Long-burning wood stoves. ​Economka stove made of brick: self-construction Economical wood-burning stoves

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Stove heating is experiencing a rebirth, and there are good reasons for this. The leitmotif of the stove renaissance is the long-burning stove. Not only and not so much because it can be done with your own hands, having mastered the basic skills of a mechanic and knowing how to somehow weld two pieces of iron to each other. Long-burning stoves have, first of all, important fundamental advantages over others.

Which ones exactly? To understand, you need to measure the total amount of heat released by one completely burned match twice in a physics laboratory, even a school one, using a calorimeter. The first time, holding it with the head down so that it burns better; the second - head up, as long as it somehow burns to the end. In the second case, the match will release significantly more thermal energy.

The point is that directly Pyrolysis of solid fuel occurs near the flame: it decomposes, releasing flammable gases; See below for more details. They are capable of providing a lot more heat, but to burn them out, in addition to oxygen, of course, you also need a fairly high temperature, from 350-400 degrees.

If you hold the match with the head down, the pyrolysis gases slip past the flame and are wasted or, in the oven, fly out into the chimney. And if pyrolysis occurs directly under the flame, pyrogen gases enter it and, with a sufficient air supply, burn, giving more heat. Another good example of the effectiveness of combining pyrolysis with flame combustion is a regular stearin candle. Just try burning a lump of stearin in a bowl! No need, there will be a stink and soot... And in a candle, stearin not only evaporates, but also undergoes pyrolysis. Have you noticed at the very bottom of its flame a narrow zone of blue-violet color? This is where pyrolysis gases are formed and ignite.

In long-burning stoves using solid fuel, it also burns from above, like a match with its head up, and is ignited from above. In “long” liquid fuel stoves, the fuel (most often oil) evaporates, like stearin in a candle, decomposes into easily flammable components by pyrolysis, and they burn. In any case, in addition to additional heat from the same mass of fuel, it becomes possible to regulate the furnace power over a wide range by dosing the air supply, and the flue gases become cleaner.

Why?

A powerful industrial heating boiler has an efficiency of almost 100%. But during the construction of heating plants, up to 30% of heat losses in the main and distribution pipelines are included in the design. New, made according to all the rules and with intact insulation. Autonomous heating of any type does not lose this 30%, and its efficiency is determined only by that of a stove or hot water boiler.

A small, low-power boiler is, in principle, more gluttonous than a large one - the square-cube law applies, and Russia is rich in fuel resources. Therefore, after the revolution in the USSR, a course was set for the development of centralized heating, especially since the environment was not yet pressing.

From memories. The author of this article, having visited Czechoslovakia in the 70s, was surprised: where are the “Aurora” boiler houses? It turned out that there were automatic, autonomous mini-boiler rooms for a house or entrance in an apartment building. Why? They explained diplomatically: “Well, your country is rich, you can afford central heating.”

A lot has changed since then. The bottom of the global fuel tank is already clearly palpable, the ecology is the same for everyone, and science and computer modeling make it possible to obtain an accurate result where in the era of slide rules and Dwight tables one had to only guess.

What does this have to do with homemade stoves? The most direct: a homemade long-burning stove can, although very clumsy in appearance, have an efficiency of more than 90%. And at the same time burn almost any solid fuel, incl. and waste, to carbon dioxide, water and ash. CO2 and H2O, of course, are also greenhouse gases, but with global fuel efficiency at 90% instead of 70%, global warming will have to calm down.

In cyclic furnaces (firing-cooling-firing-cooling-...) the efficiency rarely reaches the fundamentally important 70%. In addition, it gives more than 80%, but is complex, expensive, cumbersome, heavy and poorly adapted to the conditions of modern life. So, improving “long-lasting” stoves is not only a profitable and exciting task, but also important in general for all people.

About pyrolysis and sublimation

How do you get such high efficiency and omnivorousness? Due to the thermochemical decomposition of solid fuel - pyrolysis, firstly. In this case, components that burn easily and completely are formed, and very little flies into the chimney. Therefore, we need to talk about pyrolysis in more detail.

The stages of the pyrolysis process (see the following) can be separated in space, then it is said to be a pyrolysis oven. But pyrolysis can occur sequentially over time in the same slowly smoldering fuel layer. In this case, they say that it is a smoldering oven.

Secondly, due to the fact that a lot of heat accumulates in the mass of solid fuel and the release of volatile components occurs through dry sublimation - sublimation. For example, they are also pyrolysis, but the oil must first be evaporated, which requires heat, and it is difficult to obtain an efficiency higher than the same 70%. And the heat reserve in hot vapor is small, therefore, at the slightest deterioration in the quality of the fuel (its water content, for example), either the efficiency drops sharply, or complex injectors with a fuel preparation system are needed.

How does pyrolysis work?

The pyrolysis scheme is shown in the figure. The process consists of 4 stages (stages):

1. Drying – excess moisture is removed from the fuel deposit. Drying can be carried out either separately, during the preparation of fuel, or in the firebox, due to the heat of the kindling.
2. Pyrolysis itself - volatile components are sublimated from the fuel mass, and heavy components - resins and bitumen - decompose to volatiles. Carbonization of the fuel mass begins, i.e. its charring.
3. When the temperature reaches the flash point of pyrolysis gases, combustion begins in the presence of free oxygen. The temperature rises to over 600 degrees and the carbon begins to burn.
4. The volatiles and the bulk of the carbon burned out, and the carbon residues in the hot slag, with a lack of oxygen and a temperature of more than 400 degrees, act as a catalyst for reduction reactions: free hydrogen is released from water vapor, and carbon monoxide and carbon monoxide are released from carbon dioxide; from there and from there - free oxygen.

The last stage is harmful. A lot of energy is spent on the decomposition of water and carbon dioxide, because these reactions are endothermic. At temperatures above 250 degrees, the reduced gases immediately form the original compounds, giving back heat. But, if they cool down quickly, they will not have time to find each other again, and the energy spent on restoration will fly out into the chimney, and carbon monoxide, in addition, is poisonous. Therefore, one of the serious tasks when designing a pyrolysis furnace is to ensure retention of reduced gases in the hot zone, providing access to fresh heated air there. Otherwise, high efficiency cannot be achieved.

Note: Not a fundamental, but significant advantage of long burning is the ease of operation of the stove. Once or twice a day I loaded more fuel, once or twice a week I raked out the ash, and that’s it.

About water burners

Among amateur stove-makers there is a cohort of enthusiasts, usually called water burners. The idea is this: we discharge the cooled flue gases into the catalytic chamber. The catalyst does not have to be amorphous carbon (carbon); There are countless offers of various kinds of cunning membranes and powders. On the catalyst, what is reduced will quickly reconnect back, releasing heat, and - done! Here is a “super-unity” stove with an efficiency of more than 100%!

But the law of conservation of energy is still unshakable, although it often manifests itself in roundabout ways. In this case, it is necessary to heat the incoming reduced ones, otherwise the reaction will not proceed. It is not reasonable to compare it with car burners: the remaining fuel burns out there, still capable of giving a positive heat balance, i.e. the reaction is exothermic.

Where does the heat come from to heat the catalytic chamber? Either from adding fuel, or from an external source, an electric spiral, for example.

If we imagine a catalytic chamber, absolutely isolated from the environment, and a heat recovery system that cools the exhaust to absolute zero, then we remain the same: the heat released when combining the recovered components exactly compensates for the cost of heating the components. But, since nothing happens without heat loss (another fundamental principle is at work here - entropy), then the overall heat balance will turn out to be negative. Well, don’t burn the water, it won’t burn...

From theory to practice: firewood and coal

Outside the city, firewood is still one of the most affordable types of fuel. Therefore, a long-burning wood stove is a very relevant and in demand design. It is not difficult to burn wood from a ridge to water vapor, carbon dioxide and ash. But wood is most accessible in waste form, very, very heterogeneous in properties and quality - sawdust, shavings, wood chips, fiberboard and chipboard waste, small brushwood - khamyr, straw. Therefore systems. We will look at some of the most effective ones, in which you can achieve an efficiency of more than the coveted 70%

Potbelly stove

This stove was not called a potbelly stove because of its bourgeois gluttony. On the contrary, it is very economical, and its taste is not picky. How did this happen?

The potbelly stove appeared in Russia immediately after the revolution, during the times of military communism. It is difficult for a modern person to imagine the deprivations of that time. Mayakovsky, who was by no means a stranger to the Bolsheviks, dedicated one of his poems at that time to how he received “half a log of birch firewood” according to the order. And the “unfinished bourgeoisie”, who did not want or were unable to leave their homeland, did not have to count on any coupons. If you want to live, figure out how.

But among the “formers” there were not only bloodsucking exploiters; Those, back in the prosperous years of 1912-1913, transferred capital abroad, and in 1918, as soon as peace was concluded, they quickly scurried off in all directions. Among those who remained were the best minds in Russia. Although they were the necessary “specialists,” the victorious proletariat did not favor them; probably just for the mind. But they knew how to think.

The potbelly stove is ingeniously simple in design, see fig. Its prototype, undoubtedly, is the Russian stove (which, by the way, the “bourgeois specialists” also repeatedly improved) with its phenomenal efficiency for cyclic stoves. Fuel was thrown into the upper door, and by opening and closing the lower door, the combustion process was regulated by supplying air.

The principle of operation of the potbelly stove is also brilliantly simple, but getting to it was not at all easy.

Task: in at least one room in the harsh winter until the morning, maintain a temperature that does not exclude manifestations of vital activity. It is impossible to heat a brick oven: to warm it up you need 20 pounds of those same “half logs”. But there is a Viennese chair, which, according to physics and chemistry, should be enough if you burn it very slowly and immediately release the heat to the room. Even at the flea market, you can exchange bourgeois belongings for a pound or two of coal, which is approximately the same in terms of calorific value.

But how can a highly active, fast-burning fuel be burned slowly? Stop, there is such a thing - pyrolysis. Until now, in household stoves it was considered only a process accompanying combustion. Pyrolysis is much slower than the combustion chain reaction. Let's stretch the combustion in stages, and we'll get the same total heat slowly, little by little. The stove and chimney will have time to completely give it away, and the room will have time to absorb it.

