The most widespread are those stoves that use wood as fuel.

They are conditionally divided into two main types:

1. for intermittent operation.
2. For long burning.

In the second case, we are usually talking about a period of time from about 6 to 10 hours. Note that when using conventional type furnaces, the fuel used is completely burned out in a couple of hours.

The room heats up quickly and then cools down just as quickly. In cold weather, this can cause significant inconvenience. In order to prevent this from happening, you need to periodically load fuel.

Such a decision can be very inconvenient. At night, this will have to spend a sleepless night or the room will freeze. Part of the heat will go into the chimney along with the smoke in such a situation. Combustion, consuming oxygen in the room, can also create problems.

Long burning stoves avoid such problems. Their main feature is that they use a slow combustion process, which is created by limiting the supply of oxygen.

This construction works like this: it is placed separately, in the place necessary for heating. It usually has two sections. The intake of air for blowing is regulated by a special design - a gate. A blower is also used.

In some cases, an additional gas or liquid heat exchange system is installed. It is designed to organize the most rational use of the generated heat. A damper is actually a damper that can completely or partially close the chimney.

Device

There are two main designs:

1. Swivel design.
2. Latch design.

In some cases, additional devices may be required to limit the degree of blowing. As mentioned above, in order to achieve the effect of long burning, the supply of oxygen must be limited in the most optimal way. In addition, when using, smoke must be provided.

For their operation, loading of a large volume of fuel and combustion with a limited air supply are used. In this case, there is no rapid combustion of the fuel and this process takes a long time at a very low intensity of combustion.

The combustion temperature in this case is higher than in a conventional furnace. Also at this time, a special "fuel gas" is formed, which then also burns out, giving additional heat.

Self-manufacturing

Sawdust stove scheme

As fuel, it is convenient to use its most common type - firewood. We will tell you in detail how this can be done.

We list the tools and materials necessary for this:

• 200 liter barrel;
• 2 small pieces of steel pipe, one of them should be slightly longer than the other;
• piece of metal bar;
• hacksaw, which is used for working on metal, you also need a hammer, an ax and a mallet;
• measuring fixtures(roulette, plumb line);
• approximately 50 red bricks;
• reflector;
• Sheet steel(small piece);
• welder;
• mortar to prepare a solution;

DIY manufacturing process:

1. The main part is the barrel. To use it, you need to prepare. First of all, you need to cut off the top cover. This must be done carefully. This detail will be needed later. If it was not possible to cook the side, a piece of large diameter pipe can be used for the same purpose.
2. A circle is cut from a sheet of steel, with a diameter slightly smaller than the barrel so that it can be freely moved inside. A hole is cut in it for a longer piece of pipe. From below, horizontally located channels are welded onto the disk.
3. From the cut off top of the barrel the top cover is made. A hole is cut in it for the exit of the pipe.
4. 2 holes are made at the bottom. One higher and more for laying fuel. The other is smaller and at the very bottom for raking out ash and coal. Both openings must be equipped with doors with handles.
5. A hole is made in the upper part for the chimney and the corresponding piece of pipe is connected. It is placed on a foundation. This is due to the high heat during operation.
6. In some cases, the oven can be bricked, and the adjacent floor and walls - a reflector. But this is not mandatory.

1. for chimney It is convenient to take a pipe with a diameter of up to 15 centimeters. It is welded to the upper opening of the furnace being created.
2. Using a reflector I can greatly improve performance.
3. Not worth bricking if the oven will be used in utility rooms.
4. Near it, you need to free up space and do not place objects or materials that are not resistant to fire there.
5. The chimney must be accessible for regular cleaning.
6. Before starting operation, you need to try it in various operating modes and choose the most suitable one from them.

Advantages and disadvantages

Why is it beneficial to use this variety?

Here are the main reasons for this:

1. These structures are compact and relatively small size.
2. They have a fairly high efficiency. It can reach 75% - 85%.
3. Maximum burning time may be 10 hours.
4. Much less fuel consumption than in a normal situation.
5. Unlike most types of ovens, you can add a new portion of firewood during the burning process, without waiting for it to end.
6. Here it is possible to carry out effective adjustment the intensity of the combustion process.
7. It is allowed to use not only firewood for burning, but also coal and .
8. Cast iron stoves have a long service life. It can be up to 50 years old.
9. They have a high degree of versatility. They can be installed almost anywhere where it is possible to make a chimney.
10. They are not too heavy. Two people can effortlessly move them to a new location.
11. Attractive design. This allows the use of long-burning furnaces in a wide variety of cases.
12. Relatively low cost.
13. environmentally friendly fuel materials.

Along with the listed positive features, there are also certain disadvantages.

1. These devices are not adapted to work on the basis of liquid fuel.
2. Special requirements for a chimney due to the low speed of smoke movement (the chimney should not be curved).
3. Setting up the correct operation is quite complex.
4. Low outlet temperature leading to increased condensation.
5. Inability to work in fully automatic mode. This requires constant supervision.
6. The space around the location of the furnace must be protected from fire.

Different kinds

Buleryan

One of the popular varieties of such devices is Canadian-made stoves. It has a barrel-like shape and is made of steel. The firebox has two tiers. The ash collector is not provided in this design. There are air ducts.

The latter circumstance allows heating neighboring rooms.

Such furnaces can operate in one of two modes:

1. Kindling mode.
2. Long burning mode.

In the first case, we are talking about the first half hour of work. At this time, the furnace and the surrounding space are heated. One bookmark can burn up to 12 hours. Special requirements are imposed on the dryness of firewood laid in the firebox. In this type of furnace, the generator gas does not burn completely. Also, there is a need to provide insulation of the chimney.

"Breneran"

It is in many ways similar to the Canadian brand described above. But there are also some differences. In order to carry out heating in neighboring rooms, special aluminum sleeves must be put on the convection pipes.

But when they are used, a significant leakage of thermal energy occurs. There is an alternative. To do this, you need to purchase a special casing that will reduce heat loss. But its cost roughly corresponds to the cost of the furnace itself. The chimney has a device for collecting condensate. Unfortunately, it cannot be made completely hermetic.

On the other hand, many varieties of furnaces of this brand are produced. For each specific situation, it is quite possible to choose an oven of a suitable volume. Unlike the Canadian model, various types of solid fuels can be used here.

Also, it is possible to connect water heating. But in the latter case, the long burning time will be reduced due to the additional cost of heating the water.

"Professor Butakov"

Another fairly well-known domestic brand. It has a more thoughtful look. Grids are used here (a grate on which burning fuel is located).

Convection pipes are much more efficient here than in the previous type of ovens. During combustion, the condensate flows into the furnace and burns out completely. When installing, it is necessary to put such a furnace on a special pedestal. Long burning is less likely than in Canadian stoves. This is due to the use of grate.

Today, gas heating equipment is the most in demand, but it is perhaps too early to send solid fuel boilers and stoves to the dustbin of history. In many regions, firewood is much cheaper than gas, and in some places it is generally the only available fuel, so heat generators operating on such energy resources are still needed. Moreover, this equipment is constantly being developed and improved, getting rid of many of its shortcomings. Trying to cope with the most important of them - the need to often throw up fuel - the engineers created a whole direction, which is commonly referred to as "long-burning heat generators". How to make a long-burning stove with your own hands will be discussed in our article.

Those who had to heat an ordinary metal stove with wood or coal know well that such a unit does not allow you to relax - you have to add fuel on average every 4 hours.

This state of affairs could not leave the developers indifferent, and many of them thought about the creation of "long-playing" furnaces. Logic suggested that first of all it was necessary to increase the capacity of the combustion chamber. But this alone was clearly not enough: during normal combustion, even the largest portion of the fuel will still be used up quite quickly, it’s just that in this case we will get excess power, and the lion’s share of the generated heat will fly out into the chimney.

Long burning furnace device

A new way of burning had to be found. Several options were proposed and implemented, and what happened was called so - long-burning furnaces (they also say - long-burning). Some of them are able to work without refueling for up to several days. True, for this it was necessary to abandon complete autonomy: such stoves need power supply.

Varieties of long-burning heat generators

So, a stove or boiler with a long burning time can be easily recognized by a huge firebox: instead of the usual 50 liters, its volume can be 100, 150, and for some giants even more than 200 liters. And according to the principle of operation, such installations are divided into several groups.

Top burning stoves

Convection currents carry the flame upwards, so when ignited from above, the fuel burns longer. This simple principle underlies the operation of top burning stoves. To make the movement of the flame even more gradual, air is supplied in a limited and direct manner to the combustion zone.

Top burning model

Flaws

Since the active zone, that is, the flame area, is constantly moving from top to bottom, the air duct has to be made movable - in the form of a telescopically folding pipe. This element is difficult to manufacture, in addition, the likelihood of jamming increases.

In furnaces of this type it is impossible to install a water heat exchanger - again due to the "inconstancy" of the combustion zone.

Loading a new portion of fuel can be carried out only after the previous one has completely burned out, otherwise the new tab will light up from below and quickly burn out.

Fine-grained fuel like sawdust often sticks to the walls of the firebox.

It is impossible to make a full-fledged top-burning stove at home, but craftsmen have developed several simplified varieties with good performance. The most popular of them is the so-called Bubafonya stove (named after the developer - Afanasy Bubyakin).

pyrolysis ovens

The principle of operation of these heat generators is based on the ability of organic fuel to "melt" under the influence of high temperature, gradually turning into a gas mixture. Its composition is quite diverse - from methane to nitrogen, and almost all components are combustible. In Russian, the process of "melting" wood or coal is called "gas generation", in the Greek manner - pyrolysis. To prevent the fuel from flaring up, air access to the chamber where it decomposes is limited. The combustion of pyrolysis gas occurs in an adjacent chamber, where air is supplied in sufficient quantities.

The pyrolysis oven is a wonderful invention. It not only works for a long time without user intervention, but is also economical (due to the complete combustion of fuel, the efficiency reaches 85%), environmentally friendly (the second name is a smokeless stove) and extremely easy to use: it is actually a gas stove with a built-in gas generator unit. But it is impossible to make it yourself. The most complex node is the air supply system, which must be controlled by ingenious electronics.

With forced air supply

The creators of this heater decided to approach the matter from a different angle: is it possible to leave everything in the oven as it is, but learn how to put it out and kindle it if necessary without the help of the owner? Indeed, if such an idea could be implemented, the fuel would not burn out in the furnace immediately, since the furnace would work in short cycles. Putting out a solid fuel stove is quite simple - you just need to shut off the air supply to it.

Scheme of a furnace with forced air supply

But how to ignite it without user intervention? There is no draft in the chimney and if you just open the damper, the flame will not flare up. There is only one way out - to install a fan, which will fan the fire. With his help, you can regulate the intensity of combustion, that is, the power of the furnace.

For self-production, this option is the most affordable. It is a classic solid fuel stove equipped with an air duct and an inexpensive automation system. We will deal with the creation of such a heat generator.

Note! Some manufacturers widely advertise non-volatile long-burning stoves, which in fact turn out to be ordinary "potbelly stoves". The trick is as follows: the heater is offered to be operated not in the flaming combustion mode, but in the smoldering mode, for which you just need to cover the blower and chimney dampers.

Indeed, the fuel filling will burn a little longer, but this mode of operation has a number of disadvantages:

the fuel does not burn completely, which means that the efficiency of the furnace drops dramatically;

the furnace and chimney are very quickly overgrown with soot (smoke is intensively formed);

a large amount of carbon monoxide and other unburned particles (heavy hydrocarbon radicals), which are toxic and chemically aggressive, are emitted into the atmosphere;

the combination of low temperature and a large amount of smoke leads to abundant formation of poisonous condensate in the chimney, which is even forbidden to be drained near garden crops and fruit trees.

Nevertheless, such furnaces are quite in demand. They are indispensable in the field, for example, on an expedition or at a mobile logging station where there is no power supply. Being able to work on one tab of fuel for about 8 hours, even with low efficiency, they allow the brigade to sleep.

Description of the design and principle of operation

In terms of its design, a long-burning furnace with forced air supply is very similar to a conventional furnace, but there are a number of fundamental differences:

The firebox and ash pan doors are hermetically sealed.

Air enters the blower through an air duct, the inlet of which is located on the back of the furnace. The length of this element is chosen in such a way that the incoming air has time to warm up well.

The air duct is equipped with a KG Elektronik DP-02 fan (Poland), in front of which there is a light damper made of tin. The forced air flow makes it rise, but as soon as the fan turns off, the damper slams under its own weight and the flow of oxygen into the furnace completely stops. Fan operation is controlled by KG Elektronik SP-05 controller. It is guided by the readings of the temperature sensor. All automation - fan, controller and temperature sensor - is sold in one set.

Note! There are automation kits on sale that look similar to KG Elektronik products, but are of Chinese origin. Their reliability and durability leave much to be desired.

Control unit and fan

The principle of operation of this furnace allows, without reducing the performance, to take heat not only with air, but also with a liquid heat carrier - water or antifreeze. Thus, if the unit is equipped with a heat exchanger, then it can be connected to a radiator heating system. The recommended capacity of the heat exchanger is 50 liters. Its main volume will be located above the firebox, and a small part will cover it in the form of a water jacket.

If there is a heat exchanger, the temperature sensor is installed on its wall. When the coolant cools down, it will give a command to the controller to start the fan and the boiler will ignite. As soon as the temperature of the working environment reaches the maximum set by the user, the same temperature sensor will force the controller to turn off the fan. The gravity damper will lower and the oven will go out.

Parameter calculation

The calculation of a solid fuel heater aims to determine two quantities: the volume of the furnace, with which it will be possible to provide the required power, and the cross-sectional dimensions of the chimney. Let's consider both parts of the calculation in detail and in relation to the furnace we have chosen.

The volume of the furnace and the power of the heating furnace

Estimating the approximate performance of a solid fuel furnace in terms of heat is quite simple. Suppose the volume of its furnace is Vt = 50 liters.

The volume of firewood placed in it is calculated by the formula: Vd \u003d Vt * Kz.

Where Kz is the filling factor of the furnace, Kz = 0.63 is usually taken.

Therefore, Vd \u003d 50 * 0.63 \u003d 31.5 liters.

The next step is to determine the mass of firewood. To do this, you need to know their density - it depends on the type of wood:

pine - 470 kg / m 3;

birch - 600 kg / m 3;

beech - 620 kg / m 3;

oak - 650 kg / m 3.

We calculate the mass of firewood according to the formula: M \u003d Vd * r.

Where p is the density of the wood.

If the calculation is performed, for example, for oak firewood, then M = 0.0315 * 650 = 20.5 kg.

The amount of thermal energy that will be obtained by burning this mass of firewood, we calculate by the formula: Q \u003d M * 0.8 * T * Efficiency.

Where 0.8 - this number shows what part of the fuel burns out completely (80%);

T - specific calorific value of the fuel, MJ / kg:

oak - 20 MJ/kg;

beech - 15.5 MJ/kg;

birch - 16.5 MJ/kg;

aspen - 18.2 MJ / kg.

Efficiency - Efficiency of the furnace: for the unit considered here, the efficiency can be taken equal to 75%.

Then: Q = 20.5 * 0.8 * 20 * 0.75 = 246 MJ.

To determine the power of the heater, we use the formula: W = Q / t.

Where t is the burning time of one fuel bookmark, s. In normal mode, such a mass of firewood will burn a little longer than 2 hours, therefore, we take t = 8200 s.

Then W = 246 * 1,000,000 / 8200 = 30,000 W = 30 kW.

But this calculation is applicable to traditional furnaces, in which fuel is burned in the usual way. In long-burning heat generators, the regime is somewhat different, and the fuel combustion time can change, so the technique presented here often gives a large error.

For a more accurate assessment, if possible, use experimental data. So, according to the testimonies of users involved in the manufacture of furnaces with forced air supply, with a furnace volume of 100 liters, approximately 0.205 kW can be removed from each liter.

The stove, which in this article is proposed to be made by hand, will have a firebox with a volume of 112 liters. Then its power will be approximately 112 * 0.205 = 23 kW. The useful volume will be approximately 70-80 liters.

Considering that the average log length is approximately 40 cm, we will take the length of the furnace equal to 46 cm. Then its width and height can be taken equal to 36 cm and 25 cm, respectively.

With such dimensions, the oven will weigh about 150 kg.

The operating time without refueling is 10 - 12 hours for wood and about 24 hours for coal.

Determining the dimensions of the cross section of the chimney

The required cross-sectional area of ​​the chimney depends on the power of the heat generator connected to it. The ratio of these values ​​\u200b\u200bis given in the SNiP, dedicated to the organization of heating, ventilation and air conditioning systems:

for installations with a power of up to 3.5 kW, the cross-section of the chimney must have dimensions of at least 140x140 mm;

with power from 3.5 to 5.2 kW - 140x200 mm;

from 5.2 to 7 kW - 140x270 mm;

over 7 kW - 270x270 mm.

If the heat generator is connected to a round steel pipe, its cross-sectional area must be the same as that of the rectangular chimneys listed in SNiP. Therefore, for our furnace with its power of 23 kW, the minimum cross-sectional area of ​​\u200b\u200bthe round chimney is 27 x 27 \u003d 729 square meters. cm, that is, its diameter must be at least 30.5 cm.

Materials and tools

For the manufacture of a long-burning furnace, rolled steel is required. The ideal option is to make blanks from heat-resistant steel with the addition of molybdenum and chromium. As an example, the brands 12X1MF and 12XM can be cited. But you should be prepared for the fact that this material is quite expensive.

If the rise in the cost of a home-made "long-playing" furnace is not included in your plans, use ordinary structural steel. It costs much cheaper than alloyed, you just need to choose the right brand. The most durable home-made heat generators are obtained from the Steel 20 brand (withstand 15 years of operation). But you can use other low-carbon grades - Steel 10, St. 3, etc. Grades with a higher carbon content - from the Steel 35 grade and higher - are hardened when exposed to high temperatures. As a result, they become brittle, so they are not suitable for making a furnace.

Everything is clear with the materials, now we will consider the specific types of rental that we need:

Sheets with a thickness of 3 and 4 mm (for the manufacture of a firebox and a heat exchanger).

Sheets with a thickness of 0.3–0.5 mm with a colored polymer coating (sheathing).

Equal-shelf corner 50x4 mm (needed for the manufacture of a grate).

A pipe with a diameter of 50 mm (we will make heat exchanger pipes and flame pipes from it).

A pipe with a diameter of 150 mm - for the smoke outlet.

Rectangular pipe 60x40 mm (air duct).

Strip 20x3 mm.

In addition, you will need the following materials and products:

20 mm basalt wool with a density of 100 kg / m 3;

door handles and hinges;

asbestos cord (used as a sealant).

The design will be welded, so the home craftsman should arm himself with a welding machine. You can use electrodes of the MP-3C or ANO-21 brands. You will also need a grinder and a drill with a set of drill bits for metal. Everything else is tools for ordinary plumbing work and a tape measure with a pencil.

Preparatory work

Rolled steel must be cut into blanks. Of course, you can do this on your own - with the help of a grinder, but a more rational way is to order cutting in some workshop equipped with guillotine shears and a gas cutter. The work will be done faster and better. Yes, and it will cost a little more than manual cutting, because grinder discs also cost money.

Drawing: front and side sections of the furnace

Drawing homemade oven

Steel sheets must be cut into parts, the list of which is displayed in the table.

Table: number and dimensions of steel sheets

It is also necessary to make branch pipes from pipes and grate parts from corners.

It is clear that with a weight of 150 kg, it will be difficult to move the finished oven. Therefore, it should be collected directly at the place that is intended for installation. It also needs to be prepared:

The place is chosen so that the stove is at least 1 m away from the walls. If the walls are finished with non-combustible material, for example, vermiculite plaster, this distance can be reduced to 0.85 m.

From any non-combustible material, a stand is constructed that extends beyond the boundaries of the furnace by 300 mm in each direction. The easiest way is to lay it out of brick.

A basalt or asbestos lining is laid on the floor from the side of the furnace door, and on top of it - a steel sheet with a thickness of at least 1.5 mm. The dimensions of this fireproof coating are selected in such a way that the floor is protected by it within a radius of 1.2 m from the axis of the furnace door.

Step by step instructions with photo

Firebox manufacturing

At the initial stage, all the details - they are cut from a sheet 4 mm thick - are tacked by spot welding. The side walls are welded to the bottom, then the vault (it is also the bottom of the heat exchanger) and the frames of the door openings. What should happen is shown in the figure. As can be seen, the bottom slightly extends beyond the walls of the furnace. Its front part is simultaneously the lower frame of the ash chamber opening.

After assembling the structure, all joints are welded with a continuous seam. Then the firebox is checked for tightness.

Complete firebox

Heat exchanger with water jacket

The outer walls of the heat exchanger are made of 3 mm thick sheet steel. The thickness of the water jacket covering the furnace is 20 mm. Its volume is limited to sections of the strip, which are welded to the firebox and have an outlet of 20 mm - for the thickness of the thermal insulation. They will later be screwed to the skin. The bottom of the shirt is located at the level of the grate.

Water jacket assembly process

The water jacket is reinforced with short pieces of rod called clips. They are arranged in a checkerboard pattern. First, the clips are welded end-to-end to the firebox, then the outer wall is mounted with holes previously made for them. After that, each clip is welded from the outside to the outer wall with a continuous seam.

Clips are welded in a checkerboard pattern

At a distance of 50–100 mm from the front edge, clips made of steel strip can be installed: here they are available for welding, so they can be welded to both walls without making holes in the outer one.

All joints of the elements of the water jacket must be hermetically welded.

Flame tubes inside the heat exchanger

These elements are installed in the holes made in the front and rear walls. To the front wall, they slightly diverge, forming a kind of fan. From the end, each pipe should be welded with a continuous seam.

Flame tubes fan out

Manufacture of grate and doors

"Rods" of the lattice are made from a corner of 50x4 mm. It is important to arrange them exactly as shown in the figure - angle down. With this design, the grille becomes streamlined for the air coming from below and distributes it more evenly.

Grid drawing

The doors are rectangles cut out of the sheet, to the inner surface of which a strip is welded in two rows. A groove is formed between these rows, in which a sealant is placed - an asbestos cord. Doors are equipped with factory-made handles and hinges.

Installation of air duct and branch pipes

The air duct, made of a rectangular pipe with a section of 60x40 mm, is mounted according to the drawing. It must be equipped with a flange through which the fan will be connected. The entrance of the air duct to the ash chamber is made in the rear wall.

Furnace with nozzles installed

To connect the furnace to the heating system, branch pipes from a pipe with a diameter of 50 mm are cut into the walls of the heat exchanger.

It is also necessary to install a smoke exhaust pipe.

Installation of brackets and insulation

Brackets are the parts to which the skin will be screwed. They are welded to the internal elements of the furnace, as shown in the figure.

Installation of thermal insulation material

Now the heat exchanger with a water jacket needs to be overlaid on the side and on top with basalt wool, tying it with an asbestos cord.

Note! The use of glass wool instead of basalt is not allowed, since it already melts at 400 degrees.

Sheathing and installation of doors

There is nothing special to comment on here: decorative panels are screwed to the brackets with screws, the doors are hung on hinges. After that, they (doors) should be painted with heat-resistant enamel. Do not forget to remove the protective film from the decorative panels.

This is what the finished product looks like

Installation of the automation kit

The fan should be screwed to the duct flange, the temperature sensor is laid under the basalt wool at the rear wall of the heat exchanger. The control module with the controller is conveniently placed on the top cover.

Oven operation and maintenance

The long-burning furnace with forced air supply is extremely easy to use:

Fuel - firewood or coal - is loaded into the furnace and ignited in the usual way.

By tightly closing the door, the user sets the temperature range of the coolant on the control module. Do not forget that very aggressive condensate forms on the heat exchangers of solid fuel heaters at low coolant temperatures, so it is recommended to set the lower limit of the range at least 50 degrees.

After setting the operating mode, the user presses the Start key. The controller starts the fan and air begins to flow into the furnace. During operation, the system independently adjusts the blower rotation speed, bringing the furnace to the power required to heat the coolant.

The rest takes place in the order already described: the controller, using a fan, alternately extinguishes the furnace, then activates it again.

From time to time, the stove and chimney should be cleaned of ash and soot.

Modernization of a homemade oven

Several improvements are available to the user:

A coil can be installed in the heat exchanger for heating tap water (DHW circuit). It is made from a copper tube with a diameter of 8–12 mm and a length of about 10 m. The tube is wrapped around the flame tubes and both ends are brought out through the holes in the rear wall.

In case of a long absence of the owners, a heating element can be installed in the heat exchanger. The purpose of this device is not to fully heat the house, but to prevent the system from freezing. Therefore, the heating element can have a much lower power than the furnace itself: 3–5 kW. You don’t need to install any additional automation tools, just choose a heating element with a built-in thermostat (today these can be easily found on sale) and set it to a temperature of, say, 20 degrees.

Also, a sleeve can be inserted into the heat exchanger to install a conventional thermometer - this is in case of a power outage, without which the electronic temperature sensor, and the display showing the temperature, will be inoperative.

Video: how to make a long-burning brick oven with your own hands

With the current level of technology development, the owner of a solid fuel stove does not have to jump up in the middle of the night and run to the woodpile for another bundle of firewood. Aggregates have been invented that can work without user intervention for several days. Some of them can only be made in the factory, but there are those that even an inexperienced craftsman can easily reproduce at home. One of these models - a long-burning furnace with forced air supply - we examined in this article. The given instruction with drawings and photographs will help to carry out all work on the manufacture of the heater without errors.

The problem of heating is especially relevant in the private sectors and industrial parts of cities filled with warehouses and garage cooperatives. There are many ways to heat, ranging from underfloor heating to air guns and fireplaces. Most of these require long-term installation or serious financial costs, but there are those that allow you to enjoy the heat without much investment.

To create the optimal temperature regime in small and medium-sized rooms, you can make a long-burning stove with your own hands. From other devices, a home-made design is distinguished by a high level of efficiency and illegibility to combustion objects. It can function on wood, sawdust, paper, waste and other fuels. Accordingly, the cost of maintaining heat is minimal, and the return exceeds all expectations.

1. After laying firewood in the firebox, user participation in the heating process is not required. Energy can be released up to 20 hours, which minimizes the time spent on refueling and servicing the furnace.
2. The design does not need a solid foundation for installation, it is small in size and is characterized by low weight, as a result of which it can be installed on the ground or on a metal deck. The base must be non-combustible, otherwise a fire cannot be avoided.
3. Furnaces and easily endure long-term downtime, can only be operated in severe frosts.
4. A small amount of waste is generated due to the almost complete burnout of solid fuel, the remaining ash can be sprayed as fertilizer.
5. Despite the fact that it is mandatory in each design, a home-made stove practically does not produce caustic gases, which is very useful in densely populated areas.

The installation of heating devices of this kind is typical for rooms up to 50-70 sq.m. In larger buildings, a water circuit is required, which is not possible in this case.

The principle of operation of a homemade wood stove

Note: A do-it-yourself long-burning furnace device is possible according to a variety of schemes, but they function in the same way.

Fuel is loaded into the boiler, where it is ignited. At this time, oxygen is supplied to the furnace through special dampers. When the wood burns well, access to air is minimized, which leads to the accumulation of heavy gases such as hydrogen and methane inside the heating boiler. They give a huge release of kinetic energy. Trying to make such an increase in power in a conventional stove will lead to a lot of smoke, but will not improve the result in any way.

Preparing to create a structure

The long-burning stove consists of the main part, legs, adapters and a chimney. Like other heating elements, it must comply with all fire safety rules, otherwise sanctions may be imposed on the owner, up to and including administrative punishment. For assembly and welding, a medium-sized room is required, where it will be convenient to work with a single-phase or three-phase electrical network. If a long-burning furnace is created in an open space, then it is recommended to use generators.

Structural elements:

• a barrel, pipe, cylinder or other container with a capacity of about 200 liters, a thick sheet is also suitable;
• scrap metal or channel for assembling legs;
• steel sheets with a thickness of at least 5 mm;
• pipes with a diameter of 100-150 mm for interfacing internal departments and creating a chimney.

Home-made long-burning stoves can be assembled from improvised materials, but it is necessary to monitor the quality and tightness of the seams, as well as carefully check the fit of the dampers to avoid smoke leakage into a residential or industrial premises.

The working tools will be an angle grinder equipped with a cutting disc for metal, a welding inverter, a square and a tape measure, as well as a heavy hammer. All equipment can be found from neighbors or rented, which will significantly reduce the cost of assembling a long-burning stove with your own hands.

Note: Do not use old and rusty pipes or used raw materials - this will significantly reduce the life of a self-made long-burning stove.

You will lose a lot of time and effort, and the device will serve intermittently and malfunctions, which can ultimately lead to a fire in the room.

Structure production algorithm

1. If you took the barrel as a basis, you can skip the first step. Otherwise, from the available materials, you need to create a square or cylindrical container with a bottom, but without a top. If a cylinder is used, then it is necessary to cut off the part with the valve with a grinder, if only a sheet is available, then it must be bent, a connecting seam made with autogenous and the bottom welded with a thickness of 5 mm or more.
2. Legs are attached to the bottom of the future stove or fireplace for long burning. They serve for better stability and prevent the fire of the floor covering during prolonged smoldering of the fuel.
3. This stage involves the manufacture of a clamping part for fuel with a channel. You will need a circle of metal, the diameter of which will be slightly smaller than the inner diameter of the barrel. It should pass freely inside the cylindrical shape. A hole with a radius of 50 mm is cut out in the center of the disc, a pipe of such length must be welded to it so that 10-15 cm protrude beyond the main heating structure. This is not a chimney, this pipe will be needed because oxygen is needed for ignition. At the top, you need to make a damper to limit the amount of penetrating air.
4. To prevent smoke from entering the room, you need to make a cover. It is noteworthy that the supply pipe should also protrude from it, but there should not be large gaps between the sheet and the nozzle. 2-3 mm is enough.
5. The long-burning furnace provides for a hole for cleaning spent fuel. The container must be tightly closed with a door.
6. At the last stage, the chimney is welded. Its length depends on the location of the unit. The chimney cuts into the top cover of the structure. The diameter of the gas vent must be at least 150 mm.

Only one method is described here, but the general principles of assembly are clear. Often it is supposed to place a grate under the fuel - this simplifies the collection of ash. In some schemes, there are heat-conducting elements or a water circuit that will prevent a fire. Firewood can be laid from above or from the side - it all depends on the imagination and practicality of the master. A do-it-yourself long-burning stove is much different in functionality from store-bought counterparts, but it is characterized by a high level of efficiency. Of course, if it is properly designed.

How to use a homemade heater

After the long-burning furnace is completely ready, it must be tested. To do this, remove the top and pressure cover and tamp the tank with fuel. The denser the woodpile is folded, the longer the unit will smolder. Press down the fuel around the channel, close the tank tightly and light the fire. Instead of matches, you need to use a rag soaked in gasoline or kerosene, paper is also suitable. The fuel is ignited through an air pipe. Do not worry about the gas content of the room during the fire - all harmful resins are discharged through the chimney to the street. After 15-20 minutes, clog the damper; your participation in the operation of the heating system will no longer be needed for about 13-17 hours.

Technical nuances

A long-burning furnace is not at all the simplest design, like many others, it has its own characteristics in creation. Below are the main points that require increased attention from the master.

1. Use natural fuel whenever possible. Cones, needles, branches, dry grass - all this contains many elements for the formation of gas, which increases the operating time of the device.
2. The chimney can be split for easy cleaning, but the fewer joints, the better it will function.
3. The diameter of the pipe for the chimney should not be large - this will reduce draft, and a small one will not cope with the removal of combustion products.
4. The heating unit does not need to be placed close to objects and walls, installation near curtains, bookcases, gasoline tanks and so on is especially not recommended.
5. Make doors for cleaning all sections of the boiler, fuel should be loaded into a clean tank - this will increase heat transfer.

A home oven is just the case where size is not the main thing. The main emphasis should be on the fidelity of the design and the quality of the fit of the seams. If the discharge of the room allows and it will not look bad from the aesthetic side - place the unit in the center of the room, so you will increase the heated area to the maximum.

Solid fuel boilers, with all their advantages, have one serious drawback. It consists in the fact that fuel burnout when using this equipment occurs quite quickly. Therefore, you have to constantly monitor his work in order to timely throw the next portion of firewood into the combustion chamber. This leads to the fact that fuel is consumed uneconomically, as a result of which heating costs increase.

To solve this problem, it is necessary to replace the equipment with a more advanced and economical one - a long-burning boiler. As fuel during its operation, ordinary firewood is used. But unlike conventional plants operating on the same fuel, combustion process is longer. Firewood has to be thrown less often. The result is fuel savings. Such a boiler can be bought, but it is better to do it yourself. The scheme for its creation is quite simple, so there will be no difficulties in the course of work. In addition, there are many video instructions on the network that show the process of building such boilers.

The principle of operation of the long-burning boiler

The operation of such boilers is based on the principle of not burning, but smoldering of the fuel put into the combustion chamber. This allows you to get more heat. It is impossible to count on such a result in brick ovens, since a slightly different design scheme is used during their construction. The main reason is that there is no active traction in them.

Boilers of long burning have a number of features in terms of their design, which ensures maximum efficiency of heat release in the process of smoldering logs. Even having built a homemade long-burning stove with your own hands, one bookmark will be enough for it to work for 8 hours.

One of the features of solid combustion boilers is the presence of a regulator valve in their design. When firewood is loaded into the combustion chamber and an active combustion process begins, it is necessary to close the valve and minimize the flow of oxygen into the boiler. In the process of smoldering, firewood begins to emit flue gas. Its main constituents are methane, carbon monoxide and hydrogen.

Heat during the operation of such furnaces is created precisely thanks to flue gas. Getting into the ignition chamber, it ignites, after which it burns out with the release of a large amount of thermal energy.

How is everything arranged?

If you decide to build a long-burning boiler with your own hands, then you should not rush to start work on its creation. First you need to find a drawing for the furnace. There are plenty of them on the web. It will not be superfluous scheme of the device of such an installation. It will facilitate the work on the creation of the furnace. In addition, before starting work, you need to watch a video on how to make a boiler with your own hands.

When creating a long-burning installation, steel pipes should be used as the main material. If they are not available, then you can choose pipes with a diameter of 30-40 cm. In this case, the minimum wall thickness should be 5 mm. If it is less, then during the operation of the metal it will quickly burn out, and then the installation will be unsuitable for further use. The height of the boiler must be at least 1 m.

The created boiler is divided into three parts:

• combustion zone - it is used to remove smoke and smoldering ash;
• combustion zone - it contains smoldering solid fuel;
• loading zone - it decreases in height, which is associated with the gradual burnout of the briquette.

In any scheme of a long-term combustion boiler, there is such a component as an air distributor. The duration of burning depends on it. It limits the zone in which the combustion process takes place. In its appearance, the distributor is a disk made of sheet steel 4 mm thick. In its middle part there is a pipe. Through it, air enters the combustion chamber.

So that as the fuel smolders in the furnace, it can freely fall inside the chamber, its size is made slightly smaller than the furnace. To control the combustion zone, the distributor has an impeller, the height of which is 5 cm. With an increase in its height, its space will also increase, which will lead to an increase in the rate of burning wood in the furnace chamber.

The pipe through which the air will flow must have diameter equal to 6 cm. You can use both a solid pipe and a telescopic one. At the same time, the holes in the distributor should not be more than 2 cm. Otherwise, air will enter the furnace chamber in large quantities, which will lead to oversaturation with oxygen. A damper should be installed at the top. It will allow you to control the draft in the furnace. You can connect a long-burning boiler to the heating one of two ways:

• the water heat exchanger pipe is passed through the combustion chamber. The water in the tank will be heated by means of a coil, which is connected to this pipe;
• a chimney is passed through a remote tank. Smoke passes through it in a hot state, which leads to heating of the coolant.

Comparing these two methods, it should be noted that the first is noticeably simpler in its implementation, while the second provides high efficiency.

Instructions for making a boiler with your own hands

Before starting work on the manufacture of a long-burning boiler, you should watch the video instructions for creating the installation yourself in order to avoid mistakes. You must have a drawing of the furnace, with an orientation towards which all work must be carried out.

Tools

Required in advance prepare materials and tools that you will need during the work:

• pipes 30 cm, 5-6 cm, 10 cm. Please note that the wall thickness of each pipe must be at least 3 mm;
• steel sheet 4 mm;
• Bulgarian;
• welding machine;
• hand tools.

To place the boiler, choose a place with a solid surface.

Making a homemade oven

Installation manufacturing process includes the following steps:

Chimney and reflector

In the process of using a home-made boiler, its walls will be constantly heated, and, naturally, thermal energy will emanate from them. If the installation of the furnace is carried out for a small room, then need reflectors, which will need to be placed around it. Thanks to them, the distribution of the flow will occur, thereby increasing the amount of heat entering inside.

In the event that a long-burning boiler will be installed in a room in which people are constantly present, the issue of ensuring the safety of the installation should be considered. Brick lining the furnace will solve this problem.

To create a chimney of the furnace, you can use a pipe with a diameter of 20 mm. The diameter of the combustion chamber should exceed the straight section of the pipe by 10 cm. It should be brought out into the street with a minimum of kinks. Optimally - two bends at an angle of 45 degrees.

A few other features:

• when creating a chimney of a furnace, its design should be made collapsible. In this case, it will be possible to remove and clean its walls from soot during the season;
• sections of the chimney must be connected in the direction opposite to the movement of gas;
• objects and structures that are easily flammable under the influence of open fire must be moved to some distance from the installation.

We build the foundation

The base for the boiler can be laid out of burnt bricks or rubble stone can be used. These materials do not crack under the influence of high temperatures. If a solid foundation is required, then in this case it will be necessary to fill in a solid monolithic slab. Installation of equipment is carried out on legs. Using a channel, they can be easily welded. You can hide them from the eyes behind the brickwork.

The air in the long-burning boiler must be supplied in a certain amount. This can be achieved only if its bookmark is completed in full, without leaving free cavities. In addition to firewood, peat and sawdust can be added to the furnace.

The filling of fuel into the boiler must be carried out according to the following instructions:

• first you need to remove the cover and remove the regulator from the tank;
• further, fuel is densely laid in the chamber;
• flammable liquid must be sprayed on top of the fuel;
• after installing the regulator, the tank is covered with a lid, and then the damper opens;
• after that, a torch is thrown into the air pipe. When the smoldering process begins, the damper can be covered.

Summing up

You now have a long burning cauldron. You can install this equipment in an unheated room. It will be a great solution for heating the garage. By installing such a boiler in the workshop, you can easily provide a warm atmosphere in it. If the boiler has been manufactured correctly, then high efficiency and efficiency of its operation are guaranteed.

The simplest stove is a potbelly stove.

Solid fuel boilers and pyrolysis-type furnaces can act as an excellent source of heat, giving complete energy independence to an apartment or private house. The above appliances are installed as an additional heating element, helping people save money. After all, everyone knows about the heat losses of a centralized heating circuit, for which the consumer has to pay. Many, using a professional drawing of a long-burning furnace, are trying to build equipment on their own. To what extent will the result justify the hopes of its creator? Is it generally advisable to do pyrolysis ovens with your own hands?

The essence of pyrolysis furnaces

It is possible to read correctly the drawing of a long-burning furnace and, on its basis, make high-quality heating equipment if you understand the whole essence of the processes that occur during the pyrolysis decomposition of fuel. It remotely resembles oil cracking, but is performed with solid fuel in a slightly different temperature range.

Pyrolysis of solid fuel takes place at a temperature of 450°C and under conditions of lack of oxygen. The result is a gas consisting of fractions of wood. Its ignition temperature is much higher compared to the energy that is released when burning solid fuels. This determines the high efficiency of heating equipment (80-85%).

Stages of energy carrier conversion.

The principle of operation of a long-burning furnace is based on the following stages of solid fuel pyrolysis:

• drying of the energy carrier;
• directly pyrolysis;
• combustion of a light, volatile fraction and parallel carbonization of fuel;
• decomposition of heavy fractions to a volatile state;
• reduction reaction at +400°C.

As a result of the last reaction, pure hydrogen, carbon monoxide, is obtained. It is as a result of their oxidation that a large amount of heat is released. However, the arrangement of a long-burning furnace must be organized in such a way that the temperature in it does not fall below + 250 ° C. Otherwise, carbon monoxide and hydrogen will not oxidize, but will go outside without giving up their part of the heat.

Scheme of the furnace. Regardless of the type, shape and size of the equipment, in all cases the principle of operation of the long-burning furnace is essentially the same. The operation of the device begins with the loading of fuel.

For the above equipment, only wood is used. Coal and coke, as a result of the high combustion temperature, leads to an excessively rapid burnout of the secondary air. The oven just suffocates. The burning in it stops.

The design of the furnace in the afterburning of pyrolysis gases.

Primary air is supplied to the lower part of the chamber, firewood is set on fire. The normal combustion reaction takes place in the furnace until the temperature in the chamber rises to the required +400°C. Then the primary air is blocked. Cracking of wood begins in the chamber. The resulting gases rise to the top of the chamber. Secondary air is also supplied there, in the medium of which the afterburning of sublimated products takes place. The result is a large amount of thermal energy. The task of the furnace is to transfer heat as efficiently as possible and with the least loss either to the ambient air in the room or to the water jacket.

The structure of a long-burning furnace depends on the nature of the removal of thermal energy. So, its body can be equipped with a screen. It prevents ignition of nearby objects and improves heat transfer. In some cases, the screen is replaced by a water piping, which is connected to . In this situation, it must be borne in mind that when in contact with cold water, the furnace body will cool down quickly. This will adversely affect the pyrolysis inside. That is why either the productivity of the heating element is increased (which is very difficult), or the shirt is placed at some distance from the body.

We make a stove for a garage or cottage

A practical long-burning sawdust stove for a garage or cottage.

Homemade heating equipment is ideal for non-residential buildings or houses that are visited by people on an occasional basis. In this situation, we are talking about considerable benefits. Firstly, you do not need to spend money on expensive materials and make a device from improvised materials. Secondly, you do not need to pay much attention to the design of the product, but to concentrate on its performance. At the heart of any work is a drawing and diagram of a long-burning furnace from professionals.

Necessary materials:

• metal barrel (up to 200 liters) or metal pipe (diameter up to 600 mm);
• steel sheet;
• channel;
• pipe with a diameter of up to 200 mm and a length of up to 2.5 m;
• pipe, diameter up to 100 mm;
• welding;
• autogen;
• hacksaw for metal;
• building level.

A barrel or pipe is the body of the heating element. In the case of a pipe, the bottom is welded to its bottom. It is cut from a sheet of metal. The second stage will be the organization of smoke circulation. From is also made from a sheet of metal. Its diameter should be somewhat smaller than the diameter of the selected barrel or pipe. A channel is welded to the resulting metal "pancake". It will increase the mass of smoke circulation, as a result of which it will go down as the energy carrier burns out. A pipe is welded to a metal disk. Its length must be greater than the height of the furnace body.

Homemade oven from a barrel, the so-called "Bubafonya".

Further, holes are cut out at the top and bottom of the side of the barrel, the diameter of which is equal to the diameter of the chimney pipe. Pipes and body are connected. Pipes must be of sufficient length. This will allow them to be brought outside the building for the intake of primary and secondary air. Dampers are installed on the chimneys. The lid of the furnace was a round sheet of metal.

Such designs of long-burning furnaces do not differ in aesthetics. However, there are significant benefits here. It is low cost, easy to manage work. In the event of a breakdown, you can organize a new heating element from improvised means without spending money on repairing the old one.

Disadvantages of long burning stoves:

• low efficiency (up to 70%);
• the need for constant monitoring;
• fragility.

Therefore, the above-described heating element cannot be used for residential applications. To heat a private house, experts provide a diagram of a long-burning stove like a potbelly stove with a water circuit.

Modern potbelly stoves with a water circuit

The traditional potbelly stove is designed to heat one room due to the convection of thermal air and, in part, as a result of the generation of infrared radiation. It is also based on the pyrolysis of wood. But, unlike a solid fuel boiler, the firebox of a potbelly stove is not divided into two parts. As a result, if the furnace-chimney system is improperly organized, the pyrolysis gases quickly leave the combustion zone and go outside without giving up their heat. That is why, doing all the work with your own hands, you need to pay due attention to:

• combustion chamber volume;
• chimney pipe diameter;
• temperature control in the furnace.

So, for example, the volume of the firebox is 40 liters. In this case, the chimney is made with a diameter of up to 106 mm. Such a ratio will allow the pyrolysis gases to be retained in the upper part of the stove and the gas will have time to burn out. On the other hand, a chimney of this diameter will quickly bring out the products of combustion and prevent smoke in the room.

The second nuance in the manufacture of the furnace is the grate. In order for pyrolysis to take place in the heating element, the grate is removed. Thus, artificial inflation of oxygen into the furnace is excluded. The smoldering mass will independently draw in the right amount of air through the blower. It is made in a round shape.

The design of the stove-potbelly stove.

The third nuance: for the hasty operation of heating equipment, it is necessary to monitor the temperature inside its furnace. The easiest way to do this is by observing the temperature of the flue gases. If it drops to +100°C, this indicates a violation of the pyrolysis process. In this case, condensation will fall in the chimney. It turns into a solid mass, which makes the cleaning process difficult.

How is a long-burning stove with a water circuit like a potbelly stove arranged? It is distinguished from the traditional model by the L-shaped pipe, which is welded to the blower. It performs the function of an air duct. To do this, small (up to 8 mm in diameter) radial holes are made in its lower part. They are covered with a screw cap. By screwing or unscrewing the latter, it is easy to regulate the gas supply to the furnace, therefore, the intensity of combustion is also regulated.

A drawing of a long-burning stove with a water circuit provides for a water jacket for the home heating system. It is mounted instead of a heat shield and is a rectangular container with water.

The water jacket must not be placed close to the body of the stove. This will lead to a rapid cooling of the furnace, which will adversely affect the pyrolysis process inside.

How the long-burning furnace shown in the figure works:

• to begin with, firewood is laid;
• The L-shaped air duct opens completely, the fuel is ignited;
• as soon as the temperature of the potbelly stove body reaches the desired limit, this is judged by its red color, the duct openings are closed.

Thus, the air supply is limited. The pyrolysis process begins in the furnace. Heat from the walls of the potbelly stove is transferred to the water jacket and then to the heating system of the house. Good to know: " ".

Experts point out the disadvantages of long-burning furnaces of this type - this is low power. Here it is impractical to increase the volume of the combustion chamber, since the square-cube law will be violated. The device in the above diagram is suitable for heating a room up to 25 sq.m. It is also forbidden to take water from the circuit for household needs.

Brick kilns and pyrolysis

Brick ovens are still in demand, although their peak of popularity has long sunk into oblivion.

The principle of operation of a brick kiln is based on the opposition of burning fuel and lining. At the very beginning of the pyrolysis reaction, light volatile gases burn. Their heat is absorbed by the lining through the chimney. Thus, in the furnace and stove, the temperature rises to a fairly high level. This provides cracking of the heavier, volatile components and carbonization of the wood. The heated lining acts as a kind of thermal buffer. With a lack of heat, it releases it, with an excess, it takes it away.

New fuel is gradually introduced into the pyrolysis-type brick oven. It is impossible to use an energy carrier with a high heat capacity. Otherwise, the firebox will “suffocate”, which will adversely affect the efficiency of the equipment. It will drop to 70%. There are also options with an accident if the lining cannot cope with strong temperature fluctuations.

Which oven to choose?

Today you can find drawings and diagrams of a long-burning furnace of the most diverse design, size and performance. However, how effective will the chosen home-made equipment be and where can it be used? Experts answer this question as follows: for non-residential premises, a home-made pyrolysis oven made from improvised materials is perfect. However, it will be weak and short-lived.

For living spaces, not only aesthetics are important, but also performance. In this case, you need to pay attention to the potbelly stove in a modern modification. Its modified air duct and water jacket will allow you to heat a room up to 25 square meters. To increase productivity and heat a larger house, the size of the long-burning stove cannot be increased. To solve this problem, they opt for brick pyrolysis units. Thematic video on how to make a potbelly stove with your own hands: