Review of fuels for pyrolysis boilers and long-burning furnaces. Pyrolysis boiler for heating a house - where it is used Pyrolysis boilers for heating a residential building

There are many types of heating boilers. I note that today, the most popular and high-tech pyrolysis boilers are long burning. They have a more capacious firebox than other boilers, so there is no need to frequently fill up the fuel.

In this article I will provide a detailed description of the types of pyrolysis boilers, the features of their operation and a lot of other useful information.

Long-burning pyrolysis boilers with a water circuit are an excellent alternative source of energy in private houses in conditions of frequent gas supply interruptions.

A long-burning solid fuel boiler with a water circuit can operate on wood and other types of solid fuels: coal, wood waste, etc.

The main disadvantage of this type of boilers is the high price. In addition, unlike many other types of boiler equipment, a long-burning pyrolysis boiler with a water circuit is most often volatile.

Not only does electricity supply circulation pump and control devices, but also a built-in fan: this equipment, as a rule, does not work on natural draft.

Solid fuel wood and coal boilers are second only to gas boilers in popularity. At the same time, they have one serious drawback - the fuel must be loaded several times a day.

With the usual combustion of firewood, the efficiency of boilers does not exceed 75%, and part of the combustible substances simply flies into the chimney.

Long-burning pyrolysis boilers with a water circuit are much more practical and efficient.

It will not be a secret for anyone that pyrolysis heating boilers are currently very necessary and demanded devices for heating systems. It is for this reason that very many of our people have become interested in these particular units.

A pyrolysis boiler is a special heating boiler that can use pallets, coal, wood, and other materials as fuel.

One of the main criteria, depending on which they subdivide heating boilers, is the type of fuel they run on. Thus, in today's market you can find boilers on pallets, coal, wood. You can also find so-called universal boilers for yourself.

The most common at the moment are wood-fired solid fuel boilers, which have many advantages. The first is that fuel is considered the most readily available. It should also be noted that such boilers are sold at reasonable prices.

A distinctive feature of pyrolysis boilers is the control of the oxygen level in the combustion chamber, and, accordingly, the control of the temperature and speed of fuel combustion. A solid fuel pyrolysis boiler will ensure your independence from gas and electricity, since the cost of these energy sources significantly exceeds the cost of solid fuel.

Design features

Pyrolysis boilers are one of the types of solid fuel boilers, which in recent times is in high demand due to the constantly rising prices for gas and electricity, they are also called gas-generating boilers.

The main fuel for a pyrolysis solid fuel boiler is:

wood;
briquettes;
wood chips;
wood waste.

Hard coal or coke is very rarely used as fuel. Pyrolysis boilers are comfortable to operate, reliable and have a long service life. Before buying a pyrolysis boiler, you need to study the possibility of meeting strict requirements for the quality of the fuel used.

In the overwhelming majority, it is allowed to use wood with a moisture content of no more than 20%. When using wood with a large amount of moisture, efficiency decreases sharply.

The pyrolysis boiler works on the principle of dry distillation of fuel.

With a lack of oxygen, under the influence of high temperatures, dry wood decomposes into a solid residue and a volatile part (pyrolysis gas, which is subsequently mixed with hot air).

This air-gas mixture, which is formed during the pyrolysis process, is the fuel of the pyrolysis boiler. The pyrolysis combustion process is exothermic (accompanied by the release of heat).

It occurs at temperatures from 200 to 800 ° C and provides heating of the air entering the combustion chamber. In this case, the fuel is heated and dried in the unit chamber, due to which the release of soot and ash is minimized.

A pyrolysis or gas generator boiler is characterized by a higher efficiency compared to traditional solid fuel technology.

When burning high-quality fuel, the efficiency of a pyrolysis boiler is at the level of pellet boilers and long-burning boilers and reaches 90%.

Pyrolysis solid fuel boilers are used both in private houses and apartments, and for heating industrial premises.

Pyrolysis boilers are a very cost-effective type of heating technology. The rather high price for a pyrolysis boiler is covered by low fuel consumption.

In a conventional solid fuel unit for long-term combustion, the coolant is heated from the heat released during the combustion of fuel, then pyrolysis boilers work in a different way.

When burning fossil fuel (firewood, pellets, wood briquettes and even coal) at a temperature of 400-800 ° C, gas is released, burning which, you can get much more heat than when burning fuel.

The process of gas formation from solid fuel and the subsequent combustion of the resulting gas is called pyrolysis, and units using this principle of operation are called pyrolysis, or gas generating boilers.

There are two chambers in the pyrolysis boiler, and combustion is carried out in both:

Combustion chamber - wood or other fuel is burned (charred).
Afterburner chamber - the gas produced by the fuel is burned.

Fuel is located in the combustion chamber and ignited. Primary air is supplied to the combustion zone. When the fuel warms up to a certain temperature, gas evolution begins.

With the help of a smoke exhauster, gas, together with secondary air, is sucked into the afterburner (it is located below the fuel level) and burns there, releasing heat.

Combustion products enter the flue duct (gas duct) and enter the chimney, passing through the water jacket of the unit and heating the coolant.

As a result, the wood turns into charcoal, burning almost completely, and the smoke is cleared of unpleasant odors and carbon monoxide.

Advantages and disadvantages

Application advantages:

when burning firewood, it is impossible to obtain such a high temperature as during the combustion of pyrolysis gas (especially if the firewood contains a lot of moisture);
with the help of the control controller, we can automate the operation of the pyrolysis boiler without any special difficulties, since the process of burning pyrolysis gas is easy to control and regulate;
burning wood or coal requires much more secondary air than burning wood gas. Therefore, with the same volume of secondary air, the efficiency of combustion of wood gas, the duration and temperature of combustion will be greater;
blowout harmful substances pyrolysis boilers into the atmosphere is reduced to a minimum, therefore, a pyrolysis boiler is an almost environmentally friendly source of heat;
solid fuel boilers for pyrolysis combustion need to be cleaned from ash extremely rarely;
pyrolysis boilers can work for a very long time (up to 15 hours) on one tab of firewood, while ordinary solid fuel boilers need to be reloaded every 3-4 hours.

