Maximum heating efficiency with minimal fuel consumption can be achieved by using equipment with high efficiency rates. An example is a homemade long-burning stove that does not require constant loading of firewood. It is enough to fill the firebox with logs once so that they burn for the next 12–15, or even 20 hours. This is very convenient for heating greenhouses and small country houses. Moreover, even a novice craftsman familiar with basic welding skills can make such a design.
Types of long-burning stoves
For suburban buildings, the problem with heat sources is very acute, and without heating in winter it is almost impossible to survive. Far from cities, there is no centralized heating, main gas pipelines to garden plots and small villages are not installed, there are interruptions in electricity, and not everyone can afford solid fuel boilers.
Traditional wood-burning stoves have a significant drawback. The fuel in their firebox burns too quickly, so they need to constantly add logs. The stove cools down overnight and the house becomes cool in the morning.
In long-burning stoves operating on solid fuel, heat is released for quite a long time after filling the firebox due to its smoldering rather than combustion. Such furnaces can operate:
The most common designs include:
Each of the furnaces has its own characteristics, but they all:
- heat the room for a long time;
- easy to care for;
- economical in terms of fuel consumption;
- relatively safe;
- warm up quickly;
- quite durable.
In retail chains and online stores you can easily choose a ready-made long-burning stove of different sizes and power. They look aesthetically pleasing, but are expensive. A self-made structure will cost much less, and the materials for it can almost always be found in a barn or in a local area.
Operating principle of a long-burning furnace
A distinctive feature of the long-term combustion process is that solid fuel burns not from bottom to top, but rather from top to bottom. As the upper layers burn through, the flame falls lower, affecting layer after layer. To understand why the wood burns longer in this case, you should turn to the physical component of the process.
A simple example is a match or splinter. If you turn them with the burning end down or to the side, they will burn very quickly. But if the flame is directed upward, the combustion process will be much longer. In this case, the match will release much more thermal energy.
Long-term combustion in stoves is ensured by the smoldering of wood at high temperatures, and the intensity of heat release is regulated by the supply of air through vents or blowers.
The high efficiency of stoves based on long-term combustion is obtained through the process of pyrolysis, or thermochemical decomposition of solid fuel components. In this case, the logs burn completely, and the heat escapes through the chimney in small volumes.
Such stoves appeared during the times of war communism in Russia, when even firewood was in short supply and boiler houses did not work. These devices saved the population from the cold during World War II.
The design of the potbelly stove is ingenious and is an improved version of Russian stoves. Its design consists of a metal body with two doors and a chimney pipe. Firewood is thrown into the upper hole, and with the help of the lower door the air supply and, accordingly, the process of combustion and smoldering are regulated.
Note! The potbelly stove is omnivorous, so you can burn everything you have at hand in it - coal, firewood and even old furniture.
Thanks to the pyrolysis process, combustion occurs slowly, and more heat enters the room. A traditional stone stove consumes a huge amount of solid fuel, which cannot be said about a potbelly stove, which consumes it sparingly.
The genius of the potbelly stove lies in the absence of a grate inside the metal body. Air through the bottom door is directed directly into the fuel mass. If the vent is covered, the combustion subsides; if it is open, it intensifies.
Efficient operation of a potbelly stove is possible when the firebox is only filled to a quarter of its volume with wood. Therefore, it should not be filled to capacity, otherwise the pyrolysis process will be disrupted.
Long burning stove fireplace
Potbelly stove fireplace Expo
The fireplace attracts the appearance of an open fire, and many owners of country houses dream of having it in their living room. But some people think about the benefits of such a stove. The design of a classic English fireplace is based on the principle of long burning and allows the fire in the firebox to glow for a long time. But efficiency not exceeding 50% and low heat transfer are its significant disadvantages.
Important! Inside the firebox of an English fireplace there is a smoke tooth, which affects the internal circulation of air masses and flue gases.
It does not allow the incoming air to escape upward, directing it to the log laying area.
Another option for a long-burning stove fireplace is the so-called Dutch oven. Before kindling, the ash pan is closed, and the firebox is loaded with firewood only a quarter of the way, without closing the door when burning. Most of the heated air will still fly out through the chimney into the street, but the effect of prolonged contemplation of the fire during the evening will remain indelible.
As a stove, the bubafonya is not ideal, but using the principles of its design, craftsmen have learned to create more advanced units that allow the fuel to burn out more slowly.
