Drawings of pyrolysis solid fuel boilers. Economical and reliable, but is it safe? How to make a pyrolysis boiler with your own hands. Boiler body manufacturing

A pyrolysis boiler, like any do-it-yourself construction, requires detailed study and careful planning. This is a rather time-consuming job that will require scrupulous attention for a short time. If you decide to build a pyrolysis boiler with your own hands, then the costs will not be high, and manufacturing and operation will save you money.

Pyrolysis - the principle of operation

What is pyrolysis

Pyrolysis is a process in which wood fuel breaks down under the influence of high temperature in a vacuum space (without oxygen). As a result of the procedure, a solid carbon-type cinder and pyrolysis gas are obtained. The pyrolysis procedure is called modern and waste-free. This is because the number of pollutants in the environment is reduced.

The pyrolysis process creates an environment in which mono-fuel (garbage, firewood) burns slowly, and the amount of heat transfer is much larger compared to other heat generators. Gaseous substances, mixing with oxygen, burn at an elevated temperature. In this case, large volumes of thermal energy are released.

Work principles

• combustible fuel, in an environment limited from air, releases hydrogen (carbon monoxide);
• the hydrogen itself burns, transferring heat.

The pyrolysis technique significantly reduces air pollution, but still depends on the raw materials burned.. The procedure of the technique takes place at different temperature levels. There are two of them.

The top top of the pyrolysis boiler

Temperature levels of pyrolysis

Low temperature degree.

This is pyrolysis, the temperature of which is 450 - 900 degrees Celsius. In this process, the flue gas is released to a minimum, and the residues of raw materials, tar, are maximum. The amount of scrap (waste) is the largest. Considered environmentally friendly.

High temperature degree.

This is pyrolysis, the temperature of which is more than 900 degrees Celsius. In this process, the flue gas is released to the maximum, and the resin - to the minimum. The amount of scrap is the smallest.

As a result of pyrolysis, energy (heat and electricity), fuel oil, fuel (diesel oil, motor gasoline) can be obtained from waste. But subject to detailed sorting of garbage.

What is a pyrolysis boiler?

The pyrolysis boiler is environmentally friendly clean apparatus which is used for space heating.

You will be satisfied with the choice of a pyrolysis boiler if your requirements for the manufacture of a simple heating device:

• democratic price category;
• unpretentiousness in use (no need to fill up raw materials every 3 hours);
• uncomplicated manufacturing;
• ease of management;

Pyrolysis boiler (manufactured) is a high-tech design, which consists of:

• fan;
• pumps;
• compartments for water;
• openings and shutters for solid fuels;
• automated electric control panel;
• compartment for firewood;
• openings for collecting slag, etc.

Pyrolysis boiler from the manufacturer

Of course, these boilers are made of cast iron, covered with thermal tiles and automatic control at the highest level, but the cost is also high. Plus, in the event of a breakdown, you will think about what to grab onto (although the manufacturer’s warranty on them is large), but there are exceptions to everything.

Another thing is a do-it-yourself boiler. This is just a steel box with a chimney and a fan. It contains chambers for fuel and air.

The pyrolysis boiler uses water and electricity. But the electrician is just to connect the fan, and you don’t need much water and you don’t need to change it often. The liquid then evaporates. You can fill it with anything: garbage, brushwood, firewood, iron cans, etc.

And although the fan makes the device volatile - it is an important factor in ensuring the maximum combustion effect. The device regulates the air supply to the boiler compartments.

Do-it-yourself pyrolysis boiler

Components of a homemade pyrolysis boiler:

• box with steel compartments;
• flue pipe;
• temperature sensors;
• fan;
• pipes for water;
• slag compartment, etc.

Detailed items of equipment and how to build a pyrolysis boiler yourself are described below.

Equipment Features

Advantages of a homemade pyrolysis boiler:

• easy to manufacture;
• minimum financial costs;
• maximum efficiency;
• the possibility of easy control;
• changing the operating modes of the boiler;
• consumption of fuel materials is minimal;
• environmental friendliness of equipment;
• increased heat transfer effect;
• autonomous control time is longer than other devices of the same type;
• maximum efficiency;

Cons of a homemade pyrolysis boiler:

• creating stable conditions (firewood should not be very wet, the passage of air should be controlled);
• fan, creates dependence on electricity;

Tip for checking the degree of efficiency for a homemade boiler:

To check whether the efficiency is maximum, you just need to look at the smoke (its color and smell). But the boiler must be “turned on” at full capacity. If the smoke smells sharp and unpleasant, the color is predominantly dark tones, then the efficiency is low.

