Solid fuel pyrolysis combustion boiler with a water circuit. Pyrolysis boilers - is it worth buying

Gasification of private sectors is proceeding by leaps and bounds. But still many settlements are heated with coal or wood. And it is not known when the "blue fuel" will reach them. But the budget is not rubber. Looking at the rising prices for firewood, coal or pellets (compressed fuel), people clutch their heads. However, there is a way out of the situation - solid fuel boilers of long burning with a water circuit, saving both firewood and time. You need to heat it once a day, and some models even have enough once a week. Today we will figure out what kind of "miracle unit" it is, why it so rarely needs to be heated and how much such a boiler costs.

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Solid fuel boilers for long burning with a water circuit: advantages and disadvantages

Solid fuel boilers for long burning for heating are an opportunity to provide a home with heat and create comfortable living conditions, while spending less firewood or coal than when using a conventional stove. Such a unit has many advantages, among which it is worth highlighting:

• profitability achieved by high efficiency;
• the unit is easy to maintain;
• low cost;
• environmental friendliness and safety.

Depending on the model, such units may be equipped with additional options that facilitate the heating process. However, it is not without its drawbacks, among which it is worth noting the need for periodic cleaning and loading of fuel (in comparison with gas and electrical equipment). But these disadvantages disappear when you compare the device with a conventional stove heating.

The principle of operation of a solid fuel boiler for long burning

The principle of operation of a solid fuel boiler for heating a house is based on the properties of wood, to emit gas during combustion, called pyrolysis. This gas is not used in a wood-burning stove for a constructive reason. It is itself a fuel which, when burned, produces a large amount of heat. By using pyrolysis gas, engineers have been able to increase the efficiency of long-burning solid fuel heating boilers by minimizing open flames.

Unit classification: what to look for when choosing

The choice of a long burning boiler depends on several factors. The weight of the equipment is taken into account, but only if you plan to place the device on a wall. The main attention is paid to the main parameters. To determine with them, consider the classification of aggregates.

Fuel combustion method: which is better

There are two types of devices - volatile and non-volatile. Let's consider their differences, pros and cons.

A traditional volatile boiler is comparable in appearance to a conventional stove, which has a window in the upper part. Fuel is loaded into it. Firewood or coal inside smolders, there is no open flame, but the release of this heat is sufficient. At the same time, a special fan is periodically turned on, removing excess oxygen from the furnace. Due to the absence of an open flame, fuel economy is achieved and the time interval between its plugs increases.

Such a unit is equipped with an afterburner, which provides an increase in efficiency up to 80 ÷ 85%. These devices are reliable and durable due to the simplicity of their design, but they have the disadvantage of being volatile. In the event of a power outage, the fan stops turning on and smoldering does not occur. The way out will be the purchase of a UPS (uninterruptible power supply).

What is a pyrolysis solid fuel boiler

Non-volatile devices are called pyrolysis devices. The difference from the previous version is that the fuel is first dried, after which degassing occurs. As a result, more than 80% of substances are converted into gas, the combustion temperature of which is 2 times higher than that of firewood. To understand how it works, we suggest watching a short video:

Advantages - efficiency (up to 95%), efficiency and autonomy (power outages are not terrible).

What type of fuel to choose

An important parameter for saving the family budget is the type of fuel that the unit will use. The choice here will depend on what is more profitable to buy in a particular region. If a person lives where there is a lot of forest, naturally he will choose a wood-fired boiler. But it is worth noting that long-burning coal-fired boilers require bookmarks less often than wood-fired ones.

Number of contours: how important is this parameter

The choice for this parameter depends on the availability of hot water in the house. Double-circuit devices are more expensive, but they make it possible, in addition to heating, to organize hot water supply in the home. If there is no hot water in the house, this factor is crucial, especially if small children live in the house.

Important! An additional circuit allows uninterrupted hot water supply only if cold water is available. If there is no running water in the house, there will be no point in overpaying.

Selecting a device for heating by power

The power of the unit determines the ability to heat a given area of \u200b\u200bthe room. Nothing complicated. We get more expensive and no problems. But the question arises, why overpay for unnecessary power? And more fuel is used for such equipment. The flip side of the coin is insufficient power. In this case, the equipment will not warm up the room to a comfortable temperature - and again the money wasted.

In order not to be mistaken with the power of the solid fuel boiler, we suggest using the online calculator. He will eliminate the error in calculations that a person can make. All that is required from the user is to enter the data in the appropriate fields and click the "calculate" button. The program will display the required equipment parameter in kW.

Calculator for calculating the power of a solid fuel boiler for long burning

Coefficient of efficiency of solid fuel boilers for long burning

Efficiency is the most important parameter to which attention is paid. It depends on it how well the room will be heated, and how much firewood or coal will have to be purchased for the winter period. The higher this indicator, the greater the savings in the family budget will be received by the owner. But the cost of equipment with a high efficiency is higher.

Good to know! By overpaying when purchasing equipment with high efficiency, you will save money later. Less fuel will be consumed during the winter at the same temperature in the home.

How important is the volume of the loading chamber

The loading chamber should be as large as possible. It depends on how often fuel will have to be loaded. Models with small chambers work on one load for 8 ÷ 24 hours, but there are those that do not require fuel for 5 ÷ 8 days. But here, too, much depends on the type of fuel. The most unpretentious in this sense are coal devices.

Important! Solid fuel boilers require long burning when installing a separate room, which means that the volume of the loading chamber will depend on the area of \u200b\u200bthe furnace. When purchasing a unit with a large load, you should calculate whether it will fit in the room intended for it.

Also, many users of such boilers will be interested in the question of how much fuel the selected equipment will "eat". For this we also suggest using a special calculator.

Calculator for calculating the required amount of solid fuel

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Types of solid fuel units for long burning

Such units are divided into three types: pyrolysis, pellet and boilers with the principle of upper combustion. Each of them has advantages and disadvantages.

Unit with the principle of upper combustion of fuel

The principle of operation of such a device differs from other types in that the coal in the chamber burns from above, and the flame goes down as it burns out. It happens like this.

An air supply pipe is installed above the fuel, at the end of which there is a bell. The flame from the top layer of fuel is supported by preheated air from the bell. As the coal burns, the telescopic tube is lowered. Thus, the process is maintained until complete burnout. The heat exchanger with the coolant is located with a jacket around the firebox.

Such boilers are convenient in that they do not need to be filled frequently. One load (through the door on top) is enough for 5 ÷ 8 days. Ash removal is carried out through the bottom hatch. More expensive models are equipped with a door along the entire length of the cylinder. Here, the cost rises due to the complexity of manufacturing the unit.

Pellet boilers and their advantages over other types

Pellets are compressed fuel pellets. Advantages of pellets in shape and size, which allow automating the process of feeding into the furnace. Consider the advantages of this type of boilers.

Pressed pellets are cheaper than wood or coal, which saves the family budget during the heating season. In addition, an automatic solid fuel boiler has to be loaded less often, it requires less maintenance. The room temperature can be adjusted by increasing or decreasing the fuel supply to the furnace. For these reasons, the popularity of pellet boilers is growing every year.

But, even after studying the information presented, it will be difficult for a person who has not encountered such equipment to make a choice. To resolve this issue, we will present a rating of the best manufacturers representing long-burning solid fuel boilers on the Russian market.

Rating of manufacturers of solid fuel heating boilers for a private house

There are quite a few manufacturers of such products, but we will try to single out the top three from them. It is gratifying that the Russian manufacturer deservedly rises to the first place in today's rating.

Manufacturer of solid fuel boilers "Teplodar"

The company represents a wide range of not only solid fuel boilers, but also other heating equipment. This is one of the leaders in the market of such units not only in Russia, but also in the neighboring countries. The quality does not cause complaints from the consumer. Here's what Internet users say about this manufacturer:

Dmitry721, Ukraine: In the process of installing a heating system at one of the construction sites of our company, I first encountered the equipment of the Teplodar company. A Kupper OVK-18 solid fuel boiler was installed. With its average power, the boiler turned out to be very productive and with a fairly high efficiency. (According to the product passport, the efficiency is 80%). The first start (ignition) was carried out on wood. Although the model is designed not only for firewood, but also for coal and peat briquettes. (…) With high heating outputs, it is also economical. Structurally, the manufacturer provides for the replacement of the burner, which will allow the use of other types of fuel, but this has not been tested. It's been working confidently for the second season already ...

More details on Otzovik: http://otzovik.com/review_4183828.html

Representative of Germany "Buderus": a competitor of Russian brands

The company entered the Russian market in 2004. It was the only warehouse located in Moscow. But already in 2008 the Buderus network grew to 25 representations. German quality, known all over the world, has done its job - the popularity of solid fuel boilers of this brand is growing every year. However, although the Buderus units in quality can compete with the domestic manufacturer, they clearly lose in terms of the equipment price. The cost of boilers from this manufacturer is 3 ÷ 5 times higher than Russian ones. And therefore - the second place in today's rating.

More details on Otzovik: http://otzovik.com/review_4261815.html

"ZOTA" is another Russian in our rating

A relatively young company founded in 2007. The manufacturer is constantly improving models, the cost of which is low. Firm "ZOTA" could compete for the second place in the rating, but the not too wide range of models failed due to the youth of the company. The quality of the units is at a decent level, although there were some drawbacks. Users complain about the lack of pressure gauges, the small volumes of the loading chambers and the complexity of maintenance.

At what price can you buy a solid fuel boiler for long burning

Such equipment can be purchased both in specialized stores and on Internet resources. Let's try to summarize the information on long-burning solid fuel boilers of Russian production, as well as their foreign competitors, which we managed to collect, having considered the characteristics of some models and their cost as of January 2018.

Photo	Make and model	Power / efficiency, kW / %	Fuel type	Average price (as of January 2018), RUB
	Stropuva Mini S8	8/85	Firewood, briquettes	56100

Conord KS-T-11

11/80

Firewood, briquettes

11800

Buderus Logano G221-25

25/78

Firewood, coal, coke

115000

Wattek PYROTEK 36

36/90

Briquettes, firewood

172000

Lavoro Eco С32

32/85

Peat briquettes, coal

69300

NMK Magnum KDG 20 TE

20/80

Coal, coal briquettes

35000

Galmet top 15

15/85

Firewood, briquettes, coal

85000

Looking at the presented table, one can understand that the prices for solid fuel boilers of Russian production are much lower than their foreign counterparts.

Article

Reading time: 6 minutes

Heat supply of private houses, industries and administrative premises from solid fuel boilers is very common in areas where there is no possibility of connecting to a gas main or in the Far North. Coal, firewood, pellets and briquettes serve as fuel for such boiler houses. The general disadvantage of this type of heating is that you have to regularly supply the firebox with fuel. However, there is a kind of solid fuel equipment, where there is no such drawback - a pyrolysis boiler.

What is pyrolysis

This is the process of the formation of combustible gas and its combustion in solid fuel boilers and stoves, where, when burning wood, hot carbon monoxide is released. Provided it is combined with oxygen, it burns with heat release and the formation of carbon dioxide.

In modern technology, this physical phenomenon is 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 experimenting with designs where the fuel did not burn immediately, but smoldered with a lack 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 coal-fired models. Some run on natural draft.

The principle of operation of the pyrolysis boiler

To better understand the advantage of pyrolysis boilers, you need to familiarize yourself in more detail with the principle of their operation. Despite the classical definition of 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, a weak smoldering occurs 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 reduces fuel consumption by 40%.

Smoldering fuel forms wood gas, which enters the combustion chamber, heated air is also supplied there. This leads to the appearance of a flame - combustion occurs with the release of heat. At the same time, carbon monoxide is converted into carbon dioxide and the amount of harmful substances is less than in conventional boilers.
Using pyrolysis boilers this leads to fuel savings, because more heat is obtained from the same amount of fuel.

For example, a conventional unit may need 10 cubic meters. firewood for the heating period, and 6 cubic meters will be enough for pyrolysis. And just as importantly, you don't have to frequently refuel.

Long-burning pyrolysis boilers with a water circuit are produced in several varieties:

• non-volatile. Natural traction and mechanical control are characteristic;
• volatile. Blowing equipment is used, which contributes to higher efficiency;
• with a difference in the location of the gas afterburner. The chamber can be under the firebox or above it.

There can be many design options, but they do not differ in the principle of combustion. There are so-called long burning, which work regardless of the type and quality of fuel and are rather than heating pyrolysis installations.
The use of volatile boilers is convenient in that they are equipped with automatic devices to control combustion, depending on the water temperature and room temperature.

Long burning occurs due to two factors: low intensity of fuel smoldering and a large furnace. All this guarantees a low frequency of approach to equipment.

Long burning pyrolysis boiler design

A long-burning pyrolysis boiler has the following device:

• Control block. This device selects different modes and monitors the operating parameters;
• Housing. Made of steel and covered with heat-resistant paint;
• Thermal insulation. Used to reduce heat loss;
• Boiling device. Controls the temperature of the coolant and regulates the combustion, in order to avoid boiling, which can lead to an accident;
• Heat exchanger. A metal pipeline filled with a coolant that heats up during the combustion of the fuel, after which it enters the heating system;
• Furnace chamber. Serves for loading solid fuel into it. After that, ignition occurs, and air access stops. Smoldering occurs at 450˚C;
• The combustion chamber. In this part, the combustion of wood gas takes place, provided that air is supplied. Combustion temperature reaches 1100˚С;
• Coolant supply pipe to the heating system;
• Grizzlies. Metal grate located between the loading and combustion chambers;
• Chimney connection;
• Chimney fan;
• Primary air valve for starting pyrolysis;
• Secondary air valve for wood gas combustion;
• Return pipe connection.

Pros and cons of a pyrolysis boiler

Like any equipment, long-burning pyrolysis installations have both advantages and disadvantages.

The advantages include:

• Economical. Fuel consumption is reduced by up to 40% depending on the modification, operating conditions;
• Long burning. This contributes to the fact that after laying the pyrolysis fuel, it will not be necessary to approach the boiler soon;
• Environmental friendliness. The combustion of fuel is almost complete, therefore, practically no harmful substances are emitted;
• High heat transfer of combustion products. The temperature of the flue gases is noticeably lower than in conventional boilers;
• It is possible to use automatic power control devices 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;
• Energy dependence. Given the presence of automation and forced pyrolysis boilers, they need to be connected to the mains;
• Dimensions. The dimensions are much larger than that of traditional solid fuel plants.

The main disadvantage is still the cost, and the rest do not pose big problems.

How economical is the pyrolysis boiler

The design features of pyrolysis boilers provide it with a significant advantage over classic ones. The efficiency of a solid fuel pyrolysis boiler of long burning reaches the indicators of gas equipment and is about 90%, and the efficiency of the classic does not exceed 70%.
To figure out how economical are solid fuel pyrolysis boilers, you can perform a calculation and compare it with a type of fuel comparable in efficiency.

The price of natural gas for the population is different 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 is about 1,500 rubles per 1 cubic meter. Hence, 1 kg of firewood costs 1.5 rubles. The normative indicates that 1 kg of firewood is capable of giving 3200-3600 kcal. Calorific value of gas - 8000 kcal / cubic meter. As indicated, the efficiency of heating pyrolysis and gas boilers is comparable, therefore, in the calculation, they can be neglected.
After a simple calculation, you can make sure that you need to burn 2.35 kg of firewood to get 8000 kcal. Let's multiply by the unit cost of firewood: 2.35 kg * 1.5 rubles. We get that the cost of 8000 kcal when burning firewood will be 3.52 rubles, and when burning gas - 4.84 rubles. The use of a pyrolysis combustion boiler gives savings on fuel costs of almost 30% compared to the use of gas equipment.

Pyrolysis plants, although expensive, are the most suitable equipment for heating greenhouses, greenhouses, greenhouses. This type of equipment is also used in waste processing plants.

Is it worth it to do it yourself

If you have the necessary knowledge, capabilities and drawings, then the pyrolysis boiler can be made independently. The Belyaev pyrolysis boiler scheme is popular among the population. This technology cannot be called simple, nevertheless it is one of the most accessible and implemented.

Boiler diagram. Photo source: balserv.ru

To make a pyrolysis boiler with your own hands according to 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, a welding machine. An assistant will be needed. First, the sheet parts of the installation are made, cut off with an accurate tool, and then, following the step-by-step instructions, the rest of the work on assembling the homemade boiler is performed.

Popular models

Consider the most common and popular pyrolysis installations, among which there are both electricity-dependent and non-energy-dependent:

1. 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 is 25 kW. The efficiency is up to 95%.
2. Geyser. The boiler is designed for both domestic and industrial use. The household line of pyrolysis heating boilers has from 10 to 50 kW. The boilers are non-volatile, run on any fuel, have high efficiency, and are easy to operate.
3. Buderus. They are of high quality, mechanically controlled, and independent of electricity. The boiler heat exchanger is made of cast iron, which eliminates corrosion, and steel. The efficiency of Buderus boilers ranges from 78 to 87%, depending on the model.
4. Bastion. Non-volatile pyrolysis boilers with a water circuit, operating on all types of fuel. The power range is from 12 to 50 kW. They have cast iron heat exchangers, high-quality construction and low cost.
5. Wattek Pyrotek 36. Czech volatile single-circuit boilers with power from 26 to 42 kW. They have a copper heat exchanger and are equipped with automation. The efficiency reaches 90%. Autonomous burning up to 10 hours.
6. Viessman. German equipment equipped with an automatic control system. Power range from 25 to 80 kW. The fuel used is wood. The efficiency is 88%.
7. Dakon. Gas generating pyrolysis plants with a capacity of 18 to 40 kW. Dacon boilers run on wood and wood waste. Efficiency - up to 85%.
8. Bourgeois-K. Russian boilers with a capacity of 10 to 32 kW. The efficiency is 85%. Industrial pyrolysis boilers with a capacity above 200 kW are also manufactured.
9. Teplodar 42. Russian pyrolysis coal boilers. They have a wide range for private houses, cottages, office buildings and industry.
10. Fortan. Pyrolysis equipment for the processing of various types of waste. They are distinguished by environmentally friendly work during disposal, they process household, rubber, industrial and medical waste with high quality.
11. Sime. Italian equipment with a capacity of 22.5 to 38.7 kW. They have a cast iron heat exchanger and high efficiency.

Among Russian manufacturers, one can single out the products of LLC Klimov Pyrolysis Equipment Plant, 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 heating medium on the return pipe should be monitored so that it does not get sharp cooling. It is recommended to keep it at least 60 ° C.

This is done by mixing in the return water with hot water from the supply line. Correct strapping is of great importance.

Strapping scheme. Photo source: artosfera.ru

Before starting work, the system must be filled with water. After that, you need to adjust the mode of air supply to the combustion chamber of pyrolysis gases to ensure the required operating mode.

The quality of combustion of gases can also be determined indirectly - to evaluate the smoke coming out of the chimney: if it does not have a pungent smell and a dark shade, then the fuel burns correctly.

If, during operation, heavy pyrolysis resin flows out of the boiler, this indicates a low temperature in the furnace, an incorrectly selected chimney section or the need to clean it.

The problem can also arise in a homemade boiler. At the first time after installation, the boiler is tested and must be under constant supervision. Fuel loading should be about two thirds of the volume of the furnace. Once the test has been passed, it can be operated at full capacity.

Content

1. Diagram and device of the pyrolysis combustion boiler
2. The principle of operation of the pyrolysis heating device
3. Advantages and disadvantages of pyrolysis boilers
4. Installation and assembly of pyrolysis type boilers

Introduction

Every owner of a private house, when choosing a solid fuel heating boiler, undoubtedly wants to make the best choice. One of the main criteria that all buyers pay attention to, without exception, is economy. Among all the variety of devices on the Russian market, there is one type that uses a special method of burning it - long-burning pyrolysis boilers. Let's try to figure out how such a boiler works and how it works, and also consider its main pros and cons.

Diagram and device of the pyrolysis combustion boiler

The essence of pyrolysis can be explained using the example of a long burning boiler on wood. Under the influence of high temperatures in the firebox (about 450 degrees Celsius), wood decomposes into a solid and gaseous component. Subsequently, each of these components is burned separately. Heating devices of this type are also called gas-generating devices, and the method itself is called the dry distillation method. Thanks to this technology, better efficiency and less firewood consumption is achieved than when using the classical method, but the price of the device increases significantly.

The main types of fuel for long-burning boilers using the pyrolysis method are: wood, coal, peat, sawdust, pellets. The main fuel requirements are as follows:

• limited dimensions

  The dimensions of the bookmark should not be larger than the dimensions of the firebox. In the case of using wood logs, their length is usually limited to 40cm and diameter 20cm.

• low humidity

  To obtain high efficiency, as well as to extend the life of the boiler, it is necessary that the moisture content of the fuel used in it does not exceed 20%.

Photo 1: System for automatic feeding of pellets into the pyrolysis boiler

By the type of fuel used, all types of pyrolysis boilers can be divided into:

• wood burning

  Structurally, designed to work with wood. It is on this fuel that they give the best efficiency. The most famous model of this type is

• coal

  The main fuel is brown coal or coke.

• pellet

  Such boilers operate on pellets - pressed fuel pellets from wood processing waste.

• combined (or universal)

  They can operate on any of the above listed types of fuel. The efficiency of universal boilers for long burning is usually worse than that of those designed for a certain type of fuel.

Photo 2: Arrangement of a wood-fired pyrolysis boiler

Depending on how many contours the structure contains, they are distinguished:

• single-circuit

  The hot water boiler contains one circuit that is used to heat the house.

• double-circuit

  The design provides for an additional circuit to provide hot water supply.

Below is a diagram of a pyrolysis boiler, looking at which we will disassemble its device. A household heating boiler for long burning, usually consists of the following main elements:

Photo 3: Diagram of the pyrolysis boiler design

• Control device

  The automatic boiler control unit is designed to set different operating modes of the boiler. This device allows you to control various parameters of the heater.

• Housing

  The outer frame is made of steel and coated with a special heat-resistant and wear-resistant paint. The use of special paints in heating boilers is dictated by their operating conditions and temperature regime.

• Thermal insulation

  To reduce the heat loss of the pyrolysis boiler, it is thermally insulated. Mullite-silica slabs, asbestos, diatomite, and lime are used as materials for thermal insulation.

• Boiler anti-boil device

  This device allows you to keep the boiler temperature within the required range. Boiling the boiler is very dangerous and can lead to the failure of the boiler, and in some cases to an explosion.

• Heat exchanger

  The heat exchanger is a cast iron or steel container filled with a heat carrier. The upper and lower parts of it are equipped with valves for connecting the supply and return lines of the heating system. During combustion, the coolant inside the heat exchanger heats up and circulates through the heating system.

• Loading chamber

  The loading chamber (gasifying or combustion) is a compartment into which solid fuel is loaded. After loading and igniting the fuel, the primary air supply is reduced. The combustion process slows down and the fuel starts to smolder slowly, releasing pyrolysis gas. The temperature at which this procedure takes place is approximately 450C. The resulting gaseous mixture is pumped into the next compartment, called the combustion chamber.

• The combustion chamber

  The combustion chamber burns a mixture of wood gas and secondary air. This mixture is supplied forcibly from the gasification section. The combustion process takes place at a temperature of 1100C.

• Supply line connection

  The supply pipe is used to supply hot water from the boiler to the heating system.

• Grate

  The grate is a cast iron or steel grate located between the loading and combustion chambers. Gasification of solid fuel takes place on it, and pyrolysis gas is also injected through the holes in it into the combustion chamber located below.

• Chimney connection

  The chimney is a channel for the removal of combustion gases. The length and cross-section of the chimney must depend on the boiler output.

• Chimney fan

  Since most of them use top blowing, it is necessary to use forced draft with a fan or exhaust fan.

• Primary air valve

  Primary air is intended for preheating the fuel and starting the pyrolysis process.

• Secondary air valve

  Secondary air is necessary for the afterburning of pyrolysis gases in the combustion chamber.

• Return line connection

  Through the return pipe, the heat carrier from the heating system is returned back to the heater.

Back to the table of contents

The principle of operation of the pyrolysis heating device

So how does a pyrolysis boiler work? Let's take a step-by-step diagram of its operation using the example of a coal-fired pyrolysis boiler:

Stage 1:

Solid fuel is loaded into the furnace, in our case coal. The boiler ignites and the door to the combustion chamber is tightly closed. Since the supply of primary air is limited, the process of smoldering and the release of pyrolysis gas begins. The burning time can be controlled by adjusting the primary air supply.

Photo 4: How a coal fired pyrolysis boiler works

Stage 2:

A mixture of pyrolysis gas and primary air is forced into the combustion chamber through openings in the grate. Secondary air is also supplied there to ensure the intensity of combustion. A mixture of pyrolysis gas and secondary air is burned at high temperatures. The resulting heat energy heats the heating medium inside the heat exchanger.

Photo 5: How the pyrolysis gas afterburner system works

Stage 3:

Through the gas duct, by means of forced draft with the help of a smoke exhauster, the gaseous combustion products are removed into the atmosphere. It should be especially noted that the exhaust gases formed as a result of pyrolysis combustion contain a minimum amount of harmful impurities. Most of the flue gases are water vapor and carbon dioxide.

As you can see, the principle of operation of a pyrolysis boiler is somewhat more complicated than the traditional one. That is why their cost is usually 2 times higher. Before deciding which boiler to buy pyrolysis or classic, let's look at the pros and cons of pyrolysis boilers.

Back to the table of contents

Advantages and disadvantages of pyrolysis boilers

The use of pyrolysis technology has both advantages and disadvantages. The main advantages of pyrolysis-type long-burning boilers are:

• Burning duration

• Increased efficiency

  When using pyrolysis combustion, solid fuel burns out much better. To obtain the same amount of heat using pyrolysis, less fuel is required than with traditional combustion.

• High efficiency

  The efficiency when using pyrolysis is much higher. The range of efficiency values \u200b\u200bfor pyrolysis boilers is 85-92%.

• Sustainability

  In the composition of gases at the outlet of the pyrolysis type boiler, there are almost no harmful impurities. The majority of the exhaust gases are water vapor and carbon dioxide.

• Adjustability

  The gas generation process is easily adjustable. Therefore, most often pyrolysis boilers are automatic. Adjusting the intensity of combustion allows you to adapt to the needs of the heating system.

Photo 6: Automatic household gas generator boiler

In addition to the advantages we have considered, they also have a number of disadvantages. Let's dwell on them in more detail:

• Volatility

  The peculiarity of the pyrolysis boiler design is that the supply of primary and secondary air, as well as the draft, is carried out forcibly using fans that require electricity. However, there are also non-volatile natural-draft models, but they are quite rare.

• Requires low moisture content

  The gas generation method is very whimsical to the moisture content of solid fuels. The drier the fuel used, the better. Recommended humidity no more than 20%

• Full download required

  With a small amount of fuel, pyrolysis boilers start to burn unstably. Therefore, it is recommended not to load less than 30-50% of the manufacturer's recommended rate.

• Complexity of automatic fuel supply

  For wood-fired pyrolysis boilers, it is difficult to organize an automatic fuel supply due to the large size of the logs. It is possible to make an automatic long-burning coal boiler only if the size of the coal fractions is uniform.

• High price

  The high cost of long-burning gas-generating boilers is one of their most significant disadvantages. Such a boiler can be purchased 1.5-2 times more expensive than devices of similar power, but using the traditional combustion method.

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TO solid fuel firing is an alternative to gas and electric heating devices. Gas generating or pyrolysis boilers for long burning with a water circuit are devices that allow you to burn not only solid fuel, but also fuel gases that are released during this process. This principle of energy use is good for the environment and saves fuel. There are also disadvantages - harsh operating conditions and high price. How to determine the golden mean and get the most benefit - in the material below.

Gas generator boiler

Long-burning gas generating or pyrolysis boilers with a water circuit are boilers that generate combustible gases themselves from the fuel that is placed in them. The water circuit is at the same time part of the heating system and the boiler safety system.

Pyrolysis as a physicochemical process

Combustion is a complex process that produces a lot of soot and gases. 30% of the total volume of emitted substances is carbon dioxide, the rest is carbon monoxide, nitrogen oxide, methyl alcohol, furan, acetic acid, benzene, acetone and a huge amount of other volatile substances. Everything, except CO 2, can be further oxidized, that is, burned again, while receiving a certain amount of thermal energy.

Pyrolysis is a two-stage process in which the production of fuel gases is first stimulated and then burned. To do this, the solid fuel is set on fire and allowed to work, then the oxygen supply is reduced, stimulating smoldering. Firewood smolders at a temperature of 200 - 800 degrees, coal and hydrocarbon materials smolder at temperatures up to 1300 - 1500 degrees. At the same time, gases are actively evolved, which under atmospheric conditions are little active or inert.

In the combustion chamber inside the boiler, temperatures are extremely high, these gases react with oxygen supplied from outside. At first, atmospheric air passes through special air ducts, warms up to the temperatures described above, and only after that it is mixed with fuel gases. Intensive afterburning of the gas mixture occurs. Outwardly, it looks like the combustion of natural gas supplied under high pressure, a powerful stable torch is formed. The heat generated is 4 to 10% of the total heat produced by the boiler.

How the boiler works

Long-burning pyrolysis or gas-generating boilers with a water circuit are a chamber equipped with special partitions and air ducts. The special design of the blower allows you to regulate the amount of oxygen supplied. In the upper part of the boiler, where the afterburning takes place, there are nozzles that divide the gas into small streams in order to reduce the combustion intensity. The grate is located higher than usual, it is installed so that the distance to the bottom is not less than ¼ of the total boiler height. This is to ensure that there is sufficient space for the evacuation of gases.

Fresh air, necessary for additional oxidation, is supplied from below, passes through a special air duct up to the combustion zone of gases, while being heated to operating temperature. In the upper part of the boiler there are special tubes with holes, which help to distribute gases evenly.

The entire circulation inside the boiler is provided by an electric turbine. Without it, under conditions of oxygen deficiency, combustion and additional oxidation are impossible. In the event of a power outage, it is necessary to open the gate to ensure natural draft, while the boiler continues to operate in the mode of a conventional solid fuel installation.

Video: pyrolysis boiler: myths and reality

Types of gas generating boilers

The principle of operation of all gas-fired boilers is the same, however, there are different design options:

• A boiler with a water jacket - its body consists of two layers of metal, between which water flows.
• Coil boilers are devices with an ineffective heat exchange system; low-power devices are produced.
• Volatile and non-volatile boilers. The pyrolysis process is only possible with forced circulation. Non-volatile gas-generating boilers are a myth; without electricity, this device can only work in the mode of a conventional solid fuel boiler.

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Advantages and disadvantages

The principle of pyrolysis, which is partially implemented in domestic gas-fired boilers, is used in industry for the disposal of various waste. Combustion and repeated additional oxidation of decomposition products is a way to reduce the amount of harmful emissions into the atmosphere. After fuel and gases are burned out in a gas generator or in a domestic boiler, only carbon dioxide and water vapor are released into the atmosphere.

The environmental benefits of such boilers are obvious, but in terms of efficiency and convenience, they are seriously inferior to, for example, long-burning boilers. It is not easy to accelerate the boiler to such parameters that pyrolysis is possible. This requires a high temperature and some time. Long-term pyrolysis boilers with a water circuit are stopped under the following conditions:

• drop in return water temperature;
• power outage;
• fuel of inadequate quality.

The pyrolysis process must be stopped immediately as soon as the circulation pump in the heating system stops. Without cooling, the boiler will simply explode. To stop the process, you need to open the gate, ensuring natural draft and removal of combustible gases. The blower should be open to a minimum. After the temperature has dropped, the boiler should be extinguished. If the volume of the heating system is not large and natural circulation is possible, the boiler can continue to operate at 50% load with the gate open.

Operating conditions

Pyrolysis boilers are capable of operating within a strictly defined temperature range. The system of this device is closed, therefore it must be precisely tuned. Obviously, it is not possible to constantly monitor the quality of fuel, its moisture content, and measure the mass of firewood at the time of loading. There is always a danger of overheating or, conversely, insufficient temperature.

The first problem can be eliminated with a water circuit. The boiler body acts as a heat exchanger: its walls are double, water circulates between them. Sometimes an additional coil is added to one of the boiler walls, which serves as an emergency cooling system and at the same time as a DHW circuit.

If the temperature is lower than the operating temperature, the pyrolysis process stops or does not start at all. At the same time, the boiler operates in the mode of a conventional solid fuel device. For this reason, the return temperature should be at least 60 degrees Celsius, and at 40 degrees, pyrolysis stops in all types of boilers. For this reason, an additional jumper is installed in the heating system - a bypass, which serves as a small circuit and allows the boiler to enter the pyrolysis mode.

MUST SEE EVERYONE!

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 in 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 the circulation pump and control devices are powered from electricity, but also the 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. Moreover, 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 pipe.

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 heating boilers are subdivided, is the type of fuel on which they work. 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 fuel combustion rate. 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 have recently been 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;
• chips;
• wood waste.

Hard coal or coke is 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 vast 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-generating 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 by 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, firewood 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 in the process of burning 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 the 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;
• the emission of harmful substances from pyrolysis boilers into the atmosphere is minimized, therefore, a pyrolysis boiler is an almost environmentally friendly source of heat;
• solid fuel boilers for pyrolysis combustion needs 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 a more complex design, because pyrolysis boilers are 30-35% heavier than conventional ones, since more metal is required for their manufacture, other "disadvantages" are irrelevant.

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 decreases and it becomes necessary to clean it.

Most pyrolysis units are electronically controlled.

Therefore, 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, so 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, are distinguished by the possibility of economical use of 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.

Location of the chamber in which the content is burned.

Most of the boilers are arranged 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 position 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 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 inefficient and irrational.

It will be difficult to recoup the high cost of the boiler. Therefore, the conclusion is obvious: the best material for combustion in pyrolysis boilers is 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 is dry wood with a moisture level of no more than 10-15%.

Today there are two main types of pyrolysis units that differ in design.

Forced air boilers.

In the first variant 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. Between the chambers, a special nozzle is installed, 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 by means of an installed fan, and enters partly into the firebox 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 blown by the fan enters mainly the upper main combustion chamber.



Due to the influx 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 in the process of heating 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, in the usual mechanical way or using automation, is proportionally divided into primary and main - secondary.

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

Smoldering firewood occurs from below, and the temperature released at the same time 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 with the maximum amount of heat released takes place in 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 \u200b\u200bthe 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 streams, 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, releasing 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 main chamber damper 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 inefficient 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. Various types of solid fuels can be used as fuel: from ordinary firewood to peat.

Proceeding from this, the boiler can be heated 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

1. 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.
2. Secondly, in order to maintain gas combustion, less secondary air is required than for burning wood, respectively, the combustion temperature will be higher, and with it the efficiency.
3. 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 released into the 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 needs 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 performance of a conventional solid fuel boiler. Obviously, the choice should be based on taking into account the individual characteristics of the heating system and the preferences of the owners.

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 quickly burns out 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 long-burning boilers, choose long-burning pyrolysis boilers with a water circuit.
• The coolant contacts 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 \u200b\u200bthe room and the degree of insulation. Approximately, you need to take 1 kW per 10 m2, while throwing a few kW, taking into account also the functions of the boiler as a boiler. So, if you have an area of \u200b\u200b80 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 quality fuel, 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 operation of the equipment, a certain range of fuel combustion temperature must be observed. This range is from 2000 to 8000 C.

The device must be tuned fairly accurately. To prevent emergencies at high temperatures, the unit's water circuit is used.

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.

If 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 furnace. 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, an additional bridge (bypass) is provided in the water circuit. The bypass is regulated 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 this can cause unpleasant consequences due to the high content of polymers and rubber in them.

Pyrolysis boilers are produced only in single-circuit and cannot be used for heating water. But, in the absence of natural gas, to create comfortable conditions in the building, this type of equipment is the best solution to the problem.

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 a rough 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 installing 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 another 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-conducting 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 - in 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.

1. The fuel inlet for homemade models is usually placed slightly higher than that of conventional solid fuel boilers.
2. 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.
3. For the manufacture of the limiter, you can use a pipe with a diameter of about 70 mm, a little longer than the device body.
4. A steel disc should be welded to the bottom of the stopper, creating a gap of about 40 mm with the pipe walls.
5. To install the restrictor, a corresponding hole must be made in the boiler lid.
6. The firewood inlet should be rectangular. This opening is closed with a door with a special steel plate that ensures a secure fit.
7. A hole must be made below for ash removal.
8. 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.
9. If, after the first start-up of the boiler, there is no carbon monoxide in the combustion products, then the structure is made accurately and functions correctly. In the future, you should regularly monitor the condition of the boiler welds and promptly clean it from the accumulated ash and soot.

Pyrolysis boiler from a gas cylinder

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 pyrolysis boiler from a gas cylinder with your own hands 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 acts as 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 for the pipe is made at the top. A loading door is cut from the side, which opens access to the firebox, where the fuel is placed.

The chimney should have different diameters to ensure the best draft. This trick will allow you to maintain 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 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.