Yes, the stove should also run on coal, since it can be obtained. In terms of properties, coal is not even quite like wood, but what do they have in common in a stove? Loose, breathable filling. Now, how to organize pyrolysis in it?

It turned out that all you need to do is remove the grate and direct the air flow from the blower directly into the mass of fuel. And also, don’t overcrowd the firebox. The volume of the bookmark is no more than a quarter of the volume of the firebox.

In this case, the oven becomes self-regulating. Let's say we covered the vent. Volatiles in a large free volume burn instantly; there will be no fumes, the burning will simply subside. The temperature in the furnace will drop, the filling will cool, pyrolysis will decrease, i.e. production of volatile and flammable substances. And carbon will not produce waste: all incoming oxygen is immediately intercepted by volatiles. Let's open the vent - vice versa. In terms of reaction time constants, everything agrees well; Pyrolysis and chain, although different processes, are essentially similar.

Experience confirms the calculations: when manipulating the ash door, the hot zone of the chimney moves back and forth along its length, at the same time expanding and contracting, in exact accordance with the calculation. That's it, the potbelly stove is ready!

So what was the result? In a Russian furnace, the afterburning of volatiles and the return of the reduced ones are ensured in the furnace, due to a threshold at its mouth. In a potbelly stove, the afterburning chamber is a long, horizontal or slightly inclined part of the chimney, from the center of the room to the window. When it is made from a metal pipe, almost all the residual heat remains in the room.

The efficiency of the then-bourgeois stoves was repeatedly measured by Grumm-Grzhimailo, Kuznetsov and other authoritative heating engineers. It usually exceeds 80% if the horizontal section of the tin chimney is more than 3 m long. The potbelly stove runs on any solid fuel, except sawdust, etc. It warms up almost instantly; This . It can be made either in a box or round from a barrel. One condition: the chimney diameter is from 85 to 150 mm.

A drawing of a modern-looking potbelly stove is shown in Fig. on right. The main difference is in the design of the blower; Now there is no war communism, and small welding and turning work is quite accessible. In the generatrix of the threaded part of the L-shaped air duct pipe (for the sake of simplicity, it can be made straight) small (6-8 mm) radial holes are drilled. By screwing or unscrewing the blind screw plug, you can precisely and conveniently regulate the combustion. An indicator of proper air supply is heating of the chimney. There should be a hot spot on it, moving closer to the stove as the fuel burns out.

Any potbelly stove becomes red hot when fired, so it is not only a heating stove: its upper surface can be used as a hob. But on the sides you definitely need a screen, spaced from the walls of the furnace body at a certain distance (40-60 mm). It is impossible to weld the radiator fins to improve heat transfer and increase fire safety: a hot interior is an indispensable condition for the effectiveness of a potbelly stove. The screen not only protects the room from overheating by infrared rays. By reflecting back at least half of them, it maintains the furnace temperature at the optimal level for maximum efficiency.

Note: e If the temperature in the chimney somewhere drops below 100 degrees, condensation will form, about which, for more details, see below about sawdust stoves. In this case, a chimney of a special design is required, as discussed there.

Using a potbelly stove, you can easily get a wood-burning hot water boiler. To do this, it is enough to replace the screen with a U-shaped metal water heater; it will reflect back IR just as well. But, again, you cannot move the water heating circuit close to the furnace body - it will cool down due to contact (direct) heat transfer, and the efficiency will drop sharply. You need to maintain the same indentation as for the screen.

A potbelly stove of the indicated sizes provides a thermal power of up to 15 kW, depending on the type of fuel, and about a fifth of it will go into the water heater. Therefore, hot water from such a stove can only be obtained for household needs, and the heated area is up to 25 square meters. m. Increasing the size of a potbelly stove for the sake of increasing power is useless - theory prohibits it; due to the same square-cube law, it is not possible to achieve an optimal combustion mode. A potbelly stove was invented to heat one room in a bourgeois apartment. A long-burning furnace must be designed differently and more complex.

More about the potbelly stove

To go further, you will have to return to the potbelly stove and squeeze the very essence out of it. And its essence is in the dimensions of the fuel supply within certain limits and their coordination with the dimensions of the fuel chamber. In this case, the parameters of the stove turn out to be independent of the properties of the fuel - the potbelly stove will squeeze out of it all the heat that it is capable of giving off.

Let's look at the square-cube law in more detail. Oxygen is consumed and heat is generated by the volume of fuel mass, which depends on the linear dimensions of the stack along the cube. And its surface releases heat outward, which depends on them squarely, i.e. with increasing size it increases more slowly.

Hence the first consequence: the optimal temperature for pyrolysis in the fuel mass is ensured only within certain limits of the stack size. If the filling is too small, the excess surface will quickly cool the inside, and the fuel will simply burn as oxygen is supplied.

In a stack that is too large, on the contrary, the inside will overheat due to insufficient surface, everything there will sublimate, and slag and carbon will remain while there is still firewood on the surface. Pyrolysis is again suppressed, and the fuel simply burns layer by layer.

The dimensions of the firebox and the diameter of the chimney must also correspond to the dimensions of the fill. The fact is that the air flow from the ashpit is pressed down and directed into the fuel by the circulation of flue gases, which do not immediately go into the chimney and burn out well. To do this, the convection flow from the surface of the fuel must be somewhat excessive relative to the throughput of the chimney; The potbelly stove works, so to speak, with a virtual high.

In a fuel chamber that is too large and/or with a small filling, the fire simmers and the stove itself is only warm. Convection circulation is sluggish, oxygen from the ash spreads throughout the volume of the firebox, pyrolysis is suppressed, and efficiency is low. When a normal filling burns out, this is no longer scary: the main heat has previously been released and used. But trying to save money by heating one chip at a time is pointless: all the chips will burn one by one, and the room will not warm up - due to the low efficiency, the heat transfer of the stove will be lower than the heat loss of the room.

If the firebox is filled with wood, then there is simply no room left for the convection vortex. Oxygen is instantly consumed by a large mass of fuel, but it does not reach the interior; all of it is spent on surface combustion. The fuel in the mass gradually warms up due to thermal conductivity, but it is low, and pyrolysis is again suppressed: everything that has sublimated immediately burns, only wastingly heating up the inside. The flame does not beat in the stove, but stretches into the chimney. The stove is hot, but not red-hot, and the chimney glows red along almost its entire length.

The second and final consequence: it is impossible to make a potbelly stove of any power and size. Its dimensions are determined by the properties of the pyrolysis gases so that circulation is formed, and the size of the fuel load depends on the size of the furnace. From a potbelly stove with an efficiency of more than 75%, you can get a thermal power of approximately 8 to 20 kW.

From stove to boiler

20 kW is not enough for full heating. And to heat a multi-room home, you need a full-flow water heating circuit built into the stove. That is, it needs a long burning time. Is it possible to obtain it based on the principles inherent in the potbelly stove?

Yes, it is possible, and in two ways. Let's go back a little and squeeze out the quintessence: a potbelly stove is economical thanks to pyrolysis. Pyrolysis fails if the temperature in the fuel mass goes beyond certain limits. And the temperature of the inside of the stowage depends both on the supply of air oxygen and on the nature of convection in the fuel chamber. Let's go from here.

Boiler-1 or method one

• To control the entire process, you need to know only one parameter: the temperature in the combustion chamber. Stays within the optimum range - everything else is OK; the bulk of the heat is released here.
• To optimize heat dissipation for maximum efficiency, you also need to regulate only one value: the boost intensity. The temperature in the combustion chamber is related to the air flow from the boost by a linear relationship, and the automation is extremely simple.
• Since the combustion of pyrolysis gases occurs in a flow, the system is insensitive to the temperature of the walls of the combustion chamber, i.e. The water heater can be built in in any technically convenient way and almost all the generated heat can be transferred into the water.
• When slag with carbon remains in the pyrolysis chamber, reduction is suppressed by increasing the boost, which provides excess oxygen. The natural influx through the ashpit cannot be excessive. Analogue: water, either flowing freely under the influence of gravity, or supplied under pressure.
• It is possible to additionally load a new batch of fuel at any stage of the process and in any acceptable amount - the boost will be increased and purged. A potbelly stove can also be heated, but little by little, so as not to lower the temperature and suppress pyrolysis, otherwise the efficiency will drop sharply and most of the fuel will burn in vain.

Note: the rate of pyrolysis and the composition of pyrolysis gases significantly depend on the type of fuel. These factors can also be taken into account simply by adjusting the back pressure at the outlet by throttling the chimney. In industrial boilers, its regulator is equipped with marks corresponding to the recommended types of fuel.

In once-through boilers with a power of up to 30-40 kW, the temperature in the afterburner can be monitored indirectly, using an important operational parameter - the supply water temperature. At high powers, the thermal inertia of the system can lead to a “boost” of the process - cyclically increasing temperature fluctuations in the combustion chamber, which is already a pre-emergency situation. Therefore, powerful boilers are supplemented with thermocouples in the afterburner and pyrolysis chamber. As long as there is no smell of rocking, the water temperature is maintained. The “burning” thermocouple showed an exorbitant value - we proceed to adjust it, it’s better to let the water cool down a little. It didn’t help - we reduced the pyrolysis temperature using the pyrolysis thermocouple to a minimum. Three-stage adjustment ensures 100% performance, and emergency automation is only triggered by physical influence from the outside. The efficiency of a once-through boiler can exceed 90%

Boiler-2 or method two

A once-through boiler is good for everyone, except for one thing: it needs power. The electricity goes out - the boiler stalls, and then you need to rake out and rip out the sintered mass from the firebox, load a new fill and release your money into the chimney until the process stabilizes.