We calculate the budget for the assembly. Materials. Equipment.

Tools for making a homemade pyrolysis boiler:

• optionally, an angle grinder (for finishing the case);
• inverter welding (welding machine) of electric type (recommended - direct current);
• electric drill;
• to choose from: electric jigsaw or plasma cutter (better and more efficient).

Materials for home-made pyrolysis boiler:

• Thermal insulation materials for walls and floors.
• Sheets of steel - 3 pieces. Dimensions: 1m 25cm X 2m 50cm; thickness 4 mm - 7.5 m2.
• sheets of galvanized steel - 2 pieces (or plain steel sheet).

If you want to save more, then the interior of the device can be finished with a thicker sheet (for example, 5 mm) than the outer elements of the case (4 mm).

Dimensions:

• 1m 25cm X 2m50cm; thickness 2 mm; 3 pipes:
• the first is 57 mm in diameter; thickness - 3.5 mm; length - 8m;
• the second is 159 mm in diameter; thickness - 4.5 mm; length - 0.5 m;
• the third is 32 mm in diameter; thickness - 3.2 mm; length - 1m.
• 10 pieces of refractory bricks (chamotte);
• profile square pipe size 60 X 30; thickness - 2mm; length - 1.5m;
• profile square pipe 80 X 40 in size; thickness - 2mm; length - 1m;
• 5 packs of electrodes (or 10kg);
• 10 cut circles with a diameter of 230mm;
• blower fan;
• temperature sensor;
• steel bolts;
• thermoceramic cord;
• two handles for opening / closing metal "doors";
• electrical interrupter.

The details mentioned above are in general terms let you know how much material you need. It all depends on the size of the boiler that you make yourself. Before starting all work, it is strongly recommended to make a design drawing, and then purchase materials!

Boiler drawings

Do-it-yourself drawing of a pyrolysis boiler (25-40kW):

do-it-yourself pyrolysis boiler scheme

Table of parameter ratios in order to make a boiler with your own hands:

DIY step-by-step instructions for making a pyrolysis boiler

Do-it-yourself pyrolysis boiler assembly steps

• Choose a place to install the pyrolysis boiler. It is desirable to sheathe the floor and walls with thermally insulating material. Access to the unit must be unhindered. The distance between the walls and the unit is at least 20 cm.
• Prepare drawings for the boiler.
• Purchase materials for direct manufacturing.
• According to the drawings, cut out the elements of the device.
• The holes for the heat exchanger tubes can be cut out with a jigsaw WD 40 and a jar. Simply outline a 230 mm can on a sheet of metal and cut it out.
• First of all, weld the sheets of metal together for the afterburner.
• Weld the bottom of the asification chamber and the hole for the burner.
• Install the pipes in the pre-cut holes.
• Weld the pipes to the structure by welding.
• Mark places for spacers (they are welded to prevent deformation from pressure).
• Gradually, sheathing the resulting structure with an outer casing made of metal, weld spacers and, of course, a metal casing.
• By welding, fix the metal protrusions for the "doors" (into the combustion and ash chambers).
• Craft a loading door. Think about the attachment mechanism.
• Attach the sealing cord and handles to the door.
• Place fireclay in the boiler according to the drawings (in the gasification chamber).
• Attach the pipes to the outer casing by welding. One for air supply, the second for chimney.
• If desired, go over the sheets with a grinder.
• Install a centrifugal fan.
• Coat the body with primer. You can also apply a layer of thermal insulation paint.
• Plug in an electrical power supply.
• Attach the temperature sensor to the structure.

Making a pyrolysis boiler with your own hands, you can be sure of the quality of the device, and are also not limited by the strict limits of the characteristics of the finished product

Subtleties in the manufacture of the unit

• the opening for combustible raw materials should be cut a little higher than for boilers with a solid heating system;
• it is obligatory to install a restrictor in the fuel chamber, for air control. It (limiter) can be made from a pipe (diameter - 70mm); weld a steel disc at the bottom of the limiter. The distance between the walls - 40mm;
• make the fuel compartment rectangular;
• if in your drawing the boiler will be with internal pipes, then they need to be bent a little.

Do-it-yourself pyrolysis boiler manufacturing and safety rules

Safety rules during the manufacture of the pyrolysis boiler

• use gloves during work;
• wear a safety helmet when welding;
• when using power tools, keep a distance of at least 50cm;
• keep construction details in a protected place - away from children and animals;
• do not look at welding with the naked eye;
• the room for the boiler must be isolated from the environment. It is necessary to install a ventilation system in it;
• the walls and foundation for the boiler must consist of heat-absorbing materials.

