

If necessary, you can decorate the structure. For this they often use facing brick, stone and other materials that can withstand high temperatures.

From a gas cylinder

A metal pyrolysis furnace is often made from old gas cylinders, and it has the name Bubafonya.

The peculiarity of the Bubafonya stove is that it can be used with different fuels.

To make such a design with your own hands, you will need the following tools:

• hammer;
• Bulgarian;
• welding machine and electrodes;
• pliers.

The manufacturing process of the Bubafonya stove is carried out in the following sequence:

1. Cut off the top convex part of the cylinder.

Be careful: cut off the top of the cylinder below or above the welding seam, since the connecting seam is reinforced from the inside with a metal plate, which can complicate cutting.

2. There is a hole in the center for the air duct.
3. At the top of the cylinder body, a hole is made for the chimney.
4. Make a gas divider with a pipe through which oxygen will be supplied to the second chamber.
5. Weld the chimney.

As you can see, you can easily make a stove from a gas cylinder with your own hands. But you should pay special attention to cutting the cylinder. Before you start working with an angle grinder, you need to make sure that there are no gas residues in the cylinder; to do this, the cylinder is completely filled with water.

To ensure the normal functioning of the oven, you need to follow some professional advice:

1. For heating, solid fuel is used, the humidity of which should not exceed 20%.
2. The chimney pipe of a metal stove must be removable, which makes it easy to clean soot and condensate.
3. During operation, the stove heats up to high temperatures, so there should be no flammable objects or structures near it.
4. Study the operating modes of the stove, which will allow you to choose the best option.

Following all these tips will ensure a long service life for the stove. And don’t forget that special attention should be paid to fire safety rules.

Watch the video in which a specialist explains how to make a small pyrolysis oven with your own hands from cans:

A pyrolysis oven definitely requires learning a lot of information if you have the idea of ​​​​creating a pyrolysis oven with your own hands. And the first number on the list of knowledge will be an understanding of the pyrolysis process. The use of solid fuel gas-generating boilers in private households has become popular. However, buyers are offered only calculations of the efficiency and advantages of the installations. You should know that thermal decomposition of wood occurs in almost all cases of its combustion.

Pyrolysis process

Furnaces for efficient combustion of organic fuel decomposition products may differ from each other in design and materials of manufacture. First of all, they are distinguished by designs that use the principle of upper and lower combustion. Devices with afterburning chambers at the bottom clearly require additional pumping equipment. While some manufacturers offer devices that work using natural draft. Usually, they are called slow burning stoves.

Ignition of volatile compounds produced during the decomposition of organic matter occurs through the flames of the main combustion chamber and a smoldering mode is possible. There are also extraordinary private solutions in the form of brick structures. It is difficult to talk about the rationality and energy efficiency of such developments due to the lack of accurate and objective measurements. In other cases, alloy structural steel of different thicknesses is most often used.

What type of oven should it be?

So, you can define for yourself that pyrolysis can be called a unit in which the processes of decomposition of wood and combustion of their products are physically separated as much as possible. In this case, gas synthesis takes place under conditions of a certain temperature and low oxygen content.

1. First, we need to determine the power of the heating unit for the required area. You can use average values.
2. For heating 10 square meters rooms, average insulation, need 1 kW of unit power.
3. If you need to perform a calculation based on volume, a certain coefficient is used, equal to 40 for an insulated room and 60 for a weakly insulated room. Thus, for a room with an area of ​​100 square meters and a ceiling height of 2.6 with good thermal insulation:
   100x2.6x40=10400W ~ 11kW.
4. Now you need to decide on the size of the furnace. For calculation, you should know that when burning 3.6 kilograms of wood, you can get 10 kW of heat within an hour. This means that in our case we will need a firebox that can accommodate a similar volume approximately 10 times. For example, the weight of a dense cube of oak, air humidity, weighs more than 700 kg. For firewood 35 cm long stacked in a woodpile, the coefficient will be equal to 0.75, we get 525 “loose” kilograms per cube. 3.6 kilograms for 11 hours of work, we get 39.6 kg of firewood.
   39.6x0.75=29.7 525/29.7=17.7 1000/17.7=56.5 l. This means the “clean” size of our firebox is 0.35x0.4x0.4 m.
5. However, at this stage, we will take into account the level of efficiency of such furnaces and the corresponding ratio of useful volume to power. Therefore, we add 30 - 35% to the volume of the pyrolysis chamber, as a result, the required kilowatts can be obtained from ~70 - 80 liters.

Negative effects of reduced loads

In addition, during calculations, one should take into account the negative impact on the entire fuel system of working with a reduced load.

• With excess power, increased moisture condensation occurs on heat exchangers and chimney surfaces, in slow modes. Consequently, the installation must be selected in such a way that the vast majority of the time, combustion takes place with maximum efficient performance and coolant temperature, up to 80 - 90 ° C. Using such a unit irregularly or for periodic heating at the dacha will not be at all rational.
• The type of fuel used has no less influence in the calculations. The calorie content of which, like its humidity, significantly affects the power received and creates a certain delta of up to 25 -30%.
• When using coal, especially heat-loaded surfaces of the secondary afterburning chamber must be protected by a lining, usually fireclay brick.
• Cast iron should be used as the main material due to its resistance to fading and deformation. But, as you know, working with it in artisanal conditions is almost impossible, so making a stove of such parameters with your own hands is out of the question.
• For home craftsmen, the main material is structural steel, preferably having heat-resistant characteristics, otherwise the lack of heat resistance will have to be compensated by the thickness of the walls.

The order of assembling the base

1. So, as we strive to consider a design that has the right to be called a pyrolysis furnace, at the first stage care should be taken with the manufacture of internal channels, the supply of primary and secondary air and the burner piping. The burner lining is made of fireclay bricks. In fact, the heat-resistant nozzle nozzles themselves are made from it.
2. Next, from sheet metal, you need to cut and weld the primary gasification chamber - also known as a bunker - and the secondary gas afterburning chamber. It must be well protected from high-temperature flames and have access to convection channels.
3. In practice, a material with a thickness of 4 mm is used. But it is advisable to use large thicknesses to avoid warping and premature failure due to corrosion.
4. Ready-made - the upper and lower combustion sections are combined by piping the nozzles and air heat exchangers are connected according to the Buleryan principle.
5. After this, you can proceed to the intermediate stage, welding fasteners that prevent hydraulic deformation of the outer casing. These are metal pins that will strengthen the internal and external elements of the boiler together.
6. The casing elements are welded with simultaneous joining of all the holes of the air channels.
7. Also, it is necessary to provide in advance the holes for the levers, the chimney damper and the secondary chamber damper.
8. After welding the outer elements of the box, the doors, the external air supply pipe are installed, to which the injection pump and the hatch for cleaning the convection chimneys will be attached.

Potbelly stove

Such an example would be a simple potbelly stove with a divided firebox. To be honest, this oven performs the function of pseudo-pyrolysis, since simple design, is very far from the described theory of thermal destruction of organic raw materials with separate combustion of its products. The partition separating the firebox simulates the possibility of two separate processes, gas generation and afterburning. The presence in this case of nozzles supplying additional air gives a very dubious opportunity for the smoldering products to fully burn. This happens due to the main flame, or does not happen at all.

To make such a “gas” stove, minimal modifications to the design are required. Welded into the firebox space metal plate and you can consider yourself “ahead of the rest.” Some improvement as a result of such alterations is of course possible. But it will consist in a banal lengthening of the path traversed by hot gases. The need for pyrolysis in a brick kiln, in my opinion, is very doubtful. A medium-sized heating and cooking stove, with channels built into the wall, has very good performance characteristics, which I can verify as a user. Building such a brick structure requires more knowledge and additional materials. Non-standard dimensions and the danger of carbon monoxide penetration do not imply its placement in a residential area. Application for industrial needs is a completely different matter. Firing of clay products or tempering of metal is possible. There is a large cavity inside for holding ceramics and a high temperature can be maintained for a long time.

Benefits

In order to decide to make a pyrolysis furnace with your own hands, you need to have a good understanding of the benefits and possible problems that it will bring.
1. One of the main benefits is the savings that can be achieved if certain technical inputs are observed. But, unfortunately, it is not always possible to fulfill the necessary conditions.
2. Cleanliness of the final exhaust. It is achieved by burning gas generation products at a high flame temperature.
3. High efficiency, achievable by keeping fuel humidity at a low level.
4. The ability to finely and widely adjust the power range of the installation, but at the same time acquiring some unpleasant consequences.
5. A well-functioning system is capable of high-quality combustion of rubber, plastic and other difficult-to-burn wastes in a forced mode.
6. One of the main advantages is the long intervals between loading firewood and autonomy.
Unfortunately, listed benefits are not unambiguous. To obtain all the benefits at the same time, it is necessary to comply with a number of parameters and characteristics, both regarding fuel and modes of use.

Flaws

1. Many factors, which are almost impossible to avoid, cause the formation of condensation on heat exchange surfaces. A mixture of condensate and soot forms a viscous, tar-like, acidic coating that is difficult to clean.
2. Vigorous operation of a smoke exhauster or blower can “eat away” a significant portion of the savings brought by the device. In addition, energy dependence can lead to emergency situations, during a power outage. Additional measures are required to cool the boiler and its emergency shutdown.
3. Efficiency is directly related to the combustion mode. This forces you to burn extra fuel or have other problems.
4. Constant, frequent monitoring of the chimney system and thorough cleaning of gas outlets, which tend to become overgrown with condensation products, are required.
5. Relatively difficult to manufacture and the need for electronic control components.
6. Special attention should be paid to the chimney; it should be of a larger diameter and better insulated.
7. Wet fuel easily reduces operating efficiency.
8. High cost, sometimes reaching 1.5 and 2 times the value.

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An excellent alternative to solid fuel boilers is a pyrolysis furnace. This is a long-burning stove that operates on a special principle and allows significant fuel savings. Compared to other types of heating devices fueled with wood, such a stove can work much longer, while being in no way inferior in the efficiency of heat supply. Let's take a closer look at how such a stove works, as well as what features of its operation and construction you need to know.

Such a furnace operates on the principle of pyrolysis - organic substances during heat treatment in the absence of a sufficient amount of oxygen are decomposed into solid residues and gases, which in a conventional furnace exit through the chimney, and in a pyrolysis furnace they become the main source of heat. The more the fuel heats up with a minimum amount of oxygen, the greater the percentage of gas evolution.

This technology is developed specifically for the oil refining industry. In this way, fuel for cars is obtained through the processing of petroleum products. In domestic conditions, the pyrolysis process for heating residential premises began to be used recently, but its effectiveness and efficiency have already been confirmed by many users. The difference is the temperature required for processing. Petroleum products are processed at 800-900 C, while 500 C is sufficient for wood.

Connection diagram of the pyrolysis furnace to the heating network

The gas extracted from wood fuel has excellent flammability, and during prolonged combustion it releases a sufficient amount of heat for heating.

How the oven works

Long-burning pyrolysis furnaces are designed according to a special principle. A combustion chamber with a burner is built into the body, where firewood is placed. The main condition for the combustion chamber is tightness. It is designed so that the air flow inside is minimal. The firebox must have a tight door and a reliable valve, and there must also be a supply and exhaust fan. After laying and igniting firewood, the combustion chamber is limited in the access of oxygen.

After the firewood has charred and released gas, it rises through a separate air duct into the second combustion chamber, where it is mixed in the required proportion with secondary air and burned. This process generates heat.

The second chamber, as a rule, is combined with an air duct or the beginning of a chimney. Air is provided by a supply and exhaust fan or a separate fan. If the chimney system is well thought out, then ordinary draft with sealed dampers will be sufficient.

The body also provides a retort - a rounded part for extracting solid residues of burnt logs. A special feature of the pyrolysis furnace is that the fuel is burned almost completely, with only a small residue of ash, which is removed every few days.

Pros and cons

Based on their functional features, pyrolysis stoves for heating a home have many advantages, but they also have disadvantages. Let's take a closer look at what the operating principle of a pyrolysis furnace is based on.

Advantages:

• Saving. Fuel burns longer and with better quality, so a heating device operating on the principle of pyrolysis requires less fuel consumption than a conventional stove.
• Ecology. Pyrolysis ovens do not cause harm environment, because they practically do not emit harmful carcinogens and other chemicals. The combustion products leaving the chimney contain a very small percentage of CO.
• Fast heating. Due to the lack of oxygen, the combustion process begins quite quickly.
• Efficiency The high temperature is maintained for a long time in autonomous mode due to the massive volume of the firebox. The efficiency of a properly designed pyrolysis furnace can reach 85%.
• Power. The thermal power interval range can vary from 5 to 100%.
• Possibilities. Allows you to connect almost any circuit. Can be used not only for heating, but also for selection hot water, as well as install circuits with natural and forced circulation.
• Fuel. Even though it is recommended to use at least 70% wood of the total mass of fuel materials, you can burn almost any waste, from rubber and construction waste to polymer plastics.
• Easy to use. The operation of the furnace requires minimal human supervision; it is enough to load fuel once a day and unload ash every few days.
• Soot. It is produced in minimal quantities due to the fact that the fuel processes the material several times. You don’t have to worry about contamination and the need for constant cleaning of the chimney.

Flaws:

• Price. Despite the subsequent savings in fuel consumption, the purchase of such a unit will cost a tidy sum, so a do-it-yourself pyrolysis oven will be much more profitable.
• Massiveness. Such stoves have rather large dimensions compared to other heating structures, so the unit is not suitable for a small room. In addition, we should not forget about the fuel storage area.
• Smells. Even taking into account the absence of harmful substances, odors will be present when burning waste, so it is necessary to provide good system ventilation.
• Electricity. For the fan to operate correctly, an uninterrupted power supply is required. If a pyrolysis stove is installed for a bathhouse or other non-residential premises, access to the network must be provided.
• Condensate. At the outlet, the exhaust gases have a fairly low temperature, so condensation will accumulate in the chimney and outlet channel. The design must include a storage tank, and the outlet pipe with the chimney must be large in size with insulation from the outside of the room, otherwise condensation may freeze in cold weather.
• Humidity. The fuel for the stove must be dry, otherwise the pyrolysis process will not take place. Under the influence of heat, moisture will evaporate and dilute the pyrolysis gases.

What types of pyrolysis ovens are there?

Quite a variety of designs can operate on the basis of pyrolysis; their construction largely depends on the type of fuel that will be used in the future. Therefore, before planning a design for your needs, you need to understand what types exist.

Material

• Brick pyrolysis oven
• Metal pyrolysis furnace

Purpose and method of use

• Periodic action. The stove is built taking into account heat-accumulating materials and can release energy for a long time after the end of the combustion process.
• Constant action. The design is characterized by comparative lightness and thin walls, there is no array for heat accumulation, and fuel is burned continuously.

Heat transfer method:

• There is a water circuit.
• Heat exchangers for heating air.
• Without heat exchangers. Heating will be carried out through thermal radiation and convective heating of air in contact with the hot surfaces of the device.

Relative arrangement of chambers and type of traction:

• There is a gasification chamber on top, and a pyrolysis gas afterburning chamber on the bottom. This furnace operates on forced draft, so blowing fans and smoke exhausters are used.
• Furnaces with a reverse chamber arrangement operate on natural draft, gasification occurs from below, and afterburning occurs from above.

Fuel

The optimal raw material for pyrolysis is hardwood, but other types of organic raw materials are also successfully used as fuel.

• wood shavings and wood chips;
• pellet granules;
• straw or cake;
• fuel briquettes;
• coal, coke

If combustible waste is disposed of in a pyrolysis furnace, it is important that at least 70% organic fuel is present in the deposit.

The physical characteristics of the wood are also important. Thick bark or rot can have a negative effect on the pyrolysis process, reducing the yield of gas emissions several times. Large logs will significantly increase the duration of the process, but will also reduce energy efficiency.

Do it yourself

Making your own wood-burning pyrolysis oven is also quite an expensive undertaking, because you only need expensive materials. Despite the high cost, this method will be much cheaper when compared with purchasing a ready-made pyrolysis boiler.

Metal stove

The body of the future design must be made of particularly durable material, perfect choice in this case it will be alloy steel. You will also need tools:

• welding machine;
• refractory bricks - 15 pcs;
• electrodes - 5 packs;
• drill;
• angle grinder - diameter 230;
• metal sheet - thickness - 4mm, size - 7.5 sq. m;
• sensor for measuring temperature;
• grate;
• circles for grinder- 10pcs;
• fan;
• doors - 2 pcs.;
• pipes: section 57×3.5 mm, length - 8 m, section - 15.9×4.5 mm, length - 0.5 m, section - section -32×3.2 mm and length - 1 m;
• profiled pipes: section - 2.0×30×60 mm 1.5 m, section -2.0×40×80 mm and length - 1 m;
• steel strips: section 80×5 mm 1 m, section 20×4 mm 7.5 m, section 30×4 mm 1.5 m.

Schemes for metal pyrolysis furnaces are developed taking into account the individual characteristics of the room and the needs of the owners, but general provisions are the same for everyone.

Subtleties and useful tips:

• It is necessary to weld the body from alloy steel. If another metal is used, it is better to make the structure two-layer.
• At the locations of the ash and combustion chamber, openings for doors are cut.
• The ash pan must be separated with a cast iron grate.
• An air supply section with a damper is installed in the gasification chamber. The passage channel for pyrolysis gases and the air supply system must be made on maximum distance from each other.
• Doors made of heat-resistant steel, reinforced with angles or cast iron are installed in previously made openings.
• The inside of the chambers is lined with fireclay bricks.
• To adjust the traction in chimney gate is installed. The chimney must be made of an insulated pipe.

Brick oven

For a 30 kW furnace you will need:

• ceramic brick - 400pcs;
• fireclay brick - 100 pcs;
• steel sheet measuring 6x1.5 m, with a wall thickness of at least 4 mm;
• cast iron grates - 3 pcs;
• fan - power not less than 300 W;
• lever thermostat;
• doors for blowing and combustion - 2 pcs;
• welding machine;
• drill;
• Bulgarian women with different diameters circle;
• pipes of different diameters;
• profile pipe - 80×40;
• electrodes;
• temperature sensor.

Preparation

First of all, the installation site is prepared. In the selected area, it is necessary to dismantle the floors and dig a hole for laying the foundation, at least a meter deep. To avoid distortion of the structure, the foundation must have a larger area than the furnace. First, layers of sand and crushed stone, 10 cm each, are laid. They are tightly compacted and leveled, and filled with concrete. The height of the foundation is 8-10 cm above the floor level.

The heating system is being installed in the rooms. If water will be used as a coolant, then the project provides for the presence of a reservoir.

The bricks also need to be prepared by soaking them in water for a couple of hours in advance. This will prevent deformation of the fastening solution in the future. The seams will be rubbed with a solution of creamy consistency made from clay diluted with water. If sand is added to the clay, it must be sifted first, so that large fractions will not get into the solution. The proportion of sand in the solution should not be higher than 30%.

Order

The perimeter of the furnace is lined with ceramic bricks, the internal partitions are lined with fireclay.

1. The first row is laid over the entire area of ​​the foundation.
2. The next row is laid under the stove area.
3. Then the rows are laid out according to the prepared drawing. After every 2-3 rows, daily breaks are taken to consolidate the solution.
4. Metal parts are installed immediately when laying the corresponding row. The gaps between the masonry and the parts must be well sealed, because when heated, the metal will expand and can damage the seams.
5. A cast iron grate is installed in the firebox, which is placed with a small gap.
6. The firebox is equipped with a fan.
7. After arranging the firebox, the stove is laid out to the end, according to the chosen scheme.
8. Particular attention must be paid to the layout of the chimney. It is calculated in advance and laid out in compliance with the parameters. Violation can lead to deterioration of traction.

There is no single mechanism for laying out pyrolysis furnaces; all proportions must be calculated taking into account the space of a particular room. We have prepared several diagrams of different furnaces, but it is better to contact a furnace specialist when designing a future structure and carrying out calculations.