Reading time: 6 min
Heat supply to private houses, industries and administrative premises from solid fuel boiler houses is very common in areas where there is no possibility of connecting to a gas main or in the far north. The fuel for such boiler houses is coal, firewood, pellets and briquettes. The general disadvantage of this type of heating is that the firebox has to be regularly supplied with fuel. However, there is a type of solid fuel equipment that does not have this drawback - a pyrolysis boiler.
What is pyrolysis
This is the process of formation of flammable gas and its combustion in solid fuel boilers and stoves, where hot carbon monoxide is released when burning wood. When it is combined with oxygen, it burns with heat release and the formation of carbon dioxide.
IN modern technology This physical phenomenon widespread. For example, the oven cleaning function works on this principle. Bubbling works in much the same way.
Using this property of fuel combustion, manufacturers began to experiment with designs where the fuel did not burn immediately, but smoldered in the absence of oxygen, releasing CO (carbon monoxide).
The resulting gas was supposed to be burned in another chamber. As fuel, you can use ordinary chopped firewood or special charcoal briquettes (Tyumen Pyrolysis Plant).
In addition to pyrolysis boilers, there are models that run on coal. Some work on natural draft.
Operating principle of a pyrolysis boiler
To better understand the advantages of pyrolysis boilers, you need to familiarize yourself in more detail with the principle of their operation. Despite classic definition pyrolysis, which says that only gases burn and give off heat, in long-burning pyrolysis boilers with a water circuit, the fuel still burns in the absence of oxygen.
In fact, there is a slight smoldering with the release of carbon monoxide. In the end, two sources of heating the coolant are formed - burning, albeit weakly, fuel and combustible gas. This combustion scheme allows reducing fuel consumption by 40%.
The smoldering of the fuel produces wood gas, which enters the combustion chamber, and heated air is also supplied there. This leads to the appearance of a flame - combustion occurs with the release of heat. In this case, carbon monoxide turns into carbon dioxide and the amount of harmful substances is less than in conventional boilers.
The use of pyrolysis boilers leads to fuel savings, because more heat is obtained from the same amount of fuel.
For example, a conventional unit may require 10 cubic meters. firewood for heating season, and 6 cubic meters will be enough for pyrolysis. And just as importantly, you won’t have to refill fuel often.
Long-burning pyrolysis boilers with a water circuit are produced in several varieties:
- non-volatile. Characterized by natural traction and mechanical control;
- volatile. Blowing equipment is used, which contributes to higher efficiency;
- with a difference in the location of the gas afterburning chamber. The chamber can be under the firebox or above it.
There may be many design options, but they do not differ in the principle of combustion. There are so-called long-burning systems that operate regardless of the type and quality of fuel and are rather than pyrolysis heating systems.
The use of volatile boilers is convenient in that they are equipped with automatic controls to regulate combustion, depending on the water temperature and the room temperature.
Long-term combustion occurs due to two factors: low smoldering intensity of the fuel and a large firebox. All this guarantees a low frequency of access to the equipment.
Design of a long-burning pyrolysis boiler
The long-burning pyrolysis boiler has the following device:
- Control block. This device selects different modes and controls operating parameters;
- Frame. Made of steel and coated with heat-resistant paint;
- Thermal insulation. Used to reduce heat loss;
- Anti-boiling device. Controls the temperature of the coolant and regulates combustion to avoid boiling, which can lead to an accident;
- Heat exchanger. A metal pipeline filled with coolant, which is heated during the combustion of fuel, after which it enters the heating system;
- Combustion chamber. Serves for loading solid fuel into it. After which ignition occurs and the air supply stops. Smoldering occurs at 450˚C;
- The combustion chamber. In this part, wood gas is burned, subject to air supply. The combustion temperature reaches 1100˚С;
- Coolant supply pipe to the heating system;
- Grate bars. Metal grate located between the loading and combustion chambers;
- Connection to the chimney;
- Chimney fan;
- Primary air valve to start pyrolysis;
- Secondary air valve for wood gas combustion;
- Return pipe.
Pros and cons of a pyrolysis boiler
Like any equipment, long-burning pyrolysis plants have both advantages and disadvantages.
The advantages include:
- Economical. Fuel consumption is reduced by up to 40% depending on the modification and operating conditions;
- Long burning. This means that after adding pyrolysis fuel you will not need to approach the boiler soon;
- Environmental friendliness. Fuel combustion occurs almost completely, so virtually no harmful substances are released;
- High heat transfer of combustion products. The temperature of the exhaust gases is noticeably lower than in conventional boilers;
- Can be used automatic devices power adjustment by changing the intensity of smoldering.
The disadvantages of pyrolysis equipment are as follows:
- High price. The high cost is explained by convenience and economy;
- Dependence on energy resources. Considering the presence of automation and forced pyrolysis boilers need to be connected to the power grid;
- Dimensions. The dimensions are significantly larger than those of traditional solid fuel installations.
The main disadvantage is still the cost, and the rest do not represent big problems.
How economical is a pyrolysis boiler?
The design features of pyrolysis boilers provide it with a significant advantage over classical ones. The efficiency of a long-burning solid fuel pyrolysis boiler reaches gas equipment and is about 90%, and the efficiency of classic ones does not exceed 70%.
To understand how economical solid fuel pyrolysis boilers are, you can perform a calculation and compare it with a type of fuel comparable in efficiency.
The price of natural gas for the population varies depending on the region, but for simplicity, let’s take the city of Moscow. Its price is 4.84 rubles per cubic meter. (in other regions, generally higher). The cost of chopped firewood for heating needs is about 1,500 rubles per 1 cubic meter. Hence, 1 kg of firewood costs 1.5 rubles. The regulations indicate that 1 kg of firewood can produce 3200-3600 kcal. Caloric content of gas – 8000 kcal/cub.m. As was indicated, the efficiency of heating pyrolysis and gas boilers is comparable, so it can be neglected in the calculation.
By carrying out a simple calculation, you can see that to get 8000 kcal you will need to burn 2.35 kg of wood. Let's multiply by the unit cost of firewood: 2.35 kg * 1.5 rubles. We find that the cost of 8000 kcal when burning wood will be 3.52 rubles, and when burning gas - 4.84 rubles. Using a pyrolysis combustion boiler saves fuel costs by almost 30% compared to using gas equipment.
Pyrolysis plants, although expensive, are the most suitable equipment for heating greenhouses, greenhouses, and conservatories. This type of equipment is also used in waste processing plants.
Is it worth doing it yourself?
If there necessary knowledge, capabilities and drawings, then you can make a pyrolysis boiler yourself. The Belyaev pyrolysis boiler scheme is popular among the population. This technology cannot be called simple, however, it is one of the most accessible and implementable.
Boiler diagram. Photo source: balserv.ru
To make a pyrolysis boiler with your own hands according to the drawings, you need:
- metal pipe (D32,57,159 mm);
- profile pipe (20x20, 80x40, 60x30 mm);
- metal sheet;
- fireclay brick;
- air supply pump;
- temperature sensor.
In addition, you will need a tool and a welding machine. An assistant will be needed. First, the sheet parts of the installation are made, cut off with a precision tool, and then, following step-by-step instructions, the rest of the work on assembling a homemade boiler is completed.
Popular models
Let's consider the most common and popular pyrolysis plants, among which there are both electricity-dependent and non-electricity-dependent:
- Popov's boiler. This model is made of steel and is the main one for making a long-burning pyrolysis boiler with your own hands. Any solid fuel can be used. The large combustion chamber allows the boiler to operate autonomously for up to 1 day. The highest heating capacity of this model reaches 1000 kW, the lowest – 25 kW. Efficiency – up to 95%.
- Geyser. The boiler is designed as for household use, and for industrial. The household line of pyrolysis heating boilers ranges from 10 to 50 kW. The boilers are non-volatile, operate on any fuel, have high efficiency, and are easy to operate.
- Buderus. They have high quality, mechanical control, and are independent of electricity. The boiler heat exchanger is made of both cast iron, which eliminates corrosion, and steel. The efficiency of Buderus boilers ranges from 78 to 87%, depending on the model.
- Bastion. Non-volatile pyrolysis boilers with a water circuit, operating on all types of fuel. Power range – from 12 to 50 kW. They have cast iron heat exchangers, high-quality construction and low cost.
- Wattek Pyrotek 36. Energy-dependent Czech single-circuit boilers with power from 26 to 42 kW. They have a copper heat exchanger and are equipped with automation. Efficiency reaches 90%. Autonomous combustion up to 10 hours.
- Viessman. German equipment, equipped automatic system control. Power range from 25 to 80 kW. The fuel used is wood. Efficiency – 88%.
- Dakon. Gas-generating pyrolysis plants with power from 18 to 40 kW. Dakon boilers operate on wood and wood waste. Efficiency – up to 85%.
- Burzhuy-K. Russian boilers with power from 10 to 32 kW. Efficiency factor – 85%. Industrial pyrolysis boilers with a power above 200 kW are also manufactured.
- Teplodar42. Russian pyrolysis coal boilers. They have a wide range for private houses, cottages, administrative buildings and industry.
- Fortan. Pyrolysis equipment for processing various kinds waste. They are distinguished by environmentally friendly operation during disposal; they efficiently process household, rubber, industrial and medical waste.
- Sime. Italian equipment with power from 22.5 to 38.7 kW. They have a cast iron heat exchanger and high efficiency.
Among Russian manufacturers, we can highlight the products of Klimov Pyrolysis Equipment Plant LLC, Barnaul.
Installation
Pyrolysis boilers can be installed in systems with both natural circulation and forced circulation. When installing the boiler in a system with natural circulation, it is necessary to take into account the slope of the pipes; in a system with forced circulation It is important to choose the right pumping equipment.
Since the heat exchanger is prone to low-temperature corrosion, the temperature of the coolant in the return pipeline should be monitored so that it does not cool suddenly. It is recommended to keep it at least 60°C.
This is done by mixing the return water with hot water from the supply pipe. Proper strapping is of great importance.
Strapping diagram. Photo source: artosfera.ru
Before starting work, it is necessary to fill the system with water. Then you need to adjust the air supply mode to the combustion chamber of the pyrolysis gases to ensure the required operating mode.
The quality of combustion of gases can also be determined indirectly - by assessing the smoke coming out of the chimney: if it does not have a strong odor and a dark tint, then the fuel burns correctly.
If heavy pyrolysis resin leaks from the boiler during operation, this indicates a low temperature in the firebox, an incorrectly selected chimney cross-section or the need to clean it.
The problem can also occur in a homemade boiler. During the first time after installation, the boiler is tested and must be under constant supervision. The fuel load should be about two-thirds of the firebox volume. Once the testing has been passed, it can be operated at full capacity.
The annual rise in prices of basic energy resources, gas and electricity, forces residents to look for alternative options heating. Fossil fuels such as coal and peat are familiar to people living in the outback. Don't write it off. Firewood still remains a popular fuel resource for residents of the central and northern regions of our country. The availability and relatively low cost of solid fuel makes it a real competitor to gas and electricity, especially when it comes to individual home heating. Stove heating returns to our lives only in a different, more perfect and modernized form.
For residents of the private sector, owners country houses of increased interest are pyrolysis solid fuel boilers. Traditional solid fuel heating appliances today are giving way to new models with high technological characteristics. The reason for the popularity that pyrolysis boilers enjoy today lies in the high efficiency of units of this type.
Let’s take a closer look at what solid fuel, pyrolysis-type heating boilers are.
What is pyrolysis
A solid fuel boiler operating on coal or wood according to the old, traditional scheme is already a relic of the past. Despite the fact that solid fuel continues to remain relatively affordable, many are confused by the low efficiency of heating residential premises heated by traditional solid fuel boilers. The situation today has changed radically. Pyrolysis boilers, economical, highly efficient and powerful units, have entered the heating equipment market. Huge technological equipment This species is due to pyrolysis, an innovative process for burning solid fuels.
Pyrolysis is the process of uniform breakdown of organic compounds under the influence of high temperature. By artificially limiting the access of air, it is possible to turn ordinary fuel combustion into a slow-flowing thermal decomposition of organic compounds. During the smoldering process of organic fuel, in addition to thermal energy, a large number of gaseous flammable substance. The process produces wood gas and charcoal. Another name for the final product is coke, an organic substance consisting of 90% carbon.
Wood gas obtained as a result of pyrolysis is an excellent fuel. Getting into the secondary combustion chamber, oxygenated, during the combustion process, a gaseous substance releases a huge amount of thermal energy.
Important! When in contact with carbon, pyrolysis or wood gas burns out almost completely, leaving behind CO 2 and water vapor. The amount of carbon dioxide in this case is three times less than that released during conventional wood combustion. This quality is important in the mass use of solid fuel boilers for heating residential premises.
The amount of ash remaining after combustion of wood gas is insignificant, which greatly facilitates cleaning of the heating boiler.
Pyrolysis stages
To understand the operating principle of a pyrolysis boiler, you need to have an idea of what happens and why at each stage. A solid fuel boiler of this type has two combustion chambers. In the first combustion chamber, the wood is dried. The boiler temperature at this moment is 450 0 C. At this stage, the generation of combustion products into a gaseous substance - wood gas - begins. Mixing with heated secondary air supplied by a fan, the gaseous substance burns at a temperature of 560 0 C.
At this stage, the exothermic reaction gains strength, ultimately creating a high combustion intensity. The gas enters the second chamber, where, with the help of supplied oxygen, it burns much more intensely. The temperature in the second combustion chamber is 1100 0 C.
At each stage, the maximum possible amount of useful work is squeezed out of the products obtained as a result of combustion, and accordingly it increases significantly. To optimize the operation of the heating boiler in operating mode, the design of the pyrolysis boiler has gate valves. What is the essence of these devices?
After switching on, the pyrolysis boiler operates in normal oven mode. When the boiler is fully loaded with fuel, using a gate valve you can set the most effective pyrolysis combustion mode. Unlike traditional combustion, the exothermic reaction can be controlled. This feature made it possible to make pyrolysis boilers automated heating devices. Thanks to pyrolysis, it was possible to fully utilize the fuel potential of wood, bringing the boiler efficiency to high values as a result of combustion. Automation of the entire process minimizes the human factor and reduces fuel consumption.
In terms of fuel choice, pyrolysis boilers are omnivorous. For heating a residential building using a solid fuel pyrolysis boiler, firewood and sawdust, wood and peat briquettes, and pellets are suitable.
Design and principle of operation of the boiler
It was already said earlier that boilers of this type have chambers. The firebox is divided into a gasification chamber into which fuel is loaded and directly into the combustion chamber.
The diagram below shows the internal structure of a solid fuel pyrolysis boiler
Fuel is loaded into the first chamber, where the air flow is limited. The boiler starts and operates normally. During slow combustion, the fuel begins to pyrolyze, wood gas is released, which enters the second part of the firebox, the combustion chamber. From this moment the solid fuel boiler enters operating mode. Now processes begin that fundamentally distinguish the pyrolysis type of combustion, long-burning solid fuel heating boilers from the direct combustion process and from traditional boilers.
In the first chamber, heat loss is minimized. Typically, in models of long-burning solid fuel boilers, the space between the first and second chambers is filled with grates on which fuel is placed.
On a note: already here you can detect the first significant difference in the design of pyrolysis boilers from conventional solid fuel boilers. Primary air enters the chamber from above, so the fuel begins to burn slowly from top to bottom. The so-called top blast principle operates. The draft in the first chamber is forced.
The second part of the firebox is the combustion chamber, where combustible wood gas enters. The chamber is filled with secondary, heated air. The principle of double blowing is already in effect here.
After the boiler reaches normal operating mode, air access to the first chamber is significantly limited. The combustion process practically stops, turning into a state of smoldering. The fuel burns out gradually. Each previous layer of fuel gradually involves the subsequent layer in the smoldering process. Slow smoldering is accompanied by the constant release of wood gas. Due to this process, solid fuel pyrolysis boilers are also commonly called long-burning boilers.
For reference: with correct thermal calculations, one load of fuel can be enough for 12 hours of normal boiler operation. In maintenance mode, pyrolysis boilers can operate for a long time without human intervention. In some models this figure is 24-48 hours.
In the second, main combustion chamber, only wood gas burns, which, when in contact with secondary air (heated to 300 0 C), produces a huge amount of thermal energy. Just now thermal energy comes into operation by heating the coolant circulating in the heat exchanger. That is, in the design of solid fuel boilers of the pyrolysis type, heating of the coolant is carried out not through the direct combustion of solid fuel, but through the combustion of a secondary combustion product - pyrolysis gas, a flammable gaseous substance. This is the main difference between boilers of this type from solid fuel boilers of other types.
Advantages of gas generator boilers
Having an idea of how a solid fuel pyrolysis boiler works, what operating principle underlies it heating device, you can decide for yourself certain conclusions. Is it worth installing such a unit at home, to what extent the operation of a long-burning solid fuel boiler will be justified and effective for a home heating system. Here it is important to take into account the advantages that pyrolysis boilers have, namely:
- high efficiency, up to 85%, compared to heating boilers on solid fuels of other types;
- large loading chamber (the ratio of useful volume to boiler power is the most significant);
- simplicity and convenience of cleaning the combustion chamber (cleaning is irregular);
- steel heat-resistant heat exchanger;
- environmentally friendly combustion process (absence of combustion products harmful to health);
- wide choice of fuel resources;
- economical fuel consumption;
- automation of the process of adjusting the operation of the boiler.
Some points need to be addressed in more detail.