Safety rules for the operation of a homemade pyrolysis boiler

• do not lean your body against the boiler;
• use gloves when operating the device;
• do not forget to add water;
• do not leave open chambers for laying firewood and slag;
• do not install any structures near the unit, especially from wood;
• when removing slag, use a spatula;
• Do not put unprotected hands into the boiler chambers.

Pyrolysis boiler in the heating system

Outcome

It is quite easy to make a pyrolysis boiler with your own hands, given all the nuances of manufacturing. It is easy to use and does not require high financial costs. It does not consume much electricity or gas, which are high these days. Fuel, as in other heating systems, does not require replenishment every three hours. Plus, the unit does not pollute the atmosphere. If you decide to make a boiler with your own hands, then you will certainly be satisfied with the result and further operation.

Video on how to make a pyrolysis boiler with your own hands and check it out:

Do-it-yourself pyrolysis boiler video instruction

In regions far from central heating, each house used to be equipped with a solid fuel boiler. They heated it with coal and firewood. Unfortunately, this design was not without drawbacks. The main one was inconvenience in use.

Attention ! Quite often, people install electric heaters, but it is worth recognizing that heating a house with their help is a rather costly undertaking.

Fortunately, there is a worthy alternative in the form of a do-it-yourself pyrolysis boiler. The main schemes and drawings will be presented in this article. Devices of this class can generate heat by burning firewood or special briquettes. Moreover, you can use waste from woodworking factories.

What is a pyrolysis boiler

How does it work

From the diagrams and drawings of the pyrolysis heating system, you can understand the basic principles of its operation. But in order to create this device with your own hands, you need to understand it in more detail.

The process that takes place inside a do-it-yourself pyrolysis boiler according to the drawings and diagrams presented in the article functions due to dry distillation. When the temperature reaches 500-600 degrees Celsius, the process of decomposition begins. Its result is two substances - gas and natural coke.

The gas created inside the structure mixes with oxygen atoms. This starts the combustion. Of course, in order for everything to go according to the scheme, there must be an appropriate temperature inside the chamber, made with your own hands according to the drawings and diagrams.

Pyrolysis gas created in a do-it-yourself boiler interacts with carbon. This, in turn, starts the reaction. But for this to become possible, the device must be made clearly according to drawings and diagrams.

As a result of the pyrolysis process, which takes place in a do-it-yourself long-burning boiler according to popular drawings and diagrams, smoke is generated, but it does not contain any harmful compounds. Therefore, the harm done to the environment is minimal.

An important advantage of a do-it-yourself pyrolysis boiler made according to drawings and diagrams is that it practically does not generate waste. At the same time, a considerable amount of thermal energy is released, thanks to which it is possible to heat a considerable area.

The pyrolysis process belongs to the exothermic class. In general, this is the name of all processes, as a result of which heat is released. But not everything is so simple. The fact is that this heat is necessary in order to carry out additional heating and drying of the fuel.

Advantages and disadvantages

There is important nuances, which you need to know about before making a pyrolysis boiler according to drawings and diagrams. You need to start with the advantages and disadvantages that the design has.

The advantages of do-it-yourself pyrolysis boilers include:

• Maintaining the set coolant temperature for a long period.
• Large loading chamber.
• High efficiency.
• Possibility of recycling woodworking industry waste in a pyrolysis boiler, made according to the drawings.

However, for a do-it-yourself pyrolysis boiler to work as it should, it is necessary that the fuel contains no more than 30 percent of additional components.

Any design has its drawbacks, in this case, they can be considered:

• big dimensions,
• network dependency,
• fuel requirements.

Also, the high cost of the purchase can be attributed to the disadvantages of the pyrolysis system. But it can be significantly reduced if you create a device with your own hands according to drawings and diagrams.

Do not put undried wood into a pyrolysis boiler made with your own hands according to diagrams and drawings. The fact is that at high humidity, the pyrolysis reaction does not occur. Even with a small percentage, efficiency drops sharply. This is because heat energy is converted into steam.

The need to connect to the network is explained by the fact that the device must have a fan. It is he who allows you to provide forced draft to the pyrolysis boiler, made by hand according to drawings and diagrams.

We create a pyrolysis boiler

Analysis of diagrams and drawings

To create a pyrolysis boiler with your own hands, it is important to carefully study the diagrams and drawings. It is for them that you can choose the design and most accurately determine the amount of materials needed for construction.