If we talk about the disadvantages of this type of unit, then, in addition to the price, which is a payment for increased efficiency, and more complex design, because pyrolysis boilers are 30-35% heavier than conventional ones, since more metal is required for their manufacture, other "disadvantages" are insignificant.

For maximum efficiency, the moisture content of the wood should be no more than 20%. If the wood is damp, steam is generated when it burns, which reduces gas emission and leads to the deposition of tar and soot. As a result, the efficiency of the boiler drops, and it becomes necessary to clean it.

Most pyrolysis units are electronically controlled.

Consequently, it becomes necessary to use electricity to operate the controller, which controls the fan and the smoke exhauster.

Natural draft pyrolysis boilers exist, but they require a very high and powerful chimney, which is why such models are unpopular.

The need to fill the furnace by 50-100% - only in this case the high efficiency of the boiler will be maintained.

Long-burning solid fuel pyrolysis boilers, although twice more expensive than a conventional solid fuel boiler, differ in the ability economical use fuel with maximum efficiency, which is significantly higher than from the combustion of coal and wood in conventional units.

Types of pyrolysis boilers with a water circuit

There are many models on the market that can be divided into groups.

The location of the chamber in which the content is burned.

Most of the boilers are designed so that this compartment is located at the bottom. It is more convenient for filling the material, but after its combustion, the ash enters the chamber, where the formed gas is burned.

This obliges the owner to frequently clean the equipment. The top location of the camera eliminates this need, but has several disadvantages. The main disadvantages of such a system include the inconvenience of placing the chimney and a greater amount of materials for its manufacture.

Traction type.

It can be carried out both forcibly and by means of pressurization. Boilers, the draft power of which can be manually adjusted, require a reinforced chimney and do not depend on the power supply. Such models are not widespread.

Apparatus of the second type are equipped with automatic systems that determine the inflation time. Maintaining power assumes that the unit is volatile, but the pyrolysis output rate in it is quite high. These models are the most popular.

Fuel type.

When determining the possibility of using a particular type of fuel, one should start from the moisture level of the material. If it is higher than 20%, then the first time of the boiler operation will be spent on drying the material, which entails a decrease in the efficiency of the device.

If the moisture content of the fuel used is initially high, then the pyrolysis process will take no more than 1/5 of the entire combustion cycle. This is highly ineffective and irrational.

It will be difficult to recoup the high cost of the boiler. Therefore, the conclusion is obvious: best material for combustion in pyrolysis boilers - these are firewood, coal or briquettes, the moisture level of which is minimal.

Each of the materials has a different burning time. The smoldering time determines the quality and uniformity of heating the living space. The best option- this is dry wood with a moisture level of no more than 10-15%.

Today there are two main types of pyrolysis units, differing in design.

Forced air boilers.

In the first version of the boiler design, the primary combustion chamber, where solid fuel is placed, is located above the secondary combustion chamber, where the afterburning of pyrolysis gases is organized. A special nozzle is installed between the chambers, which has a straight section and is made of a refractory composition similar to fireclay bricks.

In this design, air is pumped into the main firebox using installed fan, and gets partly into the furnace with solid fuel, and partly into the afterburner of the emitted gases.

In this case, it is obvious that the principle of pyrolysis is initially violated, since the fan creates an excess of oxygen instead of limiting it.

But, despite this, there is an effective and complete combustion of firewood, with practically no residue of even fine ash, since dry wood or products based on it burn to fine ash, and it is easily blown out through the nozzle by a fan into the chimney.

Knowing the peculiarities of this design, it can be called an "upper blower", since the air forced by the fan enters mainly the upper main combustion chamber.

Due to the flow of oxygen, the temperature during combustion increases and the production of gas increases, but it also burns out quickly enough, leaving through the nozzle.

In this regard, firewood quickly burns out, and they have to be added quite often during the heating process of the house. This principle of operation of the boiler cannot be called pyrolysis in the full sense of the word, although such devices are sold quite often under this name.

It is another matter if the fan standing on the outlet pipe (often called "smoke exhauster") creates air movement, which is proportionally divided into primary and main - secondary in the usual mechanical way or using automation.

In this case, the primary air damper is located so that it is supplied precisely to the lower part of the fuel tab.

Firewood smolders from below, and the temperature released during this process contributes to heating - in the middle layers of the bookmark, and final drying - in the upper ones.

The main air flow will be supplied only to the nozzle area, so that the final afterburning of pyrolysis gases from maximum number the generated heat passed into the lower chamber. Such a boiler can with good reason be attributed to long-burning pyrolysis.

Natural air-fed boiler.

In a similar design of the boiler, the combustion chamber for laying firewood is located in the lower part of the device, and the section for burning the pyrolysis gases released by the fuel is in the upper area of the body.

The fan is not installed in this design, and the air for kindling the boiler and afterburning the pyrolysis gases flows in a natural way through the dampers for the primary and secondary air.

In this variant of the arrangement of the chambers and the metered supply of air flows, the pyrolysis process is carried out properly, since instead of intensive combustion, with the primary air supply shutter closed, wood smolders in the combustion chamber with the release of a large amount of pyrolysis gases.

However, this design also has its own problem. And it consists in the fact that correct debugging of the combustion process is extremely important.

When the shutter of the main chamber is completely closed, the temperature in it decreases, as well as the formation of gases. The concentration and temperature of gases becomes insufficient for their complete afterburning and the upper chamber turns into a conventional gas outlet.

The combustion products that have risen into it do not burn out, but simply give off heat to the walls of the water circuit and go into the chimney. The efficiency of the boiler during such work is sharply reduced. If the damper is opened more than is required to create the conditions necessary for pyrolysis, then the intensity of combustion in the main firebox will increase, which leads to a completely unreasonable fuel consumption and the need for frequent fuel filling.

To achieve the ideal operation of a pyrolysis boiler of this design, it is necessary to correctly adjust the supply of primary and secondary air, which is quite difficult to do, since this requires practical experience.

Modern models have automated control and process control systems, and with the correct operation of the automatic fuel loading, it is enough for 12-14 hours of operation with maximum heat transfer.

Fuel for pyrolysis boiler

Solid fuel pyrolysis boilers are almost omnivorous. A variety of solid fuels can be used as fuel: from ordinary firewood and ending with peat.

Proceeding from this, the boiler can be fired with any type of solid fuel, but nevertheless, each type differs in its inherent qualities and properties, therefore, the operation of the boiler will also differ.

Hence, the choice of fuel is a very important process.

Together with wood or briquettes, sawdust can also be used as fuel. But they should be taken no more than a third of the main part of the fuel by volume.

The operating instructions stipulate that the moisture content of the fuel should not be higher than 45%. The lower the moisture content of the wood, the greater the boiler power and the longer it can work without repair.

For example, a kilogram of wood with 20% moisture content during combustion gives heat equivalent to 4 kWh, and firewood with 50% moisture content - only 2 kWh. In addition, with an increase in the moisture content in the fuel, the specific heat of combustion decreases, and the fuel consumption increases significantly.

Why is it better to choose a pyrolysis boiler and the basic rules for its operation

Firstly, during the combustion of wood, it is impossible to reach such a high temperature as during the combustion of the gas obtained from them.
Secondly, in order to maintain the combustion of gas, less secondary air is required than for burning wood, respectively, the combustion temperature will be higher, and with it the efficiency.
Thirdly, the procedure for burning pyrolysis gas is easier to control, thus, the functioning of a gas-generating boiler is automated in the same way as an oil or gas boiler.

This equipment is based on the pyrolysis fuel combustion technology. Its essence lies in the fact that under the influence of elevated temperature and in conditions of a lack of oxygen, wood begins to decompose into a solid residue and a volatile part - pyrolysis gas.

Pyrolysis occurs at temperatures ranging from 270 - 700 degrees. This process is exothermic, in other words, it is characterized by the release of heat, which increases the drying and heating of the fuel in the boiler.

Subsequently, the mixing of oxygen with pyrolysis gas at a significant temperature leads to the combustion of the latter, which is used to obtain thermal energy.

Pyrolysis gas actively interacts with carbon, due to which, at the exit from the boiler, flue gases almost do not include harmful impurities, being considered, to a greater extent, a mixture of water vapor and carbon dioxide.

Numerous studies have shown that carbon dioxide will be emitted into environment up to three times less than from an ordinary wood-burning and, moreover, coal boiler.

The pyrolysis combustion procedure is characterized by the formation of a small amount of ash and soot, which is why this equipment rarely requires cleaning.

The advantages of long-burning pyrolysis boilers with a water circuit are environmental friendliness.

The efficiency declared by manufacturers is only 4-10% higher than the productivity of a conventional solid fuel boiler. Obviously, the choice should be based on accounting individual characteristics heating system and host preferences.

The main signs of a quality model that is worth buying:

Good, neat welds and sufficient material thickness (at least 4 mm). Thin metal in cheap boilers burns out quickly and is more susceptible to corrosion. Buying such items is a bad decision!
Ceramic nozzle and lining of the combustion chamber (this model will last longer). This material has excellent refractory properties. Make sure that ceramics are used, as the most reliable material for these parts of the boiler.
Two working chambers with the possibility of smooth adjustment of the air supply. Two chambers are the main feature of an effective pyrolysis model! If you need high performance and at the same time economical boilers long burning - choose pyrolysis boilers for long burning with a water circuit.
The coolant is in contact only with the chimney and the gas combustion chamber. If this technical point is not observed, the boiler will lose heat, since the main combustion chamber has a lower temperature (the coolant cools down on contact).
The presence of an automatic control unit and the corresponding guarantee for it. Repair of this unit, which is very important for regulating the air supply, in some cases costs up to 50% of the total cost of the equipment. Take this part of the boiler seriously.

A few more tips for choosing a boiler:

The required power can be calculated based on the area of the room and the degree of insulation. Approximately, you need to take 1 kW per 10 m2, while throwing in a few kW, taking into account also the functions of the boiler as a boiler. So, if you have an area of 80 m2, then an option with a capacity of 10 kW is suitable, but if the area is 100 m2 and the walls are not insulated, then 10 kW will not be enough;
The dimensions of the firebox are important, if you will heat with wood, the larger it is, the larger the size of the firewood can be placed there;
Burn time without reloading is usually indicated with excellent fuel quality, so take 2/3 of this figure. For example, if 10 hours are declared, you can count on 6;
Energy independence is very important for choosing a boiler for a summer residence or a place remote from electricity, in addition, it also saves electricity.

For normal work equipment, a certain range of fuel combustion temperature must be observed. This range is from 2000 to 8000 C.

It is necessary to fine-tune the device with sufficient precision. To prevent emergencies when high temperature serves as the water circuit of the unit.

The body plays the role of a heat exchanger; water flows between its walls. This feature and the built-in coil in one of the walls prevents the creation of extreme temperatures.

When the water temperature is insufficient, the formation of pyrolysis gas stops, air is supplied to the combustion chamber and the boiler operates like a conventional solid fuel stove. It is not allowed to cool water below a temperature below 600 C. In this case, the combustion process without oxygen stops in any type of pyrolysis boilers.

To ensure a small water circuit and the transition of the equipment to an operating state, it is planned to install an additional bridge (bypass) in the water circuit. The bypass is adjusted manually; temperature sensors are installed to control the temperature.

This type of equipment can work on all types of firewood, briquettes, pallets.

In reality, such a type of fuel as coal can be used. Provision is made for the processing of combustible household and industrial waste... But it can cause unpleasant consequences due to their high content of polymers and rubber.

Pyrolysis boilers are produced only in single-circuit and cannot be used to heat water. But, in the absence of natural gas, to create in the building comfortable conditions, given view equipment is the best solution Problems.

Diy pyrolysis boiler

Make a pyrolysis boiler with your own hands according to drawings, or order manufacturing from specialists (which is still cheaper than buying a ready-made one).

To make such a complex device, you need a fairly wide range of tools and materials.

Here is an approximate list of them:

Plan-diagram. Without accurate calculation, you are unlikely to be able to do everything right. The drawings do not have to be done by yourself, if you do not have the appropriate skills, you can simply download it on the Internet.
Welding machine.
Grinding machine.
Metal pipes of different diameters and lengths (120, 130 and 150 centimeters, 50, 45 and 6-8 centimeters in diameter) the boiler frame itself and the chimney will be made from the pipes.
Sheet of metal for making the door.
Hinges and handles for installation of dampers.

The manufacture of a pyrolysis boiler includes the following stages:

Frame fabrication.

The frame of the pyrolysis boiler consists of two parts of the casing and the furnace. A frame is made of two pipes of a larger and smaller diameter. One pipe is inserted into the other and welded. In this case, the large pipe acts as a casing, and the smaller one as a firebox.

The bottom and top of the pipes are welded with circles cut from a metal sheet. The space between the pipes is filled with a heat transfer agent.

The second stage is the separation of the firebox by putting on the chambers.

Firewood will be loaded into one of them, and gas will burn out in the second. The air distributor acts as a separator. This is a pipe of the smallest diameter on which a sheet of metal with blades is welded.

Further, in the lower part of the frame - the firebox, it is necessary to cut a hole-door, the door itself is made from a sheet of metal. It is very important that the door fits as tightly as possible to prevent excess air from entering the boiler.
The last stage in the manufacture of a pyrolysis boiler will be the installation of a chimney and an exhaust pipe through which unburned gas will be discharged into the chimney and outside.

In addition to the fact that the pyrolysis boiler must be properly manufactured, it must also be installed correctly:

As a rule, a pyrolysis boiler is installed in a separate room - a boiler room, this is the safest option.
Install a pyrolysis boiler at a distance of at least thirty centimeters from the walls.
The floor on which the boiler will stand must be made of non-combustible materials.
The boiler room must be equipped with good ventilation.
The boiler chimney must be well insulated in order to avoid the release of combustion products into the room.

Fuel inlet at homemade models usually placed slightly higher than that of conventional solid fuel boilers.
It is imperative to install a limiter that will allow you to control the amount of air entering the fuel chamber, as well as put firewood or briquettes in a timely manner.
For the manufacture of the limiter, you can use a pipe with a diameter of about 70 mm, a little longer than the body of the device.
A steel disc should be welded to the bottom of the stopper, creating a gap of about 40 mm with the pipe walls.
To install the limiter, a corresponding hole must be made in the boiler lid.
The firewood inlet should be rectangular. This hole is closed with a door with a special steel plate that ensures a secure fit.
Below you need to make a hole to remove the ash.
The pipe through which the coolant moves inside the boiler must be made with a bend in order to maximize the heat transfer. The amount of heating medium entering the boiler can be regulated using an externally installed valve.
If, after the first start-up of the boiler, there is no combustion product carbon monoxide, which means that the structure is made accurately and functions correctly. In the future, the condition of the boiler welds should be regularly monitored and promptly cleaned of accumulated ash and soot.

Gas cylinder pyrolysis boiler

A homemade pyrolysis boiler from a gas cylinder is capable of operating on a wide variety of solid fuels:

firewood;
coal;
slate;
waste from wood production.

Having created such a structure, you can safely forget about the lack of heat even in a large room.

A do-it-yourself pyrolysis boiler from a gas cylinder is made according to the following, not complicated principle: firewood or other solid fuel is loaded from above or from the side, and then ignited. It is necessary to wait for the fire to appear, and then cover it with a piston that plays the role of an air duct in this design.

In addition, the entire structure should be closed from above with a dense top cover with a hole for the pipe.

The optimal size of a gas cylinder suitable for the manufacture of a boiler is 50 liters.

Tools that are required for self-manufacturing of a pyrolysis boiler:

welding machine;
gas cutter;
Bulgarian.

Sheet metal, metal strip and reinforcement are used as additional materials.

The balloon is cut off at the top of it, which can be made a lid if desired. To do this, it is enough just to grind the entire structure.

After that, again, a hole is made at the top for the pipe. A loading door is cut out on the side, which opens access to the firebox, where the fuel is placed.

The chimney must have different diameters to ensure better traction... Such a trick will allow maintaining a stable pyrolysis process for 8-10 hours, that is, it will be necessary to heat the oven 1 time per day.

A pyrolysis boiler from a gas cylinder has a grate made of fittings. With the help of it, the fuel falls down, leaving a minimum of ash.

Water vapor, which may form during the operation of the boiler, condenses in a vertical pipe, in which there is a special valve, called a ball valve.

Modern boilers operating on solid fuels are increasingly using the pyrolysis process in their work. The principle of operation of heating equipment, based on the ability of wood, when burning, to emit a large amount of carbon dioxide.

A pyrolysis boiler for long-term combustion accumulates heat obtained during the combustion of fuel from wood or its waste, and afterburning of the released gas.

How do pyrolysis boilers with long burning times work?

Solid fuel pyrolysis boiler of long burning, differs from classical heat generators in several design differences and internal device... The changes affected the work processes, the combustion chamber and the flue duct.

As a result of modifications and design solutions, the following advantages and characteristics have been achieved:

Operating time from one fuel tab, from 8 to 120 hours, depending on the model and fuel quality.
Reduced wood consumption - compared to the classic version of the boiler, fuel costs have decreased by 15-20%.
Accuracy of regulation - the principle of operation used and the applied automation ensure accurate regulation of the heating agent heating intensity, with an error of no more than 1 ° С.
High heat transfer - the efficiency of pyrolysis models varies, depending on the quality of the fuel and the manufacturer, within 80-92%.

What is the process of pyrolysis of fuel

The principle of operation of a long-burning pyrolysis boiler is based on natural physical processes and properties of wood:

Wood, when heated, begins to emit carbon dioxide.
After mixing with oxygen, a flammable gas-air mixture of CO is obtained, which in normal conditions, simply goes into the chimney.
Steel solid fuel pyrolysis boilers for long burning with a water circuit, equipped with a special afterburner. The produced gas is directed to an additional furnace, where it burns at a temperature of 600-800 ° C.

The main task of pyrolysis heating equipment is to create the necessary conditions for maximum production of carbon dioxide: high temperature and limited air access.

Design features of pyrolysis boilers

Long burning pyrolysis boiler with a water circuit, from classic models equipment has several features:

Loading type - all boilers are equipped with an enlarged furnace with vertical or horizontal loading. The large capacity of the combustion chamber helps to increase the time of the pyrolysis process. About 20 minutes after firing up, the boilers work as usual. After heating to a temperature of 600 ° C, pyrolysis combustion begins.
Furnace device - there are two combustion chambers in the construction. The main firebox has convection holes for the flow and even distribution of air. The afterburner is lined with chamotte to maintain a high temperature.
The design of the heat exchanger - household pyrolysis boilers of long burning on solid fuel, use the heat generated during combustion as efficiently as possible. As such, combustion, in the full sense of the word, does not occur, the wood smolders with a limited supply of air and high temperature. Flue gases are directed to the broken flue duct of the boiler. The heat exchanger surrounds two combustion chambers and a duct. Advanced technologies make it possible to accumulate most of the heat coming from heated smoke.
Heating the coolant - models with a long burning time heat the coolant in a flowing manner. The boilers have one or two circuits. The first heating circuit is designed to be connected to the heating system. Through the second, hot water is heated. The technical characteristics of the boiler, in particular the performance, largely depend on the presence of a hot water supply coil. In double-circuit units, the power is less.
Air supply control - boilers are equipped with natural or forced air supply. Non-volatile models are controlled by mechanical ones connected to the ash pan door. The installation of automation, connected to the smoke exhausters and blower fans, provides accurate combustion control.

Dependence on electricity is solved by installing an uninterruptible power supply. The voltage consumption in boilers is 150-300 W / h.

Is it possible to increase the burning time of the pyrolysis boiler

The duration of the pyrolysis boiler operation depends on several factors, taking into account which, it is possible to extend the operating time from one tab:

Factory-made briquettes, chips and sawdust have a moisture content of 8-18%, which is the optimal moisture content for the pyrolysis process.

Which pyrolysis boiler is better

According to the statistical report, regarding the sales of pyrolysis models of heating equipment, the most popular are boilers from European manufacturers. Even the high cost of models, which is 2-3 times higher than the domestic counterparts, does not affect the popularity.

A short review of pyrolysis boilers for heating long-term burning on solid fuels helps to identify the models that are in demand by the domestic consumer:

German boilers - German Buderus, Viessmann, HDG are the leaders in popularity. The assortment is presented as completely autonomous boilers and equipment with manual control.
Czech boilers - Wattek offers non-volatile heating equipment for domestic use. The products have become available to the domestic consumer relatively recently, but are already popular.
Russian equipment - pyrolysis boilers are represented by the brands Bourgeois K, Trayan, Geyser, Termofor, Divo. The difference between the equipment is the ability to work on wood with a high moisture content. Most of the models are universal.
Bulgarian boilers are not widespread. The Russian buyer was able to appreciate the boilers Burnit, the Sunsystem company. There are no other competitive models made in Bulgaria.
Joint production - several Russian manufacturers have established joint production with European manufacturers. One of the most popular models is the Lavoro boilers manufactured by the Italian-Russian concern.

How much do pyrolysis boilers cost

To select a pyrolysis boiler, you need to take into account not only the technical characteristics and performance, but also its cost and costs for further maintenance.

Low-power boilers, up to 20 kW, depending on the manufacturer, cost from 60 to 350 thousand rubles. The most expensive are German Buderus and Wisman.

Domestic Termofor and Bourgeois-K belong to the middle price category. Czech Wattek are expensive, almost like their German counterparts, which somewhat limits their popularity.

Requirements for the installation site of the pyrolysis type boiler

Requirements fire safety to pyrolysis heating equipment are the same as to all other solid fuel boilers. During installation, the rules of industrial safety and joint venture are observed:

High-power boilers, over 40 kW, are installed in a separate room. Installation of equipment with lower performance is allowed anywhere in the house.
Before installation, prepare the base. Due to the presence of two combustion chambers, the weight of the boiler reaches several centners. Due to the large mass of the unit, a foundation is required.
When the chimney passes through the floor slabs and the roof, a special fire-prevention cut is made.
The floor and walls are faced with non-combustible finishing materials.

The minimum area of the premises used for the boiler room is 9 m². Availability supply and exhaust ventilation necessarily.

Opinions and reviews on pyrolysis heating boilers

You can find a variety of reviews from owners about long-burning pyrolysis boilers. Moreover, there are directly opposite opinions: from enthusiastic praise to extremely negative statements:

Harm to human health from the operation of a pyrolysis-type boiler. One of the most serious concerns about human exposure to equipment is unfounded. The boiler uses only natural physical laws.
Efficiency and heat dissipation are greatly exaggerated. To achieve maximum thermal efficiency, it is required to use wood and waste with a maximum moisture content of up to 20%. Improper operation leads to a decrease in heat dissipation.

The real disadvantages of pyrolysis boilers are the demands on the quality of wood and the high cost of equipment. The rest of the negative reviews are mainly related to the actual inability to use boilers.

For heating a private house without a centralized gas supply, they mainly use affordable and inexpensive solid fuel. However, traditional types of heating devices operating on this type of fuel have a rather low efficiency and laborious operation. Recently appeared long-burning boilers using the pyrolysis method are more efficient, economical in fuel consumption and easy to maintain.

Criterias of choice

Pyrolysis boilers for home heating are designed to operate on different types fuels: wood, coal, peat, sawdust, pallets. Wood-burning devices have the highest performance due to the complete combustion of fuel in the pyrolysis mode. Therefore, if it is possible to prepare firewood inexpensively and in sufficient quantities for the entire heating season, then you can buy and install just such a boiler at home.

Otherwise, it is better to purchase a universal device that can operate on any solid fuel. Structurally, they are designed so that they can burn up to 80% of fuel resources in the pyrolysis mode, and the remaining 20% in the mode of a simple solid-fuel unit.

You should also pay attention to:

unit power. When calculating this indicator, the area of the building, which will be heated by a long-burning pyrolysis boiler, and the level of protection of its rooms from heat loss are taken into account;

combustion chamber volume. A boiler with a small combustion chamber will require more frequent fuel loading, so it cannot be left without maintenance for a long time, especially in severe frosts;

the quality of the inner coating of the chambers. Chambers, whose walls are lined with ceramic concrete, are more protected from burning out, maintain their integrity at the maximum heating level and ensure correct combustion of fuel;

the duration of combustion with a full load of fuel must be at least 10 hours;

the level of automation for the safety of the device. A pyrolysis boiler for long-term burning should be not only productive, but also safe, therefore, when buying, you need to check if it is equipped with an alarm and an automatic shutdown system;

the presence of an additional circuit. A heater with one circuit can only be used to heat a room. If the boiler is planned to be used for organizing hot water supply, then you need to immediately buy a device with a double-circuit design;

price. You should not save on buying a boiler, since cheap models may not have enough technical capabilities for optimal heating of the room. It is better to purchase a boiler of proven brands that have already passed tests in the harsh Russian winters and deserve good feedback owners.

Model overview

The modern market offers many different models of long-burning pyrolysis boilers, differing in a number of technical characteristics, dimensions and prices ..

Pyrolysis Master LONGLIFE 18-250 kW

High efficiency, the presence of automatic control over the operation of the boiler and circulation allow this device to effectively perform its functions on one load for 8 - 72 hours (depending on the type of fuel used). The boiler is equipped with a digital controller, an air supply fan, a 5-way heat exchanger with a large volume of coolant, ensuring its high performance. The combustion chamber is equipped with water-filled grates and two doors for loading fuel and removing ash residue. The device works equally effectively when manually loading any type of solid fuel into the furnace section: coal, briquettes, firewood, lump peat.

Maximum heating area - 18 - 2500 m²;

power - 18 - 250 kW;

Price range depending on capacity: - 980 - 7300 conventional units.

Buderus Logano S171

The German pyrolysis boiler of this series has an increased volume of the loading section and an improved design of the heat exchanger and is adapted to work both with natural and forced ventilation coolant. Its body is made of high-alloy steel 5 mm thick, fireclay bricks with a longer service life are used for the furnace lining, two ash pan doors, one located on top and the other on the front panel, provide ease of cleaning. Uninterrupted operation of the unit and the protection function is performed by a powerful automatic system management.

Maximum heating area - 500 m²;

power - 50 kW;

Dimensions - 699х1257х1083 mm;

Average price - 3600 conventional units.

Bastion M-KST

Universal pyrolysis boilers of Russian production with a capacity of 12 to 30 kW, which differ from imported counterparts in a lower price and compact size, capable of heating an area from 100 to 300 m² (depending on power). Non-volatile devices that do not require frequent removal of ash waste. The combustion chamber is made of a low-alloy steel alloy of 09G2S grade; it simultaneously accommodates firewood, coal, wood waste from 40 - 120 dm³. They can work without refueling for 4 - 12 hours (depending on the moisture content of the fuel, wood species, chimney organization, etc.). The efficiency is at least 85%. The price ranges from $ 670 - $ 1200.

Traian T

Single-circuit devices operating on wood, fuel or peat briquettes. They can maintain a comfortable temperature in the room with one load of fuel for at least 8 hours. In T-series models, the thrust is automatically adjusted when additional equipment A heating element with a capacity of up to 3 kW will maintain the coolant temperature after burning out the wood for several hours.

Boiler models "Trayan" of T series	power, kWt	Heated area, m2	Dimensions (WxHxD), mm	Price, dollar

Pyrolysis is widely used in various industries. This chemical process is in demand and for heating residential areas.

Pyrolysis occurs with any type of solid raw material:

Firewood.
Small branches or sawdust.
Briquettes.
Peat.
Brown coal.
Pellets.
Coke.

However, the pyrolysis unit most efficiently operates on fuel with an increased level of volatile matter release - on wood. 80-100 mm thick. Together with them, pellets or wood waste are used.

Attention! It is impractical to use only sawdust or pellets - with them the boiler does not generate heat or it The efficiency is reduced to a minimum.

Pyrolysis boiler: what does it mean, its device

Design pyrolysis boiler as follows:

Chimney.
Control block.
Loading hopper.
Nozzle.
The combustion chamber.
Heat exchanger.

A pyrolysis-based heating boiler is a two-chamber unit - this is its peculiarity. The main chemical reaction in these chambers is:

Loading chamber or gasification chamber. This is where the preliminary thermal decomposition of the raw material takes place. Organic matter under the influence of high temperatures turns into a combustible gas. To maintain smoldering, primary air is directed into the chamber. Combustion at temperature 300-800 ° C.

Photo 1. Fuel loading chamber in a pyrolysis boiler. Interior decoration made with fireclay bricks.

The combustion chamber... After smoldering, the released air and gas enter here. Here the formed gas burns like ordinary natural gas. Temperature an average of 1200 ° C. It is at this stage that a lot of heat is generated, which is necessary for heating. At the same time, a strong aerodynamic drag, therefore, a forced draft is required, the role of which is played by a smoke exhauster.

Two spaces between cameras divides the grate into which the fuel is loaded. There it is ignited and the exhauster is started. The grate prevents heat from escaping from the upper loading chamber and provides a light flow of primary air.

Pyrolysis furnaces equipped with traction switches that ignite fuel. Thus, at the beginning of ignition, the boiler functions as a direct combustion device, and after closing the valve, it switches to pyrolysis.

Types of pyrolysis devices, characteristics

Pyrolysis boilers differ in their structure. So, there are:

Afterburner chamber from above. Rare. The advantages of the design are that the flue gas flows freely into the afterburner, and after burning out, it immediately enters the chimney for further cooling. Among the minuses - the location of the smoke system is uneconomical, since initially more consumables are required for the manufacture of such a structure.

Photo 2. Pyrolysis boiler with a lower afterburner chamber. The arrows indicate the component parts of the device.

Afterburner chamber from below. The most common and most comfortable type of construction. It is convenient for the user to lay firewood, since the camera is not on the floor. And also the chamber has a direct exit to the lower chimney, and from there to the chimney. However, this design also has its drawbacks. So, ash from the loading compartment clogs the second chamber, so it is often cleaned. In addition, you need to provide increased traction so that the smoke moves down.

As well as pyrolysis boilers differ in the type of thrust used:

Natural cravings. No need for an electrician. However, for operation, a fairly high chimney with a powerful natural draft is needed, which will be expensive.
Forced airflow and thrust. The boiler becomes volatile, however, the speed of reaching the mode increases. Such a unit is equipped with fans and smoke exhausters, which are controlled by automation - the dependence on weather conditions completely disappears and the combustion efficiency increases. This type of firebox can operate at maximum efficiency for a period of 4-5 hours and this 20% more than a natural draft boiler.

According to the heating method, two types are distinguished. pyrolysis devices:

For hot water heating. Water acts as a heat carrier, which is heated in a heat exchanger, then poured through pipes into radiators. The temperature is maintained by constant circulation.
For air heating. V living conditions used much less often. Often used for heating outbuildings or in industries. Thermal energy distributed in the room using warm air masses. They warm up as a result of the combustion of raw materials. Heat is distributed by means of aluminum pipes and blowers... Such a system is controlled by automation, so the owner can easily customize it in accordance with his needs.

How to choose such a device

When choosing a unit based on pyrolysis pay attention to its key characteristics:

The quality of the case. Previously, the furnace body was made mainly of cast iron.

Now manufacturers produce an all-welded body made of sheet material.

The main thing here is its thickness.

It depends on the power of the boiler:

15-65 kW: internal structures 5 mm, outdoor - 4 mm;
75-110 kW: internal - 6 mm, external - 5 mm;
135-195 kW: inside - 8 mm, outside - 6 mm;
200 kW and more: internal components - 10 mm, outdoor - 8 mm.

Power. This indicator depends on the heated area. There are many methods for determining power. The simplest and most optimal among them is to take as a basis 1 kW for 10 square meters heated area.

Experts recommend the unit with 10% power reserve. So, for placement on 120 square meters a boiler for 16 kW. If the area of the territory 160 square meters, the power of the device must be at least 18 kWt, and further on the same principle.

Reference. If the height of the ceilings in the heated room exceeds 3m, for each additional meter, the boiler power is added by 1-3%.

Energy efficiency. Indicates the ratio of useful heat, which was consumed, with the volume of consumed raw materials. This indicator depends mainly on the fuel. So, for effective heating, extremely dry expendable materials.

However, the volume of the loading chamber, which holds firewood, is also taken into account. up to 60-65 cm. Besides, both cameras cover with a special a layer of ceramic concrete- it maintains a suitable temperature inside. As a result, fuel is burned more efficiently and efficiently.

Important! The optimal boiler is the one that provides at least 10 continuous burning hours raw materials and serves smoothly throughout 20 years.

Price. Pyrolysis boilers are more expensive than other types of heating boilers. However, there are options here as well. So, domestic 2-3 times cheaper imported, and the characteristics are not inferior to foreign counterparts.

Pros of using

Burning duration.

After one bookmark, such a device works smoothly. till 12 o'clock, that is, you have to load it 2 times less often than other solid fuel boilers.

However, it all depends on the type: an ordinary firebox with firewood works about 4 hours, and with top burning - on average 30 hours on the wood and 5-7 days on coal.

This effect is provided due to the controlled combustion process... In many modern models, automatic regulation of work. The burning time also depends on the volume of the living space, the air temperature in the room and outdoors, the design of the unit and its capacity.

Efficiency 85—90%.

Complete combustion of raw materials.

Less consumption of raw materials, less often it is necessary to clean the gas ducts and ash pan.

Environmental friendliness.

Smoldering wood or similar fuels releases 3 times less harmful substances than in other solid fuel boilers. In addition, harmful emissions into the atmosphere are minimized by the hot temperature in the upper chamber.

Profitability.

Even large, non-chopped wood is suitable for burning. In addition, dual combustion reduces the excess air in the flue gas, which also increases savings. Compared to other types of solid fuel boilers, the efficiency of pyrolysis units is higher by 5-8%.

Minuses

Volatility... Most often, such boilers cannot work without a smoke exhauster. Forced draft requires a system with a generator. The fan uses at least 80-100 watts.
High price. Average 1.5-2 times more expensive other types.
Fuel moisture sensitivity... Maximum dryness is required. So, when burning 1 kg firewood with 20% humidity, the power of the equipment will be 4 kW. If you take 1 kg firewood with 50% humidity, power decreases 2 times and achieves everything 2 kW.
Unstable operation of the unit at low loads (below 50%), build-up of tar in the gas outlet.
Large dimensions pyrolysis equipment.
Exclusively single-circuit pyrolysis boilers... To heat water for domestic needs, you will need a separate unit.
It is impossible to automate the process of loading fuel- downloaded exclusively by hand.

Safe use

The functioning of the pyrolysis boiler involves working at the highest possible temperatures. Therefore, each manufacturer makes high demands on the installation and operation of equipment.

The installation is carried out by a specialist with the necessary competence. The boiler is placed in a separate room with good ventilation; a chimney is installed on the unit.

Consider also the following operating rules:

In the absence of sufficient draft or the required heat carrier, the boiler must not be operated.
Do not trust children or any unauthorized person to load and light up the equipment.
The temperature of the water in the system of pipes passing through the boiler should not exceed 95 ° C... If the indicator is exceeded, the flame in the unit chamber is temporarily weakened with sand. In parallel with this, all possible chimney dampers are opened.
The boiler gets very hot during operation, so there should be no flammable materials or objects near it.
It is strictly forbidden to modify the boiler structure or use it for other purposes.

Photos of pyrolysis boilers

Photo 3. Pyrolysis boiler installed at home. Firewood is stored next to it for kindling.

Photo 4. Pyrolysis boiler from the manufacturer Viessmann. The device is equipped with electronic control.

Photo 5. Pyrolysis boiler with a lower type of fuel loading of a rather large size.

Useful video

Watch a video that demonstrates the operation of a pyrolysis boiler, it tells how to heat it.

conclusions

Pyrolysis boiler - a good alternative to direct combustion units. However, some experts recommend buying pyrolysis equipment as a backup heat source complete with an electric or gas boiler. If, nevertheless, the pyrolysis plant is installed as the main heat generator, you will need competent design and highly qualified specialists for installation.

Combustion of fuel in classic solid fuel boilers is a good alternative to using traditional energy sources for heating a house, such as natural gas or electricity. But these devices do not fully use the energy of burning wood. During the operation of a conventional boiler, the gas released from the fuel at high temperatures simply goes outside together with the combustion products. The principle of operation of the pyrolysis boiler allows the use of this gas, thereby increasing the efficiency of the unit and the duration of the interval between fuel loads. Such devices are also called gas generators.

What does a gas generator set consist of?

The main difference from the classic wood-fired boiler is the presence of an additional combustion chamber, in which the released gas is burned out, and in the primary firebox it is generated from wood at insufficient quantity oxygen. The layout of the chambers and the device of the pyrolysis boiler can be different, the firebox can be located both from the bottom and from the top, this does not change the principle of operation. Traditionally, it is located at the bottom, above the ash pan, in which a drawer is placed for easy cleaning. The ash pan lid is folded up and in operating mode serves to adjust the amount of air entering the furnace. This is done using a chain drive that is tensioned or released by a thermostat. The latter is installed at the top of the boiler.

All the main elements and details of the installation can be seen by examining detailed drawing pyrolysis boiler. The main firebox is equipped with a door for loading firewood and is tightly closed during operation. Above it is a secondary combustion chamber, in which the air supply devices are located. They can have different configurations in the apparatus different manufacturers, but their task is the same: to supply heated air into the afterburner through many holes of a certain diameter. The air is heated along the path from the ash pan door to the distributors.

The design of the pyrolysis boiler provides for the ability to clean the upper afterburner chamber, for this it is equipped with a special door. The spaces of both chambers are interconnected by a channel through which gases for combustion rise. The outer shell of the body is a water jacket heated by both furnaces. To supply the coolant to the heating system, threaded branch pipes are cut into it. Water temperature and pressure control is carried out by devices installed on the front panel.

The chimney for a pyrolysis boiler is no different in its structure from pipes for the emission of combustion products of classical units. One of the requirements is sufficient draft for the operation of the boiler. Most simple construction the unit does not provide for the installation of a blower fan, therefore combustion is due to natural draft. The second requirement is that the part of the pipe located outside is insulated. Reason - low temperature flue gases (up to 150 ⁰С), therefore, there is a very high probability of condensation on it and rapid destruction of the pipe material.

Description of the scheme of operation of pyrolysis boilers

A complete picture of the operation of the unit can be given by circuit diagram pyrolysis boiler. First, the main firebox is loaded with fuel and ignited. In this case, the ash pan flap is as open as possible. After the wood fires up, the door starts to close, the combustion process slows down and turns into decay. Then the intensive release of wood gas begins, which rises and enters the secondary afterburner. Heated air is supplied there through a set of calibrated holes. The latter enters the channel from the same opening under the ash pan cover and on the way receives heat from the hot wall of the furnace.

The entire technological process proceeds due to the natural draft created by the chimney, therefore the speed of movement of air and flue gases in the channels is low. The scheme of the pyrolysis boiler operation is that in the secondary chamber the heated air enters into a thermochemical reaction with wood gases and ignites them. As a result, not only gases are burnt, but also small volatile particles, due to which the smoke from the chimney is practically invisible. In fact, pyrolysis fuel combustion is more environmentally friendly than traditional combustion, since the combustion products from it contain much less carbon and nitrogen oxides, as well as ash particles.

The wood in the firebox burns slower than usual, so one load can be enough for 10-12 hours of operation, depending on the power of the gas generator and the moisture content of the wood. The setting of the pyrolysis boiler consists in limiting the combustion air supply. Too little of it will not allow the thermochemical process to start in the secondary furnace, and too much will cause incomplete combustion of gases and a decrease in the efficiency of the unit. For a device operating on natural draft, it will be necessary to adjust the air flow rate in each individual case, since the height and diameter of the chimney can be very different. Accordingly, the traction force will be different. In some cases, it must be increased by raising the pipe to a greater height.

If the chain drive of the ash pan cover is equipped with a thermostatic regulator, then the device setting is reduced to setting the desired coolant temperature. The thermocouple, built into the water jacket of the gas generator set, acts on the chain drive depending on the water temperature and itself closes or opens the damper, regulating the combustion intensity.

To create an artificial draft, which will not depend on the parameters of the chimney, pyrolysis-type boilers are additionally supplied with a blower fan and a set of automation that regulates its operation. If a conventional unit can operate with an efficiency of about 85–90%, then the blowing machine helps to develop it up to 93%. There is a drawback here - dependence on external energy sources.

Advantages and disadvantages

Heat sources of this type have many advantages:

The principle of operation and operation of pyrolysis boilers allows achieving excellent efficiency indicators when burning solid fuel - 90–93% efficiency.
The process is more environmentally friendly, much less harmful substances are emitted into the atmosphere.
The interval between fuel loads is no less than that of long-burning units - 12 hours; you will have to work as a fireman no more than 2 times a day.
Maintenance and cleaning of the unit is not a problem, the entire interior space is accessible, and many devices are equipped with drawer ash pan. The principle of operation of the pyrolysis boiler is practically waste-free, very little ash and ash remains, so the operation must be performed infrequently.
Profitability. Approximate fuel consumption per 100 m² of premises with a height of up to 3 m is 10 kg per day.
Natural draft plants do not depend on the availability of electricity in the network.

Like any other solid fuel apparatus, pyrolysis heating boiler needs protection against boiling of the coolant inside the water jacket... This can lead to rupture of casings and costly repairs. For this reason, manufacturers put on their products additional water cooling heating elements, which can simultaneously serve as a source of hot water for household needs.

Among the disadvantages of pyrolysis-type aggregates are the following:

Fuel with a low moisture content is required, the moisture content of the wood should not exceed 25%... The process of intensive release of gases for afterburning is very difficult if the firewood is frankly damp. This negatively affects the operation of the pyrolysis boiler, reducing its efficiency.
The practice of operation shows that deposits of tar and tar appear on the walls of the primary chamber over time, since the temperature in it is relatively low, and birch or coniferous wood is most often taken as fuel. This plaque must be removed periodically, as it makes it difficult to transfer heat to the water jacket.
The cost is higher than that of a classic solid fuel boiler. This is justified, because the process technology is more progressive and gives high performance, which will allow saving during operation.

Conclusion

When choosing a heat source for a home, it is better to focus on products of the middle price category; you should not save a lot in this matter. After all, the comfort and warmth of your home depends on how the pyrolysis boiler works.