Ecology is the most important factor that attention is paid to during the operation of solid fuel boilers. In this regard, pyrolysis boilers are simply a gift for the owner of the house. During the combustion of fuel, instead of smoke and burning, carbon dioxide and water vapor are released, odorless and colorless substances. The number of unburned particles of organic fuel in this case is reduced to a minimum. Thanks to pyrolysis, boilers of this type can operate on almost any organic fuel.
The minimum amount of soot and soot accumulated at the bottom of the combustion chamber can be easily removed when cleaning the boiler.
On a note: Waste from woodworking and clothing production can be used as fuel. Here it is appropriate to talk about the use of recycled materials as fuel. Simultaneously with heating, waste is recycled in pyrolysis boilers. Such boilers are usually installed at woodworking enterprises and used in clothing and leather production.
The large loading chamber allows you to load a significant amount of fuel into the boiler at one time. Pyrolysis boilers have the highest ratio of useful volume to boiler power among all solid fuel boilers. In other words, the more fuel is loaded, the longer the boiler works without your participation. The recipe for high efficiency is built on this heating devices this type.
The table shows the technological parameters of pyrolysis solid fuel boilers of various capacities
| Rated power | kW | 15 | 18 | 25 | 30 | 40 | 50 | 65 | 98 | 130 | 150 |
| Efficiency | % | 85 | |||||||||
| L/D logs, no more | cm | 38 x 15 | 40×15 | 41 x 15 | 45 x 15 | 45×15 | 70 x 15 | 72×15 | 90 x 20 | 90×20 | 95x25 | kg | 20 | 22 | 24 | 30 | 50 | 62 | 75 | 170 | 185 | 200 |
| Duty cyclemin | hour | 8-12 | |||||||||
| Water pressure, max | Bar | 1,5 | |||||||||
| Noise levelmax | dB | 8 | |||||||||
Unlike other models, which are very difficult to adjust due to their inertia, pyrolysis boilers, on the contrary, are perfectly controllable. The presence of automation on new models ensures almost complete autonomy of long-burning solid fuel boilers.
Disadvantages of gas generator boilers
The operating principle of long-burning solid fuel boilers is so practical and beneficial that talking about the presence of shortcomings for this heating equipment only takes time.
The only significant drawback of such equipment is the high cost of the equipment. Despite the fact that boilers are highly profitable and will pay for themselves during operation, initially you will have to invest quite a large amount of money.
Another aspect that should be taken into account is the significant technological limitations on fuel moisture. Pyrolysis is only possible with dry and prepared fuel.
On a note: if the wood or pellets have a moisture content of more than 20%, your gas generator will remain cold. After supplying primary air, the weak flame will simply go out.
Most models of pyrolysis units for industrial use operate on forced draft. Here it is appropriate to talk about the need for constant power supply to injection pumps.
Combustion in the first chamber of a pyrolysis-type heating device may disappear due to the low temperature of the coolant circulating through the heating circuit. When heating large rooms, situations often arise when cooled coolant flows back. To prevent unscheduled shutdown of the device during connection, an additional circuit with an admixture is often used through a three-way valve. You can get by by installing a bypass - a bypass pipe.
Using boilers at home
As a result of getting acquainted with pyrolysis-type units, it has already been said about where and how equipment of this type can be used. Ideal place Woodworking production, furniture and pulp and paper enterprises will be suitable for solid fuel devices. In a word, objects where industrial wood waste is constantly available in huge quantities.
If you want to equip your home with autonomous heating based on a pyrolysis boiler, you should think about a wood storage facility. At the same time, all firewood will have to be pre-dried. A pellet boiler will help solve the problem faster and easier.
Heating equipment of this type is similar in design and design to long-burning pyrolysis units. The only difference is that the fuel used is combustible granules or pellets, products of secondary processing of wood and organic waste.
Almost all models are equipped with an automated feeding device, which greatly simplifies the process of loading the combustion chamber. The compact dimensions of pellet devices make them easy to install in private homes.
Proper connection, fuel storage and compliance with operational requirements make solid fuel gas generators an effective and convenient source of heat.
The following advantages are worth noting:
- automatically adjustable power;
- maximum efficiency and productivity;
- Ease of use;
- long-term operation.
Prices for long-burning solid fuel pyrolysis boilers primarily depend on the policies of manufacturers, as well as the situation on foreign exchange market.
Solid fuel gas generator boilers
When using wood-fired gas generator boilers, solid fuel must meet certain requirements. First of all, we are talking about the presence of a large amount of light substances in the composition and the absence of high humidity (no more than 30%). For boilers with a similar operating mechanism, the following fuel options are suitable:
- wood or firewood, the dimensions of which allow them to be easily loaded into the device;
- waste from woodworking activities, shavings;
- briquettes from pressed wood dust;
- biofuel pellets;
- coal or coke;
- brown coal and so on.
In other words, this heating equipment is capable of using a large number of different types of fuel, which makes this purchase quite universal, since you can easily use such equipment in any region of the country.
The price of a long-burning solid fuel pyrolysis boiler also primarily depends on the rated power of a particular model. Choice suitable option depends on the size of the heated room, as well as the characteristics of the climate and the thermal insulation of the room.
You can also buy a pyrolysis boiler in St. Petersburg at the company’s representative offices, whose contact details you can easily find on the website.
Long-burning pyrolysis boilers with a water circuit
Using a long-burning pyrolysis boiler with a water circuit for heating, you can also provide your home with hot water.
Pyrolysis boilers in our online store are represented by both domestic samples and imported models. The final choice depends entirely on your individual preferences.
The price of a wood-fired pyrolysis boiler in the Technodom online store is distinguished by its objectivity and the absence of unreasonable trade markups. You will find all the necessary information about a particular model in our catalog, where detailed descriptions, technical specifications and photographs.
In our catalog you can buy a solid fuel gas generator boiler in 1 click. If you still have specific questions regarding the features of using the heating equipment models you are interested in, call the numbers provided and you will receive comprehensive answers to your questions.
The operation of the pyrolysis boiler is based on a special chemical reaction- pyrolysis. This term means thermal process decomposition of organic fuel (wood) into gas and coal. The process takes place in a closed chamber without oxygen at a temperature of 350* and above.
In fact, pyrolysis (decomposition and partial gasification under the influence of heat) occurs with any method of burning solid organic fuel.
Solid fuel pyrolysis boiler made of brick. Long burning with afterburning.
Long burning wood burning pyrolysis boiler
As is known, during combustion oxidative processes occur, one of the main participants of which is oxygen contained in the air. If there is little oxygen, the reaction slows down and the wood burns slowly; in fact, in such conditions it simply smolders. This releases a certain amount of thermal energy, ash and flammable gas (Pyrolysis).
The pyrolysis process does not end there. The gas obtained by burning the primary fuel mixes with air masses and also burns. As a result, it releases significantly more thermal energy than when operating standard heat generators.
Therefore, pyrolysis boilers demonstrate very decent efficiency compared to their purely solid fuel “brothers”, and also often provide the opportunity to significantly save on heating.
The advantage of heating equipment of this type is that the principle of its operation and design is relatively simple. The amount of air entering the combustion chambers is controlled by a conventional mechanical damper. The simple design ensures the reliability of the device; breakdowns for pyrolysis boilers are not a frequent occurrence.
This diagram clearly demonstrates all stages of the pyrolysis combustion process. The temperature inside the device can reach 1200°C (+)
Another “plus” of pyrolysis boilers is a long combustion period. Fully loading the device with fuel allows you not to interfere with the process for several hours, sometimes more than a day, i.e. there is no need to constantly add wood to the firebox, as happens with open burning.
Of course, this does not mean that the pyrolysis boiler can be left unattended. As with other heating equipment, there are strict safety regulations.
It is worth remembering that a pyrolysis boiler is not omnivorous - the fuel moisture content should be low. Otherwise, part of the precious thermal energy will be spent not on heating the coolant, but on drying the fuel.
When implementing pyrolysis combustion, the fuel burns almost completely; the device will have to be cleaned much less frequently than when operating a traditional solid fuel boiler. The fine ash obtained after cleaning is used as fertilizer. Fuel combustion in such boilers occurs from top to bottom.
Therefore, the possibilities for natural air circulation in the firebox are noticeably limited. The use of forced air injection using a fan significantly improves the efficiency of the device, but at the same time makes the boiler energy-dependent, since the fan requires electricity to operate.
Design and operation of a pyrolysis boiler
Schematic design of solid fuel pyrolysis furnaces (2 and 3)
The firebox of the pyrolysis boiler is divided into two sections. In the first, firewood is burned, and in the second, secondary combustion of a mixture of pyrolysis gases and air is carried out. The first chamber is separated from the second by a grate, on which the fuel is placed.
The air is usually forced by a small fan. Although in small models sometimes a smoke exhauster is used to create draft.
This diagram shows the structure of a bottom combustion pyrolysis boiler. Firewood burns slowly with little oxygen and releases flammable gas (+)
Availability forced ventilation can be considered the main difference between a pyrolysis boiler and a classic solid fuel model. The device body consists of two parts inserted into each other. The space between the walls is filled with a coolant, the role of which is traditionally played by water.
First, fuel is loaded into the first compartment of the furnace of the pyrolysis boiler, then the fan is turned on and the fuel is ignited. The resulting flammable gases move to the second compartment, mix with air and burn.
The combustion temperature can reach 1200°C. The water in the external heat exchanger is heated and circulated through the heating system of the house. Remains of combustion products are removed through the chimney.
Devices that use the pyrolysis combustion principle can be reproached with a relatively high price. A conventional solid fuel boiler costs significantly less. But in long-burning boilers, wood burns almost completely, which cannot be said about a classic boiler.
Firewood for a pyrolysis boiler has certain requirements in terms of size and humidity. Detailed information can be found in the manufacturer's instructions
When choosing a pyrolysis boiler, you should remember that inexpensive low-power models are usually designed only for firewood. Expensive modifications can work on different types fuel.
Moreover, you will have to load fuel into the device to the maximum; reducing the load leads to increased formation of ash and soot, and also negatively affects the operation of the unit as a whole.
Top combustion boilers
One of the options for a pyrolysis device is an upper combustion boiler. The operating principle of these two units is very similar.
In the same way, a large amount of low-humidity solid fuel is loaded into the firebox, air is forced in and the fuel is allowed to smolder with a reduced amount of oxygen. The valve that regulates the flow of oxygen is installed in the desired position.
Diagram of a top combustion boiler. The firebox of such a boiler has a solid bottom, particles of combustion products are removed through the chimney (+)
But long-burning boilers have neither an ash pan nor a grate. The bottom is a blank metal plate. Such boilers are designed so that the wood burns completely, and the small amount of ash remaining in the firebox is blown out with air.
Such devices are characterized by high efficiency and also operate at temperatures above 1000°C.
The main feature of such devices is that they really provide a long service life when fully loaded. The fuel chamber in such devices is usually made in the shape of a cylinder.
Fuel is loaded into it from above, and the air necessary for combustion is pumped from above, in the center.
In top-burning boilers, the air injection device is a movable element that moves down as the wood burns
This ensures slow smoldering of the top layer of fuel. The fuel gradually burns, its level in the firebox decreases. At the same time, the position of the device for supplying air to the firebox changes; this element in such models is movable and it practically lies on top layer firewood
The second stage of combustion takes place in the upper part of the firebox, which is separated from the lower compartment by a thick metal disk. Hot pyrolysis gases formed as a result of combustion of fuel below expand and move upward.
Here they mix with air and burn, additionally transferring a significant portion of thermal energy to the heat exchanger.
The beam holding the disk that divides the combustion chamber into two parts, like this disk itself, is constantly under the influence of high temperature during the operation of the top combustion boiler. Over time, these elements burn out and will have to be replaced periodically.
A draft regulator is usually installed at the outlet of the second part of the fuel chamber. This is an automatic device that determines the temperature of the coolant and, depending on the data received, regulates the intensity of movement of the combustible gas. It protects the device from possible overheating.
It is worth noting that the external heat exchanger in such boilers reacts to changes in the speed of liquid circulation in the heat exchanger, i.e. to temperature fluctuations. A layer of condensate immediately forms on the surface of the device, which causes corrosion, especially when it comes to steel boilers.
It is preferable to take a device made of cast iron, which resists such effects much better.
Although fuel in long-burning pyrolysis boilers should burn without residue, in practice this is not always the case. Sometimes the ash cakes, forming particles that are difficult to remove with a stream of air.
If a large amount of such residues accumulates in the firebox, a noticeable decrease in the heat output of the unit may be observed. Therefore, the top combustion boiler should still be cleaned periodically.
The peculiarity of devices of this type is that as the fuel burns, it can be reloaded without waiting for the entire fuel load to burn. This is convenient when you need to get rid of flammable household waste.
There are also varieties of top-burning boilers that run not only on wood fuel, but also on coal. There are no complex automatic control units in pyrolysis boilers of this type, so serious breakdowns are extremely rare.
The design of the top combustion boiler allows the firebox to be loaded only partially, if necessary. However, in this case, igniting the top layer of fuel may not be easy. The fuel itself must be dried; firewood from an open woodpile is not suitable for such a boiler.
Fuel of large fractions should also not be used for this type of equipment, i.e. The wood will have to be chopped into small pieces.
Features of operation of gas generator boilers
The operating efficiency of a pyrolysis boiler largely depends on the type and quality of fuel. Technically, not only wood, but also coal and even peat can be loaded into the firebox; most modern boiler models are designed to use several types of fuel.
Wood burns in about 5-6 hours, depending on the type. The harder the wood, the longer it burns.
Modern models of pyrolysis combustion boilers can operate on various types of wood fuel: firewood, briquettes, pellets, coal, peat, etc.
It will take about ten hours to burn black coal, and the same amount of brown coal will smolder for eight hours. In practice, pyrolysis technology demonstrates the highest heat transfer when loaded with dry wood. Firewood with a moisture content of no more than 20% and a length of about 45-65 cm is considered optimal.
If access to such fuel is not available, you can use coal or other organic fuel: special sawdust briquettes and wood pellets, waste obtained from wood processing, peat, materials with cellulose, etc.
Before starting to operate the boiler, you should carefully study the device manufacturer’s recommendations regarding fuel.
In pyrolysis combustion boilers, the air supply is regulated by conventional mechanical valves. The absence of complex electronics ensures high fault tolerance of the device
Too wet fuel in such devices is unacceptable. When it burns in the firebox, additional water vapor is formed, which contributes to the formation of by-products such as tar and soot.
The walls of the boiler become dirty, heat transfer decreases, and over time the boiler may even stop working and go out.
If you use wood with too high a humidity for a pyrolysis combustion boiler, conditions will arise inside the device for the formation of tar, which will worsen the heat transfer of the device and can lead to breakdowns
If dry fuel is placed in the firebox and the boiler is configured correctly, the pyrolysis gas produced as a result of the operation of the device will produce a yellow-white flame. Such combustion is accompanied by an insignificant release of by-products of fuel combustion.
If the color of the flame is different, it makes sense to check the quality of the fuel, as well as the settings of the device.
Pyrolysis gases mixed with air burn with an even yellow-white flame. If the color of the flame has changed, you may need to check the boiler settings or fuel quality
Unlike conventional solid fuel devices, before loading firewood into pyrolysis boilers running on solid fuel, the firebox must be preheated.
To do this, perform the following steps:
- Load small dry kindling (paper, wood chips, etc.) onto the bottom of the firebox.
- They set it on fire using a torch made of similar materials.
- Close the combustion chamber door.
- The loading chamber door is left slightly open.
- Add portions of kindling as it burns.
- The process is repeated until a layer of smoldering coals forms at the bottom.
By this moment, the firebox has already warmed up to approximately 500-800°C, creating conditions for loading the main fuel. Do not use gasoline, kerosene or any other similar liquid substances to light the kindling. Before warming up the furnace of a long-burning boiler, you should make sure that the device is ready for use.
A characteristic feature of pyrolysis combustion boilers is a small amount of ash and ash, which facilitates the process of cleaning the device and its maintenance
To do this, check the presence of draft, the tightness of the doors, the serviceability of locking mechanisms and control equipment, the presence of coolant in the heating system, etc.
Then you should turn on the thermostat to make sure that voltage is supplied to the device. After this, open the direct draft damper and ventilate the boiler for 5-10 minutes.
Review of popular models
It should be understood that any pyrolysis boiler is a fairly heavy unit that is not intended for hanging on the wall. Such devices can be used for heating small house, and for spacious cottages. Like other heating units, long-burning boilers vary in power.
When choosing a pyrolysis combustion boiler, you should focus on such indicators as the thermal power of the device, the size of the loading chamber, the presence of a secondary circuit, etc.
Buyers usually focus on this indicator.
Among the popular models of such equipment we should mention:
- Atmos (Ukraine) - presented by devices that can operate on both wood and coal, power varies from 14 to 75 kilowatts.
- Attack (Slovakia) - capable of heating areas up to 950 sq. m, some models are able to continue working even during power outages.
- Bosch (Germany) - high-quality products from a well-known brand, power varies between 21-38 kilowatts.
- Buderus (Germany) is represented by the Elektromet and Logano lines, the first is well known in Europe as a classic version of a pyrolysis boiler, the second is more modern versions intended for private homes.
- Gefest (Ukraine) – high-power devices with efficiency up to 95%.
- KT-2E (Russia) is specially designed for large residential premises, the unit power is 95 kilowatts.
- Opop (Czech Republic) - relatively inexpensive boilers, reliable and durable, power 25-45 kilowatts.
- Stropuva (made in Lithuania or Ukraine) with a power of seven kilowatts or more are quite suitable for a small home, but the model range also includes more powerful devices.
- Viessmann (Germany) - an ideal choice for private households, power starts from 12 kilowatts, application modern technologies allows you to save fuel.
- “Buran” (Ukraine) with a power of up to 40 kilowatts is another popular option for owners of large cottages.
- “Logika” (Poland) high-power devices of 20 kilowatts easily heat rooms up to 2 thousand square meters. m, it is rather a boiler for industrial needs: heating workshops, offices, greenhouses, etc.
When choosing a pyrolysis boiler for a private home, you should pay attention to models with two circuits, in order not only to heat the home, but also to provide it with an autonomous hot water supply.
The heat exchanger for hot water supply can be storage or flow type. For the latter option, boiler models with increased thermal power are used.
If you want to save money, you can try making a pyrolysis boiler with your own hands. The technology for its assembly is described in this article.
What to do if a country house is not gasified, but electric heating not considered due to the high cost of electricity? If it is possible to regularly purchase or procure inexpensive solid fuel, then it is quite possible to organize efficient water heating in such conditions. Nowadays, quite a lot of different heating devices are produced for this purpose, and among this diversity, long-burning pyrolysis boilers with a water circuit stand out.
These units are able to fully satisfy the heating needs of even a large house. At the same time, to maintain them you do not have to make any special efforts and spend a lot of fuel, which is used as wood in its various forms, coal or briquettes. Despite the fact that wood is the most ancient type of fuel, its use remains relevant to this day, due to its affordability, environmental friendliness, and ease of use.
The history of the appearance of pyrolysis-type heating devices
Even in the times of the Ancient World, it was noticed that using charcoal for heating a home or for cooking is more rational than ordinary firewood, since it does not burn intensely, but smolders slowly for a long time, effectively giving off heat. Therefore, the technology for its production was invented by burning wood in chambers with minimal air access. In fact, such dry distillation of wood into coal is a classic a clear example pyrolysis process.
Previously, holes dug in the ground were used for this - the process of transformation took place in them. regular firewood into charcoal. These chambers did an excellent job, but making charcoal also produced a large amount of thermal energy, which did not bring any benefit. The gas released by wood during oxygen-free combustion has a powerful energy potential. By the way, this made the profession of a charcoal burner extremely dangerous, since gases sometimes escaping from the pits led to severe thermal explosions.
Over time, people have learned to make the most of the natural energy contained in wood. Furnaces were developed that successfully combined several processes - the pyrolysis conversion of wood into coal, followed by combustion of the latter, and afterburning of gases that are released during the primary thermal decomposition of fuel. Moreover, all the thermal energy obtained from these processes is used for human needs almost without losses.
At first, they tried to make conventional stoves using this design. Over time, heating devices using the principle of afterburning pyrolysis gases began to be equipped with a water circuit, due to which they began to be used in the water heating systems that are most familiar to us.
Thanks to its rational design and efficient use of natural energy potential wood, pyrolysis boilers fully cope with the task of a full-fledged high-power heating unit. Nowadays, not only firewood is used for their operation - more efficient and compact modern types of wood-based fuel have also been created.
Pyrolysis boiler design
General principles of the device
For a clearer understanding of how this type of solid fuel boiler works, it is necessary to familiarize yourself with information about its fundamental structure. This will greatly facilitate the further operation of the equipment.
For example, consider the following diagram:
In the diagram, digital indicators indicate:
1 – Combustion chamber, where firewood is placed.
2 – Channels for supplying secondary air, which will initiate afterburning of the gases released during thermal decomposition of the fuel.
3 – Grate-grid, which is cooled by the coolant circulating in the water circuit, thus becoming part of the heat exchange system of the boiler.
4 – Door for the production of fuel filling of the boiler.
5 – Door of the combustion chamber cleaning chamber.
6 – Door for adjusting the supply of primary air required when igniting the fuel filler.
7 – Door for cleaning the upper afterburning chamber of pyrolysis gases.
8 – Ash pan, for collecting and regularly removing solid combustion products.
9 - Pipe for connection to the chimney system.
10 – Branch pipe with a coupling or flange connection for connection to the “return” pipe of the heating circuit.
11 – Connection pipe to the supply pipe of the heating circuit.
12 – Thermal insulation layer.
13 - External casing of the heating device.
14 – Along the arrow, as well as all areas shaded in blue – this is the water circuit (“jacket”) of the solid fuel boiler.
15 – Cooling circuit, which is often connected to provide hot water supply through the boiler indirect heating.
The operating principle is as follows. After adding fuel, access to primary air for ignition opens. At the first stage of work, the wood burns normally until the temperature in the combustion chamber reaches about 400 degrees, which is necessary to start the pyrolysis process. After this, the access of primary air is reduced to a minimum, and in parallel with this, the secondary air supply channel opens. The necessary combination of oxygen, condensation of pyrolysis gases and temperature for their complete combustion leads to active afterburning with a large release of heat. This heat is taken away by the coolant circulating through the water jacket, which transfers it to the heat exchange devices of the entire heating system of the house.
Green arrows show the movement of combustion gases from the fuel fill into the afterburner chamber and further into the chimney system. The blue arrow is the flow of coolant from the return line, the red arrow is the movement of hot coolant into the supply pipe of the heating circuit.
Design features of various pyrolysis boilers
So, long-burning pyrolysis devices, in contrast to the design of conventional solid fuel boilers, are equipped with two chambers, which can be located in different ways. The first combustion chamber is intended for loading solid fuel. In it, with a minimal dosed access of oxygen, the process of its combustion (smoldering) and the release of gaseous combustion products, that is, pyrolysis gases, occurs. Then, the gases enter the second chamber of the device, where, due to the supply of secondary air, they are burned. However, it should be noted that not all existing boiler designs, called pyrolysis, fully correspond to their name.
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 afterburning of pyrolysis gases is organized. A special nozzle is installed between the chambers, having a straight cross-section and made of a refractory composition similar to fireclay bricks.
In this design, air is forced into the main firebox using an installed fan, and partly enters the firebox with solid fuel, and partly into the afterburning chamber of the released gases. In this case, it is obvious that the principle of pyrolysis is violated initially, since the fan creates an excess of oxygen instead of limiting it.
But despite this, effective and complete combustion firewood, with virtually 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 pipe.
Knowing the features of this design, it can be called a “top blowing device”, since the air pumped by the fan enters mainly into the upper main combustion chamber. Due to the influx of oxygen, the temperature during combustion increases and gas production increases, but it burns quite quickly, escaping through the nozzle. In this regard, firewood quickly burns out, and it has to be added quite often in the process of heating the house. This principle of boiler operation cannot be called pyrolysis in the full sense of the word, although similar devices are sold quite often under this name.
It’s another matter if the fan standing on the outlet pipe (often called a “smoke exhauster”) creates air movement, which is proportionally divided into primary and main - secondary using the usual mechanical method 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 filler. The smoldering of firewood occurs from below, and the temperature released during this process promotes heating - in the middle layers of the stack, and final drying - in the upper ones.
The main air flow will be supplied only to the nozzle area so that the final combustion of pyrolysis gases with maximum number The generated heat passed through the lower chamber. Such a boiler can rightfully be classified as a long-burning pyrolysis boiler.
Boiler with natural air supply
In such a boiler design, the combustion chamber for storing firewood is located in the lower part of the device, and the combustion section of the pyrolysis gases released by the fuel is in the upper area of the body.
A fan is not installed in this design, and the air for lighting the boiler and afterburning pyrolysis gases is supplied naturally through dampers for primary and secondary air. In this version of the arrangement of the chambers and the dosed supply of air flows, the pyrolysis process is carried out properly, since instead of intense combustion, with the primary air supply damper closed, wood smoldering occurs in the combustion chamber with the release of a large amount of pyrolysis gases.
1 – fuel filler.
2 – fuel smoldering zone with the release of pyrolysis gases.
3 – primary air supply damper to ensure ignition and smoldering of the fuel fill.
4 – channel for supplying secondary air to form a gas-air mixture and ignite it.
5 – nozzles for supplying secondary air to the rear area of the combustion chamber.
6 – zone of mixing of released pyrolysis gases with the air flow and their ignition.
7 – damper of the channel for additional air supply into the afterburning chamber of pyrolysis gases.
8 – chamber for intensive afterburning of the gas-air mixture with maximum heat release.
9 – pipe connecting the boiler to the chimney system.
However, this design also has its own problem. And it lies in the fact that the correct debugging of the combustion process is extremely important. When the main chamber damper is completely closed, the temperature in it decreases, as well as the formation of gases. The concentration and temperature of the gases becomes insufficient for their complete afterburning and the upper chamber turns into a regular gas outlet. The combustion products that rise 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 operation is sharply reduced.
If the damper is opened more than required to create the conditions necessary for pyrolysis, then the intensity of combustion in the main firebox will increase, which leads to completely irrational fuel consumption and the need for frequent refills.
To achieve 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 for this you need to have practical experience. Modern models have automated monitoring and control systems for processes, and with correct operation of automatic fuel loading, it is enough for 12–14 hours of operation at maximum heat transfer.
Fuel for pyrolysis boilers
Many pyrolysis boilers are capable of working not only with wood. Peat or chip briquettes, sawdust, pellets, black or brown coal can be used as solid fuel.
Each type of fuel has a different burning time, and depending on how often it is planned to add it to the firebox to fully heat the house, one or another material is selected. In addition, the duration of combustion also depends on the amount of fuel placed in the chamber. Thus, the smoldering time of soft wood is about 7 hours, hard wood and compressed sawdust or peat - 9-10 hours, brown coal 10-11 hours, and black coal 12-14 hours. True, we must not forget that different types of fuel also differ in their energy potential.
Manufacturers of solid fuel pyrolysis boilers still call dry wood with a moisture content of no more than 20%, the logs of which are 450÷650 mm long, depending on the depth of the combustion chamber, as the optimal fuel option. It is natural firewood, especially dense hardwood, that provides the proper power of the device and maximum durability of the equipment.
It is not recommended to use wet firewood because during the combustion process they release a large amount of evaporating moisture, which leads to the formation of soot and tar deposits in the boiler chambers and chimney pipe. Such phenomena sharply reduce the efficiency of heat exchange with water circulating along the circuit, and if there are significant build-ups on the walls of the chimney, the boiler will constantly extinguish due to insufficiently intense draft.
You might be interested in information about how it works
Prices for black coal for heating
black coal for heating
Criteria for choosing a long-burning pyrolysis boiler
When deciding to purchase this type of heating device for heating your home, you need to pay attention to some factors on which the efficiency of the boiler will depend:
- The first thing you need to pay attention to is the type of solid fuel allowed for use. Of course, this factor will depend on the availability of a particular type of fuel in local conditions and the profitability of its use.
- Heating boiler power. This parameter depends on a number of initial data, ranging from the climatic conditions of the region of residence to the characteristics of the building. In the appendix to this article, the reader will find a convenient algorithm for independently calculating the minimum required power for heating his home.
- The efficiency of a boiler is assessed by its efficiency. The higher the efficiency, the greater the heat transfer will be obtained with equal consumption of the same fuel.
- The most important parameters in this case are the dimensions and weight of the boiler. As a rule, such products are quite bulky, that is, it is necessary to evaluate in advance the location of their planned installation and correlate it with the dimensions of the proposed models. It would also be useful to evaluate the path along which the stabbing will be brought into the room. And a considerable mass (this applies especially to cast iron models) sometimes forces you to take steps to strengthen the base of the floor for installation of the unit.
In addition, quite often solid fuel boilers are used in conjunction with indirect heating boilers, and maximum efficiency and convenience can be achieved by installing a buffer tank (heat accumulator). Both of these devices are also very bulky and heavy, so the layout of the boiler room should be thought out in advance.
What does installing a buffer tank for a solid fuel boiler give?
The operation of any solid fuel boiler is characterized by cyclicity - alternating periods of loading, ignition, maximum heat transfer and cooling. All this is not entirely convenient for the operation of a water heating system. Installation allows you to eliminate this drawback as much as possible and increase the convenience and efficiency of operation, which is described in detail in a separate publication on our portal.
- Frequency of loading and ease of boiler maintenance. It is recommended to give preference to models with a large fuel chamber and a tray for collecting solid combustion products. In these cases, fuel can be added once or twice a day, and when using dry firewood as fuel, the pan can be cleaned once every two to three months.
- Material for making the heating device. Cast iron is considered the most durable material for this equipment. The service life, subject to all rules, is at least 30 years. However, if you plan to use it as fuel coal, then cast iron is undesirable (this alloy does not like excessive thermal loads), and it is better to purchase a boiler made of alloy steel.
By the way, the durability of a high-quality device is often limited not by its failure, but simply by “obsolescence”, when the owners come to the conclusion that it is time to purchase something more modern.
- Degree of automation. Of course, the more the boiler is saturated with automation that controls the formation of pyrolysis gases and their complete afterburning, the higher the efficiency and economy of heating, the easier the daily operation.
But solid fuel boilers themselves are quite expensive products, and the higher the degree of automation, the higher the cost of the model. So, you probably need to be able to choose some “ golden mean" In addition, we must not forget about the dependence of automated boilers on the availability and stability of the power supply. If this happens in your area of residence common problems, then quite significant costs for purchasing a backup source and (or) stabilizer are inevitable.
- Finally, it is necessary to evaluate the model from the point of view of ensuring the safety of its operation. It would be completely unacceptable, for example, if insufficient thermal insulation of the external casing of the boiler leads to a high probability of getting a burn if accidentally touched.
The main advantages and disadvantages of solid fuel pyrolysis boilers
In addition to the criteria for choosing such a device for heating a house, you need to know the main “pros” and “cons” of pyrolysis boilers.
To their merits can be attributed:
- In the absence of gas supply, this type of heat generators is the best option for heating a house due to its simplicity and efficiency in operation.
- Wood itself is environmentally friendly pure species fuel that does not pose a danger during transportation and storage. With high-quality afterburning, the release of environmentally harmful substances into the atmosphere is minimized.
- Such boilers, unlike other solid fuel boilers, do not require frequent loading. As mentioned above, this process is performed once or twice a day, depending on the specific model, additional equipment boiler room, outside temperature and the need for heating intensity.
- Such boilers are characterized by rapid heating of the coolant, and therefore the premises of the entire house.
- Cleaning from solid combustion products will also not be a big inconvenience: their quantity is minimal.
Disadvantages boilers of this type can be considered the following:
- High price for devices. It exceeds the cost of conventional solid fuel boilers by 1.5÷2 times.
- Pyrolysis boiler models can have only one circuit - the heating circuit. Therefore, if you plan to simultaneously equip your house with a hot water supply system, you will have to choose another version of the device or install an indirect heating boiler in combination with a pyrolysis boiler. Some models have pipes specially designed for these purposes.
- High demand for fuel. Pyrolysis boilers do not work well on wet wood.
- Units of this type cannot operate fully automatically, so you will have to load fuel manually and monitor its amount in the fuel chamber. There are exceptions - pellet boilers with automated feeding, but it is better to classify them as a different category of equipment.
- Boilers of this type are not compact.
Review of models of solid fuel pyrolysis boilers
In specialized retail outlets, as well as in online stores, you can find a considerable number of models of various heating devices, including pyrolysis boilers with a water circuit. They are represented by domestic and foreign manufacturers and have a fairly wide range of prices and characteristics.
Domestic pyrolysis boilers
Among the most popular solid fuel units for heating a private home by consumers are the products of such domestic manufacturers as the KZKO Geyser LLC company and TeploGarant of the Burzhuy-K series.
Boilers of the company KZKO "Geyser" LLC
The Geyser plant is one of Russia's leading manufacturers of heating devices of various types and designs. The offered assortment also includes solid fuel pyrolysis models “Geyser”. The equipment is manufactured using innovative technologies from the highest quality materials.
Pyrolysis boilers are non-volatile, easy to maintain and reliable in operation, capable of heating large areas at minimum costs. In addition, heating devices have increased functionality and efficiency, since fuel consumption is significantly reduced due to its complete combustion and heat transfer to the coolant.
Pyrolysis solid fuel floor standing boilers with the Geyser water circuit of the VP series have the following technical characteristics:
- Boiler power - 10,15,20,30,50, 65,100 kW.
- The type of fuel used is peat and sawdust briquettes, coal and firewood.
- Efficiency is about 85%.
- Product warranty from the manufacturer is 2 years
The proposed range of pyrolysis single-circuit boilers of the Geyser VP series includes models with the following characteristics and approximate cost (as of autumn 2016):
| Model name | power, kWt | Chimney diameter, mm | Device weight, kg | Approximate price level | |
|---|---|---|---|---|---|
| "Geyser" VP-6 | 10 | 130 | 390×1050×700 | 170 | 46,500 rub. |
| "Geyser" VP-15 | 15 | 150 | 390×1200×700 | 210 | 60,000 rub. |
| "Geyser" VP-20 | 20 | 150 | 490×1200×850 | 240 | 70,000 rub. |
| "Geyser" VP-30 | 30 | 180 | 600×1350×930 | 340 | 89,000 rub. |
| "Geyser" VP-50 | 50 | 200 | 660×1600×1050 | 650 | 145,000 rub. |
| "Geyser" VP-65 | 65 | 250 | 660×1930×1050 | 750 | 155,000 rub. |
| "Geyser" VP-100 | 100 | 250 | 800×1930×1200 | 900 | 230,000 rub. |
The Geyser boiler is an all-welded steel structure with several combustion chambers. The lower one is intended for storing fuel and gas formation, and in the upper one the gases are burned.
At low combustion intensity, that is, smoldering, the boiler has a higher thermal performance than stoves with conventional combustion. When operating these boilers, a minimum amount of harmful emissions and solid waste is generated. The recommended diameter of the logs used for burning is 40÷100 mm, and the length is selected in accordance with the depth of the combustion chamber.
Prices for boilers of the “Geyser” line
Sauna stove TMF Geyser
If coal is used to heat a building, it is recommended to choose a fraction of no more than 40 mm. Fuel is added to the firebox in portions, every 8-12 hours - this frequency will depend on the quality and type of fuel used.
The expected minimum service life established by the manufacturer is 10 years.
Pyrolysis solid fuel boilers from the TeploGarant plant, Burzhuy-K series
The TeploGarant plant is on Russian market no less famous brand than the previous manufacturer, and its products have gained wide popularity among consumers.
It is interesting that TeploGarant is the only manufacturer on the world market that mass-produces heating devices with a power above 140 kW. The boilers of this company have their own name - “Burzhuy-K”, and are intended for wide use both in private homes and in the industrial sector. Let's consider several models of this brand.
"Bourgeois-K Exclusive"
A series of heating units with decorative external finishing, which the consumer can select and order individually.
Therefore, if it is necessary to install a boiler in one of the rooms of the house, without violating the overall design harmony, then with the “Bourgeois-K Exclusive” series this becomes quite possible. The heating pyrolysis devices of this manufacturer are also energy-independent, easy to operate, heat the house quickly enough, and also save money on the use of expensive fuel.
Long-burning pyrolysis floor-standing boilers of the “Bourgeois-K Exclusive” series have the following technical characteristics:
- The power of the devices is 12.24 and 32 kW.
- The type of fuel used for heating is coal, firewood, sawdust and peat briquettes.
- The efficiency of these models reaches 82÷92%.
- Manufacturer's warranty – 2.5 years.
Pyrolysis single-circuit boilers of the “Bourgeois-K Exclusive” series are represented by the following series of models, with the characteristics shown below. But the price in this case can fluctuate significantly, since it depends on the chosen exterior finish.
This model of pyrolysis boilers is intended for use in residential and commercial premises. The water circuit can be with natural or forced circulation, that is, with a circulation pump installed in the circuit. The device is equipped with a draft regulator, which will provide automatic control over the combustion intensity, and this factor adds comfort to the operation of the boiler.
The boiler itself is a welded structure made of corrosion-resistant and heat-resistant steel, divided into several chambers. The combustion chamber is located in the lower part of the body, and the afterburning chamber is located in the upper part. For higher heat retention and transfer, the internal walls of the device have a fire-resistant lining. In addition, between the outer wall and the water circuit there is a layer of heat-insulating material - in this case, basalt wool is used for this. External decorative cladding is made from natural stone.
The pyrolysis process in this boiler model is carried out in the same way as in other models of devices of this type. Thanks to afterburning, high-quality insulation of walls and lining, the required thermal power of the boiler is ensured with sufficiently low fuel consumption.
In the heating circuit, ordinary tap water with an acidity value not exceeding 7.2 pH, or special water can be used. However, when using the latter, the power of the heating boiler will be significantly reduced. However, this is typical for all types of boilers.
What is used as coolants in heating systems?
In terms of its heat capacity and absolute availability, water has no equal. However, there are situations when the use of water becomes impossible, and you have to resort to others. More details about this can be found in a separate publication on our portal.
The boiler kit comes with a capillary-type thermomanometer, designed to indicate the pressure of the coolant as it exits the boiler into the circuit, as well as its temperature.
Control of the set temperature of the coolant when leaving the boiler into the circuit is carried out by an automatic draft regulator. If the temperature drops, the adjustment door, under the influence of a special chain, will begin to open.
Removal of combustion product residues occurs in this design using natural traction. Bourgeois-K Exclusive boilers are energy-independent and easy to use, and if desired, this design can be supplemented with a thermal protection circuit and hot water supply.
The minimum service life established by the manufacturer is 10 years.
"Bourgeois-K Standard"
"Bourgeois-K Standard" has almost all of the characteristics listed above, with the exception of dimensional parameters and some differences in power gradation.
These models also do not have exclusive external cladding. In this embodiment, a coating of heat-resistant paint is used, applied to a metal body thermally insulated from the inside using spraying. In addition, adjustment in these models is done manually.
The parameters of boilers in this line are shown in the table below.
| Model name | power, kWt | Chimney diameter, mm | Dimensions (width, height, depth), mm | Device weight, kg | Approximate price level |
|---|---|---|---|---|---|
| "Bourgeois-K Standard-10" | 10 | 130 | 380×780×650 | 180 | RUB 36,800 |
| "Bourgeois-K Standard-20" | 20 | 150 | 480×950×750 | 270 | RUB 52,300 |
| "Bourgeois-K Standard-30" | 30 | 180 | 530×1120×840 | 380 | 66,000 rub. |
The location of the chambers also does not differ from the models of the “Bourgeois-K Exclusive” line; the process of pyrolysis and afterburning of gases is carried out according to the same principle.
Prices for boilers of the “Bourgeois-K Standard” line
Burzhuy-K Standard
The efficiency of this range of models is 82÷89%, the possible power control range is 30÷110%. The operating time from one load of fuel is about 12 hours for firewood, and up to 15 hours when using high-quality coal.
"Bourgeois-K TA"
Pyrolysis heating unit“Bourgeois-K TA” differs from its “predecessor” in that the regulation air flow and traction is produced in it automatically. The boiler is equipped with a water heating circuit, through which the coolant can circulate naturally, under the influence of temperature changes, or forcibly, using a circulation pump installed in the system.
This boiler model has all the positive features mentioned above and works on the same principle. The lower combustion chamber is also the main one, and afterburning is carried out in the upper area of the boiler body.
The table presents some characteristics and approximate price levels of Bourgeois-K TA boiler models of various capacities:
| Model name | power, kWt | Chimney diameter, mm | Dimensions (width, height, depth), mm | Device weight, kg | average price |
|---|---|---|---|---|---|
| "Bourgeois-K T-50A" | 50 | 200 | 690×1580×1210 | 580 | 145,000 rub. |
| "Bourgeois-K T-75A" | 75 | 250 | 820×1670×1120 | 900 | 200,000 rub. |
| "Bourgeois-K T-100A" | 100 | 250 | 780×1890×1420 | 900 | RUB 225,000 |
| "Bourgeois-K T-150A" | 150 | 300 | 940×2000×1820 | 1350 | 330,000 rub. |
The efficiency of these pyrolysis boilers is 82÷92%. They are energy-independent and economical in fuel consumption, easy to maintain, operate and manage. The devices are quite reliable, safe and durable, but for all models of this line of units it is already necessary to equip a separate boiler room.
"Bourgeois-K Modern"
"Bourgeois-K Modern" is produced in three versions of models, different in power. they all work on the pyrolysis principle. Can operate in systems with forced and natural coolant circulation
The location of the chambers in these models does not differ from the boiler designs presented above. For normal operation, it is recommended to use dry wood, but if necessary, the device can also operate on damper wood, with humidity reaching up to 50%.
The efficiency of Bourgeois-K Modern boilers is 82÷92% with economical fuel consumption.
The unit is similar in layout and level of equipment to the devices of the “Bourgeois-K TA” line, but has a lower level of thermal power, is designed for a smaller building, and can easily be installed not in a dedicated boiler room, but in a separate room in a residential area.
The minimum service life of the heating device established by the manufacturer is also 10 years.
Main technical characteristics model range"Bourgeois-K Modern" are shown in the table:
| Name of parameters | "Bourgeois-K Modern-12" | "Bourgeois-K Modern-24" | "Bourgeois-K Modern-32" |
|---|---|---|---|
| power, kWt | 12 | 24 | 32 |
| Chimney diameter, mm | 130 | 150 | 180 |
| Dimensions (width, height, depth), mm | 500×1180×800 | 500×1180×800 | 600×1270×860 |
| Device weight, kg | 220 | 310 | 430 |
| Heated area, m² | 120 | 250 | 330 |
| Required chimney draft, Pa | 18 | 20 | 22 |
| Max. coolant temperature | 95 | 95 | 95 |
| Combustion chamber volume, l | 55 | 61 | 189 |
| Heat exchanger material | steel | steel | steel |
| Contents of delivery | With draft thermostat and thermomanometer | ||
| Log length, mm | 550 | 600 | 660 |
| Duration of firewood burning, hour. | 5-12 | 5-12 | 5-12 |
| Average price level | 63,000 rub. | 75,000 rub. | 94,000 rub. |
Video: presentation of long-burning solid fuel boilers of the “Burzhuy-K” series
Boilers from foreign manufacturers
In addition to domestic solid fuel boilers for home heating, products from foreign, mainly European, manufacturers are on sale. The high quality of the models and the well-deserved authority of the companies makes it necessary to briefly review some of them.
Pyrolysis boilers from Buderus, Logano S171 W series
The German company Buderus specializes in the production heating equipment and produces boilers various types, including solid fuel, operating on the principle of afterburning pyrolysis gases.
The Buderus Logano S171 W model range includes four models of heating devices of varying power, designed specifically for installation in private homes. The peculiarity of these boilers is that they can work not only autonomously, but also in conjunction with units running on diesel fuel, gas or electricity.
Pyrolysis boiler “Buderus Logano S171 W 50”
However, it should be immediately noted that all devices of the “Logano S171 W” model range require a separate boiler room, carefully prepared in accordance with current rules, since for safety reasons they are prohibited from being installed in residential areas of the house.
The design of these models includes built-in control of an indirect heating boiler, provided in case there is a need to simultaneously install hot water supply in the house.
Heating devices "Buderus Logano" are equipped with modern automation, which allows you to effectively manage the entire heating system.
Prices for boilers of the Buderus Logano line
Pyrolysis Buderus Logano
The boiler body is covered with a special insulating material, which significantly reduces heat loss and also acts as a sound absorber, providing the unit with virtually silent operation.
In the design of Logano S171 W boilers, the main combustion chamber is located in the upper part of the body, and the afterburning chamber is in the lower part, the latter being insulated with fireclay lining. This arrangement of the chambers is convenient because pyrolysis begins to occur without igniting the entire fuel load.
Some characteristics and average price levels are in the table:
| Model name | power, kWt | Chimney diameter, mm | Dimensions (width, height, depth), mm | Device weight, kg | Approximate price level |
|---|---|---|---|---|---|
| "Logano S171-22 W" | 20 | 150 | 620×1136×1019 | 362 | 185,000 rub. |
| "Logano S171-30 W" | 30 | 150 | 620×1136×1019 | 362 | 215,000 rub. |
| "Logano S171-40 W" | 40 | 150 | 699×1257×1083 | 466 | 230,000 rub. |
| "Logano S171-50 W" | 50 | 180 | 699×1257×1083 | 466 | 245,000 rub. |
A few more design and operational features:
- The efficiency of boilers in this line reaches 90%, which is an excellent indicator for any solid fuel units.
- The thickness of the steel from which the device body is made ranges from 3 to 5 mm.
- Large volume of the loading chamber, which means a long fuel burning time.
- The boiler, in accordance with its design, is equipped with a fan for forced smoke removal.
- The built-in heat exchanger will keep the device from overheating.
- Automatic control of the unit of a modern type - a clear interface, LCD display, advanced options for connecting additional modules.
- It is possible to connect DHW when installing an indirect heating boiler with coordinated control of the latter’s operation.
- Complete thermal insulation of the device ensures maximum operating safety and minimal heat leakage.
You might be interested in information on how to choose
Pyrolysis boilers of the Viessmann company of the Vitoligno 100-S type VL1A series
Another famous one German company which represents its products on the Russian market is Viessmann. The series of boilers “Vitoligno 100-S type VL1A” also works on the principle of pyrolysis, and has all the advantages characteristic of high-quality devices of this class.
In addition to the use of firewood, briquettes or coal, this unit provides the ability to connect replaceable burners operating on gas or liquid fuel.
Heating pyrolysis boilers of the Vitoligno 100-S series have the following characteristics and price parameters:
| Model name | power, kWt | Chimney diameter, mm | Dimensions (width, height, depth), mm | Device weight, kg | Approximate price level |
|---|---|---|---|---|---|
| "Vitoligno 100-S type VL1A, 25" | 25 | 150 | 526×1063×1005 | 461 | 160,000 rub. |
| "Vitoligno 100-S type VL1A, 30" | 30 | 150 | 586×1263×1005 | 551 | 215,000 rub. |
| "Vitoligno 100-S type VL1A, 40" | 40 | 150 | 586×1363×1089 | 629 | RUB 265,000 |
| "Vitoligno 100-S type VL1A, 60" | 60 | 200 | 655×1757×1134 | 822 | 340,000 rub. |
| "Vitoligno 100-S type VL1A, 80" | 80 | 200 | 749×1757×1134 | 864 | 455,000 rub. |
In addition, it is necessary to mention the features and equipment of the boiler that are not included in the table:
- The depth of the main fuel chamber, located in the upper part of the boiler body, is 500 mm.
- Since the fuel chamber is located in the upper part of the furnace body, the design is equipped with a forced fan “smoke exhauster”.
- The thickness of the steel used to make the case is 5 mm.
- The design is equipped with an electronic controller that identifies operating modes.
- A protective heat exchanger is installed in the boiler to protect it from overheating.
- The efficiency of this boiler is 87%
- Easy adjustment of combustion intensity using primary and secondary air dampers - they can be adjusted manually.
- The nozzle installed between the fuel chamber and the pyrolysis combustion chamber is made of fireproof fireclay.
You might be interested in information about what it is
Pyrolysis boilers of the Wattek company of the PYROTEK series
Another European manufacturer- the Czech company “Wattek”, which is well known in Russia for the quality of its products, and therefore quite popular among owners of one- or two-story private sector mansions.
Modern solid fuel boilers operating on the principle of afterburning pyrolysis gases are represented by the PYROTEK model line.
You may be interested in information about what they are
Table of the Wattek product range of the PYROTEK series with some technical characteristics and price levels:
| Model name | power, kWt | Chimney diameter, mm | Dimensions (width, height, depth), mm | Device weight, kg | Approximate price level. |
|---|---|---|---|---|---|
| "PYROTEK-26" | 26 | 152 | 530×1145×915 | 318 | 165,000 rub. |
| "PYROTEK-30" | 30 | 152 | 530×1145×915 | 322 | 175,000 rub. |
| "PYROTEK-36" | 36 | 152 | 530×1145×1115 | 372 | 195,000 rub. |
| "PYROTEK-42" | 42 | 152 | 530×1145×1115 | 376 | 200,000 rub. |
In addition, devices in this line are characterized by the following features:
- The efficiency of boilers of this series is 90%.
- The ability to maintain combustion from one load of fuel for 10÷12 hours.
- It is possible to connect an indirect heating boiler to the boiler with general management- for arrangement of hot water supply.
- PYROTEK heating devices are equipped with a copper heat exchanger protected from overheating.
- Full automation of the boiler operation process, as it has a modern control panel that ensures maximum simplicity and ease of operation.
- PYROTEK boilers are volatile, that is, they require connection to a stable power supply.
- The unit body has high-quality thermal insulation made of basalt wool located between the outer wall and the water circuit.
To conclude the topic of long-burning pyrolysis heating devices, it must be said that if the decision is made to install this boiler, then the purchase should be carefully thought out, since the prices for such equipment, as you can see, are very impressive. When choosing a specific model, you need to very carefully study its passport characteristics and check the product’s package contents.
You might be interested in information on how to equip
By the way, you can think about an individual order for the manufacture of such a boiler of the required power. In our area there are always many craftsmen who can make a boiler that in operation will be no worse than the factory model. To prove this thesis, watch the following video:
Video: long-burning pyrolysis boilers - individual production
APPLICATION
How to determine the required boiler power?
One of the key parameters when choosing any boiler equipment is its power. By the way, other characteristics of the boiler largely depend on it, including dimensions, weight, the possibility of installation in a residential area or the need for a mandatory separate boiler room. This means that it is necessary to find a value that would be guaranteed to provide efficient heating of all rooms of the house, but without unnecessary excess power, which entails an increase in size and a sharp increase in the cost of the model.
In addition, operation of the boiler at reduced power (and this happens during most of the heating season) sharply reduces the efficiency of the device and, therefore, the efficiency of fuel consumption. And the higher the difference between optimal value power and its rated value, the more sensitive, and at times, there will be completely unnecessary losses.
When determining power, they are often guided by the ratio of 1 kW of thermal energy per 10 m² of room area. The approach, frankly speaking, is very approximate, since it does not take into account many important factors relating to both the specifics of the region and the characteristics of the building.
As an option, we offer our own calculation algorithm. It is based on the fact that for each room of the house an individual calculation of the required thermal power is carried out to maintain an optimal microclimate in it. Then all that remains is to sum up the obtained values and get the total value, which will become a guideline when choosing a boiler.
If it is necessary to make specially designed for this purpose can help.
Before you begin the calculation, familiarize yourself with the calculator interface below. For convenience, you can create a table in the rows of which you enter one by one all the rooms of your house where heat exchange devices will be installed, and in the columns - the necessary data characterizing this room.
Please note that the heat loss of each room is affected by its location relative to the cardinal points and the prevailing winter winds. If the user is not clear with these data, he can leave them as default, and the program will calculate the power for the most unfavorable conditions.
The minimum temperatures requested in the corresponding input field should not be extreme - you must indicate a level that is normal for the region of residence (for the coldest decade at home). But at the same time they do not remember some monstrous frosts, for example, five years ago, which were remembered only due to their obvious abnormality.
Further data entry fields will probably not raise any questions.
The resulting value already takes into account the operational reserve, and after summation total power no amendments are required anymore. When choosing, pay attention to models whose power is higher than the obtained value, but closest to it. This will become optimal solution. you can find out by following the link.