The diagram and drawing of the pyrolysis boiler shows the main elements, without which it is impossible to build a structure with your own hands:

• regulators,
• smoke channels,
• air holes,
• pipes for water supply,
• water pipes,
• the combustion chamber,
• fan.

When making a pyrolysis boiler with your own hands, it is very important to adhere to the drawings and diagrams. The fact is that this is a complex device in which high-temperature processes will occur. Therefore, the slightest mistake can turn into an emergency.

For a private house, a pyrolysis boiler with a capacity of 40 kW will be enough. Don't aim for high power. The fact is that in this case the design becomes much more complicated. Not only that, the final cost also increases.

The choice of power of the pyrolysis boiler that you are going to create affects the size of the key parts in the drawing or diagram. The correct functioning of the device depends on the correct selection of sizes.

Advice ! If you are the owner of a small house, then you can opt for a boiler with a power of 30 kW. This will be more than enough.

Tools needed to make a boiler with your own hands

In order to make a structure based on a pyrolysis reaction according to drawings and diagrams with your own hands, you need to stock up on some equipment. To bring your idea to life, you will need the following materials and tools:

• Bulgarian,
• welding machine,
• grinding wheels,
• electric drill,
• electrodes,
• pipes of various diameters,
• steel strips,
• temperature sensor,
• fan,
• metal sheets.

This is a basic set that is needed to create a do-it-yourself pyrolysis system according to diagrams and drawings. Of course, in the process of work, there may be a need for additional tools and materials.

Attention ! The thickness of the steel for the case should be 3 mm, and preferably 4.

Assembly subtleties

After you select the appropriate scheme, you can start assembling. In doing so, you must adhere to the following recommendations:

1. The hole through which firewood and briquettes will enter the furnace should be slightly higher than that of conventional solid fuel structures.
2. Don't forget the limiter. Its main task is to control the amount of air. To create it, you need a seventy-millimeter pipe in cross section. Its length should be greater than the body.
3. A disk is welded to the limiter. The element must be made of steel. The place of welding is the bottom of the structure. As a result, you will get a gap of 40 mm. To make the installation of the limiter possible, it is necessary to make holes in the corresponding places of the cover.
4. The best shape for the hole through which firewood will be loaded is a rectangle. In this case, it is important not to forget about the door. It should have a special pad for better fixation.
5. Also in the design it is necessary to provide a hole through which the ash will be removed.
6. The pipe for the coolant must be made with a bend. This will increase the heat transfer.

Another important element according to any scheme and drawing is a valve. With it, you can control the amount of coolant entering inside. Therefore, it is best to place it in a convenient and easily accessible place. You can see the algorithm for creating a pyrolysis boiler with your own hands according to the drawings in the video below.

To create a pyrolysis boiler that works efficiently and smoothly, you should understand the processes taking place in this device.

Pyrolysis is the process of decomposition of complex substances when exposed to high temperatures without the involvement of additional reagents. To simplify, under the influence of heating, the molecules are split into simple components with a smaller mass. That is, when organic fuel is burned in a furnace, the substances obtained during pyrolysis burn more easily, more completely, while giving off more heat.

The principle of operation of the pyrolysis boiler

Pyrolysis in its pure form implies the decomposition of a portion of the fuel in the absence of air access, which occurs in the retort. The gases obtained in the process of pyrolysis enter the accumulator-receiver and, depending on the need, are used. This principle of operation was used in pyrolysis plants used in cars during the Second World War. In this case, the retort was heated by the heat of the exhaust gases.

The use of pyrolysis in its pure form has a low efficiency, due to the deposition of part of the combustible components during the cooling of the pyrolysis gas. These components are capable of supporting combustion, but their use in a carburetor is not possible. Also, before the trip, it is necessary to heat the retort from an external heat source, and when moving, it was necessary to maintain pressure in it so that it was possible to start when stopped.

pyrolysis boiler

Due to the fact that there was no shortage of solid fuel before, and there is no now, the design of automotive units was based on gas generation. This process took place as follows: after loading the wooden chocks, they were ignited, and then slowly smoldered. The source of the temperature required for pyrolysis was partly the fuel itself, and the pyrolysis gases were sent directly to the carburetor. During parking they were pitted into the air. The advantage of using the principle of gas generation in such installations is the ability to heat while moving, using any solid fuel.

Absolutely all modern pyrolysis boiler equipment is gas generating, which makes it possible to have an efficiency of 65-70%. At the same time, there is no mistake in the name, since over 90% of the energy is obtained from the pyrolysis combustion of gases. In fact, pyrolysis and gas generation are synonymous denoting the same process.

Note: it is customary to consider the boiler to be pyrolysis if there is a long process of burning solid fuel in it. In them, the main amount of thermal energy is generated during the pyrolysis process. Long-burning oil devices produce more than 50% of energy due to the pyrolysis of light fractions, while heavy fractions settle in the form of sludge. Thus, oil-fired furnaces can be called pyrolysis furnaces with a very large assumption.

Terminology

Pechniks express themselves in their own language, which, at times, is not understandable to other people. So, hailo is not a swear word, but represents the mouth of the firebox, built according to a certain design. The hog is a horizontal part of the chimney, the damper is a damper that is necessary to regulate air flow and smoke. In the case of a pyrolysis boiler, flue and chimney are different concepts. In the first of them, no processes occur, and in the second, thermochemical reactions continue to occur.

Pyrolysis boiler in section

Work principles

All boilers operating on the principle of pyrolysis function in the same way:

• In the chamber where gasification takes place, the process of fuel smoldering takes place. Primary air enters it from outside.
• A certain volume of oxygen present in it is spent to ensure that smoldering does not stop and provides the temperature required for gasification.
• Passing hail gases released during pyrolysis move into the combustion chamber.
• Secondary air enters it, and the process of burning pyrolysis gases takes place.
• In the presence of a catalyst, which is fuel carbon, a reduction reaction of part of the pyrolysis gas takes place. Its result is carbon monoxide and nitrogen oxides. This process requires the expenditure of thermal energy.
• In the afterburner, the components obtained during the reduction are oxidized with the release of heat.
• The combustion products that have entered into the reaction move through the heat exchanger of the hot water register, and then are sent to the chimney.
• To maintain the required temperature at which complete combustion occurs, a special thermostatic system is used.

pyrolysis boiler

Note: if you select thermal energy during the stages of operation of the apparatus, when gasification, combustion and afterburning occur, then the efficiency of the heat engineering device is significantly reduced. In the course of the process carried out in this way, the formation of gases takes place, which are not only harmful, but also dangerous. The amount of heat circulating in the pyrolysis boiler is much greater than is required for the self-sustaining process. Therefore, the design of pyrolysis boilers for do-it-yourself execution should take place with an understanding of the processes occurring in it, so as not to create not only an inefficient, but also a dangerous device.

Operating modes of the pyrolysis boiler

Ignition

At this stage, it is necessary that the gate is in the open state. Combustion products move directly into the chimney

Work mode

The device operates with the shutter closed, thus ensuring the flow of the pyrolysis process. Creation of thrust in the gas duct is achieved by force or in a natural way.

Additional loading of fuel

At this moment, the gate is closed, but the draft in the flue is still present for some time. The pyrolysis process does not end. The addition of fuel must be carried out as quickly as possible, otherwise it may simply burn out.

Principle of operation

Advantages and disadvantages

The advantages of pyrolysis boilers include:

• The principle of operation of the device allows achieving a high efficiency of up to 85%, since the fuel is burned almost without residue.
• Daily loading of fuel is made no more than twice a day.
• Fuel economy is achieved by the ability to adjust the heat supply to the heated room.
• Environmental friendliness of the heating device.

Pyrolysis boilers used in everyday life are demanding units:

• Dehydrated fuel over 30% drastically reduces efficiency. This is due to the need to spend additional energy on the evaporation and decomposition of water vapor.
• The technical characteristics of the boiler, obtained by calculation, can only be achieved if fuel is used, which contains a significant amount of complex organic compounds.
• During combustion, a strong jet of gases is formed, which has a high chemical activity. This factor necessitates the use of high-quality materials for the combustion chamber device.
• Small power limit. The boiler boost limit is a maximum of 50%.
• Substantial cost.

Standard pyrolysis boiler device

Pyrolysis

The design of the pyrolysis boiler provides for the presence of two combustion chambers. This feature of the device allows you to fully use the effect of pyrolysis.

The first chamber is used for fuel loading and its pyrolysis. The processes of decomposition of organic compounds take place in it, as a result of which ash and pyrolysis gases are formed, which move to the second chamber.

The chambers are separated from each other by means of a grate.

In addition, a characteristic feature of the pyrolysis boiler is the creation of an upper blast. Due to the fact that the processes in the furnace are accompanied by increased aerodynamic resistance, it becomes necessary to organize forced draft. For this purpose, smoke exhausters or fans are used.

The high level of fire hazard of this heat engineering unit implies the fulfillment of a number of requirements for the installation of a pyrolysis boiler:

• Boiler equipment should be placed in a separate room specially designed for it.
• For safe operation, it is necessary to build a ventilation hole with an area of ​​100 square meters. cm.
• The boiler must be installed on a foundation made of brick or concrete.
• The protection of combustion chambers from sheet steel should be equipped.
• Must have free space between pieces of furniture, walls and boiler casing at least 200 mm.
• It is necessary to carry out measures to insulate the chimney. If this condition is not met, heat loss is inevitable. In addition, the lack of reliable thermal insulation will cause increased wear and tear of the device due to the occurrence of soot and condensation.

pyrolysis boiler

Do-it-yourself pyrolysis boiler

The growing popularity of pyrolysis boilers is due to a number of advantages of this heater, one of which, among other things, is independence from the gas supply to the home. The high cost of factory copies of equipment gave impetus to the manufacture of pyrolysis boilers on their own.

Choosing tools and materials

Before assembling the pyrolysis boiler, it is necessary to determine the type of device, its design features and select a suitable standard design design.

To create a pyrolysis boiler, you will need:

• steel thick-walled pipe;
• sheet steel 4 mm thick;
• profile pipes;
• round steel with a diameter of 20 mm;
• centrifugal fan;
• fireclay brick;
• temperature control automatics;
• nuts, bolts, washers.

The minimum set of tools for assembly work consists of:

• welding machine for electric arc welding;
• Bulgarian;
• electric drill;
• locksmith tool kit.

Assembly diagram

To determine the exact amount of materials for the pyrolysis boiler, it is necessary to use the drawings that can be found in the reference literature. It makes no sense to independently create the design of the device, it is enough to choose the most suitable one from those already available. In the scheme of the pyrolysis boiler, the following should be indicated: the furnace, the heat exchanger and the organization of the water supply.

Assembly diagram

Pyrolysis oven as an alternative to a boiler

Experts believe that the manufacture of low-power pyrolysis boilers is impractical. Therefore, in houses with a small area in the absence of the possibility of electric or gas heating, the construction of a pyrolysis oven is a suitable option. The principle of operation of such a device is similar to that used in boilers for the combustion of solid fuels.

construction classic version a brick oven equipped with a water circuit is a good technical solution to the problem of organizing heating. This design combines the advantages of two units: a traditional furnace and a long-burning boiler.

pyrolysis oven

In a large part of Russia, wood is still the most affordable type of fuel, and many are heated by wood-burning boilers. Everything would be fine, but in ordinary solid fuel boilers, the bookmark burns out in 2-3 hours, which is completely inconvenient - you won’t leave the house for a long time. There are long burning boilers. In them, one bookmark of firewood can burn up to 8-10 hours, but they cost a lot of money. However, as usual, there is a way out - to make a pyrolysis boiler with your own hands. Not to say that this is an easy job - welding skills must be at a high level, and the materials cost a lot. However, there are many homemade pyrolyzers.

The principle of operation of the pyrolysis boiler

In relation to heating boilers, pyrolysis is the combustion of fuel with an insufficient amount of oxygen. At the same time, the fuel emits a large amount of gases, almost all of which are combustible. These gases are sent to a special combustion and afterburner chamber, where secondary air is supplied. The gas-air mixture ignites, releasing a large amount of heat. Much more thermal energy is released than can be extracted by conventional combustion of wood or coal. The fact is that many of the volatile substances formed during the combustion of fuel have very high temperature combustion. As a result, pyrolysis boilers extract more heat from the same amount of fuel.

Due to the peculiarities of the combustion process (emission a large number gases) such installations are also called gas-generating boilers.

A design feature of pyrolysis boilers is a firebox consisting of two chambers. Fuel is placed in one (often this is the upper part of the furnace), gases are released in it, and therefore this part is called the gas generation chamber. Through a narrow neck, gases enter the second chamber - afterburning. Here they mix with secondary air, flare up and burn out almost without residue.

On average, the efficiency of pyrolysis machines is above 85%. There are models that can give out 92% and even a little more. But these indicators are possible only and exclusively when using dry fuel. Its humidity should be 5-8%. At 40% moisture content, combustion can completely die out, and at 20% it will simply be ineffective. And this is one of the main disadvantages of this technology: firewood and coal have to be dried beforehand, for example, by making a platform near the chimney. Just firewood dried in will not go, like coal taken from a pile on the street.

The video shows a boiler in which the afterburner is at the top. Although boilers of this type have a simpler structure (the resulting gases themselves rise up), do-it-yourselfers prefer a chamber with a lower location of the afterburner (as in the photo above).

What to pay attention to when making

If you are going to make a pyrolysis boiler with your own hands, you need to clearly understand not only the mechanism and principle of its operation, but also take into account all the unpleasant moments that these units have. First of all, it must be said that almost all pyrolysis gases are toxic. That is, the unit must be completely sealed, must be of the highest quality.

In addition, to ensure safety, a combustion process control system (temperature, smoke, draft sensors) and automation are needed, which, depending on the readings of the sensors, regulates the combustion processes. If you are going to make a home-made pyrolysis boiler on natural draft, automation can be the simplest - non-volatile. If there is a blower fan to supply air to the current, more serious (and expensive) devices are needed, and they are powered by a 220 V network. The operation of a boiler of this type without automation is dangerous, because an uninterruptible power supply is needed that will ensure the operation of the fan and automation for 10 -12 hours is the burnout time of the bookmark.

Second moment. In some models of pyrolyzers, the temperature in the active phase reaches 1000°C and above. Ordinary structural steel under such conditions will quickly burn out. In order for the boiler to exist for a long time, heat-resistant steel and an internal lining of the most thermally loaded parts are necessary. If the pyrolysis boiler is made by hand, the lining is most often made of fireclay bricks. In the working phase, fireclay heats up to a crimson glow and becomes very fragile. If, all of a sudden, you have to operate in the furnace at this time, be careful - it is easy to damage the lining at the moment, but it is long and difficult to repair.

How much will materials and parts cost?

How much a do-it-yourself pyrolysis boiler will cost exactly depends on the required power and the chosen design. However, if you buy heat-resistant steel, grate bars, make a lining, install automation (albeit inexpensive), the amount runs up to $ 850-1200. This is the cost of materials and components, but with self-welding. They are voiced by those who have already welded and use pyrolysis. If you have to pay for welding, then the costs should be doubled.

As you can see, in the case of owning welding, there are savings, but far from the biggest. You can find ready-made options for solid fuel pyrolysis boilers for $ 1500. Although, as you know, a cheap product has a low price for a reason. Saved on something. And you can even guess on what: on the lining. It is the secrets of protecting the walls of the furnace from burning out that manufacturers cherish the most, and spend a lot of money on research in this area. This is why high quality equipment costs a lot of money.

Video project of a pyrolysis stake, assembly process

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Recently, they have become increasingly popular among owners of private houses, shops and small industries.

This type of solid fuel heating equipment is the most promising for a number of reasons:

• its efficiency is more than 90%;
• the fuel burned in its furnaces, and we are talking mainly about pellets, is environmentally friendly and cheap;
• modern technologies make it possible to create such perfect boilers that they can be installed even in city apartments.

Given all this, it is not surprising that people want to make such a unit with their own hands. So, let's see if it is possible to make a properly working one in a home workshop.

The principle of operation of a solid fuel boiler

Stages of operation of the pyrolysis boiler

This unit in its work uses the principle of decomposition of solid organic fuel into coke and pyrolysis gas, with further afterburning of the latter.

In fact, the process of heat generation in such a boiler is divided into two stages:

1. Normal combustion of solid organic fuel in the first furnace with insufficient oxygen supply (smoldering with the release of a large volume of pyrolysis gas).
2. Combustion of volatile substances in the second furnace.

The method of supplying air to the combustion chambers

Particular attention should be paid to indicators such as the diameter and height of the chimney, especially for natural draft boilers.

It should be enough to overcome the resistance of the boiler and the chimney, as well as to create a vacuum inside the furnace of the order of 16 - 20 Pa. The diameter of the chimney must correspond to the outlet pipe, and its height must be 5 meters or more.

As for the forced air supply, it can be carried out according to three different schemes:

1. Installing a blower fan (cheapest option).
2. Installing a smoke exhauster at the outlet of the boiler (the safest design, since it does not allow the flame to be ejected towards the operator when the furnace doors are opened).
3. Installation of fans on both sides (more often used on high power boilers).

Combustion control

Boiler control automation should be of the highest quality possible, since not only the heat in the house, but also the safety of the residents depends on its proper operation.

The processor is able to control the purge modes, the pump that pumps the coolant in the heating system, the speed of the fans, and a room thermostat can be connected to it. At the request of the owner, you can switch from automatic control mode to manual and vice versa.

The nozzle of the pyrolysis boiler is a slit-like opening between the gasification and combustion chambers, through which pyrolysis gas is forcibly supplied.

Self-manufacturing methods

On the network you can find a lot of options for the manufacture of pyrolysis boilers from a variety of improvised materials. Consider the most common of them.

The first option is a simple boiler from a gas cylinder. It would seem that rounded steel containers made of fairly thick steel are ideal for making fireboxes, especially since it’s not easy for a do-it-yourselfer to give the desired shape to an iron sheet 5 mm thick, but here almost everything is ready.

But, unfortunately, nothing good will come of this venture. Conventional structural steel used for the manufacture of cylinders does not have the necessary level of heat resistance and chemical resistance, so the walls of furnaces made from them will quickly burn out.

But it is still possible to find a use for a cylinder in a heating system. It will make an excellent fuel tank for a mining boiler.

The second option is a brick pyrolysis boiler. Such a pyrolyzer has an efficiency of up to 90%. This indicator is achieved due to the high level of thermal inertia of the brick, which allows maintaining the optimal temperature level in the gasification and combustion chambers, regardless of the intensity of the thermochemical reactions inside them.

In addition, a brick boiler can be converted in such a way that two gasification chambers come out. And to make sure that they work on different ones - one on wood, and the second on coal.

Due to the different duration of gas formation, as well as the shift in the time of loading the fuel, it is possible to ensure that the boiler never cools down.

And the third option is a mini-oven that runs on sawdust, shavings, and rags. It is made from a pair of cans from under canned food of various diameters inserted into each other. Fuel smolders in the lower jar, and pyrolysis gas is drawn into the holes punched with a knife in the bottom of the upper jar and burns there.

Materials and tools

A set of tools and consumables depends on what kind of boiler it was decided to make.

For example, in order to make an all-metal long-burning pyrolysis boiler with your own hands, you will need:

• welding machine;
• powerful "grinder" with cutting and grinding wheels;
• electric drill;
• electrodes;
• control automation;
• blower fan;
• sheet metal 3-4 mm thick;
• a set of thick-walled pipes with a diameter of 20, 32, 57 and 159 mm;
• steel strip30X4 mm 80X5 mm;
• steel professional pipe 60X30X2 mm and 80X40X2 mm;
• asbestos cord;
• steel bar;
• stamping brick;
• boiler diagram.

For a brick pyrolyzer, you will need slightly different consumables:

• ceramic brick;
• fireclay brick;
• steel sheet with a thickness of 4 mm or more;
• cast iron grates;
• blower fan;
• control automation;
• firebox and blower doors;
• boiler diagram.

Assembly nuances

First of all, a detailed drawing of the future unit should be drawn up. After that, all parts of the boiler are selected or manufactured, according to the developed drawing.

1. For the manufacture of both chambers, alloyed heat-resistant steel with a thickness of at least 5 mm is best suited, however, to reduce the cost of construction, you can also use simple carbon steel, but be sure to lay out the lower part of the gas generation chamber and the bottom of the combustion chamber, on which the fire torch is directed, with using refractory bricks.
2. Water jacket, lid, doors are made of steel 3 mm thick.
3. A fire tube heat exchanger should be placed inside the water jacket, for the manufacture of which seamless pipes with a diameter of 48 or 57 mm made of carbon steel are ideal.
4. Both chambers should be made as round as possible, since unheated corners significantly reduce efficiency.
5. The nozzle of the nozzle is made in the form of a longitudinal slot, since this shape is less conducive to clogging with ash than a circle.

People who decide to use pyrolysis boilers to heat their homes and structures, for their full and long-term operation, should follow a number of simple rules:

1. It is better to make a chimney with a height of 5 to 7 meters and higher from sandwich pipes.
2. For the first time, the boiler should be heated at maximum power, for at least 5 hours, while the room should be well ventilated.
3. The chimney is cleaned every couple of months.
4. Stacking firewood in the gas chamber should be as dense as possible.
5. Cleaning of a small boiler is carried out with a scraper or a metal brush, and large units - with compressed air, with an open smoke damper.
6. Before the end of the heating season, the fuel is completely burned out, and as soon as the structure cools down, the boiler is cleaned. All moving parts are lubricated.

Homemade pyrolysis boilers are becoming increasingly popular due to the high cost of such factory-made boilers. The only drawback of such units can be considered only their exactingness in the preparation of fuel (its moisture content should not exceed 25%).

Well, otherwise, a self-made pyrolysis boiler will become a worthy alternative to any of the varieties of ready-made heating units on the market.

Watch the video, which shows in detail how to make a pyrolysis boiler with your own hands: