Homemade heating boilers. How to make a heating boiler for a private house with your own hands DIY homemade boilers

Firewood is the most accessible, environmentally friendly and inexpensive type of fuel that has been used by humans since the beginning of time. The main advantages of wood-burning heating systems are energy independence, high efficiency with comparative ease of use. Despite the variety of gas and electric heating systems, wood-fired heating boilers have not lost their relevance now and are popular among most Russians. Wood-burning installations have another indisputable advantage - this is the simplicity of the design, which allows you to easily make a boiler for heating a house with your own hands. This is what will be discussed in this publication.

Design and principle of operation

Before proceeding directly to the instructions for creating a homemade solid fuel boiler, you need to understand how a wood-burning boiler installation works.

In the simplest wood-burning boiler with a heat exchanger, during the combustion of firewood, thermal energy is released, which heats the walls of the heat exchanger (water jacket) and the heat carrier itself. Combustion products passing through the soot collector are removed through the chimney. The draft is regulated by the position of the ash pan door and the chimney damper. The heat exchanger is connected to the heating system, which includes main pipes, radiators and an expansion tank. The circulation of the coolant can be carried out both naturally and forcibly by including a circulation pump in the heating system (CO).

The simplicity of such a boiler is "compensated" by the low efficiency of this design: most of the heat energy literally "flies into the pipe" along with the combustion products. But the main disadvantage is the low level of automation: all operations for loading fuel into the furnace and maintaining the combustion process must be done manually. Therefore, wood-fired boilers for pyrolysis combustion are considered the most popular. Making such a heating boiler with your own hands will not be difficult for any home craftsman.

Homemade pyrolysis boiler

The fuel is loaded into the fuel chamber in full immediately. Under conditions of oxygen deficiency in the gasification chamber, the fuel smolders with the release of pyrolysis gas. Smoldering occurs with the release of heat, which is spent on heating the coolant in the heat exchanger. The pyrolysis gas, together with the combustion products, enters the afterburner, which in this design also serves as an ash pan. Due to the fact that the access of oxygen to the afterburner is not limited, the combustion of the combustible gas occurs with the release of a high temperature, as a result of which the efficiency of the device is significantly increased. All the work of the pyrolysis boiler can be roughly divided into four stages:

1. At the first stage, wood is dried and pyrolysis gas is released from the fuel.
2. The second stage of the operation of this installation is the combustion of a mixture of secondary air with combustible gas in the afterburner.
3. The third stage is the passage of incandescent gases through the heat exchanger.
4. Removal of the combustion products that gave the "lion's share" of thermal energy.

A self-made solid fuel boiler should be equipped with controls and automation that make it possible to simplify and secure its maintenance as much as possible. The operation of the unit can be controlled by changing the position of the ashtray (ash pan) door and the chimney damper. The automatics of a homemade wood boiler are usually represented by a pressure gauge, an air vent and an explosive valve (security group). Quite often, domestic "Kulibins" equip their heating installations: with a temperature sensor, thanks to which the primary air fan is switched on and off, as well as pressure sensors in the water circuit.

Let's digress a little, as we want to inform you that we have compiled a rating of solid fuel boilers by fashion. You can learn more from the following materials:

Preparation of materials and tools

Before answering the question of how to make a solid fuel boiler yourself, you should decide on the design of the device. The simplest option is a classic combustion boiler. In other words, "Burzhuyka" with a water heat exchanger. A more efficient boiler unit is considered to be a classical combustion installation, divided into two chambers: in the lower one, the process of burning firewood will take place; at the top - heating water for the needs of the owner.

After choosing the optimal design of a wood-burning heating installation, you should decide on the size of the device. Ideally, the next step in creating a heating boiler with your own hands is drawings that can be ordered from a specialized organization.

Important! We do not knowingly publish drawings of a wood-fired heating installation. All information is given for informational purposes only.

Material selection

If you own the art of welding and the possibility of plasma cutting, then to create a wood-burning boiler you need to use sheet metal with a thickness of 3-5 mm. The boiler blanks are cut out of the metal, which are welded according to the scheme.

The simplest case is a piece of thick-walled steel pipe, 4-6 mm thick; length 800 - 1000 mm; with a diameter of 300 mm. The grates and supports can be made of reinforcement, rolled steel or channel bars. You will also need metal to create the bottom of the boiler (50 mm thick), lid (3-5 mm thick), air diffuser (10 mm thick), hinges and valves. In addition, you need to stock up on a metal pipe with a diameter of 60 mm. The pipe height must be 50 mm higher than the body height. A steel pipe with a diameter of 100 mm is required for the chimney.

To assemble the simplest wood-burning boiler, you will need a tool, namely:

• Welding machine.
• Powerful angle grinder ("Bulgarian").
• Drill and drill bits for metal.

The build process can be divided into several stages:

1. A circle should be cut out of 50 mm metal, corresponding to the diameter of the case. After welding, it will be the bottom of the wood boiler.
2. A circle should be cut out of the metal, which is 20 mm smaller in diameter than the body. Then, in the middle of the circle, you need to drill a hole with a diameter of 20 mm. A piece of air distribution pipe (d 60mm) should be welded to the hole. On the opposite side of the circle, impeller-shaped plates are welded on.
3. A circle is cut out of sheet metal with a thickness of 3-5 mm, which will serve as the upper cover of the boiler. In the middle of the circle, a hole should be made in which the air distribution pipe will move freely (d 60 mm).
4. A chimney is welded to the upper part of the body.

Important! For correct flue gas discharge, it is necessary that the chimney section 50 cm long is strictly horizontal from the boiler.

Fuel is loaded into such a boiler through the top cover. It is necessary to load the space of the fuel chamber as tightly as possible so that there are no gaps. Ignition is done through the top. As soon as the fuel has ignited, the air diffuser and the top cover should be installed in their original places. As it burns out, the air distributor disc will lower, building up pressure in the lower chamber. Due to this, the amount of oxygen in the fuel chamber will be reduced, the combustion process will turn into slow smoldering. The whole structure of this wood-burning boiler is as follows

Tip: this scheme of a homemade boiler plant requires a chimney. If there is no possibility of arranging a smoke exhaust duct, and there is a need for a heating device, then you can create the simplest induction heating boiler with your own hands, if you have a welding inverter at hand.

From copper wire with a cross section of 2 mm, a winding of 50-100 turns should be made, the core of which will be a steel pipe. Under the influence of magnetic induction, the section of the pipe (core) will heat up along which the coolant will move.

What is the cheapest fuel for a boiler? Of course, this is gas. Therefore, all owners of houses and cottages for the most part prefer the installation of gas heating boilers - cheap and cheerful. However, gasification has not been carried out in all areas of our vast Motherland. Therefore, in some regions, people are forced to heat their houses the old fashioned way - using wood, coal, pellets, etc. If you are interested in the cost of a solid fuel boiler, then the figure will unpleasantly surprise you - it starts from 50,000 rubles and above. We will offer you to create a solid fuel boiler with your own hands. You will need some equipment, and, of course, some useful wizard skills.

Materials and tools

So, inspect your arsenal in the garage and in the country and find the following.

Materials (edit):

• Plates for creating a firebox- made of heat-resistant steel 4-5mm.
• Steel sheets 2-3 mm- from them the body of the device will be made.
• Steel tubes- they will be needed to create a heat exchanger. Their diameter and length will be calculated based on your specific situation.
• Metal pipes- a chimney will be built from them in the future.
• Grate and cooking stove.
• Ash pan door and combustion chambers.
• Heat-resistant brick.
• Cement mortar.

Instruments

• Welder- it is better to also stock up on it with a bundle of electrodes.
• Gas cutting machine.
• Pipe bender.
• Bulgarian with disks.
• Roulette, level, marker.

Types of solid fuel boilers

Today, 4 types of solid fuel boilers are available, which differ not only in design, but also in efficiency, circuit complexity and maintenance. First, let's get acquainted with the general scheme of work of each of these 4 types.

Classic solid fuel boiler

Classic solid fuel boiler

They are equipped with a cast iron or steel heat exchanger: the efficiency of such boilers is about 85%. The principle of operation is simple: firewood (any other solid fuel) is loaded into the firebox. During their combustion, a tank with water heats up, which later enters the heating system and hot water supply. And the smoke that forms during combustion is removed through the chimney.

Pellet boiler

Pellet boiler

The efficiency of such a boiler is already slightly higher and amounts to 90%. The advantage of this type of boilers is the automation of work, since the fuel is supplied as it burns out by the bunker + auger system. However, this advantage also became a disadvantage: such a design is very difficult to manufacture.

Pyrolysis boilers

Pyrolysis boiler

The efficiency of such boilers is already about 92%. It increases due to the fact that the entire combustion process is divided into 2 stages: at the first stage, the fuel itself burns out with a lack of oxygen. As a result of this process, pyrolysis gases are released, which enter another chamber. There the combustion of these gases takes place and also the release of heat as a result. This is what contributes to an increase in the efficiency of the boiler, as well as to the achievement of savings in fuel consumption.

Long burning boilers

Long burning boiler

As you probably understood from the name, the main feature of this equipment is the long burning process. This means that you need to add fuel less frequently than for other types of boilers (once every 2-3 days). The point is in the design features of boilers: the combustion process is divided into several stages. At first, a large volume of fuel slowly smolders in the furnace with a minimum of oxygen supply. As a result of this smoldering, gas is formed, which is then fed into the combustion chamber and ignites there due to the active supply of oxygen. Burning firewood in such boilers starts from the top. This helps generate more heat.

Solid fuel boiler operation diagram

How to design a device without knowing its principle of operation and basic details? Of course, this is not possible. Therefore, first we find out how the whole process of fuel combustion, water heating, etc. takes place directly. It is worth noting that hereinafter we will analyze the scheme of operation of a classic solid fuel boiler.

The combustion chamber- it is with her that the boiler begins to work. You open the chamber door and put a portion of the fuel inside. An operating burner starts the process of fuel combustion.

The volume of the combustion chamber can be determined in several ways. 1. Calculate it according to your conditions (formulas are provided in abundance on the Internet). 2. Take a ready-made calculation (the volume of the combustion chamber, depending on the heating area, boiler power, features of the heating system, piping schemes, etc.)

Hot gas evacuation chamber- is part of the combustion chamber. It is through it that hot gases are transported to the upper part of the boiler to the chimney for further removal to the outside.

Heat exchanger- the heart of any heating boiler. It is through it that the coolant passes and heats up, and then enters the system. But everything is in order. After the hot gases formed in the combustion process go to the "outlet", along the way they pass through the heat exchanger, transferring heat to it. And he then transfers this heat to the water flowing through him.

Further, the hot coolant simply squeezes cold water, thus circulating throughout the entire heating system. He returns back to the boiler already cold. In fact, the entire operation of the device is based on the law of thermodynamics.

All the above-described assemblies and parts are enclosed in a boiler body, which is made of strong sheet steel with a thickness of 4-6 mm.

What affects the efficiency of a homemade solid fuel boiler?

Of course, I want the future self-made design not to pump up and function with maximum heat transfer for it. And something is quite within your power to do, but first, let's figure out what efficiency primarily depends on. There are 2 fundamental factors:

1. Features of the design of the heat exchanger

The larger the area of ​​the heat exchanger plates, the faster the coolant will heat up, passing through it and up to a higher temperature.

1. Duration of fuel burning and combustion efficiency

The fuel must burn completely, giving off gas. If the boiler design is incomplete or incorrectly calculated, the firewood (coal, pellets, etc.) will not burn completely. And this, in turn, will lead to the fact that the water will be heated slowly and to low temperatures. To prevent this from happening, all stages of the design and creation of the boiler must be approached as responsibly as possible.

The steel for the boiler drum must be 5 mm thick or more. The best choice would be a heat-resistant steel grade, but it certainly costs more. The thickness should also be such that the boiler does not heat up very much and does not work to heat the room in the literal sense of the word with its body. Therefore, the average wall thickness of the boiler drum must be 8 mm.

It is better to take pipes for the internal piping of the boiler with a wall thickness of 3-4 mm and a diameter of 50 mm.

The diameter of the pipes through which the coolant moves must change. In order for the liquid to circulate faster, it is necessary to reduce the diameter of the pipes on the path of hot water movement to the batteries (from 50 mm to 25 mm). And expand them on the way back, when cold water flows to the boiler.

Heat exchanger options for a homemade boiler

As we have already said, the efficiency of the boiler depends on the design and quality of the heat exchanger. Of course, you want it to work efficiently, but for this you need to choose a scheme for its manufacture. As you yourself understand, there are quite a few such options, however, we will consider only 2 of the most effective in our opinion. Let's get started.

Option number 1

Heat exchanger for solid fuel boiler

1 - rectangular pipes 60x40 mm. 2 - round pipes 50 mm. 3 - round pipes 40 mm. 4 - heated water outlet pipe 50x50 mm. 5 - cold liquid return pipe 50x50 mm.

Dimensions: a= 36 cm; b= 40 cm; v= 300 mm; G= 80 cm.

It will be a horizontal type heat exchanger, for the manufacture of which we need pipes of 2 sizes - rectangular 60x40 mm and round, where d = 40 and 50 mm.

Rectangular pipes are used to create a frame, and only then round ones are welded to them. In addition, rectangular pipes will be much more convenient to attach to each other, compared to round ones.

Study the diagram and prepare the required number of pipes of the required length.

It is optimal if the wall thickness of the pipes for the heat exchanger is 3 mm, and preferably all 5 mm.

• To assemble the structure into a single whole, you will have to cut holes for round pipes in rectangular pipes with a grinder. We do it as follows: on the side of the heat exchanger, which will be closer to the furnace door, cut 4 holes with a diameter of 50 mm in the vertical pipes. This can be done with both a cutter and a welder.
• From the other end, we also need to prepare 4 holes with d = 50 mm (in the edge 60 mm wide) in the vertical racks and 4 holes with d = 40 mm - in the edge with a width of 40 mm.
• Next, we cut out holes for connecting pipes that are responsible for the supply and removal of the coolant.
• Are all holes ready? Then we assemble the entire structure. It will be more convenient to place it by placing one end on the floor so that the pipes are perpendicular to the end and the floor surface. We weld all the pipes, not forgetting the pipes for the fluid supply.
• Do not forget to weld the ends of rectangular pipes with small iron pieces.
• We check the heat exchanger for leaks: pour water through one hole, close the second and leave it like that for a while. If no leaks are found, then the heat exchanger is ready for further operation.

Option number 2

Heat exchanger for a solid fuel boiler: the second option

1 and 3 - pipes for supplying cold liquid to the heat exchanger and removing the hot heat carrier, respectively, diameter 50 mm; 2 and 4 - rectangular pipe 60x40 mm; 5 - pipes d = 40 mm; 6 - steel sheets with a thickness of 3-5 mm; 7 - Reinforcing cross member made of rectangular pipe.

As you have already noticed, in this case, round pipes are replaced with sheet metal 3-5 mm thick. The principle of operation is absolutely identical to option No. 1. The holes are made with angle grinder and sanded with it.

Step-by-step instructions for making a solid fuel brick boiler

Solid fuel brick boiler: general diagram

In general, a brick solid fuel boiler is considered one of the most efficient and simple boilers in design. Using his example, we will analyze the topic of self-execution.

First, we will make sure in a little more detail that the brick cauldron is really that good.

• Simple and reliable design
• Relatively uncomplicated manufacturing process- since the main building material is brick, there is not so much welding work for the whole process.
• Multitasking- such a boiler will look like a stove in appearance. This means that it can be adapted for some similar oven tasks, namely, for cooking. In addition, he will be able to heat the room in which he is located.

So, let's get down to the workflow. Please note that we have already manufactured the heat exchanger (we hope you have chosen a suitable scheme for you).

Step 1... Such a boiler is stationary. That is, you must choose in advance the room in which it will be located, as well as the place. At this point, pour the foundation specifically for the boiler (concrete slab + cement mortar + reinforcement frame + brickwork). Lay roofing material on top of the prepared foundation - it will serve as an insulating gasket.

Step 2... With the help of refractory bricks, we form the lower part of our future boiler: the bottom of the furnace chamber and an ash pan with a door. Do not forget that they are separated by a grate.

Step 3... A heat exchanger is mounted on the lined base so that it goes up to the point of intake of the hot coolant. Remember the main rule: there should be a minimum gap of 10-20 mm between the brick and the walls of the heat exchanger. The pipes for supplying and removing the coolant must protrude beyond the walls of the housing.

Installation of a heat exchanger for a solid fuel brick boiler

Position the boiler as follows: all points on the top of the heat exchanger must be below the hot water outlet mark. The difference in height between the lowest point of the TO (upper right corner of the front of the boiler) and the upper point of the liquid outlet should be 10-15 mm.

This will help to avoid the formation of an air blockage in the heating system during the further operation of the boiler.

Step 4... We make a door for loading fuel in the front of the topic. In the back, you need to leave room for the chimney hole.

Step 5... The hob (if you still want to use the device for this purpose) or a regular sheet of metal is placed on top of the combustion chamber. In turn, a layer of bricks is placed on top of the slab or sheet, or the vault of the chamber is laid out.

Step 6... Now we get down to the chimney. It is usually located at the top or side of the boiler relative to the combustion chamber. The chimney itself is made either from an iron pipe or from a brick (a passage is formed). If you want to use a pipe, see step 4 - this is where you left the hole.

Step 7... Chimney flap line: it is installed in the chimney body.

Step 8... Now let the solution set and dry completely. Only then connect all boiler pipes.

Horizontal solid fuel boiler from a barrel

Diagram of a horizontal solid fuel boiler

Another alternative to the brick boiler is the steel boiler.

He heats the water due to the "water" jacket: one pipe is located in another pipe and is washed by a coolant.

The main plus of a horizontal boiler is a long combustion process. Due to the horizontal design, a large amount of fuel can be loaded, which will burn slowly, releasing thermal energy. This will allow you not to visit the boiler room so often for additional refueling. Agree, this is very convenient.

So, step by step we make a boiler from an iron barrel.

• Select a piece of steel pipe so that its diameter of the piece is 16-24 cm less than the diameter of your barrel (8-12 cm should remain on the sides between the boilers). The length of the segment should be equal to the length of the main body.
• Place the lower part of the combustion chamber, ash pan and grate inside the selected pipe section. The grate can be welded from dense steel plates. It is better to lay the lower part of the firebox with refractory bricks.
• Now we cork a large container by welding steel circles from both ends. Next, we weld the legs on which the boiler will stand.
• In the front end, in the area of ​​the inner pipe of the angle grinder, we cut out the future doors of the firebox and ash pan.
• In the rear end, that is, on the opposite side, a hole is cut out for the chimney and the flange is fixed by welding for its subsequent installation.
• At the bottom of the large barrel, you need to make a passage for the pipe that feeds cold liquid to the heat exchanger. Likewise at the rear for the outlet pipe.
• To reduce heat loss, tie the body of the future equipment with heat-insulating material.
• Connect the resulting structure and check it for leaks, and then carry out a test run.

Vertical solid fuel boiler from a barrel

Vertical solid fuel boiler

Now let's look at the process of creating a vertical device in order.

• An iron flap made of 3-5 mm sheet metal is welded into the central part of the iron barrel. It will separate the top, where the liquid heats up, and the bottom, where the fuel burns.

Do not forget to make a hole in the valve before that: the inner pipe is connected to it (by welding). It goes right through from the combustion chamber to the top of the device.

• In the upper part, weld a round sheet with a pre-cut cut for the installation of the internal chimney and a flange for the installation of the external chimney.
• Weld on the legs for the subsequent stable positioning of the boiler.
• Cut a hole for mounting the inlet pipe at the bottom of the barrel and weld it on. On the cap of the barrel itself, perform the same operations for installing the branch pipe. Check the resulting structure for leaks.
• At the bottom of the barrel, prepare holes for the future doors of the ash pan and firebox.
• Place the combustion chamber, ash pan and grate at the bottom of the barrel. If there is no grate, then you can use fire-resistant bricks.
• Do not forget about the thermal insulation, which must be wrapped around the boiler drum.
• Connect the boiler to the heating and water supply system and carry out a test start.

How to increase the efficiency of a homemade solid fuel boiler

Of course, to be sure - a home-made device will not be able to compare with a factory model. The latter is designed and designed for economical fuel consumption, convenient operation and maintenance. And, of course, high efficiency. You yourself understand that at home you will not be able to recreate a completely similar device. However, it is in our power to slightly improve the quality of water heating with a solid fuel boiler, made by ourselves. And here are some helpful tips:

• Make the flue pipe longer... Ideally, if the distance between the combustion chamber and the highest point of the chimney was 7 meters or more. This is possible if you mount the device in the basement.
• Installation of a spare heat shield. In its design, an additional winding pipe must be provided for the removal of combustion gases. This shield should be located directly above the boiler.
• Installation of a backup water tank. It will be heated by the heat of the combustion products. So you will have a supply of water that can be used for any of your needs.
• Installation of a circulation pump. This is a proven method that increases system efficiency by at least 20%.

Manufacturing a solid fuel boiler: video

In more detail, you can see the whole process of creating a solid fuel boiler with your own hands in the following story:

Conclusion

Remember to start working on this project if you have the skills of a welding master. Otherwise, all welding work will need to be ordered from a specialist, or you shouldn't take on the project at all. However, if you are confident in your abilities, then a homemade unit will allow you to heat your home and save a decent amount of money on buying a factory model.

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“A boiler is truly a stove in a barrel of water” ... and the efficiency of such a unit will be at best 10%, or even 3-5%. Certainly no, and a solid fuel boiler is not a stove at all, and a solid fuel stove is not a hot water boiler. The fact is that the combustion process of solid fuel, in contrast to gas or flammable liquids, will certainly be extended in space and time. Gas or oil can be completely burned right away in a small gap from the nozzle to the burner diffuser, but wood-coal cannot. Therefore, the requirements for the design of a solid fuel heating boiler are different than for a heating stove; it is simply impossible to put a heating circuit water heater in it in continuous circulation. Why this is, and how a continuous heating boiler should be arranged, and this article is intended to clarify.

Your own heating boiler in a private house or apartment becomes a necessity. Gas and liquid fuels are steadily increasing in price, and instead, inexpensive alternative fuels appear on the market, for example. from crop waste - straw, husks, husks. This is only from the point of view of the owners of the house, not to mention the fact that the transition to individual heating will allow getting rid of energy losses in the highways of the CHP and power transmission lines, and they are by no means small, up to 30%

You cannot make a gas boiler yourself, if only because no one will give permission to operate it. It is forbidden to use individual boilers on liquid fuel for heating residential premises due to their high fire and explosion hazard during decentralized use. But a solid fuel boiler can be made with your own hands and formalized, just like a heating stove. This is perhaps the only thing that they have in principle in common.

Features of solid fuel

Solid fuel does not burn very quickly, and not all components that carry thermal energy burn in its visible flame. For complete afterburning of flue gases, a high, but quite definite temperature is required, otherwise conditions will arise for the occurrence of endothermic reactions (for example, nitrogen oxidation), the products of which will carry the fuel energy into the chimney.

Why isn't the boiler stove?

The furnace is a cyclic device. So much fuel is loaded into its furnace at once so that its energy is enough until the next heating. The excess combustion energy of the fuel load is partially used to maintain the optimum temperature for afterburning in the gas path of the furnace (its convective system), and is partially absorbed by the furnace body. As the load burns out, the ratio of these parts of the fuel energy changes, and a powerful heat flow circulates inside the furnace, several times more powerful than the current needs for it for heating.

The body of the furnace is, therefore, a heat accumulator: the main heating of the room occurs due to its cooling after heating. Therefore, it is impossible to take away the heat circulating in the furnace, this will in one way or another disrupt its internal heat balance, and the efficiency will drop sharply. It is possible, and even then not in every place of the convection system, to take up to 5% to feed the hot water storage tank. Also, the furnace does not need an operative adjustment of its thermal power; it is enough to load fuel based on the required hourly average for the time between fires.

A water boiler, no matter what fuel, is a continuous-action device. The coolant circulates in the system all the time, otherwise it will not heat up, and the boiler must at any given moment give exactly as much heat as it went out due to heat loss. That is, the fuel must either be loaded into the boiler periodically, or the thermal power must be quickly regulated within a fairly wide range.

The second point is flue gases. They should come up to the heat exchanger, firstly, as hot as possible in order to ensure high efficiency. Secondly, they must be completely burnt out, otherwise the energy of the fuel will settle on the register with soot, which will also need to be cleaned.

Finally, if the stove heats up around itself, then the boiler as a heat source and its consumers are spaced apart. The boiler requires a separate room (boiler room or furnace): due to the high concentration of heat in the boiler, its fire hazard is much higher than that of the stove.

Note: an individual boiler room of a residential building must have a volume of at least 8 cubic meters. m, ceiling not less than 2.2 m high, opening window not less than 0.7 sq. m, a constant (without dampers) inflow of fresh air, a smoke channel separate from other communications and a fire interchange from the rest of the rooms.

From this it follows, firstly, boiler furnace requirements:

• It must ensure fast and complete combustion of fuel without a complex convection system. This can be achieved only in a firebox made of materials with the lowest possible thermal conductivity, because a high concentration of heat is required for fast afterburning of gases.
• The firebox itself and the parts of the structure associated with it in terms of heat should have the lowest possible heat capacity: all the heat that went into heating them will remain in the boiler room.

These requirements are initially contradictory: materials that do not conduct heat well, as a rule, accumulate it well. Therefore, an ordinary stove furnace for a boiler will not work; you need some kind of special one.

Heat exchange register

The heat exchanger is the most important unit of the heating boiler, it basically determines its efficiency. By the design of the heat exchanger, the entire boiler is called. In household heating boilers, heat exchangers are used - water jackets and tubular, horizontal or vertical.

A boiler with a water jacket is the same "stove in a barrel", a heat exchange register in the form of a tank surrounds the firebox in it. A jacketed boiler can be quite economical on one condition: if the combustion in the furnace is flameless. A fiery solid fuel furnace certainly requires the afterburning of exhaust gases, and in contact with the jacket, their temperature immediately drops below the value required for this. The result is an efficiency of up to 15% and enhanced deposition of soot, and even acid condensate.

Horizontal registers, generally speaking, are always inclined: their hot end (supply) must be raised above the cold (return), otherwise the coolant will reverse, and the failure of forced circulation will immediately lead to a serious accident. In vertical registers, the pipes are located vertically or with a slight slope to the side. And there, and there, the pipes are arranged in rows in a checkerboard pattern so that the gases are better "entangled" in them.

With regard to the directions of movement of hot gases and coolant, pipe registers are divided into:

1. Flowing - gases pass generally perpendicular to the coolant current. Most often, such a scheme is used in horizontal industrial boilers of high power for the sake of their lower height, which makes the installation cheaper. In everyday life, the situation turns out to be the opposite: in order for the register to properly catch the heat, it has to be made stretched up above the ceiling.
2. Counterflow - gases and coolant move along one line towards each other. This arrangement provides the most efficient heat transfer and the highest efficiency.
3. Stream - gases and coolant move in parallel in the same direction. It is rarely used in boilers for special purposes, because At the same time, the efficiency is poor, and the wear of the equipment is high.

Further, heat exchangers are made of fire tube and water tube. In a fire tube, the flue gas tubes pass through the water tank. Fire-tube registers work stably, and vertical ones give good efficiency even in a flow-through scheme, because an internal water circulation is installed in the tank.

However, if we calculate the temperature gradient optimal for transferring heat from gas to water based on the ratio of their density and heat capacity, then it turns out to be about 250 degrees. And in order to push this heat flow through the wall of a steel pipe of 4 mm (it cannot be less, it will burn out very quickly) without noticeable losses on the thermal conductivity of the metal, you need about 200 more degrees. As a result, the inner surface of the fire tube should be heated up to 500-600 degrees; 50-150 degrees - operational reserve for fuel water cut, etc.

Because of this, the service life of the flue pipes is limited, especially in large boilers. In addition, the efficiency of a fire-tube boiler is low, it is determined by the ratio of the temperatures entering the register of hot gases and leaving the chimney. It is impossible to let the gases cool below 450-500 degrees in a fire-tube boiler, and the temperature in an ordinary furnace does not exceed 1100-1200 degrees. According to Carnot's formula, it turns out that the efficiency above 63% cannot be obtained, and even the efficiency of the furnace is not more than 80%, so that in total it turns out 50%, which is very bad.

In small household boilers, these features are less pronounced, because with a decrease in the size of the boiler, the ratio of the register surface to the volume of flue gases in it increases, this is the so-called. square-cube law. In modern pyrolysis boilers, the temperature in the combustion chamber reaches 1600 degrees, the efficiency of their furnace is at 100%, and the registers of branded boilers are made only thin-walled from heat-resistant special steel for 5 years or more. In them, gases can be allowed to cool down to 180-250 degrees, and the overall efficiency reaches 85-86%

Note: cast iron is generally unsuitable for smoke tubes, it cracks.

In water-tube registers, the coolant flows through pipes placed in a fire chamber, where hot gases are supplied. Now the temperature gradients and the square-cube law act the other way around: at 1000 degrees in the chamber, the outer surface of the pipes will be heated to only 400 degrees, and the inner one - to the temperature of the coolant. As a result, pipes made of ordinary steel serve for a long time and the boiler efficiency is about 80%

But horizontal flow-through water-tube boilers are prone to the so-called. "Booze". The water in the lower pipes turns out to be much hotter than in the upper ones. It is pushed into the supply in the first place, the pressure drops, and the colder upper pipes "spit out" the water. "Buhtenie" not only gives noise, warmth and comfort as much as a neighbor is a drunkard and a brawler, but is also fraught with a rush in the system due to water hammer.

Vertical water-tube boilers are not coiled, but if a water-tube boiler is designed for a house, the register must be located at the lowering of the chimney, in that section of it where hot gases go from top to bottom. In a flow-type water-tube boiler with the same direction of movement of gases and a coolant, the efficiency drops sharply and soot is intensively deposited on the pipes near the supply, and it is generally unacceptable to make a return flow above the supply.

About the capacity of the heat exchanger

The ratio of the capacities of the heat exchanger and the entire cooling system is not taken arbitrarily. The rate of heat transfer from gases to water is not infinite; the water in the register must have time to absorb heat before it leaves the system. On the other hand, the heated outer surface of the register gives off heat to the air, and it is wasted in the boiler room.

Too small register is prone to boiling and requires precise fast adjustment of the furnace power, which is unattainable in solid fuel boilers. The large-volume register takes a long time to warm up and with poor external boiler insulation or its absence it loses a lot of heat, and the air in the boiler room can warm up above the permissible fire safety and technical specifications for the boiler.

The value of the capacity of the heat exchanger of solid fuel boilers ranges from 5-25% of the capacity of the system. This must be taken into account when choosing a boiler. For example, for heating, according to the calculation, there were only 30 sections of radiators (batteries), 15 liters each. With water in the pipes and an expansion tank, the total capacity of the system will be about 470 liters. The boiler register capacity must be within 23.5-117.5 liters.

Note: there is a rule - the greater the calorific value of solid fuel, the greater the relative capacity of the boiler register should be. Therefore, if the boiler is coal, the register capacity must be taken closer to the upper value, and for the wood boiler - to the lower one. For boilers of slow combustion, this rule is not true, the capacity of their registers is calculated based on the highest boiler efficiency.

What to make a heat exchanger from?

Cast iron as a material for the boiler register does not meet modern requirements:

• Low thermal conductivity of cast iron leads to low boiler efficiency, because it is impossible to cool the exhaust gases below 450-500 degrees, as much heat will not pass through the cast iron into the water.
• The large heat capacity of cast iron is also its minus: the boiler must quickly give off heat to the system before it evaporates somewhere else.
• Cast iron heat exchangers do not fit into modern requirements for weight and dimensions.

For example, let's take the M-140 section from the old Soviet cast-iron battery. Its surface area is 0.254 sq. m. For heating 80 sq. m. of living space you need a heat exchange surface in the boiler of about 3 sq. m, i.e. 12 sections. Have you seen a 12-cell battery? Imagine what the boiler should be, in which it will fit. And the load from it on the floor will definitely exceed the limit according to SNiP, and a separate foundation will have to be made for the boiler. In general, 1-2 cast-iron sections will go to the heat exchanger feeding the DHW storage tank, but for a heating boiler the question of the cast-iron register can be considered closed.

Registers of modern factory boilers are made of heat-resistant and heat-resistant special steel, but production conditions are required for their manufacture. The usual structural steel remains, but it corrodes very quickly at 400 and higher degrees, therefore, fire tube boilers made of steel must be chosen for purchase or developed very carefully.

In addition, steel conducts heat well. On the one hand, this is not bad, you can expect to get a good efficiency by simple means. On the other hand, the return flow should not be allowed to cool below 65 degrees, otherwise acid condensate will fall out of the flue gases on the register in the boiler, which can go through the pipes within an hour. You can exclude the possibility of its precipitation in 2 ways:

• With a boiler output of up to 12 kW, a bypass valve between the boiler flow and return is sufficient.
• With a higher power and / or heated area of ​​more than 160 sq. m, an elevator unit is also needed, and the boiler must operate in the mode of overheating of water under pressure.

The bypass valve is controlled either electrically from a temperature sensor, or non-volatile: from a bimetallic plate with a draft, from wax melting in a special container, etc. As soon as the temperature in the return flow drops below 70-75 degrees, it lets hot water from the supply into it.

The elevator assembly, or simply the elevator (see fig.) Acts the other way around: the water in the boiler is heated to 110-120 degrees under a pressure of up to 6 atm, which excludes boiling. For this, the combustion temperature of the fuel is increased, which increases the efficiency and excludes condensation. And before being fed into the system, hot water is diluted with a return flow.

In either case, forced water circulation is required. Nevertheless, it is quite possible to create a steel boiler with thermosyphon circulation, which does not require power supply for the circulation pump. Some constructions will be discussed below.

Circulation and boiler

Thermosiphon (gravitational) water circulation does not allow heating a room with an area of ​​more than 50-60 sq. m. The point is not only that it is difficult for water to squeeze through the developed system of pipes and radiators: if the drain valve is opened with a full expansion tank, water will pour out in a strong stream. The fact is that the energy for pushing water through the pipes is taken from the fuel, and the efficiency of converting heat into motion in a thermosyphon system is scanty. Therefore, the efficiency of the boiler as a whole falls.

But the circulation pump needs electricity (50-200 W), which can be lost. UPS (uninterruptible power supply) for 12-24 hours of autonomous operation is very expensive, so a properly designed boiler is expected to have forced circulation, and in the event of a power outage, it should switch to thermosyphon mode without outside interference, when the heating is barely warm, but still warms up.

How is the boiler installed?

The requirement for the minimum own heat capacity of the boiler directly results in its small weight in comparison with the furnace and the weight load from it per unit of floor area. As a rule, it does not exceed the minimum permissible according to SNiP for flooring 250 kg / sq. m. Therefore, the installation of the boiler is permissible without a foundation and even parsing the flooring, incl. and on the upper floors.

Place the boiler on a flat, stable surface. If the floor is playing, it will still have to be disassembled at the boiler installation site to a concrete screed with a sideways extension of at least 150 mm. The base for the boiler is covered with asbestos or basalt cardboard 4-6 mm thick, and a sheet of roofing iron 1.5-2 mm thick is placed on it. Further, if the flooring was disassembled, the bottom of the boiler is lined with cement-sand mortar to the floor level.

Around the boiler protruding above the floor, thermal insulation is made, the same as under the bottom: asbestos or basalt cardboard, and on it is iron. Removal of insulation to the sides of the boiler from 150 mm, and in front of the firebox door not less than 300 mm. If the boiler allows additional fuel loading before the previous portion burns out, then the removal in front of the firebox is needed from 600 mm. Under the boiler, which is placed directly on the floor, only heat insulation, covered with a steel sheet, is placed. Removal - as in the previous case.

For a solid fuel boiler, a separate boiler room is required... Requirements for it are given above. In addition, almost all solid fuel boilers do not allow power adjustment over a wide range, so they need a full-fledged piping - a set of additional equipment that ensures efficient and trouble-free operation. We will talk about it further, but in general the boiler piping is a separate big topic. Here we will only mention the immutable rules:

1. The piping is installed in a counterflow to the water, from the return to the supply.
2. At the end of the installation, its correctness and quality of the connections are checked visually according to the scheme.
3. The installation of the heating system in the house is started only after the boiler is piped.
4. Before loading fuel and, if required, power supply, the entire system is filled with cold water and all joints are monitored for leaks during the day. In this case, water is water, and not some other coolant.
5. If there are no leaks, or after they have been eliminated, the boiler is started on water, continuously monitoring the temperature and pressure in the system.
6. Upon reaching the nominal temperature, the pressure is controlled for 15 minutes, it should not change by more than 0.2 bar, this process is called pressure testing.
7. After pressure testing, the boiler is extinguished, the system is allowed to cool completely.
8. Drain the water, fill in the standard coolant.
9. Once again, the joints are monitored for a day. If everything is in order, the boiler is started. No - they eliminate leaks, and again daily control before starting.

Choosing a boiler

Now we know enough to choose a boiler based on the intended type of fuel and its purpose. Let's get started.

Wood burning

The calorific value of firewood is low, with the best ones - less than 5000 kcal / kg. Firewood burns rather quickly, releasing a large volume of volatile components requiring afterburning. Therefore, it is better not to rely on high efficiency on wood, but they can be found almost everywhere.

Wood burning in the house

A home wood-burning boiler can only be burning for a long time, otherwise it beats it in all respects. Industrial structures, e.g. the well-known KVR, cost from 50,000 rubles, which is still cheaper than building a furnace, do not require power supply and allow power adjustment for heating in the off-season. As a rule, they work both on coal and on any solid fuel, except for sawdust, but on coal the fuel consumption will be much higher: heat transfer from one load is 60-72 hours, and for specialized coal - up to 20 days.

However, a long-burning wood-burning boiler can be useful in places where there is no regular coal delivery and qualified heating service. It costs one and a half times cheaper than coal, its jacket design is very reliable and allows you to build a thermosyphon heating system with an area of ​​up to 100 sq. m. In combination with the smoldering fuel, a thin layer and a rather large volume of the jacket, boiling of water is excluded, so the piping is the same as for titanium. Connecting a boiler for long burning on wood is also no more difficult than titanium, and can be done independently by an unqualified owner.

About brick boilers

Diagram of the boiler "Blago"

Brick is a friend of a stove and an enemy of a boiler due to the fact that it gives a structure a large thermal inertia and weight. Perhaps the only brick boiler in which the brick is in place is Belyaev's pyrolysis "Blago", diagram in fig. And then, its role here is completely different: the lining of the combustion chamber is made of fireclay bricks. Horizontal water-tube heat exchanger; the problem of coiling is solved by the fact that the register pipes are single, flat, elongated in height.

Belyaev's boiler is really omnivorous, and there are 2 separate bunkers for loading different types of fuel without stopping the boiler. On anthracite "Blago" can work for several days, on sawdust - up to a day.

Unfortunately, the Belyaev boiler is quite expensive, because of the fireclay lining it is poorly transportable and, like all pyrolysis boilers, requires complex and expensive piping. Its power is regulated within small limits by the bypass of flue gases, therefore, it will show good efficiency on average per season only in places with prolonged severe frosts.

About boilers in the oven

The boiler in the stove, which is now being talked and written about so much, is a water-tube heat exchanger walled up in the stove masonry, see fig. below. The idea is this: after firing, the stove should give off heat more to the register than to the surrounding air. Let's say right away: reports of an efficiency of 80-90% are not only dubious, but simply fantastic. The best brick oven itself has an efficiency of no more than 75%, and its outer surface area will be no less than 10-12 square meters. m. The surface area of ​​the register is hardly more than 5 square meters. m. In total, less than half of the heat accumulated by the stove will go into the water, and the overall efficiency will be below 40%

The next moment is furnace with a register immediately loses its property... In no case should you drown it out of season with an empty register. The TCR (temperature coefficient of expansion) of the metal is much greater than that of a brick, and the heat exchanger swollen from overheating will break the furnace before our eyes. Heat seams will not help business, the register is not a sheet or beam, but a volumetric structure, and it is bursting in all directions at once.

There are other nuances here, but the general conclusion is unambiguous: a stove is a stove, and a boiler is a boiler. And the fruit of their violent unnatural union, the stove boiler will not be viable.

Boiler piping

Boilers excluding boiling water (long-burning jacket, titanium) cannot be made for a power of more than 15-20 kW and are extended in height. Therefore, they always provide heating of their area in thermosyphon mode, although a circulation pump, of course, will not interfere. Their piping, in addition to the expansion tank, includes only an air drain valve at the highest point of the supply pipeline and a drain valve at the lowest point of the return.

The piping of solid fuel boilers of other types should provide a set of functions, which is better understood in Fig. on right:

1. safety group: an air drain valve, a general pressure gauge and a breakthrough valve to release steam when boiling;
2. emergency cooling storage tank;
3. its float valve, the same as in the toilet;
4. thermal valve for starting emergency cooling with its sensor;
5. MAG-block - drain valve, emergency drain valve and pressure gauge, assembled in one housing and connected to a diaphragm expansion tank;
6. forced circulation unit with a check valve, a circulation pump and a three-way bypass valve electrically controlled by temperature;
7. intercooler - emergency cooling radiator.

Pos. 2-4 and 7 make up the power shedding group. As already mentioned, solid fuel boilers are regulated in power within small limits, and with a sudden warming, the entire system may overheat unacceptably, up to a gust. Then the thermal valve 4 lets tap water into the intercooler, and it cools the supply to normal.

Note: the owner's money for fuel and water at the same time quietly and peacefully flows into the sewer. Therefore, solid fuel boilers are not suitable for places with mild winters and a protracted off-season.

The forced circulation group in the normal mode bypasses part of the supply to the return line so that its temperature does not fall below 65 degrees, see above. When the power supply is cut off, the thermal valve slams. The heating radiators receive as much water as they will pass in the thermosyphon mode, if only it would be possible to live in the rooms. But the thermal valve of the intercooler opens completely (it is kept closed under voltage), and the excess heat again carries the owner's money into the drain.

Note: if water disappears along with the electricity, the boiler needs to be extinguished urgently. When water flows out of tank 2, the system will boil.

Boilers with built-in overheating protection are 10-12% more expensive than conventional ones, but this is more than pays off by simplifying the piping and increasing the reliability of the boiler: excess overheated water is poured here into an open expansion tank of large capacity, see fig., From where it cools down and flows into return line. The system, in addition to the circulation pump 7, is non-volatile and goes into thermosyphon mode smoothly, but in case of sudden warming, the fuel is still wasted, and the expansion tank must be installed in the attic.

As for the pyrolysis boilers, the typical scheme of their piping is provided for information only. All the same, its professional installation will cost only a small fraction of the cost of the components. For reference: a heat accumulator alone for a 20 kW boiler costs about $ 5000.

Note: membrane expansion tanks, unlike open ones, are installed on the return flow at its lowest point.

Chimneys for boilers

Chimneys of solid fuel boilers are calculated in general in the same way as stove ones. General principle: a chimney that is too narrow will not give the required draft. This is especially dangerous for the boiler, because it is heated continuously and the waste can go at night. Too wide a chimney leads to a "whistle": cold air descends through it into the firebox, chilling the stove or register.

The boiler chimney must meet the following requirements: the distance from the ridge of the roof and between different chimneys is at least 1.5 mm, the extension above the ridge is also at least 1.5 m. Safe access to the chimney must be provided on the roof at any time of the year. At each break in the chimney outside the boiler room, there must be a clean door, each passage of the pipe through the ceilings must be thermally insulated. The upper end of the pipe must be equipped with an aerodynamic cap, which is mandatory for the boiler chimney, in contrast to the stove. Also, a condensate collector is required for the boiler chimney.

In general, the calculation of the chimney for a boiler is somewhat simpler than for a stove, because the boiler chimney is not so tortuous, the heat exchanger is considered simply for a lattice barrier. Therefore, it is possible to build generalized graphs for different design cases, for example. for a chimney with a horizontal section (hog) of 2 m and a condensate collector with a depth of 1.5 m, see fig.

Based on such graphs, after accurate calculation using local data, it is possible to estimate whether there was a gross error. If the calculated point is somewhere around its generalized curve, the calculation is correct. In extreme cases, you will have to build up or cut the pipe by 0.3-0.5 m.

Note: if, say, for a pipe with a height of 12 m, there is no curve for a power less than 9 kW, this does not mean that a 9 kW boiler cannot be operated with a shorter pipe. It's just that for pipes lower than a generalized calculation, it is no longer possible, and you need to calculate exactly according to local data.

Video: an example of the construction of a solid fuel boiler of mine type

conclusions

The depletion of energy resources and the rise in fuel prices have radically changed the approach to the design of domestic heating boilers. Now they, like industrial ones, require high efficiency, low thermal inertia and the ability to quickly regulate power over a wide range.

In our time, heating boilers, according to the basic principles laid down in them, finally parted with stoves and were divided into groups for different climatic conditions. In particular, the considered solid fuel boilers are suitable for areas with harsh climates and prolonged severe frosts... For places with a different climate, heating devices of other types will be preferable.

Despite the huge number of heating devices on the market, a long-burning solid fuel boiler is a popular option.

Homemade TT long burning boiler

This unit can be used as the main source of heating in remote areas where gasification and electrification are not provided. Reliable, efficient and economical, it is an excellent solution for heating a country house, a cottage in the city or a summer cottage.

Unlike a conventional boiler, where the main heat comes from the flame itself, the TT long-burning boiler works on a completely different principle. This article will discuss how to properly make a solid fuel boiler for long burning with your own hands, and the drawings and installation diagram will help you not to make a mistake and do everything technologically correct!

In conventional solid fuel units, one tab is enough for 6-7 hours of burning. Accordingly, if the next portion of resources is not added to the firebox, the temperature in the room will immediately begin to decrease. This is due to the fact that the main heat circulates through the room according to the principle of free gas movement. Heated from the flame, the air rises up and out.

The thermal resource of a long-burning boiler is enough for about 1-2 days from one firewood bookmark. Some models can keep warm for up to 7 days.

How is this economy and efficiency achieved?

A long-burning boiler differs from a conventional boiler, TT by the presence of two combustion chambers at once. In the first, the fuel itself burns out in a standard way, and in the second - the gases released during this.

An important role in this process is played by the timely supply of oxygen, which is provided by the ventilator.

This principle has been implemented relatively recently. In 2000, the Lithuanian company Stropuva presented this technology for the first time, which has gained respect and popularity as a result.

Today it is the cheapest and most practical way to heat a country house, where gasification is not provided and there are power outages.

Such units operate on the principle of burning top fuel. As standard in all stoves, the firebox is located at the bottom, which allows cold air to be taken from the floor, heated and raised.

The principle of operation of this boiler is somewhat like a pyrolysis one. The main heat is released here not from the combustion of solid fuel, but from the gases released as a result of this process.

The combustion process itself takes place in an enclosed space. Through a telescopic tube, the released gas enters the second chamber, where it is completely burned and mixed with cold air, which is pumped up by the fan.

This is a continuous process that continues until the fuel is completely burned out. The temperature during such combustion is reached very high - about 1200 degrees.

As mentioned above, this boiler has two chambers: the main one is large and the other is small. The fuel itself is put into the large chamber. Its volume can reach 500 cubic dm.

Any solid fuel can act as a resource for combustion: sawdust, coal, firewood, pallets.

A built-in fan provides constant air flow. The advantage of this method is that solid fuel is consumed extremely slowly.

This significantly increases the efficiency of such a heater. Why is wood burning so slowly compared to a standard stove?

The bottom line is that only the top layer burns out, since the air is blown in by the fan from above. Moreover, the fan adds air only after the top layer has completely burned out.

There are many models on the market today that work according to the same principle, but, depending on the dimensions, material of execution, additional options, have different efficiency and economy.

Universal TT boilers operate on absolutely any fuel, which will greatly simplify their operation for their owners. A more budgetary option is a wood-burning TT long-burning boiler. It runs exclusively on wood and you cannot put any other type of fuel into it.

Design feature

Any long-burning boiler is equipped with an impressive chamber where fuel is placed. The larger the chamber the boiler is equipped with, the more time the wood will burn.

Today you can find two technologies implemented in long-burning TT boilers, which successfully compete with each other. This is Buleryan's principle and Stropuv's method.

Due to the high price of Stropuv and the complexity of the construction, this method is not so popular in Russia. But according to the Buleryan method, folk craftsmen with great dedication design units for heating summer cottages and country houses.

A boiler according to the Buleryan method looks like this: a metal case, inside which there are two chambers. In the lower chamber, fuel is burned, and in the second, gas is burned coming through the tube from the first chamber.

The door for loading fuel is located in the upper part of the boiler body, since the entire lower part is reserved for a large resource tab.

In the upper part of the boiler there is a flue pipe, which is connected to the chimney. An ash chamber is built into the lower part, through which the boiler is cleaned.

One more nuance should be mentioned. In standard furnaces, the ash pan acts as a blower through which the air necessary for combustion is blown in. Here, the ash chamber is absolutely sealed, since air enters through the upper air chamber, which plays the role of a recuperator.

The oxygen supply to the boiler is regulated by a damper located at the top of the air chamber. As the wood burns out, the fuel gradually settles and the distributor is lowered. This ensures a continuous supply of oxygen.

When reloading fuel, just pull up, returning to distribute to its original position. By the position of this lever, you can easily determine how much fuel is left in the boiler and when to start the next load.

Separately, it should be said about the environmental friendliness of this heating option. Due to the complete combustion of fuel and gases, carbon dioxide is practically not emitted into the atmosphere.

The main elements of the boiler TT:

1. Combustion chamber. This is the main element of any boiler and furnace, where fuel is directly burned.
2. Gas combustion chamber. Hot gases from smoldering wood come here.
3. Ashtray - ash gathers here. This unit must be regularly cleaned to keep the boiler in good technical condition.
4. A chimney is a unit through which combustion products are removed to the outside.

All these units are enclosed in a steel case, which is made of sheet metal with a thickness of 5-6 mm.

Advantages and disadvantages

Due to its large dimensions, the complexity of the design scheme, it is rational to use such a unit for heating a large cottage. But for a small summer cottage, this option is not suitable, since it will not justify the economy.

pros

• high efficiency (about 95%);
• autonomy of the heating system;
• profitability;
• reliability and durability;
• high efficiency;
• fuel availability;
• environmentally friendly home heating option;
• versatility of fuel (coal, firewood, sawdust, pellets).

Minuses

• bulkiness of the design;
• a special room must be equipped for the device;
• the complexity of the design and installation;
• the need for constant cleaning.

A long-burning boiler does not have to be bought ready-made, because its price is several times higher than conventional stoves. Such a structure can be made independently if you have at least a little experience in construction and repair.

A homemade design, in comparison with a factory analog, has a number of advantages:

• low cost;
• the ability to make the boiler universal for any type of fuel;
• the possibility of improving the design and adding power.

The only difficulty is the cylindrical shape of the boiler. It is very difficult to give such a shape to metal without a rolling machine.

But there is a good solution. Empty propane cylinders or any suitable pipe diameter can be used. Choose pipes with a wall thickness of at least 5 mm.

For a village and a small summer cottage, you can fold a small brick oven and enjoy its effectiveness. But for a large cottage, this option will be less practical, since it will require a large supply of firewood for the winter. Caring for a conventional stove, in comparison with a long-burning boiler, is much more difficult, and large temperature drops in rooms far from the stove do not at all allow organizing a comfortable microclimate in the house.

If you do not have enough money to create a full-fledged heating system for a house, or the construction of such a system itself is impractical, it would be much wiser in this situation to make a solid fuel boiler for long burning with your own hands and not worry about its safety and aesthetics of appearance.

Any solid fuel is suitable for the operation of the TT boiler, the diagram of which we attach below:

• bituminous and brown coal;
• anthracite;
• firewood;
• wood pellets;
• briquettes;
• sawdust;
• shale with peat.

There are no special indications on the quality of fuel - any will do. But keep in mind that with a high moisture content of the fuel, the boiler will not give a high efficiency.

Security measures!

In order for such a boiler to really be an efficient and economical heating option, to serve a long service and not cause burns or accidents in the house, consider the main points of fire safety.

1. It is necessary to monitor the temperature in the system and prevent it from overheating.
2. Do not install a shut-off valve on the pipeline.
3. Do not keep flammable objects near the boiler.
4. It is necessary to monitor the ventilation in the room.
5. A separate room must be equipped for the boiler.

At the stage of preparatory work, think over the place where the boiler will be installed.

Ideally, of course, equip a separate boiler room, because the operation of a long-burning TT boiler is somewhat different from the usual brick wood-fired stove. And outwardly, this unit will not please the eye, and serve as a decoration for the house.

Considering that solid fuel still creates a certain amount of dirt, it is better to install a long-burning TT boiler in a non-residential area.

But if its power is small (does not exceed 30-35 kW), then you can simply separate (zone) the main room from the "boiler room" using a brick wall.

Be sure to provide a ventilation system in the room where this boiler will be used. Oxygen must be supplied from the street on an ongoing basis.

Do-it-yourself step-by-step instructions for creating a solid fuel boiler for long burning

The project of a solid fuel boiler is not an easy task and it will not be easy for a beginner to cope with it. Before starting construction, prepare drawings and sketches.

Also prepare the following tools:

1. Welding machine.
2. Tools for working with metal: pliers, grinding wheel.
3. Electric drill.
4. Building level and tape measure.
5. Marker.
6. Bulgarian.
7. Gloves and eye shield.

Attention! When performing work on the manufacture of a home-made TT boiler for long-term burning, you should be very careful and have at least basic practice with a welding machine. Always use protection when working with welding.

Of the materials you will need:

1. Empty gas bottle.
2. Sheet metal.
3. Asbestos cord.
4. Steel pipe with a cross section of 60 mm.
5. Metal hinges and handles.
6. Metal corner or blades.
7. Metal hood.
8. Basalt fiber for the passage of the chimney.

Before starting production, we suggest that you familiarize yourself with the video instructions on how to properly cut an empty gas cylinder, look carefully and do not neglect safety measures!

Step 1. Marking the case and making the case

Use a marker to mark out the propane cylinder according to the drawing.

We make a small rectangular hole under the ash pan door, through which the boiler will be cleaned.

On the top of the balloon (along the entire perimeter), draw a straight line to cut the top.

With the help of a grinder, cut off the top along the line.

Now in the center we make a marking for the hole through which the pipe will pass. The hole, accordingly, must be larger than the pipe diameter.

We cut a hole in the lid and weld on a metal ring that will tightly grip the pipe inserted into the cylinder.

We weld with a small sheet metal ring (4-5 mm) on the outside and inside the cylinder itself, on which the lid will be put on.

Step 2. Making the pipe

We take a metal pipe with a length of 80 to 100 cm. If you do not use a standard propane cylinder, but cook the body for the boiler yourself, keep in mind that the height of the pipe should be 20-25 cm higher. After all, the essence of the work is that as the fuel burns out, the pipe inside the body will go down.

We weld a metal circle - an air distributor to the pipe in the lower part of it.

We cut out fasteners from sheet metal, which we securely weld along the cut line of the cylinder, having previously laid an asbestos cord.

We fix the cut off top in such a way that it can be easily removed and put back. Make metal handles and weld them to the body for easy removal.

Step 3. Making a pipe to the chimney

We make markings on the cylinder in the upper part of it under the opening of the pipe.

We cut it out with a grinder and weld on the pipe to remove the combustion products.

Then a steel flue pipe is connected to this pipe.

Step 4. Making an ash pan

According to the previously made markings for the ash chamber, we cut out a hole with the help of a grinder.

Separately, we make a door from sheet metal, which will then need to be screwed onto the brackets to the boiler body.

For convenience, you can make a small loop of thick wire or reinforcing bar and screw it as a handle.

Step 5. Prepare the air supply system

Measure the inner diameter of the cylinder body. Now draw a circle on the sheet metal that is 5mm less than the inner diameter of the cylinder.

Use a grinder to cut out this circle.

We take a metal corner and cut it into 6 equal parts. Each piece measures ½ the diameter of the metal circle. For these purposes, an impeller with old blades is still well suited.

We weld metal circles in the same direction counterclockwise.

Step 6. Making a heat exchanger

We will make a heat exchanger designed according to the principle of a water circuit.

The size of this heat exchanger depends on your personal preference. The larger it is, the more firewood you can put in it, which means that your boiler will differ in the longer burning duration.

We cut out sheets from sheet metal 5-6 mm thick according to the diagram and weld them into a reliable case, inside which our gas cylinder will be located.

In the upper and lower parts of the body, we make pipes for connecting the supply and return lines.

In the central part, it is necessary to provide an opening through which fuel will be placed. We carry out the marking with a marker and cut it out with a grinder.

Step 7. General assembly and installation of the boiler

We attach the ash pan door to the firebox.

We mark on the heat exchanger body the place where access to the ash pan will be made and cut it out with a grinder. We also equip this opening with a door, which must close very tightly, blocking the access of oxygen to the body.

We insert the balloon inside the heat exchanger.

Using a welding machine, we weld the tank from above, as a result of which we obtain an absolutely sealed casing, inside which there is a round firebox.

The essence of the TT boiler for long-term combustion is in the limited air supply from above, the function of which is performed by the oxygen supply system.

Fuel (wood, coal, briquettes) should be loaded very tightly so that there is as little space as possible between the layers. If the firewood is different in size and it is not possible to complete them tightly, then between the layers you can fill it with chips, paper. The denser this solid fuel mixture is, the longer the wood will burn.

• we take out the air supply restrictor from the case;
• we load fuel through a special door. It is better to first sprinkle the fuel with a special liquid for ignition;
• put back the pipe limiter;
• we throw a lighted match inside the boiler;
• after making sure that the fuel is gradually starting to smolder, close the door tightly.

As the wood burns out, the pipe inside the cylinder will gradually lower. By its height, you can always find out how much firewood you currently have inside.

Step 8. Heating up the boiler

You can make such a simple boiler right outside in the warm season and test it outdoors by equipping it with a temporary chimney.

If the area of ​​the room exceeds 30-40 square meters, then you can weld two cylinders vertically, thus increasing the laying of firewood.

Step 9. Installing the boiler indoors

Take the boiler fire safety issue very seriously.

It is better to allocate a separate room for it or make a small fence from the tenants in order to exclude burns. Still, the boiler body is metal and, unlike a stone stove, there is a high probability of getting burned.

Install in a place where there is a possibility of chimney outlets. You can remove the chimney in two ways: through the roof or.

Keep in mind that you must have direct access to the boiler, so nothing should stand at a distance of 50 cm.

• Make a brick base for the boiler, laying solid bricks in 2 rows. Check the slope of the base with a building level.
• Observe the distance from the walls (regulated by SNiP). The distance from the furnace door to the wall must be at least 125 cm. The distance between the side parts and the back of the boiler and the wall must be at least 700 mm.
• If the walls in the house are made of wood or any other combustible material, it is necessary to protect the junction of the boiler to the ceilings with sheet metal or basalt. You can use ordinary brick as thermal insulation, which should be placed around the place where the boiler adjoins to the wall around the perimeter.

In the place where the chimney exits through the wall or roof, it is also necessary to provide adequate thermal insulation. For this, basalt fiber is suitable, which should be tightly laid between the chimney and the ceiling.

• Place the boiler on the prepared foundation and again check with a level level how level the appliance is. Please note that the gas outlet must be flush with the flue pipe. If the line is not horizontal, then the thrust may be broken during operation.

Step 10. We connect the boiler to the chimney.

Attention! It is imperative to lubricate the joints of all parts of the chimney with a sealant.

We connect the chimney pipe to the TT pipe of the boiler. The diameter of the chimney must be at least as large as the TT pipe of the boiler. If these parameters are not observed, then the throughput of the gas outlet will decrease.

As you can see, by doing everything with your own hands, you can get an excellent one, everything is not as difficult as it seemed at first glance! If you strictly followed the instructions, then you will quickly appreciate the high performance and economy of a solid fuel boiler for long burning, which is many times superior to its competitors with the principle of an open flame. This will maintain a comfortable indoor climate with minimal maintenance.

DIY solid fuel boiler - video instruction

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The use of natural resources in a house or apartment should be rational, which will help to avoid high utility bills. Therefore, many homeowners decide to acquire a heating system and think about how to make a boiler with their own hands. This type of work does not require special skills and abilities, you only need to follow the instructions that will be given below.

To install a solid fuel boiler with your own hands, you should take into account many factors, which include the room where the device will be installed, connecting it to other communications in the house, the type of fuel used, etc. It is also worth adhering to safety precautions and minimizing costs.

Heating boilers differ according to the following criteria:

• The material from which the boiler is made. The main options are cast iron and steel.
• The way the boiler is installed. The equipment can be hung on the wall or on the floor. Floor standing boilers are equipped with an expansion tank and a circulation pump. They need a separate boiler room. Wall-mounted boilers can be double-circuit and single-circuit. Double-circuit ones are used to heat the room and perform the function of a boiler; they are well suited for small private houses. Single-circuit boilers only work to heat the room or heat carrier.
• The need to use electricity. If forced circulation is carried out in the boiler, then the use of electricity is mandatory.
• The exhaust gases are removed either forcibly (by a fan) or in a natural way.

Depending on the source of energy, boilers are as follows:

• Gas - one of the most popular, especially those that are equipped with inflatable burners.
• The population has been using solid fuel boilers for a long time. The ideal use case is space heating and water heating in homes or at work. This type of boilers does not need electricity. Do-it-yourself wood-burning boiler is easier to make than all other types.
• Electric boilers have a built-in temperature control program. They are used as a backup option for a solid fuel boiler if firewood or coal is burnt out. You do not need to take special permission to install them. This is the ideal boiler for small spaces where there is no gas supply.
• Combined - allow you to use several types of fuel for heating at once. It can be gas, diesel or electricity.

Instruments

A DIY heating boiler is assembled using the following tools and materials:

• Asbestos cord to seal openings.
• Basalt cotton wool.
• For decorative cladding, you will need thin sheet steel.
• Flame tubes inside the heat exchanger, pipes for connecting the heating system.
• Sheets of 4mm structural steel for body assembly.
• Steel sheets - needed for the manufacture of a firebox. The best in this case is alloy steel.
• A branch pipe for connecting a smoke exhaust pipe.
• Steel strip.
• When designing a home-made solid fuel boiler made of structural steel (without alloy additives), you need to choose grades with a low carbon content.
• Door handles.
• Air intake pipe.

It is better to find out from a specialist in advance how to weld a heating boiler. When welding parts, it is better to use MR-3S or ANO-21 electrodes.

Drawings and diagrams

Before manufacturing, you need to carefully study the drawing of a solid fuel boiler.

Diy heating boiler heat exchanger

• Initially, the fuel compartment is designed. From the bottom to the firebox, a steel strip is horizontally welded, which should serve as the bottom of the water jacket.
• Sections of pipe are welded sideways to the walls of the firebox - these will be clips, they will help to give rigidity to the structure.
• The outer walls of the heat exchanger with pre-made holes for clips are welded to the bottom.
• Holes are cut above the firebox into which the flame pipes are welded.
• The pipes are welded to the heat exchanger to connect to the heating system circuits.

Step-by-step instruction

1. They make a body with side walls and framing.
2. Inside the body, the corners are welded onto which the grate is laid.
3. The grate is welded.
4. A firebox with a heat exchanger is welded to the corners on which the grate is located.
5. The doors of the firebox and ash pan are made of steel.
6. Weld the smoke exhaust pipe and the air duct.
7. The air duct is led into the boiler.
8. The door hinges and several brackets are welded to which the boiler casing will be attached.
9. The heat exchanger is covered with basalt wool, which is then pulled together with a cord.
10. The insulation will heat up, so its composition should categorically not contain toxic substances.
11. The automation controller is placed on top of the heat generator, and a fan is attached to the air duct.

If you make heating boilers with your own hands in order to use them as water heaters, then you can equip them with a second circuit.

Diy wood-fired boiler

Advantages and Disadvantages:

• inexpensive fuel;
• durable;
• do not require the use of electricity;
• low efficiency (except for pyrolysis, i.e., having 2 combustion chambers);
• automatic temperature control is not possible;
• heating the room takes a relatively long time;
• coal and firewood burn very quickly, constant monitoring is needed.

Electric boilers

Advantages and Disadvantages:

• high level of security because no open fire;
• convenient to use and install;
• compact and small in size;
• work silently;
• do not pollute the environment;
• a chimney and a separate boiler room are not needed;
• consume a lot of electricity;
• sometimes separate three-phase wiring is required,
• low efficiency.

Design and work features

Before making and installing a solid fuel boiler with your own hands, you need to clearly know its functions and principle of operation. The boiler consists of such parts (Figure 2)

• Boiler “boxes” - the maximum volume of burning elements must be less than the main one, since it is impossible to fill the entire available volume with fuel.
• The grate on which the fuel is placed.
• Heat exchanger. It is located above the firebox, but with its lower part "hugs" it from three sides, like a water jacket.
• Smoke exhaust pipes, which are attached to the top of the firebox. The horizontal heat pipes are located inside the heat exchanger itself.
• Ash pan and furnaces, which are hermetically closed, and air is supplied through a pipe in which a fan and a damper are installed.

Advantages and disadvantages

Gas-fired installations have the following advantages:

• convenient to use.
• as automated as possible.
• have high efficiency.
• reliable and easy to install.
• do not make noise.
• gas is a fairly affordable fuel.
• you need permission to install.
• in the room where the boiler is installed, a good ventilation system and access to fresh air are needed.
• there is always a risk of fuel leakage, which requires compliance with additional safety regulations.

Oil fired boilers:

• use diesel fuel as fuel.
• can be installed in rooms where gas is not supplied.
• the smoke outlet may be smaller than in other types of boilers.
• no installation permission needed.
• high efficiency.
• can be converted to gas.
• the cost of liquid fuel is rather big.
• the installation requires a separate boiler room.
• quite noisy compared to gas-fired boilers.
• diesel fuel strongly contaminates the furnace, impurities can cause corrosion of the equipment.