However, with a power of up to 50 kW, you can make a pyrolysis furnace with a water heater, which does not require automation and electricity (on the right in the figure). The principle of its operation is based on the opposition of two square-cube laws to each other: in the filling of fuel and in the lining of fireclay bricks. This brick oven works according to the following algorithm:

1. At the beginning of pyrolysis, it proceeds most intensely due to the sublimation of the lightest volatiles. This “first heat” passes through the smoke circulation and is absorbed by the lining. In a potbelly stove, the first heat is spent on the formation of a vortex, and in a once-through boiler it is suppressed by reducing the pressure.
2. At the stationary stage of the process, the lining acts as a thermal buffer: when there is an excess of pyrolysis heat, it absorbs it, and releases it when the filling cools.
3. After complete carbonization of the filling, the lining gradually releases heat, preventing the temperature in the furnace from falling below critical, and the reduced ones have time to react before they reach the cold parts of the smoke tract. This is possible because the mass and heat capacity of the lining (proportional to volume) is greater than that of the slag pile. The lining causes it to cool at its own rate, the carbon burns out before the temperature drops, and the reduction catalyst is no longer available below the critical temperature.

A fresh supply of fuel must be loaded gradually into a pyrolysis boiler with a thermal buffer, like into a potbelly stove. A very inertial lining will not be able to fend off sharp temperature fluctuations. And, if the properties of the fuel differ too much from the permissible ones, the furnace with a heat accumulator can either stall (from sluggish fuel), or go into overdrive until it crashes, from fuel that is too flammable. And the efficiency, due to the fact that the first heat is not suppressed, does not exceed 76-78%, which is lower than bourgeois, because the lining eliminates instant heat transfer to the outside.

Incidentally, about fireplaces

Fire is attractive, and its decorative and aesthetic significance is great. There are almost more stoves and fireplaces than heating appliances. And not only oligarchs who can afford any fuel costs want to sit by the fire. Hence the question: is it possible to make a long-burning stove-fireplace? Efficiency and heat transfer are not so important here, as long as the light glows until the end of the evening.

What is there - isn't it possible? There is such a device. This is the good old one, shown in section in the figure.

Note the smoke tooth. It, like a threshold in a Russian stove, forms a circulation of flue gases that does not allow fresh air to escape upward and pushes it into the fuel deposit, as in a potbelly stove. Probably, its unknown authors sat by the fireplace in their “former” bourgeois well-being.

Note: When you light an English fireplace with damp wood, you can see how smoke billows out at the mouth without escaping into the room.

The efficiency of the fireplace due to the large mouth is low even if there are smoke circulations in the chimney; it does not exceed 50%. And smoldering with the release of heat lasts from late evening until morning only when Cornish coal or similar coking coal is added. In the Donbass, anthracite layers of this quality have long been selected, and Karaganda coal burns out in 4-6 hours. They say that in the old days, English lords preferred to heat with the rhizomes of pine trees that grew on coastal cliffs, but now this type of fuel is hardly available to anyone at all.

Along the way. An English lord sits in the evening after a fox hunt by the fireplace, sipping whiskey and smoking a cigar. He lifted his legs up onto the fireplace grate and stared thoughtfully at the fire. The butler approaches: “Sir, I apologize for interrupting your rest, but may I draw your attention to the fact that your socks are starting to smoke” - “Socks? James, do you mean boots?” - “The boots, sir, are already burnt.”

The second option for a “long” fireplace stove is a regular one. Before lighting, you need to close the ashpit, load fuel into a quarter of the firebox by volume, like in a potbelly stove, and keep the firebox door wide open. Most of the heat will fly away into the chimney, but the evening light will last with a rare small flood, and the decorative effect is obvious.

For example

The boilers described above require complex professional work and/or industrial conditions for production. Here, as an example, we provide a drawing of a long-burning stove that can be manufactured by a skilled home-made craftsman at home. Pay attention to the prefabricated unit B, which moves up and down on a telescopic rod. We will soon examine its purpose in detail.

The power of such a furnace is about 35 kW. It runs on coal or fuel pellets. The efficiency is up to 85%; Burning time is about 12 hours. When loaded with firewood, the efficiency decreases to approximately 75%, and the burning duration decreases to 8-10 hours.

Ha ha! Sawdust and dust!

A sawdust stove is a good touchstone for a heating engineer. But not because sawdust and other woodworking waste are lying in heaps everywhere. Saw waste, let the reader know, is a valuable secondary raw material and is disposed of in many ways for a variety of purposes.

But in nature there are huge and almost untapped reserves of mineral fuel, as high in calories as sawdust, and just as poorly burning - oil shale. Until now, the technology for complete and safe combustion of oil shale on an industrial scale does not exist. Underground gasification of shale deposits is environmentally very dangerous, no matter what the authors of the latest developments claim. The United States, which actively offers its shale discoveries to foreign partners, gasifies shale at home sporadically and on a small scale.

But a household sawdust stove is a different matter. Here, enthusiasts have something to apply both their minds and their hands. And there are already examples of successful designs.

Bubafonya

The Baltic states have been actively engaged in shale since the times of the USSR; they have large reserves there; in fact, oil shale is the only type of natural fuel readily available in the Baltics. The STROPUVA oil shale boiler has been mass-produced in Lithuania for a long time. Runet was introduced to it by a user under the pseudonym bubafonja, and now the bubafonja stove is a favorite model for copying by amateur stove makers.

– the stove is not ideal, but its design contains principles that allow the creation of more advanced devices. Therefore, we need to understand the bubafone in more detail. The bubafoni diagram is shown in Fig.

The principle of operation of bubafoni is simple: the fuel filler smolders on top in a thin layer as a solid mass. If you put a solid round wooden block into a bubafonya, it will decay in exactly the same way. All stages of pyrolysis are mixed both in space and time. In the cavity above the filling, minor volatile residues are burned.

Air enters the center of the smoldering zone through a vertical pipe-air duct. And what prevents it from going upward is the pressure with the blades, colloquially called a pancake (part B, remember? Its configuration has been modified for active fuel), welded onto the mouth of the air duct. Contrary to popular belief, the pancake does not press down the bookmark. It needs heaviness in order to fall down under its own weight following the burning fuel without jamming, otherwise the stove will easily stall, and it is very difficult to pick out the unsmoldered sintered filling.

The blades of the pancake are not just partitions that form air channels. They must be curved so that the flue gases escaping from under the pancake swirl clockwise when viewed from above. This is necessary so that the gases, before escaping into the chimney, make several revolutions over the pancake, linger in the firebox and burn out. If the pancake has straight partitions, the efficiency of bubafoni is unlikely to exceed 60%. The incorrect (left) and correct pancakes are shown in Fig.

Note: an unusable sprocket welded in the center of the correct pancake will prevent a column of unburned fuel from forming there (if it is too wet), plugging the air duct. And through the central hole of the sprocket, air will pass into the center of the smoldering zone. A very smart decision.

About the chimney and condensate

For normal operation of the bubafoni, an expanding, smoothly or abruptly, chimney is required, the so-called. a chimney with a draft uneven along its length. A “whistling” chimney of equal cross-sectional length will draw air from under the pancake into itself before it has time to react with the fuel. That is why it is recommended to collect the bubafoni chimney in a countercurrent to the flue gases, i.e. gradually increasing the diameter of its constituent pipes. But this is difficult, but an L-shaped joint of two pipes of different diameters (the far one is larger) will give the same effect due to the formation of a pressure surge at the joint.

For optimal combustion in a bubafone, the size ratios of the gas-air path are also important. The diameter of the air duct should be 1/5-1/7 of the diameter of the fuel chamber. The chimney should be one and a half times wider, and the chimney should be another one and a half times wider. In most cases, this is ensured with a diameter of the air duct of 100 mm, the chimney - 150 mm and the chimney - 250 mm.

Both wood and slate suitable for combustion contain from 8% to 30% moisture. Bubafonya will also digest fuel with 50% humidity. This moisture (by the way, it is this that seduces water burners) in the chimney, where the temperature drops below 100 degrees, forms abundant condensation. It literally pours out of the chimney like a stream. Therefore, it must also have a water collector with a drain ball valve. It is the ball valve - the condensate, to put it mildly, is far from being pure, and the ball valve can be easily cleaned with wire without disassembly.

Bubafonya-cauldron

You can put a water heating circuit on the bubafonya (on the right in the figure above), observing the same condition as for a potbelly stove - a small indentation from the walls. Otherwise, the efficiency will drop sharply, and soot caked into stone will settle on the walls, which will not be removed later. By the way, a screen for a bubafoni is needed in the same way as for a potbelly stove. For normal operation, the bubafonya must also be red-hot. Combustion in the bubafon is regulated by a throttle on the air duct.

A homemade bubafonya from a barrel is shown in Fig. on right. These are its maximum dimensions, and the minimum are:

• The total height, excluding the protruding part of the air duct, is 600 mm.
• The internal diameter of the combustion chamber is 200 mm.
• The diameter of the pancake is 140 mm.
• The diameter of the air duct is 75 mm.
• The diameter of the chimney is 85 mm.
• Chimney diameter – 100 mm.

What's wrong with bubafon?

As already said, bubafonya is not an ideal oven. Firstly, it does not work on highly active fuels - coal, pellets, etc. More precisely, it works for some time after kindling, and then suffocates. When it comes to carbonization, the smoldering layer with the pancake becomes so hot that local microconvection simply does not let air in. When the hot layer cools down, the unnatural, top-down air supply is not enough to flare up again. It is useless to set the boost - a forced impact on the self-regulating system leads to the fact that the air flies over the fuel and flies out into the pipe, taking with it unspent oxygen.

Secondly, the efficiency of the bubafon is, at best, somewhere around 75-78%. Thirdly, the bubafon is not suitable for cooking: the only place where a hob can be installed is occupied by the air duct. And, finally, there is no way to reload fuel until the previous portion has decayed; the loading itself is a bit heavy and inconvenient: you need to lift and somehow fix the heavy air duct with a pancake. So for now, only the Baltic states make bubafoni in series.

Video: example of homemade bubafoni

Slobozhanka

The Slobozhanka stove seems to be a product of folk art in Slobozhanshchina; this is a significant part of the Kharkov, Sumy, Belgorod and Voronezh regions. Although it is similar in principle to bubafonya, it was born independently of it. And, I must say, the result turned out to be much better than the product of former Soviet industrial research institutes, which later became national research centers.

Slobozhanka - . The release of the upper surface under the pans with boiled-off residues is achieved due to the fact that air is supplied to the smoldering layer from the side, describing a U-shaped path: first down the L-shaped air duct, and then through the perforated casing covering it (pos. A in the figure). The solution is, of course, a product of purely Russian ingenuity:

• The air, heating up above the fuel, tends, of course, to go upward, unsupported by anything. But the fuel deposit sags more near the casing, and the flow of oxygen slides over its surface without any pancakes, and the fuel takes as much as it needs.
• The smoldering layer sucks in air as needed, and the excess goes up, ensuring the neutralization of the reduced ones.
• Due to the possibility of air access to all layers of fuel, the hot layer turns out to be thicker than in bubafon, and pyrolysis is more active.

Due to the latter circumstance, the Slobozhanka works perfectly on coal with pellets. Easily combustible pyrolysis gases enter the carbonized layer from below, providing a temperature at which carbon completely burns. Therefore, Slobozhanka is an economical stove. Its efficiency exceeds 80%

The ratio of sizes, the design of the smoke duct and the water heater for Slobozhanka are the same as for bubafoni. A screen is also necessary. But with the same dimensions, its power can be increased at the cost of some complication of the design. To do this, the internal perforated casing must be stretched over the entire circumference and connected to the external incomplete partitions. To arrange a blower with a throttle, you will have to make a third, narrow casing that covers the air intakes on the outside (pos. B in the figure; the stove shell is conventionally turned into a plane). In this case, the fuel filling sags from the center to the edges.

Slobozhanka with fungus

The classic, so to speak, Slobozhanka, has two drawbacks. Firstly, it does not tolerate tarry and greasy fuel. Fiberboard, chipboard and household waste produce hard deposits, and most of all exactly where it is most harmful - on the perforated air duct casing or at the edges of the holes in the internal casing.

Secondly, you need to carefully refill the unsmoldered filling. At least a small smoldering area near the perforation of the casing should remain free. This is not always convenient: you only have time to plop everything down at once, and when you leave, the stash will burn out and the stove will cool down, you need to relight it again, enduring the cold and releasing your hard-earned money into the chimney.

Meanwhile, in small remote garrisons of the Soviet Army (individual companies, stationary communications points, etc.) back in the 70s one could find a heating-cooking-incinerator stove produced by some kind of post office, see pos. B in Fig. This is the same Slobozhanka, but with a central conical perforated air duct equipped with a mushroom cap. The cone was inserted freely into the discharge hatch of the firebox and removed for cleaning. The bookmark sagged from the edges to the center.

The role of the fungus was apparently twofold. Firstly, its protruding edges threw the “plumped” fuel to the edges, and under the cap there was always a smoldering ring, sufficient for the stove to “ignite” again. It was possible to add fuel at any time and as much as needed.

Secondly, the brim of the hat directed additional air flow into the smoldering zone. This ensured complete omnivory. What the careless orderlies didn’t throw into the stove - it’s sickening for a decent person to remember...

The efficiency and power of the stove were not measured by the author, but one and a half buckets of coal-seeds were enough for 14 souls of personnel in a single army tent in the frosty winter to sleep well in one cotton and without boots, under army flannel blankets.

Of the shortcomings of the “slobozhanka with fungus”, only one was noticed: when burning with household garbage or damp pine, it was necessary to check the carbon deposits every 2-3 days. If you missed it, the cone stuck tightly in the socket, and it was difficult to swing it and take it out without distorting it.

Video: assembling a homemade Slobozhanka from a barrel

Should I buy it?

Isn’t such a wonderful stove mass-produced? Is it possible to buy it ready-made somewhere? Large manufacturers seem to have focused on those that are in high demand for greenhouses and do not become hot when fired. But small private producers do it and offer it. The sample is shown in Fig.

This Slobozhanka has a small but useful improvement: an external ash pan lying freely under the hearth, second from the left, pos. It can be carefully taken out and emptied without causing ash dust in the living space. But you still have to climb into the oven: the cover of the unloading hatch (it is visible on the bottom in the position on the far right) must be closed when firing.

About fuel

There is no need to look for fuel for a long-burning stove at a household or industrial landfill. Manufacturers are vying with each other to offer excellent smoldering pellets at a price of about 4,000 rubles. per ton. Considering the cost-effectiveness of “long” stoves, this comes out quite inexpensively.

Pellets are made from any burning biomass: the same sawdust, wood chips, straw, onion and garlic peels, sunflower husks, cones, bark, citrus peels, nut shells, etc., etc., see fig. The technology is somewhat reminiscent of MDF production: dry pressing at elevated temperatures.

In terms of thermal properties, fuel pellets are similar to coal. They are produced from “dust” with a diameter of 6 mm to 30-70 mm logs. During the production process, components that can produce harmful volatiles are removed from the mass of raw materials, so the pellets are easily burned to carbon dioxide and water. In general, it is a very good fuel with stable properties.

Long-burning stoves have become increasingly popular in recent years. The operating principle of these devices is based on separate combustion of fuel and released gases in different chambers. Thanks to this design, wood or other material burns more slowly than in a conventional stove, using less oxygen and releasing more heat. Such heating devices, which are also called pyrolysis or gas generator furnaces, are successfully used in private homes, cottages, baths and saunas, industrial and utility premises.

How to choose a long-burning stove

Long-burning heating devices are supported by their undoubted advantages - economy, environmental friendliness, compactness, ease of operation, high efficiency (up to 70-85%), long service life, accessibility.

Power

The main criterion when choosing a heating device with a long combustion cycle using solid (wood) fuel is its power. It must correspond to the volume of the heated room. There is no point in installing a high-power stove in a small room, since some of the heating material will burn irrationally. In addition, a large device will take up a lot of space, and the room temperature will be too high. On the contrary, a low-power stove in large rooms will work at the limit of its capabilities, which will quickly cause it to fail.

Fuel

When choosing, you should decide on the type of fuel that is supposed to be used - firewood, pellets, coal, fuel briquettes, etc. You should know that the moisture content of wood fuel is of great importance, since water vapor diluting the gases interferes with combustion, reduces the power of the device and promotes the formation of condensation. In some cases, excessive moisture in the burned material can lead to spontaneous extinguishing of the furnace. Firewood for long-burning fireboxes, for example, should have a moisture content no higher than 20-35%.

Remember, the use of fuel not specified in the operating instructions and the use of heating material that does not correspond to the size and design of the firebox is strictly prohibited!

Material

The metal or alloy from which the long-burning furnace is made is also an important selection criteria. The thicker the material of the device body, the slower the device cools and the longer its service life. Some models of long-burning stoves made of cast iron last up to 50 years (!) and, moreover, are not subject to corrosion.

Elements of many modern stoves - firebox, hob, trim, door - are made from different materials (cast iron, vermiculite, steel, stainless steel, heat-resistant glass, etc.), which allows you to increase service life, improve design, improve ease of use and long lasting time to maintain appearance.

Design

The appearance of the heating device often plays no less important role than other factors. A stove for a living space should have a modern design and fit harmoniously into the interior. There are many imported models on the market, from which you can choose a ready-made stove for any home. Canadian, German, Polish, French long-burning stoves and fireboxes made in Serbia are very popular. Russian stoves with a long combustion cycle are also presented in an equally extensive range.

Homemade products

For a service or utility room (greenhouse, garage, warehouse), you can make it yourself or order it from craftsmen a long-burning heating device from a gas cylinder such as Slobozhanka, Bubafonya, etc. Sometimes metal barrels are used for the artisanal production of such devices. Although such devices do not have an elegant and original design, they can provide effective heating with minimal manufacturing costs.

Functionality

In some cases, additional features play a decisive role when choosing a heating device. This may be the presence of a hob, the possibility of using a heat exchanger, a thermal accumulator, the presence of a high-quality automation system, etc.

Features of operation

All long-burning stoves are supplied with instructions, but they often do not mention some nuances that must be taken into account:

• It is necessary to provide free space around the stove and protection from fire;
• for easy maintenance (cleaning), the chimney should have a collapsible design if possible;
• pipes must be installed in the direction of gas movement;
• due to low draft, the chimney should not have a curved shape;
• During operation, condensation may form in the chimney.

It should also be noted that liquid fuel cannot be used in long-burning stoves; some models are quite difficult to set up and require constant supervision.

Popular stove models on the market

There are many varieties of long-burning solid fuel heating systems, from which you can choose a device for almost any room, regardless of its purpose, volume and method of heating (water or air).

The most widespread are long-burning furnaces such as Buleryan, Breneran, and the “Professor Butakov system.” The most famous brands on the market of solid fuel heating devices:

• Klondike;
• Buderus;
• Sogra;
• Siberia;
• Thermal;
• Bubafonya;
• Germa;
• Alaska;
• Slobozhanka;
• Teplodar;
• Stropuva;
• Umka;
• Buran;
• Chenille;
• Vira;
• Supra;
• Stoker (Ermak);
• A week.

Review of long-burning stoves

Choosing a heating device is a subjective process. It is necessary to independently determine what tasks a solid fuel device should solve - heating, cooking, equipping a bathhouse, water heating equipment, etc. Our rating includes boilers, stoves, fireplaces, long-burning heating devices of industrial and handicraft production for private houses, summer houses, baths, saunas, utility rooms, etc., which enjoy the greatest success among users.

Stoker 100-C (Ermak)

Long-burning heating stove Stoker 100-S, made in Russia (Kirov) is a device with high convection characteristics and additional capabilities, designed for heating a country house, cottage, and other residential and commercial facilities. An analogue of the presented device, but without glass, is the Ermak-thermo 100 long-burning stove.

Characteristics:

• Efficiency - 75%;
• power - 6 kW;
• fuel - firewood, pellets;
• material - structural steel;
• burning time (fuel consumption) - up to 12 hours (about 2.4 kg/h);
• hob - yes (with burner);
• ash pan - yes;
• combustion adjustment - coarse and fine.

Advantages:

• transparent door with SCHOTT ROBAX glass;
• directional heat exchange system (convection);
• soft infrared radiation;
• the possibility of optionally using a heat accumulator and heat exchanger to supply hot water;
• affordable price.

Flaws:

• quick cooling of the device in the basic configuration.

Application area: residential, utility and domestic premises.

Approximate price: from 14,000 rub.

MBS Vesta

The MBS Vesta gas generator stove made in Serbia is one of the most popular long-burning stoves and fireplaces on the market. A special feature of the model is its modern design and the ability to choose a device with a color of the side surfaces that matches the interior (burgundy, cream, red).

Characteristics:

• the volume of the heated room is up to 60 cubic meters. m;
• power - 9 kW;
• Efficiency - 85%;
• fuel - fuel briquettes, firewood;
• material - cast iron, enameled steel;
• fuel consumption - about 3 kg per hour;
• hob - solid (cast iron);
• ash pan - yes (retractable);
• combustion adjustment is precise.

Advantages:

• heat-resistant glass SCHOTT ROBAX (Germany);
• design;
• tightness;
• movable cast iron grate.

Flaws:

• relatively high fuel consumption;
• price.

Application area: country houses.

Approximate price: from 32,000 rub.

Week KO-60

The automatic long-burning boiler Nedelka for water heating (Russia) is so named because of its ability to function under certain conditions for 6-7, and in some cases up to 9 days, without human intervention. Nedelka is heated with coal of any type and quality.

Characteristics:

• heated room area - up to 400 sq. m;
• power - 60 kW;
• Efficiency - up to 92%;
• fuel - coal;
• material - steel;
• burning time for a heated area of ​​100 sq. m - up to 6 days;
• hob - no;
• loading and cleaning system - yes;
• combustion control is automatic.

Advantages:

• service life - over 20 years;
• reliability;
• imported automation;
• absence of moving parts in the design;
• safety - in case of power failure it goes out slowly;
• long period between lighting and cleaning.

Flaws:

• difficulty in installation;
• high price.

Application area: residential buildings, buildings with office and industrial premises.

Approximate price: from 126,500 rub.

SUPRA Gotham

The first Supra fireboxes (France) appeared on the market back in 1878. Since then, the company has not changed its profile, accumulating experience in the development and production of heating systems. Today you can purchase Supra fireplace stoves and other long-burning fireboxes in both traditional and modern styles. SUPRA Gotham wall-mounted stoves are suitable for any living space. They effectively provide heating, create coziness and comfort.

Characteristics:

• room volume - up to 200 cubic meters. m;
• power - 14 kW;
• Efficiency - 78%;
• fuel - wood;
• material - cast iron (cladding - metal);
• burning time - up to 10 hours;
• hob - no;
• Ash pan - yes.

Advantages:

• effective “clean glass” system;
• design;
• possibility of installation at a short distance from the wall (35 cm);
• reliability;
• durability;
• quality that meets the French standard Quality Charter “Flamme Verte 2009” (carbon monoxide emissions - no more than 0.3%, efficiency - 70% and above).

Flaws:

• high price.

Application area: country cottages, private houses, dachas.

Approximate price: from 117,000 rub.

Vira Gori Clear Legion-160 C

A cooker and heating device with a long combustion cycle Vira Legion-160 C (Gori Yasno) manufactured in Russia allows the user not only to heat the room, but also, thanks to the presence of a hob, to cook or warm up food. Devices of this brand have deservedly received the unofficial name “folk fireplace”.

Characteristics:

• power - 8 kW;
• fuel - firewood;
• room volume - up to 160 cubic meters. m;
• material - structural and stainless steel, cast iron;
• burning time for a full load is up to 6 hours;
• hob - yes (with cast iron burner);
• ash pan - yes;
• combustion adjustment - yes.

Advantages:

• door with window;
• design and availability of models in different colors;
• quick and easy installation;
• high maintainability;
• compactness;
• weight - 61 kg;
• price.

Flaws:

• relatively short service life of a steel firebox.

Application area: residential and household rooms in country houses and dachas, temporary change houses, saunas, baths, etc.

Approximate price: from 13,000 rub.

Chenille S100

The gas generator stove Chenille S100 is a product of Russian defense technologies that embodies the best qualities of Western analogues, the traditional Russian stove and the famous “potbelly stove”. At least that's what the manufacturer claims. This device can operate effectively in two modes - maximum (“potbelly stove” mode) and main (“gas generation” mode). Thanks to this, you can quickly achieve the required temperature in a heated room and then maintain it for a long time and economically. The manufacturer also produces models designed specifically for baths and saunas.

Characteristics:

• Efficiency - up to 80%;
• power - 6.7 kW;
• fuel - firewood, wood waste, cardboard, peat;
• heated room volume - up to 120 cubic meters. m;
• material - steel, cast iron (grid bars);
• bookmark burning - 8-12 hours;
• ash pan - retractable;
• hob - yes;
• combustion adjustment - yes.

Advantages:

• weight - 46 kg;
• door with glass;
• possibility of loading whole logs;
• compactness;
• suitable for large rooms;
• price.

Flaws:

• It is difficult to find 140 mm pipes on sale.

Application area: household and residential facilities.

Approximate price: from 10400 rub.

Buran-12

Boilers Buran (Ukraine) using long-burning solid fuel are distinguished by their unpretentiousness and ease of operation. Their valuable advantage is energy independence, which is extremely important in conditions of unstable power supply. Products under this brand are used in individual homes and other small facilities.

Characteristics:

• power - 12 kW;
• room area - up to 120 sq. m;
• Efficiency - 82%;
• fuel - firewood, wood waste, briquettes, brown coal, anthracite;
• burning time - up to 30 hours;
• material - boiler steel;
• hob - no;
• draft adjustment - mechanical (for the wood-burning version), forced (fan for the coal version).

Advantages:

• possibility of using coal;
• efficiency-cost ratio.

Flaws:

• complexity of installation;
• fragility of some elements (air distributor);
• price.

Application area: organization of autonomous water heating in residential and industrial premises, objects with large heat loss (greenhouses).

Approximate price: from 73,000 rub.

Umka 150

The Umka 150 long-burning heating and cooking furring furnace is used for heating cottages and private houses with a volume of up to 150 cubic meters. m. Modern technologies have ensured the durability, efficiency and reliability of this model, and the cast-iron hob has increased the functionality of the product. The Foehringer company (Russia) also produces wood-burning stoves for arranging saunas and Russian baths.

Characteristics:

• material - steel, cast iron;
• fuel - firewood;
• power - 9 kW;
• heated volume - up to 150 cubic meters. m;
• burning time - 7 hours;
• hob - cast iron;
• combustion adjustment - yes.

Advantages:

• weight - 28 kg;
• observation window made of ROBAX glass and the “clean glass” system;
• efficiency;
• service life in normal mode is at least 10 years;
• reliable patented door closing system.

Flaws:

• paint takes a long time to fade;
• The hob gets dirty.

Application area: residential and domestic premises.

Approximate price: from 15,000 rub.

BOSCH SFU 24 HNS

The Bosch 24 kW boiler, produced in the Czech Republic, belongs to the Solid line of the famous German brand BOSCH. The main differences between long-burning heating devices of this brand are “fuel omnivorousness”, a high-quality automation and control system, as well as an optimal price-quality ratio.

Characteristics:

• power - 24 kW;
• room area - 230 sq. m;
• Efficiency - 78%;
• fuel - brown coal (main), firewood, coke;
• material - steel;
• burning time - about 6 hours;
• control - mechanical.

Advantages:

• perfect management and control system;
• possibility of using different types of fuel;
• energy independence;
• possibility of use in gravitational systems;
• ease of operation and maintenance.

Flaws:

• fuel consumption - 10 kg per hour.

Application area: for organizing autonomous heating or integration into an existing system.

Approximate price: from 58,000 rub.

STROPUVA S15

Boilers in Stropuva (Lithuania), operating on solid fuel, depending on the modification, are capable of operating on one tab:

• on wood - up to 40 hours;
• on briquettes - up to 70 hours;
• on coal (universal) - up to 7 days.

The company's developers managed to achieve such high performance, as well as economy and safety, through the use of patented innovative technologies. The STROPUVA S15 model belongs to the class of long-burning wood heating devices.

Characteristics:

• room area - up to 150 sq. m;
• fuel - firewood, fuel briquettes;
• power - 15 kW;
• Efficiency - 85%;
• material - boiler steel;
• burning time - up to 30 hours.

Advantages:

• economy;
• ease of operation;
• safety;
• energy independence.

Flaws:

• complexity of installation;
• price.

Application area: for water heating in private houses.

Approximate price: from 92,000 rub.

Teplodar OV -120

Decorative stove Teplodar OV-120 type “fireplace” (Ukraine) has a stylish appearance. The door with large heat-resistant glass makes the device as similar as possible to a classic fireplace. The device is equipped with a special hob. This model is available in angular and straight versions. It is ideal for quickly creating coziness and comfortable conditions in a country house.

Characteristics:

• heated volume - up to 120 cubic meters. m;
• fuel - briquettes, firewood;
• material - heat-resistant high-alloy steel;
• hob - yes;
• ash pan - retractable;
• traction control - yes.

Advantages:

• service life - 10 years;
• exquisite design;
• presence of a compartment for drying firewood;
• fast temperature set;
• ease of operation.

Flaws:

• overpriced.

Application area: dachas, country cottages.

Approximate price: from 23,000 rub.

Alaska 150

Alaska 150 (Russia) is another highly efficient fireplace-type heating device. The rectangular body of this long-burning stove, made of high-quality steel, ensures high efficiency in heating the room. A SCHOTT ROBAX glass window in the door allows you to admire the fire, as if near a real fireplace. The hob makes it possible to cook and heat food.

Characteristics:

• power - 9 kW;
• fuel - firewood;
• hob - yes;
• room volume - up to 150 cubic meters. m;
• Efficiency - up to 70%;
• material - steel;
• ash pan - yes;
• combustion adjustment - yes.

Advantages:

• appearance;
• functionality;
• reliability;
• availability.

Flaws:

• relatively low efficiency;
• price.

Application area: private houses.

Approximate price: from 14,000 rub.

Slobozhanka

The Slobozhanka stove made from a gas cylinder belongs to the category of inventions of domestic craftsmen. To make it, a metal barrel or other suitable container or sheet steel can be used. This is an inexpensive, productive, reliable and easy-to-use long-burning heating device.

Characteristics:

• power - up to 16 kW;
• material - steel;
• Efficiency - up to 90% (!);
• fuel - firewood, straw, wood waste, pine cones, etc.;
• burning time - up to 12 hours.

Advantages:

• simplicity;
• low cost of production;
• efficiency.

Flaws:

• appearance.

Application area: outbuildings.

Approximate price: cost of basic and consumable materials.

Germa

The Germa household stove (Russia) has a so-called “bell” design - hot air is collected in a “hood” at the top of the product, cools a little and goes down under the pressure of a new portion. This principle in a long-burning firebox ensures continuous air circulation and promotes maximum heat transfer.

Characteristics:

• Efficiency - 80%;
• power - 13 kW;
• fuel - firewood, peat, brown coal;
• room volume - up to 250 cubic meters. m;
• burning in economical mode - up to 8 hours;
• material - steel;
• hob - yes;
• ash pan - yes;
• traction control - yes.

Advantages:

• appearance;
• additional niche (oven) for heating and cooking;
• SCHOTT ROBAX screen;
• efficiency.

Flaws:

• price.

Application area: country houses.

Approximate price: from 30,000 rub.

Bubafonya

Bubafonya is a long-burning gas cylinder stove using vegetable fuel, which began its journey to the consumer from the workshop of a craftsman. Today, some manufacturers are establishing industrial production of these devices. The main advantages of such devices, as well as Slobozhanka-type furnaces, are ease of manufacture, low cost, reliability and efficiency. On the basis of this invention, a long-burning Bubafonya furnace with a water jacket is also manufactured.

Characteristics:

• Efficiency - up to 85%;
• burning of a full load - up to 8-10 hours;
• fuel - firewood, plant waste;
• material - steel;
• hob - missing.

Advantages:

• high performance;
• autonomy;
• weight - 28 kg;
• mobility;
• simplicity and reliability of design.

Flaws:

• appearance.

Application area: outbuildings.

Approximate price: Cost of materials.

Thermal 100

Thermal 100 is a long-cycle furnace made of steel that can operate for over 20 years. The developers have achieved such durability thanks to the use of an original design in which the firebox is constantly blown with circulating air, which prevents premature burnout of the elements.

Characteristics:

• power - 10 kW;
• fuel - firewood, pellets, briquettes, peat;
• room volume - up to 100 cubic meters. m;
• material - steel;
• Efficiency - 80%;
• burning time - up to 8-10 hours;
• hob - yes (with a hinged lid);
• Ash pan - yes.

Advantages:

• durability;
• reliability;
• price;
• efficiency.

Flaws:

• no air supply adjustment.

Application area: cottages, household and utility premises.

Approximate price: from 8400 rub.

Siberia BV-120

The long-burning solid fuel stove Siberia BV-120 (Russia) has a Buleryan type design. This type of air-heating heaters has gained great popularity among users due to its high efficiency. Such two-chamber devices are successfully used in a wide variety of places - from residential premises to domestic and outbuildings for various purposes.

Characteristics:

• Efficiency - up to 85%;
• heating volume - up to 120 cubic meters. m;
• fuel - firewood, cardboard, peat briquettes;
• power - 8.4 kW;
• material - steel;
• The burning cycle of the bookmark is 8-12 hours.

Advantages:

• efficiency;
• durability;
• safety;
• reliable lock.

Flaws:

• no hob.

Scope of application: utility and household buildings, industrial premises, country houses, dachas.

Approximate price: from 13,000 rub.

Sogra 2

Sogra 2 is an ultra-light class solid fuel stove from the Mobiba company (Russia). Its weight is only 13 kg. It is suitable for heating country houses, expedition tents, rooms with small volumes, etc. This stove with a long combustion cycle is completely safe when used in cramped conditions. It is suitable for boiling water and cooking. This device is one of the best for use in the field.

Characteristics:

• firebox volume - 25 l;
• material - heat-resistant stainless steel;
• fuel - firewood;
• burning time for a full load is up to 10 hours;
• hob - yes.

Advantages:

• weight - 11-13 (!) kg;
• compactness;
• functionality;
• carrying handles;
• faceted shape, giving additional rigidity;
• The set includes support legs and a carrying bag.

Flaws:

• fast cooling.

Application area: small rooms, tents, mobile baths.

Approximate price: from 12,000 rub.

Buderus Logano G211-20D

The floor-standing solid fuel boiler Buderus Logano G211-20D (Germany) is intended for use in a main water heating system, as well as for connection to an existing system with liquid fuel or gas boilers. Optionally, an additional heat exchanger can be attached to it. This long-burning device can operate both in gravitational heating systems and in heating networks with forced circulation.

Characteristics:

• fuel - firewood (main), coal;
• power - 16 kW;
• heated room area - up to 200 sq. m;
• Efficiency - up to 78%;
• material - cast iron;
• burning time - up to 4 hours;
• control - mechanical.

Advantages:

• durability;
• unpretentiousness;
• design;
• versatility.

Flaws:

• complexity of installation;
• price.

Application area: residential and administrative premises.

Approximate price: from 93,000 rub.

Klondike NV-100

This model has been a bestseller in many online stores for several years now. This is explained by the successful combination in the Klondike NV-100 stove of a highly efficient Buleryan-type design, high quality workmanship and affordable cost. The manufacturer assures that the money spent on the purchase of this firebox will be returned in a year in the form of savings on fuel.

Characteristics:

• power - 6.2 kW;
• room volume - up to 100 cubic meters. m;
• Efficiency - about 80%;
• fuel - all types of wood fuel, cardboard;
• material - steel;
• combustion cycle - 8-10 hours;
• combustion adjustment - two dampers.

Advantages:

• high performance;
• economy;
• reliability;
• durability;
• availability;
• simplicity and ease of use.

Flaws:

• no hob.

Application area: residential and commercial premises.

Approximate price: from 10500 rub.

Results

• the best stove (“price-efficiency-quality”)- Klondike NV-100;
• best industrial furnace with high efficiency- Siberia BV-120;
• the best fireplace stove- Alaska 150;
• best design- Teplodar OV-120;
• best oven with long service life- Thermal 100;
• best camping stove- Sogra 2;
• best powerful oven- SUPRA Gotham;
• the best oven with increased functionality- Germa;
• the best oven with additional options- Stoker 100-S (Ermak);
• best multipurpose oven- Chenille C100;
• the best stove for a summer house- MBS Vesta;
• the best stove for baths and saunas- Umka 150 (Vöhringer brand);
• best folk oven- Vira Legion-160 C;
• best homemade stove- Bubafonya;
• best budget oven- Slobozhanka;
• best boiler- Buderus Logano G211-20D;
• best powerful boiler- BOSCH SFU 24 HNS;
• the best universal boiler- STROPUVA S15;
• the best non-volatile boiler- Buran 12;
• boiler with the longest combustion cycle- Week KO-60.

Experience in operating long-burning solid fuel heaters in Canada, Finland, Sweden, Norway, the USA and other countries shows that the use of such devices makes it possible not only to save money on fuel resources, but also helps to improve the ecological state of the environment. Such products are confidently conquering the markets of many countries, including Russia.

The popularity of modern long-burning wood stoves is constantly growing, as it allows you to obtain more thermal energy, and with less solid fuel consumption. This is especially true for populated areas where there is no centralized gas supply, and problems arise from time to time with electricity supply.

The effect of pyrolysis and its application in furnaces

The functional purpose of long-burning heating units is based on the effect of pyrolysis, a process that is the decomposition of natural chemical compounds in the absence of oxygen. As a result, a large amount of heat is released.

Pyrolysis refers to the decomposition of solid fuel. The fact is that when it burns, it is the gaseous products that are released when heated that ignite, and not the wood itself. Thus, if an ordinary fire is lit, a person is faced with pyrolysis.

The difference is that under standard conditions, wood combustion occurs in the presence of oxygen, and this ultimately negatively affects the overall efficiency of the heating device. A full-fledged pyrolysis process requires limiting the supply of oxidizer and burning gases separately from smoldering solid fuel.

Now there are many options and design solutions for how to make a long-burning stove. Such devices, despite the presence of technical differences, have a similar operating principle.

In order to ensure efficient use of fuel, economy units operate using the pyrolysis process. As a result, the main amount of thermal energy is produced through the combustion of gases that are released as a result of smoldering wood - hydrogen, methane and others. In this case, oxygen is supplied to the furnace in doses using a regulator.

First, the fuel is given the opportunity to burn well for about 30 minutes, and then the access of the oxidizer to the firebox is minimized. Smoldering firewood under such conditions releases the maximum amount of flammable gases, which, when burned in a separate chamber, can provide heating to the body of the pyrolysis unit.

Pros and cons of long-burning stoves

There are many advantages that economical wood stoves have:

1. Maximum complete combustion of the solid fuel load. For this reason, boilers that burn wood for a long time have excellent efficiency, reaching 85%.
2. These heating units are quite easy to clean and maintain, since after the wood has burned through, there is practically no ash left.
3. Environmental friendliness of the pyrolysis process. With complete combustion of natural organic compounds, the only oxidation products are carbon dioxide and water vapor. In a pyrolysis furnace, solid fuel decomposes completely, so all kinds of industrial waste can be used as a source of thermal energy, which under normal conditions is allowed to be burned only at a considerable distance from residential buildings in specially equipped landfills.
4. You will need to load the next portion of firewood or other solid fuel much less frequently, or rather once every 10 to 15 hours, which is an undeniable advantage of these units compared to conventional stoves and potbelly stoves. Some models of factory-made pyrolysis boilers are capable of operating for a longer period of time on one bed.
5. Fast heating of the coolant, provided there is a heating heat exchange circuit for private houses.
6. The ability to perform precise and high-quality adjustment of the unit’s power indicator. Under normal operating conditions, it is quite difficult to control the operation of heating devices using solid fuel compared to analogues that use gaseous or liquid fuel. Since in a long-burning wood-burning stove the gas released during the pyrolysis process is burned in a special compartment, this problem can be solved quite easily.

Pyrolysis plants have a number of disadvantages, including:

1. High price for ready-made heating boilers. This negative point can be eliminated if you make economical wood-burning stoves with your own hands.
2. Increased requirements for the moisture content of solid fuels. If you decide to use poorly dried firewood and try to put the unit into operation before it is completely dry, the fire will most likely go out and the full pyrolysis process will not be completed.
3. Quite large dimensions. In addition to the fact that it is necessary to prepare a place for installing a pyrolysis boiler, it will be necessary to arrange the area where solid fuel will be stored.
4. Inability to provide fully automatic operation. Firewood must be loaded into the unit manually.
5. When installing an industrial model of a pyrolysis boiler, additional blowing of the combustion chamber is often provided and pumping equipment is installed to circulate the working medium in the heat supply circuit. Therefore, for the uninterrupted operation of the installation, it is necessary to ensure a high-quality power supply.
6. There is a risk that the pyrolysis chamber may go out as a result of using too cool coolant coming from the heating circuit. To prevent such a nuisance, a bypass pipe called a bypass is installed in the device. Using it, hot water is added to the cooled working medium. As a result, the design of the heating boiler becomes more complicated and at the same time its price increases. But a self-assembled pyrolysis stove without connecting a heating system does not have this drawback.

Making an economical wood stove with your own hands

Of course, purchasing a ready-made long-burning heating unit is easier than making it yourself. But, as already mentioned, such installations are inexpensive.

If you want to make an economical wood-burning stove yourself, you can use an old gas cylinder, metal barrel, sheet steel and other available materials suitable for this purpose.

First of all, you need to prepare the basic materials that may be required:

1. Metal drum with a capacity of approximately 200 liters without rust or other obvious damage. Its walls must be strong, made of cast iron or steel alloy.
2. An old large capacity fire extinguisher that will make a good base for the unit.
3. A section of thick-walled wide metal pipe.
4. An old gas cylinder.
5. Steel sheets with a thickness of at least 5 millimeters.

A boiler with a round base requires support legs, which can be made from:

• pieces of reinforcement;
• pieces of thin pipes;
• metal profile.

In addition, the home craftsman will need:

1. Steel sheet having a thickness of 5 millimeters. You will have to cut circles out of it, the size of which coincides with the diameter of the metal barrel.
2. Metal profile.
3. Stove door - you can purchase it or make it yourself.
4. Metal pipe with a cross section of 10 centimeters. Its length should exceed the diameter of the barrel by 15 centimeters.
5. A chimney pipe is 5 meters long and has a cross-section of 15 centimeters. Read also: "".

The list of tools required for work is small:

• stationary or portable electric welding installation;
• grinder or autogen;
• ax with hammer;
• level, plumb line, tape measure.

Of no small importance is the room in which the economical wood-burning stove will be assembled. When carrying out installation work, the home craftsman must always have access to power, good lighting and a sufficient level of ventilation.

You need to choose a spacious utility room with good sound insulation, reliably protected from precipitation, in which you can safely store already manufactured parts of the pyrolysis stove.

The long-burning heating unit is assembled in the following sequence:

1. Remove the lid from the metal barrel. When a cylinder or fire extinguisher is used for the base, its upper part is carefully cut off with a grinder or using an autogen. Before making a cut, you need to open the valve in advance and pour water inside. There is no need to throw away the top, as it will still be useful. By the way, the square-shaped case, which can be made of sheet steel, is more stable.
2. Support elements made of channels, tubes or fittings are welded to the round bottom - base.
3. Next, a pressure circle is cut out of the steel sheet; it should pass freely inside the barrel.
4. The circle is connected to the pipe. For this purpose, a hole with a diameter of 10 centimeters is cut out in the center of the clamping element and the pipe is welded to the circle. The resulting part, after being placed inside the barrel, should protrude approximately 15 centimeters above its level.
5. On the reverse side of the circle, channels are welded crosswise, facilitating a tighter fit of the firewood during the smoldering process.
6. A lid is made for the furnace unit. It can be either the upper part, which was cut off at the first stage, or another steel circle. A round hole should also be made in the lid so that the inner section of the pipe with the pressure circle moves freely under its own weight and at the same time fits tightly to the walls of the structure.
7. Install the door. At the bottom of the base of the future pyrolysis stove, a hole is cut out for the door and it is secured so that after the solid fuel has burned through, the ash can be removed without any problems.
8. Install the chimney. For this purpose, a circle with a diameter of 15 centimeters is cut out in the upper part of the body, and the chimney pipe is secured using a welding machine. The main thing to remember is that its minimum length must exceed the cross-section of the barrel or any other base.

It is desirable that the chimney has a valve that allows additional adjustment of the draft force. To clean it, many craftsmen make it dismountable or install a door for cleaning.

You should also insulate the places where the chimney structure passes through the walls, ceiling and roof surface. An umbrella or fungus should be installed at the end of the smoke exhaust pipe - an element that prevents precipitation from entering inside.

After completing the assembly of the pyrolysis device, it is advisable to cover it with brick, which will not only accumulate heat, but will also protect surrounding furnishings from excess fat.

Features of using a long-burning stove and maintenance

Due to the presence of structural differences, long-burning wood-burning stoves have several individual features related to the operation and maintenance of a product manufactured in an industrial environment.

Long-burning stoves are lit in a certain way:

1. Remove the cover from the unit and remove the pressing circle to which the pipe is welded from the barrel.
2. Load firewood or any other solid fuel. The stove's maximum load level with wood should be located at the lower edge of the chimney pipe. Firewood must be stacked very tightly, leaving only minimal gaps. On top of the logs you need to place a small amount of dry small branches, which are covered with rags soaked in kerosene or other kindling liquid. When there is no rag, it can be replaced with ordinary paper.
3. The pressure circle is returned to the barrel and covered with a lid. Only after this is a piece of rag or paper set on fire and thrown inside the pipe with the circle.
4. To light a pyrolysis installation, you should not use matches, since the time they fly inside the stove will extinguish the fire.
5. After the fuel burns well, after 30 minutes you need to limit the access of air to the stove using a damper. Then all that remains is to enjoy the warmth and comfort for long hours.

When installing an economical wood-burning stove in a room, you must follow certain rules:

1. Due to the fact that a long-burning unit can become very hot, any flammable and fusible materials and objects must be placed away from it.
2. A lot of free space should be left around the pyrolysis device. It should be placed at a distance from interior items and walls so that they are not damaged due to excessive heating. This problem is partially solved by laying bricks along the perimeter of the heating device.
3. When cleaning the stove, you should always leave some ash behind. This measure can protect the device from burning out its bottom and, accordingly, failure of the boiler.

Types of solid fuel for pyrolysis stoves

Of course, dry wood is considered the best choice of fuel for such a heating unit. But since one of the main reasons for installing long-burning appliances is to save money on heating the home, other types of combustible materials that are constantly at hand by the owners are also suitable.

In addition to them, coal is suitable, but this natural fuel is capable of generating powerful thermal energy. When used, it must be loaded into units with thick steel casing walls, otherwise they will quickly become unsuitable for use.

At all times, people have tried to achieve high efficiency at the lowest cost. This applies to many processes, including heating your home. One of the most common methods of heating is heating a house with a wood stove.

Furnaces have many modifications, types and sizes. Despite their advantages, most of them have one significant drawback - you have to constantly monitor the combustion process and add new firewood every two to three hours. The operation of a simple conventional wood stove is sometimes not enough to last all night, and in the morning you have to wake up in a cool room.

The market demanded something new, more economical and efficient. And a solution was found thanks to Canadian stove inventors. They designed and built with their own hands economical wood-burning long burning stoves for the home, called “Buleryan”.

At first, these stoves had good reviews from American consumers, and then from European consumers. In Russia, heating units began to be produced under license under a similar brand “Breneran”.

Review and design of gas generator furnaces

Long-burning stoves Buleryan or Breneran have a rather original appearance, are made of steel, painted with heat-resistant black enamel, and can operate in normal mode and in gas generation mode.

Long-burning stove "Breneran"

The furnaces have a high efficiency of up to 80%. They are intended for heating a house or other premises: a warehouse, garage, cottage, small workshop, with a volume of 30 to 1000 cubic meters.

All furnaces are divided into five types depending on thermal power:

– type 00 to 100 m3
— type 01 up to 200 m3
— type 02 up to 400 m3
— type 03 up to 600 m3
— type 04 up to 1000 m3

On the front side of the stove there is a loading door, a gate for power adjustment and a special apron to prevent solid fuel from getting on the flooring in the house. The loading door can be with or without heat-resistant viewing glass.

On the back side there is a pipe for removing combustion products, to which the chimney elements are mounted. At the bottom of the stove there are pipes for taking cold air from the room, at the top there are pipes from which hot air is supplied.

Breneran furnace structure

The Buleryan stove consists of two combustion chambers:

— gasification (below)

— gas combustion (top)

The pipes located at the front contain special injectors for afterburning the resulting gases. If smoke comes through these pipes when the stove is operating, this means that your chimney is not of sufficient height or is clogged from the inside.

Operating principle of a long-burning furnace

Efficiency in the operation of the Buleryan furnace is achieved through the pyrolysis process, the same as in pyrolysis.

Heating of the air in the room occurs not due to the combustion of the solid fuel itself, but due to the combustion of gases emitted by this fuel. That is why furnaces of this type are called gas generators.

When exposed to heat in such a furnace, solid fuel begins to smolder, so gas-generating furnaces can operate for up to 8-10 hours without additional loading. From the diagram below we see:

Operating principle of a gas generator furnace

1. Power regulator

2. Full gas combustion injectors

3. Regulator-gasifier

4. Conversion of solid fuel into gas

In order for the furnace to start working in economy mode, you need to close the gate on the back side of the furnace by 2/3. This gate is called a gasifier regulator.

Using the power regulator on the door, you can set the required temperature in the house. When it opens, oxygen enters the firebox, which promotes more intense combustion, which will lead to an increase in air temperature. If you need to reduce the temperature, turn the damper knob.

It is also important to know that the smoldering process in a furnace is only possible if the chamber is completely filled with solid fuel.

The following fuels can be used for this furnace:

- firewood (preferably large or briquettes)
- cardboard
- peat

Chimney for long-burning stove Buleryan (Breneran)

In order for your long-burning stove to operate efficiently, it is very important to correctly design and install the chimney. A particularly important parameter is the height of the chimney.

For each type of Breneran stove, this parameter has its own meaning:

— type 00 not less than 4.5 m
— type 01 not less than 6 m
— type 02 not less than 7 m
— type 03 not less than 8 m
— type 04 not less than 9 m

Diagram of the correct installation of a chimney for a Breneran-type stove

The first element of the chimney should be a tee with a condensate collector. The maximum permissible length of the horizontal section of the chimney should not exceed one meter.

Do not under any circumstances try to narrow the diameter of the chimney. It is different for each type of oven. For example, for the smallest Breneran the diameter should not be less than 120 mm, and for the largest it should not be less than 180 mm.

Use only stainless steel sandwich pipes, especially in those sections of the chimney that are located on the street, as well as in interfloor passages and on the floors themselves. Do not forget to insulate the areas where the chimney comes into contact with the floors and roof. Basalt cardboard, brick, etc. can be used as thermal insulation.

If you do everything correctly, then you can see the benefits for yourself. long burning stoves Breneran. When using these, significant savings in time and money are achieved. And finally, let’s look at a video about baking Buleryan.

Solid fuel stoves running on wood have one serious drawback: it is very difficult to automate the combustion process, and for some designs it is impossible. From time to time you have to take a break from your work and add firewood, which burns out in about an hour. To extend the operating time of the furnace on one load, the furnaces are equipped with a long-burning mode.

Wood combustion is a complex physical and chemical process that occurs in several stages. When ignited, while the temperature in the stove is low, the wood heats up and darkens. At temperatures above 200 degrees, pyrolysis begins - decomposition under the influence of temperature into solid residues and pyrolysis gases. These gases themselves are flammable because they contain hydrogen, carbon monoxide, organic vapors and carbon in the form of soot. It is the combustion of pyrolysis gases that produces a bright flame with a high temperature.

In a conventional furnace, complete combustion of pyrolysis gases does not occur due to a lack of oxygen. In long-burning furnaces, a separate chamber or combustion chamber is intended for afterburning of pyrolysis gases, where they are enriched with atmospheric oxygen. Thanks to this, fuel is burned more completely, less soot and other harmful substances are released into the air, and the efficiency of the stove increases.

To avoid excessive temperature in the wood pre-combustion chamber, air access into it is limited. The firewood begins to smolder, releasing a large amount of pyrolysis gas. Due to the slow smoldering of firewood, the operating time of the stove on one load increases significantly, in some cases reaching 6-8 hours. This phenomenon is called the “long burning mode”.

Long-burning sawdust stove: video

Advantages and disadvantages of long-burning stoves

Like any other unit, such ovens have their pros and cons.

The undeniable advantages include:

• economical consumption of firewood;
• high efficiency, up to 85-90%;
• versatility in the choice of fuel, firewood, waste from woodworking enterprises, sawdust, and pellets are suitable;
• small sizes;
• ease of control - using an air damper;
• simplicity of design, thanks to which it is easy to make a long-burning stove with your own hands.

Long-burning stoves are not without their disadvantages:

• during combustion, condensate is released, on which soot is actively deposited in the chimney, therefore special requirements are imposed on the chimney design - it should not have corners, bends, its design should be as accessible as possible for cleaning;
• To switch to the long-burning mode, the stove must first be heated in the usual mode to warm up the stove itself and the chimney, otherwise the combustion process will stop.

All the described features of long-burning stoves are relevant both for industrial heating units and for home-made stoves.

You can increase efficiency by adding to the stove, as shown in the video.

Design of long-burning furnaces

Long-burning stoves have design features. They consist of two chambers or combustion zones, in one of which pyrolysis of wood occurs, and in the other, afterburning of wood gases occurs. The location of the cameras relative to each other may be different.

In some models, fuel is loaded from above; as a result of primary smoldering, the firewood compacts and settles, and gases enter the afterburning chamber, which can be located either below or through a partition on the side of the first chamber. Such stoves are often equipped with blower fans to direct the draft into the desired channel.

In other models, the pre-combustion chamber is located at the bottom, and the pyrolysis gases rise into the upper chamber without forced draft. Such stoves do not require a fan, but their loading chamber volume is usually smaller.

To regulate the combustion intensity, an air supply channel with a damper is provided. It can also have different shapes and depends on the type of stove. To compact the fuel and make smoldering more intense, some stoves are equipped with a weight that lowers as the wood burns. Usually they have this design.

Application of pyrolysis furnaces

Long-burning stoves using wood, pellets or sawdust are often used to heat utility rooms and workshops, garages, and greenhouses. They can also be used to heat a house, but it is necessary to ensure that the stove is sealed, as carbon monoxide may be released.

If you use a pyrolysis stove to heat a garden or residential building, it is better to equip it with a water circuit connected to the heating radiators, and install the heating unit itself in the boiler room.

tells how to simply make a smokehouse for cold smoking, which at home will help you prepare real delicacies from the most ordinary products.
You can find out how to make a smoke generator for cold smoking by taking a look.
Here you will find the most understandable drawings for creating an effective potbelly stove with your own hands:

Materials for making a long-burning stove

Long-burning stoves can be made by hand from sheet metal or various metal structures. Examples and drawings of such stoves are given below.

Barrel stove

A home-made heating device intended for heating utility rooms, made from a two-hundred-liter metal barrel. The stove runs on sawdust, shavings and other woodworking waste. Inside the large barrel, a small barrel for loading fuel is installed on a stand. Below it is an ash pan - a drawer made of sheet metal.

The stove itself is placed on a stand, the role of which is played by a car disk. A smoke pipe is made from pipe scraps with a diameter of 100-150 mm. The barrel is equipped with a sheet metal lid with a handle and an opening for air supply.

A log sharpened to a cone is installed inside a small barrel; it is indicated in the drawing. Sawdust is poured around it. After compaction, the log is removed and the sawdust is set on fire. During the smoldering process, gas is released into the space of a large barrel, where it is burned.

Furnace with water circuit made of metal pipe

A homemade long-burning stove made of a metal pipe, which can burn wood or sawdust, is equipped with a water circuit. Loading is done from below; to intensify combustion, an air distributor is installed inside the stove, pressing the smoldering wood.

A telescopic hollow pipe is installed in the center of the disk, through which air flows directly into the combustion chamber, where, thanks to the ribs welded onto the disk, it is evenly distributed over the entire surface of the firewood. It lowers on its own as the fuel burns out. You can lift it before loading using a cable.

The loading door is located in the center of the oven. At the bottom there is a cleaning door and an ash pan. At the top there is a chimney. The stove is equipped with a water circuit with pipes for water inlet and outlet. Such a stove with a water circuit can heat small houses and other premises quite efficiently, and you can make it with your own hands from scrap materials.

Furnace from a waste gas cylinder

A stove can be made from a gas cylinder without extra costs or searching for suitable material. The dimensions of the 50-liter cylinder are perfect for making such a stove, and the wall thickness and tightness make it safe to use.

The design of the furnace as a whole does not differ from the previous model, this can be seen in the drawing. A propane tank with a cut off top is used as a body. You can make a cover of suitable size with your own hands from sheet metal with a hole for the air distributor pipe.
Fuel is loaded through the top, filling the volume of the cylinder almost to the chimney. This stove operates on sawdust and other waste, as well as small firewood. The fuel is carefully compacted, ignited using wood chips or an ignition agent, an air distributor is installed, and then covered with a lid.

The efficiency of such a stove is quite high, and thanks to its sealed housing, it can be used to heat rooms where people stay for a long time. If desired, it can be equipped with a water circuit by passing the chimney through the boiler.

Stove "Bubafonya" from a gas cylinder

Making a long-burning stove with your own hands from a fifty-liter gas cylinder is presented in the video.

The design of the stove is as simple as possible; it consists of only a few parts: a body, a lid, an air distributor and a chimney. For stability, the stove can be placed on legs from the corner. To remove ash from below, you can make an ash pan with a door.

Another video.

Sequencing

1. The remaining gas is released from the gas cylinder and washed several times with water.
2. Cut off the top of the cylinder. You can use it to make a furnace lid by making a hole with a diameter of 65 mm in the center. The edges of the lid and the furnace body are ground so that the lid fits tightly onto the body.
3. In the upper part of the cylinder, a hole with a diameter of 100 mm is made for the chimney and a piece of pipe 30-40 cm long is welded horizontally.
4. At the bottom of the cylinder, a cleaning door is made for the ash pan. To do this, cut out a rectangular section of the cylinder body, grind the sections, weld the hinges and install the door on the resulting hole. The door is equipped with a latch.
5. The balloon is placed on legs for stability. They can be made from a corner, pipe scraps or a wheel rim.
   For ease of carrying, rod handles are welded on the sides.
6. The most important part of the furnace is the air distributor. It must be heavy enough to effectively press down sawdust and wood chips, withstand the high temperature of the oven, and also have diverging blades. They can be made from corner scraps. The distributor itself is made of thick-walled steel - at least 6 mm. Cut out a circle with a diameter 20-40 mm smaller than the inner diameter of the oven with a hole in the center. A pipe with a diameter of 60 mm and a height greater than the height of the stove is installed in the hole. Air will flow through it to the combustion chamber. The blades are welded at the bottom of the disk.
7. You can paint the stove body yourself with paint based on organosilicon compounds, having previously removed scale, rust and dirt from its surface. Any other paint will quickly burn, since the stove heats up to high temperatures during operation.

The temperature of the walls of a gas cylinder stove can heat up to 350 degrees during combustion! To avoid serious burns, use caution!

The homemade sawdust stove “Bubafonya” can be equipped with a water circuit. In this case, it is installed in a permanent place. Typically, this stove is used as a mobile stove: it can be placed in a greenhouse during freezing periods, used to heat a workshop or barn in the winter, or used to heat a garage. Subject to fire safety requirements, Bubafonya is safe and effective.