Heating boiler structures. Making a wood-fired boiler with your own hands. Horizontal solid fuel boiler from a barrel

The heating system of a private house is a complex pipe layout, the heart of which is the heating boiler. It heats up the coolant, which, under the action of the laws of physics or with the help of a circulation pump, moves through the pipes, enters the radiators, where it gives off its heat, and returns to the boiler when cooled down. And this process is repeated ad infinitum.

The modern market for boiler and heating equipment today offers a huge range of heating devices. Unfortunately, the price of many models is not affordable for everyone. Therefore, some consumers face the question of whether it is possible to make a heating boiler with their own hands, whether this homemade device work as efficiently as factory counterparts? You can make a boiler if you are a good welder and it will work just as well.

Types of heating boilers

First of all, you need to decide which boiler you need for your home. This will depend on the fuel used for the kindling. Hence the classification:

gas;
electrical;
solid fuel;
liquid fuel.

Electrical

Any of these boilers can be made by hand. The simplest one is electric. In fact, this is a tank in which a heating element is mounted. Two branch pipes still come out of the tank, connected to the supply and return circuits. There is no chimney or combustion chamber, everything is simple.

They are all good, but they have two drawbacks. First, electricity is the most expensive fuel. Second: when the voltage in the network drops (and this happens with an enviable constancy), the boiler stops working correctly. Its power decreases, the temperature of the coolant decreases.

Gas

Other types of constructions are more complex. And they are all almost similar to each other with some differences. As for the gas boiler, its installation will require a permit from the gas service.

Representatives of this organization may not accept such a heating unit for installation. First of all, they will require it to be pressure tested in their laboratory.

The presence of an act is a guarantee that you will still be given permission.

The operation of this option is associated with great difficulties. First, you will have to build a separate warehouse near the house, where the fuel will be stored. Everything in it must meet the requirements fire safety.

Secondly, a pipeline will have to be pulled from the warehouse to the boiler room. It must be insulated. Thirdly, a special burner is installed in a boiler of this type, which must be adjusted. This is not so easy in terms of customization.

Solid fuel

It is this type of boilers that are most often produced by home craftsmen with their own hands. For small summer cottages and cottages, this is the best option. Moreover, firewood is by far the cheapest type of fuel.

We will talk below about how to make a solid fuel boiler for heating a house.

What do you need?

As mentioned above, in order to weld a heating unit, you must be a good welder. An amateur level job will not work here.

Tools

What is required to carry out this work. From the tools you will need:

electric welding machine;
gas cutter;
bulgarian;
hammer;
roulette;
marker or chalk.

Materials

From materials:

seamless pipe with a diameter of 425 mm;
pipe with a diameter of 100 mm;
pipe with a diameter of 25 mm;
metal sheet 4 mm thick;
two squeegees with a diameter of 25 mm;
small loops;
corner 25 mm;
reinforcement with a diameter of 8 mm.

Project

Many beginners are looking for boiler drawings on the Internet or special technical literature and are already working on them. Basically, this is the right way.

The most important thing is to find drawings that indicate the dimensions of the heater.

Manufacturing of the case

So, first of all, the details of the future unit are being prepared. The body of the heater will be made from a 425 mm pipe. For a small heating boiler, a height of 1.0-1.2 m, taking into account the small diameter, is the best option.

We cut the pipe to these dimensions using a gas cutter. We process the edges with a grinder.

Now you need to cut two holes in the body: for the firebox and for the blower. They should be rectangular. For the firebox, a size of 20x10 cm is suitable, for a blower 20x3 cm. They are located one above the other, the furnace hole is higher.

The distance from the edge of the pipe to the blower is within 5-7 cm. The distance between the holes is 5 cm. The edges of the hole are processed with a grinder. The cut piece of the pipe wall for the firebox will be used as a door. Its edges are also stripped.

With the help of the cutter, two more holes are cut for the supply and return pipes with a diameter of 25 mm. The holes are located opposite each other. In this case, the return hole is cut out on the side of the boiler above the furnace: from the furnace hole at a distance of 15 cm.

At a distance of 5 cm only from the upper edge of the housing, a hole is cut out for supplying the coolant. Two squeegees can be welded to these holes right there.

Three pancakes are cut from a metal sheet: two with a diameter of 425 mm, one with a diameter of 412 mm. The latter will be installed inside the case, and since the pipe wall thickness is 6 mm, then 12 mm falls on the diameter, plus 1 mm for free entry.

In one of the pancakes with a diameter of 425 mm and in a circle of 412 mm, a hole with a diameter of slightly more than 100 mm is cut in the center. A chimney is being prepared from a 100 mm pipe. For this, a segment of 120-130 mm is cut. Pieces of 50 mm length are cut from a 25 mm pipe for the boiler legs. A grate for the ash pan is made from the reinforcement, the size of the inner diameter of the body is taken as a basis.

Assembling the heating unit

First of all, a chimney is welded to a 412 mm pancake. Then, inside the body, at a height of 30-35 cm from the combustion hole, temporary stops must be welded. This can be wire or reinforcement. A pancake with a chimney falls on top of them.

Main joints

And now the most important point is to weld the pancake and the boiler body together. It is imperative to boil the seam on both sides and it must be done with high quality. This joint is the interface between the firebox and the water tank.

The next step concerns the combustion chamber. On the reverse side of the chimney, a ready-made grill from fittings is inserted into the body.

Then, several pieces are cut out from a corner of 25 mm with a grinder, which are welded inside the boiler between the furnace hole and the blower. These will be the stops on which the lattice will rest.

Lower body

And the last thing. It is necessary to weld a 425 mm pancake to the lower edge of the body, weld to it four legs from a 25 mm pipe with a height of 5 cm. Further, the hinges are welded onto which the firebox door is hung.

Blower valve design

The design can be different: in the form of a conventional door, in the form of a gate (this is a damper that moves in the plane of the hole), in the form of a rotary damper with holes in the body. Finished products are sold, which are simply welded in place.

You can weld a one-piece structure with your own hands and attach it to the boiler. Of all the options offered, the simplest is either a door or a gate.

Testing and connecting to the system

The solid fuel boiler for heating the house is ready. Now you need to check it. To do this, a plug is screwed onto one of the sills, and water is poured into the second. If water does not pass through the welds, then the welding was carried out at a high level.

There is no need to fear that the heating unit will leak during operation. The finished unit is connected to the heating system country house... That is, the squeegees are connected to the supply and return pipes of the coolant.

The chimney is being installed. Please note that this element of the device must protrude vertically upwards. If it is not possible to arrange it this way, then there should be a minimum number of taps.

In an unheated attic, it will have to be insulated.

First kindling

It is very important to carry out the first firebox correctly. In this case, you cannot use a large amount of fuel. A small tab should heat the unit itself, especially for the chimney. With a sharp increase in temperature, condensation may form on its walls, which will turn into tar, narrowing the diameter. And this is a decrease in draft, which is responsible for the correct operation of the heater.

Clearance adjustment

During the heating process, the gap in the ashtray is adjusted. Need to find optimal sizewhich will provide combustion chamber the required amount of fresh air (oxygen).

Be sure to pay attention to the height of the bookmark. Its top edge should be 20 cm from the inner pancake. This distance will ensure optimal combustion of wood or coal. At the same time, smoke and carbon monoxide will be freely discharged through the chimney.

Principle of operation

Essentially, a traditional solid fuel boiler works like a conventional stove. There is also a firebox in which wood (coal, pellets and other solid fuels) burns. The released energy heats the coolant located in the container above the combustion chamber.

Heating of the coolant in this design is carried out both from the internal pancake and from the chimney, which penetrates the container with water through and through. At the same time, the boiler drum also heats up, which creates an accumulating effect that restrains rapid cooling when the unit is turned off.

The heated coolant rises up and goes out through the upper branch pipe into the supply circuit of the heating system. The cooled coolant enters the boiler through the lower branch pipe connected to the return circuit.

Other options

For heating the house, it can be made in the form of a cube from a metal sheet 4 mm thick. This is a more complex design, in which you will have to assemble a separate combustion chamber. It turns out that a combustion chamber is installed in the boiler body. And a coolant will circulate between the walls of the two structures. This is a more efficient option, but difficult to manufacture. There are many welds in it, which reduces the reliability and safety of operation.

"The boiler is really 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 immediately 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 heating furnace, it is impossible to simply put a water heater of the heating circuit 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 becoming more expensive, and instead, inexpensive alternative fuels appear on sale, 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 when used in decentralized manner. 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 endothermic reactions (for example, nitrogen oxidation), the products of which will carry the fuel energy into the pipe.

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 will be 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 stove 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 firing.

A water boiler, no matter what fuel, is a continuous 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 has gone outside due to heat loss. That is, the fuel must either be periodically loaded into the boiler, or the thermal power must be quickly adjusted 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 fuel energy 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 separated. 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 valves) inflow of fresh air, a smoke channel separate from other communications and a fire interchange from the rest of the rooms.

From here follow, firstly, requirements for the boiler furnace:

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 the gases to burn out quickly.
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 furnace 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 domestic 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 inclination to the side. And there, and there the pipes are arranged in rows in a checkerboard pattern so that the gases get entangled in them better.

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

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.
Counterflow - gases and coolant move along one line towards each other. This arrangement gives the most efficient heat transfer and the highest efficiency.
Flow - gases and coolant move in parallel in the same direction. It is rarely used in boilers for special purposes, because 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 must be heated to 500-600 degrees; 50-150 degrees - operational reserve for fuel water cut, etc.

Because of this, the service life of the fire tubes is limited, especially in large boilers. In addition, the efficiency of a fire-tube boiler is not high, 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 the total is 50%, which is very bad.

In small household boilers, these features are weaker, because with a decrease in the boiler size, 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 furnaces 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 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 is much hotter than in the upper ones. It is pushed into the supply first, 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 being designed for a house, the register must be located at the lowering of the chimney, in that section where hot gases go from top to bottom. In a flow, with the same direction of movement of gases and a coolant, a water-tube boiler, 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 for solid fuel boilers ranges from 5-25% of the system capacity. This must be taken into account when choosing a boiler. For example, for heating, by 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 capacity of the boiler register must be in the range of 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 slow-burning boilers, 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:

The low thermal conductivity of cast iron leads to a 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 high 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 an old Soviet cast iron battery. Its surface area is 0.254 sq. m. For heating 80 sq. m. of living space needs 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 hot water 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. There remains the usual structural steel, but it corrodes very quickly at 400 and higher degrees, so 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 \u200b\u200bmore 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 thrust, 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. To do this, the combustion temperature of the fuel is increased, which increases the efficiency and eliminates condensation. And before entering 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 designs will be discussed below.

Circulation and boiler

Thermosiphon (gravitational) water circulation does not allow heating a room with an area of \u200b\u200bmore than 50-60 square meters. 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 may be lost. UPS (uninterruptible power supply) for 12-24 hours autonomous work are very expensive, therefore a properly designed boiler is reckoned on forced circulation, and in the event of a power outage, it should switch to thermosiphon 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 its weight load 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 have to be disassembled at the place of installation of the boiler before concrete screed with a side offset of at least 150 mm. The base under 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 a 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 iron on it. Removal of insulation to the sides of the boiler from 150 mm, and in front of the furnace 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 is placed, covered with a steel sheet. Removal - as in the previous case.

A solid fuel boiler requires a separate boiler room... 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:

The piping is installed in a counterflow to the water, from the return to the supply.
At the end of the installation, its correctness and the quality of the connections are checked visually according to the scheme.
The installation of the heating system in the house is started only after the boiler is piped.
Before loading fuel and, if required, applying power, the entire system is filled cold water and check all joints for leaks during the day. In this case, water is water, and not some other coolant.
If there are no leaks, or after their elimination, the boiler is started on water, continuously monitoring the temperature and pressure in the system.
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.
After pressure testing, the boiler is extinguished, the system is allowed to cool completely.
Drain the water, fill in the standard coolant.
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 small, the best ones have 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-fired boiler can only be long burningotherwise it beats him on all counts. 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 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-fired boiler can be useful in places where there is no regular coal supply 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 \u200b\u200bup to 100 sq. m. In combination with the smoldering of fuel, a thin layer and a rather large volume of the jacket, boiling of water is excluded, therefore, 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 the structure a large thermal inertia and weight. Perhaps the only brick boiler in which the brick is in place is Belyaev's pyrolysis "Blago", the 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 requires, like all pyrolysis boilers, 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 oven, which is now being talked and written about so much, is a water-tube heat exchanger walled up in the oven masonry, see fig. below. The idea is this: after heating, the stove should give off heat more to the register than to the surrounding air. Let's say right away: reports of 80-90% efficiency 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 at least 10-12 square meters. m. The surface area of \u200b\u200bthe 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. Thermal seams will not help business, the register is not a sheet or beam, but a volumetric structure, and it is bursting at once in all directions.

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:

safety group: air drain valve, general pressure gauge and breakthrough valve to release steam when boiling;
emergency cooling storage tank;
its float valve, the same as in the toilet;
thermal valve for starting emergency cooling with its sensor;
MAG-block - drain valve, emergency drain valve and pressure gauge, assembled in one housing and connected to a diaphragm expansion tank;
forced circulation unit with a check valve, a circulation pump and a three-way bypass valve electrically controlled by temperature;
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 in case of 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 unsuitable for places with mild winters and protracted off-seasons.

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 thermosyphon mode, if only it is possible to live in the rooms. But the thermal valve of the intercooler fully opens (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 must be urgently extinguished. When water flows out of tank 2, the system will boil.

Boilers with built-in protection against overheating 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: the excess of overheated water is poured here into an open expansion tank of large capacity, see fig. return line. The system, in addition to the circulation pump 7, is non-volatile and goes into thermosyphon mode smoothly, but with a sudden warming, the fuel is still wasted, and the expansion tank must be installed in the attic.

As for 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, in contrast to 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 furnaces. General principle: too narrow chimney 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. The roof must provide safe access to the chimney at any time of the year. At each break in the chimney outside the boiler room, there must be a clean door, each pipe passage through the ceiling must be thermally insulated. The upper end of the pipe must be equipped with an aerodynamic cap, which is mandatory for the boiler chimney, unlike the stove. A condensate collector is also required for the boiler chimney.

In general, the calculation of the chimney for the boiler is somewhat simpler than for the stove, because the boiler chimney is not so winding, 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 1.5 m deep, see fig.

Based on such graphs, after an accurate calculation using local data, it is possible to estimate whether there was 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 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.

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Before proceeding with the independent production of solid fuel boilers, it is necessary to prepare sketches. They should reflect the main and additional elements. It is proposed to take the drawings of solid fuel boilers for long burning as a basis. It is quite possible to make them with your own hands.

The appearance of a homemade design

Analogues with support for long-term combustion differ from conventional boilers by the presence of two working chambers at once. In the first of them, the directly embedded fuel is burned, and in the second, the released gases. The timely supply of oxygen plays an important role. An ordinary fan with simple automation can be used as a device for blowing air.

Of the advantages of the units, it should be noted:

the minimum number of fuel fillings;
high work efficiency;
using different types solid fuel;
a small amount of soot in the pipes during operation;
design reliability.

Note! Among the disadvantages, it is necessary to mention the complexity self-made... Although, when using ready-made drawings of solid fuel boilers for long burning with your own hands, it is still possible to make the unit.

The process of making solid fuel boilers for long burning with your own hands: drawings and assembly

It should be noted right away that structures can have both an upper combustion chamber and a lower one. In the first case, the combustion products enter the working compartment under the influence of natural forces, and in the second - with the help of an additional device for air injection.

Since boilers with a lower afterburning chamber are difficult to manufacture and require the installation of additional equipment during installation, it does not make much sense to consider them. It is faster and more economical to make a design with an upper combustion chamber.

Applicable elements

To manufacture the structure you will need:

pipe with a section of 500 mm and a length of 1300 mm;
pipe with a diameter of 450 mm and a length of 1500 mm;
pipe with a cross section of 60 mm and a length of 1200 mm;
two rings 25 mm wide and 500 mm in diameter;
metal corners and pieces of the channel;
metal sheet;
asbestos cloth;
hinges and handles.

Body assembly procedure

First of all, pipes with a cross section of 1500 and 1300 mm are nested into each other. They are connected using a ring made from a corner measuring 25x25 mm. A circle with a diameter of 450 mm is cut out of a metal sheet and fixed to the end of the pipe. It acts as a bottom. The result should be a small barrel.

On the underside of the structure, a rectangular hole of 15x10 cm is cut for the ash pan door. The sash is attached to the opening with hinges, and a latch is also installed.

A rectangular hole is made just above for the fuel chamber. The dimensions can be determined by yourself. The convenience of loading firewood or other fuel will depend on the correct dimensions. A door with a latch is installed using the same technology.

In the upper part of the home-made structure, an exhaust pipe is made, with the help of which the exhaust gases will flow into the chimney. On the sides, by means of welding, the pipes are fixed, which are necessary for connection to the heating system of the building. Threads are necessarily cut in them.

Air distributor device

A circle with a cross-section 20-30 mm less than the diameter of the inner part of the boiler is cut out of a piece of sheet metal. A round hole is made in the central part for the air distribution pipe. Its diameter should be 6 cm. A pipe is inserted directly into the hole and welded to the base.

Pieces of the corner are attached to the bottom of the metal pancake. On the other hand, a loop is fixed by welding, which is necessary to move the structure up and down. To adjust the air supply directly to the combustion chamber, a damper is arranged.

A circle with a diameter of 500 mm, cut from a suitable piece of metal, is inserted into the structure. The upper end of the pipe is inserted into the hole, after which the upper boiler cover is welded tightly. A cable is fixed to the loop, which allows lowering and raising the distributor.

Note! The simplest of all schemes of solid fuel boilers for long burning was presented. Assemble with your own hands robust design it is not so difficult, especially if you have experience with welding and other tools.

DIY long-burning solid fuel boiler: video for acquaintance

Another option is to use a gas cylinder for the body. It can be used to create a completely effective structure for heating buildings. small size... To familiarize yourself with the features of a homemade heating device, it is suggested to look at the video. A long-burning boiler with your own hands without drawings can be made according to it.

Are there any negative reviews about a solid fuel boiler for long burning?

Sometimes consumers leave negative reviews about designs, but they are more likely associated with common disadvantages, which are inherent in solid fuel devices in general.

The following disadvantages can be highlighted:

to store fuel, you have to use special rooms or structures;
fuel in any case must be loaded manually, despite the reduced number of loads;
when installing any models of solid fuel boilers, special safety measures must be taken;
it is impossible to regulate the process of fuel combustion in the combustion chamber with particular precision.

Note! There are a lot of disadvantages, but still solid fuel boilers are the only way out of a situation when gas and electricity main lines are not available.

On the cost of finished models for heating with solid fuel

If you can't make a long-burning boiler or you simply don't want to, then you can purchase a ready-made structure. It must be admitted that models for heating large rooms are not cheap. In the table you can find the prices for the Stropuva boilers.

Article

At dachas and in country houses you cannot do without autonomous heating systems based on boilers of various types. We must pay tribute to the manufacturers who offer efficient models with automation and a wide range of options. But for heating small country houses or greenhouses, the installation of expensive equipment is inappropriate, since it will be cheaper to make a heating boiler yourself. According to the main characteristics, it will be no worse than the factory models.

The choice of the type of homemade heating boiler depends on what kind of fuel it will operate on. Hence the classification:

TO electric boilers heating does not have high safety requirements. The design consists of a container, which is easy to make from a pipe section with a diameter larger than that of the supply pipes of the heating system. Heating elements are installed inside. Despite the simplicity of manufacturing, such a boiler for heating is not economically viable, since the price of electricity is high. Therefore, this option is chosen for periodic heating of small country houses.
Gas boilers have high efficiency and low fuel prices. However, due to the explosive nature of the gas, the requirements even for factory models are very high. Therefore, it is almost impossible to obtain permission to install and operate a home-made heating boiler, and theoretically when installed in a basement.
There is nothing complicated in making a liquid fuel boiler with your own hands. But for normal operation, you will have to install a tank for storing fuel oil or diesel fuel and lay an insulated pipeline from it. The price of the burner and the difficulties in setting it up can discourage the desire to make such a boiler. Moreover, you will have to negotiate with the fire inspectorate to obtain a permit for the installation.
Most often, a solid fuel heating boiler is installed for heating a private house. It is heated with wood, coal, peat, oil shale. For homemade boilers of this type, the outlet temperature reaches 120 - 150 ⁰C.

Construction of a solid fuel and pyrolysis boiler

A traditional solid fuel heating boiler works like a conventional stove. It is assembled from two steel or cast iron containers inserted into one another. Firewood burns in the inner (firebox), water is heated in the outer (tank). The structure consists of the following parts:

fireboxes with a door;
grate bars;
ash pan with a door;
a collection of soot;
chimney;
gate valve;
branch pipes for connecting the supply and return pipelines of the heating system;
legs;
lids for closing the heating tank.

Outside air enters the firebox through the ash pan and grate. The intensity of combustion is regulated by the amount of door opening. Cravings can be natural or forced. With a properly calculated and made heating boiler, the efficiency reaches 79%.

The advantages of classic solid fuel boilers:

low fuel cost;
no electricity is required for work;
fuel versatility;
the possibility of burning wood waste.

But when choosing this type of boilers, disadvantages should also be considered:

one fuel load is enough for a maximum of 6 hours;
space is required to store fuel stock;
the complexity of care, since you will have to regularly remove combustion products;
combustion of solid fuel is inertial, so there are difficulties with regulation.

Pyrolysis boilers for heating by the principle of operation differ from the classical version in that not only fuel is burned, but also gases emitted from it. The structure consists of the following parts:

afterburner chambers with built-in nozzle;
gasification chamber;
air supply systems;
chimney system with a butterfly valve;
heat exchanger;
water circulation systems;
temperature sensor and manometer;
safety valve.

To light up the boiler, the gasification chamber is filled with wood through the upper door. After igniting the kindling with an open throttle on the chimney, a fan is started. When the wood fires up, the door is closed and the throttle is closed. Due to a decrease in the amount of air supplied, the wood begins to smolder at a temperature sufficient to trigger the pyrolysis reaction. The released gases, after passing through the nozzle, mix with the secondary air in the combustion chamber, ignite, heating up to a temperature of 1100⁰C, and are sent to the heat exchanger.

On a boiler without a smoke exhauster, before adding firewood, open the throttle on the chimney, wait some time required to remove the pyrolysis gas. After loading the fuel, closing the door and the throttle valve, the boiler continues to operate normally.

Compared to conventional heating boilers, pyrolysis boilers have many advantages:

due to complete combustion, there is no need for frequent cleaning of the ash pan and gas ducts;
ease of control of the intensity of combustion;
duration of work without adding fuel from 5 hours to several days;
the possibility of burning non-chopped firewood;
use of scraps from fiberboard, chipboard, MDF and plywood as fuel;
in pyrolysis heating boilers, the content of harmful compounds in the smoke is 3 times less.

However, there are also disadvantages:

Since the fan or fan is powered by electricity, an uninterruptible power supply may be required.
Fuel with a moisture content of more than 20% reduces efficiency.
At low loads, malfunctions are possible, which cause an increase in tar deposits in the gas ducts. To normalize the operation of the boiler, heat accumulators are installed, into which excess heat is removed.
To prevent the formation of condensation on the walls of the heat exchanger, which accelerates the corrosion process, the water temperature in the heating return line must be at least 60⁰C.
Due to the high consumption of materials, the costs are 2 times higher than for conventional boilers.

A traditional solid fuel heating boiler works like a conventional stove. Pyrolysis boilers for heating by the principle of operation differ from the classical version in that not only fuel is burned, but also gases emitted from it.

Diy pyrolysis boiler for heating

If you weld a heating boiler at an amateur level, then emergency situations during operation are provided. Therefore, it is better not to start work without good skills.

Calculation of the power and dimensions of the boiler

Making a heating boiler with your own hands begins with determining the dimensions, which depend on the amount of power sufficient for heating. When calculating, it is assumed that 1 kW of power is needed per 10 m² of heated area. It is easy to calculate that heating a house with an area of \u200b\u200b300 m² requires a boiler with a capacity of at least 30 kW. To compensate for heat loss, a small margin is needed.

It is unlikely that it will be possible to correctly design a pyrolysis heating boiler from scratch without knowledge of heating technology. Therefore, it is better to find on the Internet a ready-made drawing for the required power. It is desirable that the service life of the unit made according to this project was not 1 year. If necessary, you can contact the author to clarify unclear points.

Required tools and materials

To work, you need to stock up on the following tools:

electric drill and drills;
grinder with circles;
gas cutter for cutting large holes;
a set of locksmith tools.

And also materials:

sheet steel with a thickness of 5 mm for the manufacture of chambers and 4 mm for the outer skin;
round pipe 57x3.5 for the heat exchanger and 159x4.5 for the hog (horizontal section of the chimney at the outlet of the boiler);
fireclay bricks;
round pipe 32x4.5;
professional pipe 80x30x2 and 80x40x2;
steel strip 30x4 mm;
fan;
thermometer and manometer.

The number of materials is calculated according to the drawing.

Manufacturing process

To save time, it is advisable to chop sheet metal blanks on a guillotine, since it is difficult to make a perfect cut with a grinder. This service is provided to customers at metal depots. A homemade heating boiler is made in the following order:

A gas and a combustion chamber are welded from the blanks.
Air ducts from a professional pipe 60x30x2 with pre-drilled holes with a diameter of 10 mm are welded to the side walls of the gas chamber. A cutout is made at the back for the chimney.
A tube is led out into the combustion chamber through which secondary air will be supplied. It is connected to the front side of the boiler with a 20x20 profile.
The heat exchanger is made of two blanks in which 2 rows of holes are cut for gas pipes with a diameter of 57 mm. After cutting to size and setting in place, they are scalded.
The finished heat exchanger is installed in place.
They make and mount a chimney throttle valve.
The front wall of the chambers is welded with pre-made holes for pipes through which primary and secondary air will be supplied.
In the place where the gas duct comes out and the throttle is installed, the back wall and the hog are welded.
After cleaning the welds, the inner box is ready.
To fix the outer skin to the box, pieces of corners with a shelf of 25 mm are welded.
On the casing in the places where the corners are installed, holes with a diameter of 10 - 12 mm are drilled.
Through the holes, the sheathing is welded to the corners on all sides of the box, except for the top.
To check the tightness of the joints, plug all the holes, pour water through the top. Leak points are marked with chalk.
The air dampers are adjusted with threaded studs. Then the air holes are closed with a casing with an air duct from a professional pipe.
They make and hang doors on the cameras. They are lined with cast iron plates or fireclay bricks.
The bottom of the gas chamber is laid out with sawn bricks.
To attach the fan to the end of the duct pipe, a flange is welded.
The lining of the combustion chamber is made of fireclay bricks.
To improve heat transfer and ease of cleaning, it is recommended to install swirlers (turbolizers) in the gas ducts.
The boiler is checked for tightness with a pressure of 4 bar, which is created by a pressurizer after filling with water. If the pressure does not drop within half an hour, the boiler is ready for operation. Otherwise, you need to look for a leak.
To prevent emergencies, a safety group is installed on the supply pipeline of the heating system, consisting of a pressure gauge, a safety valve, an air vent.
If desired, the pyrolysis boiler can be easily equipped with an automatic control system.

Connection and commissioning

Before starting, the heating boiler is connected to an external chimney and filled with water. To control its temperature, a thermometer must be installed. The boiler is put into operation in the following sequence:

A power cable is connected to the fan, the quality of its work is checked. Air flaps should be in the middle position.
A little paper is put into the gas chamber, a few poles on top, the door is closed.
The choke on the chimney is opened to failure, the fan is started, the paper is set on fire.
After the wood has lit, the throttle is closed.
The ignition of pyrolysis gases is monitored through the lower door. If the torch does not ignite, the amount of air supplied to the gasification compartment is reduced, and the amount of air supplied to the combustion chamber is increased.
When the torch lights up, adjust the intensity of the flame, achieving a white-yellow color using the air dampers.
After closing the door, the time until the water boils is recorded. At a temperature of 100⁰C, the fan is stopped. The torch should go out.

We make a boiler from a solid fuel pipe

It does not take much time to make a boiler from a pipe with your own hands. In contrast to the rectangular sheet steel structure, this option is more reliable, since it is assembled with fewer welded joints.

What is needed for manufacturing

Getting started, you need to stock up on the necessary tools:

welding machine and electrodes;
gas cutter;
grinder;
a set of locksmith tools.

And material:

a piece of pipe with a diameter of 425 mm for the body, as well as 100 and 25 mm;
sheet steel 4 mm thick;
two nozzles 25 mm;
hinges for hanging doors;
corner 25 mm;
reinforcing bars with a diameter of 8 mm.

Step by step manufacturing process

First, prepare the parts from which the boiler will be assembled from the pipe:

A piece with a length of 1 - 1.2 m is cut from a pipe with a diameter of 425 mm. This will be the body of a vertical heating boiler.
Two rectangular holes are cut on the pipe. For a furnace with a size of 200x100 mm, for a blower 200x30 mm at a distance of 50 mm from each other. Doors are made from the cut pieces. The distance from the bottom edge of the body to the blower is 50 - 70 mm.
On the side in the upper part of the case, 2 holes with a diameter of 25 mm are cut one under the other. The lower one is at a distance of 150 mm from the firebox door for the return pipe, and the upper one is 50 mm from the top of the housing for the heating system supply.
2 circles with a diameter of 425 mm are cut out of sheet steel for the housing covers and 1 with a diameter of 412 mm for the partition between the firebox and the tank.
Holes are made in the top cover and partition for the chimney, which is made from a 100 mm pipe.
The legs are made from pipe 25.
A grate in the form of a lattice is welded from reinforcing rods.

When all the parts are ready, proceed to assembly:

The chimney is welded to the partition and installed on the reinforcement supports tied inside the body at a distance of 300 - 350 mm from the firebox. Then they are fastened by welding on both sides.
A top cover is put on the end of the chimney. Both joints are scalded.
A grate is inserted from the bottom of the body. Then the pieces of corner 25 are welded on which it will stand.
The bottom cover is welded, and legs 50 mm high are welded to it.
The hinges are welded, the blower and firebox doors are hung.

Connection and first kindling

The finished boiler for heating is checked for tightness. To do this, a plug is installed on the lower branch pipe. Water is poured through the top. If there are no leaks, the boiler is connected to the heating system.

It is better to bring the chimney out strictly vertically. If this is not possible, it is mounted with a minimum number of bends. Horizontal sections are installed with a slope of at least 0.1% of the length.

A small amount of wood or coal is sufficient for the first kindling. Otherwise, with a sharp increase in temperature, tar will begin to deposit on the walls of the chimney. Therefore, due to a decrease in the passage, the thrust will become worse.

To ensure that a sufficient amount of air enters the firebox, adjust the position of the blower door. More convenient for this purpose is a slide gate, which you can buy or make yourself.

Self-welded boilers for heating are not recommended to be installed in a residential area, since, unlike factory models, they do not have a guarantee of safe operation. In the event of an emergency, you will have to answer for the consequences yourself. But even when installed in a separate room, fire safety rules should be strictly observed.

From the author: welcome, dear friends! Many country house owners appreciate individual approach to the creation of a heating system, almost always preference is given to homemade equipment. How to make a water heating boiler with your own hands, taking into account safety precautions and maximum efficiency? In the article, we will study the topic of assembling and installing several types of devices.

For heating private houses and cottages, experts advise using exclusively safe types of fuel, namely: electricity, coal, wood or pellets.

Note that in this material you will not find instructions for assembling gas and diesel boilers, since their installation in the house is prohibited. The competent authorities will not allow the boiler to be assembled by you into the gas pipe loop. If such violations are detected "retroactively" then you, as the owner of the living space, will be brought to administrative responsibility.

Benefits of manual assembly

Why do experienced craftsmen advise you to assemble boilers for the heating system yourself? These devices have certain pros and cons, but there are still more advantages. Thus, a manually assembled heating boiler will be cheaper than its factory counterpart, although the latter will show a higher efficiency.

The principle of operation of such equipment, regardless of what it works on, is quite simple. When combusted, fuel releases heat energy. It enters the heat exchanger and heats the water circulating in the system.

The boiler operation scheme, its external parameters and characteristics directly depend on two main factors:

what materials you will use to make the boiler;
what type of fuel is most affordable in your area.

And yet, back to the disadvantages of boilers, which are assembled according to their own drawings. First of all, there is no guarantee that the boiler will serve you faithfully without any unpleasant surprises. The factory boiler can always be returned or exchanged for a new one until the warranty period has expired. The owner can be calm in this respect. The quality of the work of a homemade boiler depends only on your qualifications and what parts were used in its assembly.

However, hand-assembled boilers also have a very important advantage - they are focused on the individual needs of your household. In this respect, everything depends only on you.

Efficiency

Experts say that the quality of the heating boiler operation depends on two main factors:

heat exchanger device. The amount of heat that is transferred to this heat carrier itself (usually water) directly depends on the area of \u200b\u200bdirect thermal contact between the container with the coolant and the firebox;
completeness of fuel combustion. With an unsuccessful boiler design, pyrolysis gas can go into the pipe along with the combustion products. The fact is that its afterburning significantly increases the efficiency of the unit. Another sign of an ill-conceived heating boiler assembly is an insufficient oxygen supply to the combustion chamber.

We draw conclusions:

when designing a boiler for hot water heating, the master must take care of the maximum low temperature of the combustion products. This indicator is inversely proportional to the efficiency of the device;
strive to ensure the safety and durability of the boiler? Then take care of the same indicator - the temperature of the combustion products. The lower it is, the better;
for factory models of boilers, this indicator ranges from +120 to +150 degrees.

How a water boiler works

You already know about the principle of operation of boilers for water heating of a home, both factory and home-made. It is implemented in two main ways:

a water boiler of the "samovar" type. In this design, the fuel burns out inside the container with the coolant (water). Usually this type of boiler is used in Russian baths;
water boiler with a coil. In it, the coolant flows through the pipes of the heat exchanger laid through the firebox. This type of boiler has a popular version, in which the coil does not pass through the firebox, but directly behind it - where the combustion products come out.

The master decides for himself which type of boilers to give preference to. His choice depends on the availability of materials necessary for the assembly, his own skills and the characteristics of the operation of the device. Whatever type of boilers you take as a basis, it is important to remember that this unit is a device of increased danger!

Remember that domestic boilers require a thermometer to determine the temperature of the water in the system, a pressure gauge to measure the pressure, and a valve that is used to relieve excess pressure (if necessary).

Preparation for manufacturing

Before figuring out how to connect a self-assembled heating boiler, it is important to figure out what tools and materials you need to complete the assembly and installation.

Boilers are usually made of sheet steel. The optimum material thickness is 4–5 mm. If you can afford it, go for the heat-resistant variety. Considering that it is quite expensive, many craftsmen take ordinary stainless steel.

The first step preceding the development of a diagram of the future unit is to determine the way of circulation of the coolant through the heating system. If the water moves independently, using the principle of gravitational circulation, then the water tank will need to be raised to a rather large height. In this case, you will need large diameter pipes throughout. If the pipe diameter is not large enough, then you cannot do without installing a circulation pump.

It is worth describing in a few words the features of the heating system with forced circulation of the coolant. It has both advantages and disadvantages. The pipes used in this system have a small diameter, which means they are cheaper. In addition, the tank that warms up the coolant does not need to be raised high. These were pluses, and among the minuses one can note the dependence of the system on the availability of electricity. The boiler can simply explode if the power goes out in your home.

Pro tips:

heating circuits and pipes welded to the boiler are recommended to be made of pipes with a diameter of at least 32 mm;
considering that during an emergency stop of the circulation pump, the water temperature rises sharply, and its movement slows down, you should take care of the health of the heating circuit. It is better to assemble it using galvanized pipes. Do not forget to ensure the tightness of the connecting thread with red lead and linen tow.

Types of boilers

Homemade heating boilers are usually classified depending on what kind of fuel they use. The wood-fired boiler is most in demand for self assembly due to its simple design, the availability of materials and tools needed to make it. In addition, firewood is a fairly inexpensive fuel, and you can buy it in the right amount in almost any region. The advantages of a wood-burning boiler include versatility and simplicity, and the disadvantages are rather low efficiency.

The simplest version of such a unit looks like this: a tube that acts as a firebox is inserted inside another tube (larger diameter) with thick walls. The cavity between them is filled with water. Note that wood-fired boilers can be easily fired with other types of solid fuel, namely: coal, peat briquettes.

A pyrolysis boiler is more efficient than a wood-burning boiler, although it runs on the same fuel - wood. The fact is that if you burn a tree with a lack of oxygen at temperatures from +200 to +800 degrees, then it will decompose into two elements: pyrolysis gas and wood coke. If oxygen is added to the gas, ignition will occur with intense heat release.

Thus, you can increase the efficiency of a homemade boiler up to 92%. A portion of firewood that burns in a wood-burning boiler for 4 hours will give off heat energy in a pyrolysis boiler 3 times longer. The advantages of this design include the absence of solid residues after combustion and the ability to regulate the combustion of gases in automatic mode.

This type of heating unit also has disadvantages: it is important to comply with the requirements for the moisture content of firewood (no more than 30%), and the materials for the manufacture of such a stove will cost much more than for a wood-burning analogue. True, the cost of the boiler should pay off pretty quickly.

Waste oil boilers can also use diesel fuel as fuel. The principle of their work is as follows: oil drips onto a hot pan and evaporates, transforming into gases, and those, burning, heat the coolant.

They consist of a heating element placed inside the tube. The tube is upright. From above, the supply is brought to it, and from the bottom - the return. Water circulates naturally.

Tools and materials

It is quite simple to make a water heating boiler with your own hands, besides, you will not have the need to purchase any special tools, equipment or parts that are difficult to find on sale. Everything you need for work, most likely, you will find in your workshop, namely:

sheet metal (metal barrel, decent diameter pipe, old stove);
steel tubes;
profile pipes or radiators (if you have chosen water as a heat carrier);
bolts, nuts;
dampers (you can make it yourself or buy it, used ones are also suitable);
door.

As mentioned above, it is important to install the very minimum of automation on the boiler: a pressure gauge, a thermometer. Make sure that the materials you select are free from flaws and are of good quality - without traces of rust, holes. Experts recommend adding a pump to the boiler, which would be responsible for the circulation of the coolant.

We suggest that you familiarize yourself with the video on assembling a boiler for water heating of a private house with your own hands.

Installation in a brick oven

Suppose you want to place a hot water boiler inside. In this case, the step-by-step algorithm of your actions will look like this.

Think over the location of the boiler installation.
Lay out the layout and prepare the foundation.
Prepare the mortar required for laying bricks. Take sand and clay in a 2: 1 ratio. Please note that the percentage component parts mortar will depend on the quality of the clay. The clay should be soaked overnight, then mixed using a special drill attachment.
When the foundation is ready, it's time to take care of the waterproofing. You can use a sheet of roofing material for this. How to pick it up? The dimensions of the sheet must exceed the dimensions of the boiler by at least 10 cm.
Roofing material must be poured with a cement screed and leveled.
The outer contour of the future stove is laid out with red brick. Silicate is not suitable for these purposes. You can also put a fight inside the structure.
The wall must be brought to the level of the blower door. Next, lay the metal sheet at an angle outward. This is necessary to make it easier to remove the ash.
The next step is to mount the door.
Now you can lay out the contour of the blower.
Install the boiler itself and the furnace door.
The last step is to lay out the chimney and you can start operating.

https://www.youtube.com/watch?v\u003dg3vQT3uUKwM

Summing up, we note that the manufacture and installation of a boiler for a water heating system is quite a feasible job for experienced master... On the net you can find many sensible training videos on this issue. We hope that this material will be useful to you, and you will cope with the task perfectly. Good luck and see you soon!