At the heart of the bubafoni there is a steel cylinder with incoming and outgoing pipes, as well as a “pancake” located inside in the form of an oppression with blades and an incoming air duct welded to it. As the fuel burns, the load gradually falls down under its own weight. The blades have a curved shape, thanks to which the gases scroll several times over the pancake until they burn out as much as possible.
The chimney for bubafoni is made to have an irregular cross-section so that the air that has not reacted with the fuel is not drawn out.
The fuel combustion process begins from the top layer, where air enters through the inlet pipe. The combustion zone then moves lower.
The disadvantage of bubafoni is its inability to work on coal and pellets, as well as its low efficiency. It will not be possible to add further portions of logs to it until the previous ones have completely decayed. And the top cover of the stove is not suitable for cooking, like that of a potbelly stove.
Slobozhanka
The stove was named after the historical area where it was “born.” It is a full-fledged heating device with a hob.
According to the principle of operation, the Slobozhanka is similar to the Bubafone, but the air flow here is from the side. Next, it is pulled into the perforated casing located inside the housing and rises up. In this case, the fuel takes in as much air as is required for smoldering, and the excess moves on.
The air in the slobozhanka enters all the fuel layers, so the pyrolysis process occurs more actively, and the furnace operates more efficiently.
Conclusion
All the designs of long-burning furnaces described above can be made independently. To do this, you need to stock up on drawings and necessary materials. Homemade stoves will cost less than purchased ones, although they will be less attractive in appearance.
Homemade long-burning stoves: choosing the best
Homemade long-burning stoves can be very different in their functionality and appearance. But they all cost much less than their factory-made counterparts.
Making a homemade long-burning wood stove
Manufacturers and craftsmen have always been attracted to models capable of producing maximum heat with minimal fuel consumption. Numerous attempts to create such equipment led to the appearance of a long-burning furnace. A homemade stove is used for heating small apartments and small storage facilities - warehouses, greenhouses and utility rooms. The second advantage of this stove is its simple design, which can be assembled with your own hands.
Advantages of the model
Why is wood-burning equipment so popular?
What does a long-burning wood stove consist of?
Original long-burning potbelly stove
The answer lies in its strengths:
- The device continues to function even after the fuel burns out (some models can work from 10 to 24 hours);
- The long-burning stove is a self-contained design;
- Small dimensions;
- Versatility in the choice of fuel - consumes coal, sawdust, wood chips, etc.;
- A homemade structure does not require a foundation;
- Does not require regular use. That is, the period of inactivity does not affect its performance in any way;
- Quite high efficiency - 85-90%;
- Over a long period of operation, the stove produces virtually no smoke;
- It can even be constructed from an ordinary metal barrel.
The unconditional advantages of this design also include its low cost on the heating equipment market. Constructing a device with your own hands does not require large expenditures on material or key elements.
The stove in question, however, is not without its drawbacks. A long-burning stove cannot cope with heating large rooms, since it is not designed to connect a water system with your own hands.
List of required materials
The first step is to decide on the type of room for which you will make the equipment yourself. Be sure to ensure that your workspace has access to electrical outlets, plenty of free space, and a canopy that reliably protects you from the weather.
Long burning sawdust metal stove - drawing
The list of necessary materials for making a structure with your own hands includes the following elements: sheet steel, sections of thick-walled metal pipe, an old gas cylinder and a large fire extinguisher.
The main component is a large 200 liter barrel made of cast iron or steel. Before choosing a barrel for a long-burning stove, carefully inspect its surface - there should be no visible damage or rust on it. The thicker the walls of the barrel, the longer the homemade structure will last.
- Materials for legs (small pipes, fittings or channels);
- 2 steel circles with a cross section of 5 mm;
- Channel;
- Door made of cast iron or stainless steel;
- A pipe with a diameter of 100 mm is slightly longer than the barrel (by 15-20 cm);
- Pipe with a diameter of 150 mm (for the chimney);
Heating equipment assembly
Step-by-step instruction
The main element for the stove should not have a top. In the case of a balloon, you need to cut off its top.
In the case of a gas cylinder, before cutting off the top, it is necessary to carry out the procedure for evaporating the remaining gas:
- Unscrew the valve and fill the bottle with water to the brim. Only after this can you begin to cut off the surface;
- A metal base is welded to the bottom of the future long-burning stove with your own hands, preferably square in shape, since it is more stable and reliable; in addition, legs are easier to attach to such a structure;
- Making a pressure circle. A circle slightly smaller than the diameter of the barrel is cut out of a piece of steel. A small hole of 10-15 cm is made right in the center of the cut out structure for the chimney. We insert the pipe into the barrel and check how much it comes out of the stove. Remember, a wood-fired structure needs a chimney that extends at least 15-20 cm above the heating equipment;
Elements of a homemade long-burning stove
- In another part of the barrel, a cross-shaped channel is welded - this part is responsible for supplying fuel;
- The furnace lid is either made by hand from new materials, or a previously cut top is used for it. It is necessary to cut a small hole in the lid for the pressure circle pipe.
- Don't rush to cut the hole for the pipe. First, coordinate its dimensions with the dimensions of the barrel (the circle should smoothly descend into the structure with barely noticeable contact with the walls);
- A small hole is cut out from the bottom of the barrel for the ash pan. Remember to consider the size and shape of the ash pan doors when cutting the hole at the bottom of the barrel. Practice has shown that for a long-burning stove it is better to provide a rectangular ash pan;
- At this stage, all components are welded;
- All that remains is to cut a hole in the upper part of the body for a pipe with a diameter of 150 mm. The chimney pipe is also welded to the structure and reliably sealed.
It is worth noting that it is advisable to seal all joints by welding, since fire-resistant sealants will not withstand very high temperatures for a long time.
Several technical features
The stove should not be located close to walls or flammable interior items - armchairs, sofas, beds, linoleum, etc. Make sure that there is always free space around the long-burning stove, surrounded by fire-resistant materials.
Long burning stove location
Remember, a structure that runs on wood is prone to severe overheating, so once again make sure that no flammable objects are near the equipment during its operation.
Practice has shown that it is better to make chimneys dismountable, since sooner or later the time comes to clean the structure. It is easier to clean a long-burning stove with a removable chimney. It is better to design a homemade chimney as follows: the joints should be located in the opposite direction to the moving gases.
How to use the constructed structure correctly?
A long-burning stove has several nuances of its use:
- First, remove the cover and remove the clamping device;
- Fuel is loaded at the very bottom. It is worth noting that the amount of loaded fuel should not exceed the level of the chimney;
- The main requirement is that the firewood must be compressed, that is, stacked as tightly as possible. This way you will achieve a slight increase in efficiency - by 5%;
- Kindling materials are placed on top of the firewood: small branches or paper. It is better to pour the top layer of firewood with kerosene or oil;
- Light the wood and close the structure with a pressure circle;
- When the fuel burns well, do not forget to close the air supply damper.
Conclusion
Long-burning stoves are the most promising type of heating equipment at the current stage of development, despite the fact that its technology was patented back in 1920. The heating system is characterized by high efficiency, excellent performance and complete autonomy.
Homemade long-burning wood-burning stove
Homemade long-burning wood-burning stove - an overview of the advantages, a list of materials needed to create it, assembly instructions, operating rules.
How to make long-burning stoves with your own hands
Owners of greenhouses, garden plots, garages and other buildings that need heating will be interested to know whether it is possible to make a long-burning wood stove with their own hands. In other words, a stove that can be loaded with wood once and then not touched for a couple of days.
Long-burning boiler design diagram.
Yes, such a long-burning stove can be built as a homemade stove - if you have the most basic construction skills.
Homemade long-burning wood stoves: diagram and principle of operation
If the air supply is free and the draft is strong, dry firewood burns very quickly.
If, with a full load of firewood, the combustion is transformed into smoldering by controlling the air supply, the heat release will drag on for hours or even days.
Here is the design of a simple but quite effective wood-burning stove, oriented towards long-term combustion, which repeats the design of the Stropuva boiler. This stove is popularly called “bubafonya” (after the name of the person who first posted the stove diagram on the Internet).
Diagram of a homemade long-burning stove.
Making such a stove is no more difficult than a potbelly stove, which is more familiar to the general public.
However, the combustion principle and design of such a furnace are completely non-standard. Combustion does not proceed from the bottom up, as in ordinary stoves, but, starting from the upper layers, goes down while the wood burns out.
The firewood under the pancake in the firebox is lit from above, thanks to the air supply pipe. When burning, gases seep through the edges of the pancake and exit into the chimney. The pancake goes down as the wood burns. It is possible to control the air supply using a damper at the ends of the air supply pipe.
Materials for long burning wood stove:
- 200-liter iron barrel with a sealed bottom (for fuels and lubricants);
- a circle (pancake) cut from metal with a slightly smaller diameter compared to the barrel (the circumference of the pancake is slightly less than the circumference of the barrel);
- 4 corners or channels 50-60 mm high and less than the radius of the pancake;
- a 100 mm metal pipe (blower) with a length 5 cm greater than the height of the barrel;
- 150 mm metal pipe (for the chimney), preferably 5 m long.
Homemade “bubafonya” with long burning
Using a grinder, cut off the weld seam from the top end of the barrel and smooth out the sharp edges. The result is a cylinder and a lid with a finished flange. Using a hammer or sledgehammer, bend the edges of the cylinder inward. And bend the flange of the lid outward. Turn the cap over and place it on the cylinder. The lid will sit securely in place without slipping.
Using a chisel, cut a hole for the blower pipe in the center of the lid (so that it fits freely into the hole, it is enough to use a diameter of 102 mm).
Bubafoni assembly diagram.
The hole for the plug on the lid can be sealed tightly, but it is better to leave it: by looking inside you can regulate the combustion process.
Then, at the top of the barrel, a place is marked for attaching a piece of the chimney pipe.
The intended hole is cut out and a piece of chimney pipe 20-25 cm long and 150 mm in diameter is welded. You can install a shut-off valve directly inside the pipe. The stove body is ready.
Next in line is the air supply device. For greater rigidity, the edges of the pancake are bent (so that the pancake does not curl from the heat). A hole is cut in the center of the pancake for the blower pipe, and it is welded. If a lid from another barrel is used for the pancake, then the hole for the cork is sealed tightly: during combustion, gases will pass only around the circumference of the pancake. Channels or corners are welded to the pancake from the bottom side. The air supply device is also ready.
It will be inserted inside the cylinder. An adjustment valve of the same diameter as the pipe is placed at the top of the blower pipe. A threaded pin is welded vertically to the inner wall of the pipe; a hole is drilled at the edge of the damper for this pin, ensuring that the damper mounted on the pin closes the pipe exactly.
After installing the damper, tighten it with the wing nut. By loosening the nut, moving the damper towards the edge of the pipe and tightening the nut back, it will be possible to regulate the flow of air into the firebox.
Place the lid on top and the entire stove is ready.
All that remains is to install the chimney pipe. Its diameter must be less than 150 mm, otherwise combustion products will not be completely removed. For good traction, it is better to have a pipe 5 m long. Install it near the stove, preferably on legs. Weld the bottom of the pipe hermetically.
Connect the stove end-to-end to the elbow, which is welded to the chimney pipe, tighten it with a clamp, placing fiberglass under it for tightness. To drain the condensate that collects in the pipe, a ball valve is welded under the pipe elbow (a rod can be used to clear the blockage).
This tap is absolutely necessary, since freezing of the condensate can cause the weld to rupture. Condensation, in addition, can flow into the stove, and through leaks in the connecting clamp - out.
Now you can now heat the “bubafonya” stove. After removing the cover, pull out the air supply device. Place the firewood - the height should not exceed the height of the lower edge of the chimney elbow. If you place firewood vertically, more will go in. You can choose large logs, up to 20 cm in diameter - they will burn without any problems.
A top layer of finely chopped wood chips is formed. Place a rag or paper on top and pour a little kerosene on it. Now the firewood is covered with a pancake of the air supply device, and the stove lid is strung on top. When opening the air damper, throw a piece of lit paper or rag inside the air supply pipe (matches quickly go out due to strong draft).
When the firewood flares up with a characteristic crackling sound, the blower damper is completely closed. Bubafonya can work in this mode without any supervision for days.
This long-burning wood stove produces little ash due to the fact that the wood burns almost completely. The ashes may not be removed for a long time.
As you can see, it is quite possible to construct Bubafonya stoves with your own hands. Many craftsmen make them not only from barrels, but also from old gas cylinders and large fire extinguishers. The main requirement for a future furnace is strong steel walls.
This is how you can make a long-burning stove.
Homemade long-burning stoves: operating principle
Homemade long-burning stoves, regardless of operating conditions, can be very effective. The main requirement for such a furnace is strong steel walls.
Pros and cons of a homemade long-burning wood-burning stove
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.
What is 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”.
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.
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. Typically, long-burning sawdust stoves 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.
You can find out how to make a smoke generator for cold smoking by looking here.
Here you will find the most understandable drawings for creating an effective potbelly stove with your own hands: http://gidpopechkam.ru/pechki/burzhujki-chertezhi.html
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
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.
- The remaining gas is released from the gas cylinder and washed several times with water.
- 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.
- 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.
- 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.
- 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.
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.
Long-burning wood-burning stove: homemade design from scrap materials
This article talks about various designs of homemade long-burning wood-burning stoves, their operating principle, advantages and disadvantages.
Are there ways to increase the efficiency of conventional potbelly stoves and stoves made from a barrel? How to make a long-burning stove with your own hands? What do you need to know about the reactions that take place during the release of heat? You will find answers to these questions, as well as step-by-step instructions in our article.
We have repeatedly mentioned the low efficiency and high fuel consumption of conventional direct-burning stoves. The reason for this is the direct access of oxygen and the free release of exhaust gases. The initial stage of solving this problem was given in the latest design - with a chimney heat exchanger. In addition, there are the following problems with fuel combustion:
- Rapid uncontrolled combustion. In this case, the temperature in the area of the source is too high, and the metal quickly loses its properties.
- Incomplete combustion of material. This is especially true when recycling plastic and other polymers (in household waste). Acrid smoke from rubber and PVC, thick car exhaust is the result of incomplete combustion of petroleum products.
- Frequent (up to 1 time per hour) fuel loading and the risk of fire extinguishing. You can’t leave such a stove overnight - it will go out and cool down. It is worth noting here that an important advantage of steel furnaces is their rapid heating.
The main idea that we will develop in this article will be the regulation of the oxygen supply for combustion. This will require more precise execution of shutter (doors, dampers) and adjustment (gates, movable and rotary dampers) devices.
Grateless stove (BKP) with a “Buleryan” damper
In essence, this is a potbelly stove, but without a grate. It is included in our classification because it is more effective and requires the qualifications of a master. Despite the fact that such a stove uses fewer parts than a potbelly stove, it has one difficult-to-make element - the firebox door. This element is the only one fundamentally similar to the parts of “Buleryan” (but at the same time the most important). The door must close hermetically; it is combined with a supply channel (blower).
Design. Steel firebox of any shape - cube, parallelepiped, horizontal or vertical cylinder - with a "Buleryan" type door in the front lower part and a chimney in the rear upper part.
Effect. In a grate firebox, oxygen for combustion is abundantly supplied to the hearth from the space under the grate from all sides. This leads to intense combustion and rapid temperature reduction by a cold stream of fresh air. As a result, unburned food is discharged through the chimney.
Without a grille, oxygen passes only through the supply channel, which is quite precisely regulated. As a result, the burning time increases and the products decompose better. At the same time, hot gas lingers longer in the firebox and heats the walls more efficiently. As a result, more heat remains indoors.
How to make BKP with your own hands
The only secret of such a stove is the sealed firebox door. It can be of any shape, but, as a rule, it is made round or square.
1. From a pipe with a diameter of 200-350 mm (wall 2-4 mm), cut a ring 50-100 mm wide. Align and clean the edges. This element is called a “collar”.
2. From a sheet of 3-4 mm, cut out a circle exactly along the outer diameter of the collar. This will be the door.
3. Based on the dimensions of the furnace, we select the diameter of the air supply channel (air channel - VK). We can conditionally divide household-use BCPs into 2 categories - small (0.13-0.18 cubic meters) and medium (0.18-0.25 cubic meters). For small ones, a diameter of 76 mm will be enough, for medium ones - 102 mm. The size of rectangular channels is calculated through the cross-sectional area S = Pr 2.
4. The VC must have an adjusting valve or gate.
Damper:
- We cut out a round damper (metal 2-3 mm) that blocks the stroke of the VK with an eye for the diameter of the bolt thread (M10-12). We weld a rod (handle) to it opposite the eyelet.
- We weld a nut to the VK pipe parallel to the air flow, flush with the outer edge.
- We install the damper on the VK pipe on the bolt through the spring and secure it with a lock nut.
The manufacturing process of the damper is more complex, but in terms of convenience and effect it has no advantages over the above-mentioned damper. It can be copied from a factory copy.
5. Cut a hole in the door for the VK.
Attention! The door opening should not be smaller than the diameter of the VC. The channel itself should be shifted down from the center and its lower edge should be located 20-30 mm from the door cuff.
6. From a strip 2-3 mm thick and 20-30 mm wide, take a segment equal to the circumference of the door.
7. We weld the strip overlay around the circumference of the door.
8. We make a loop device. To do this, in four sections of a 60-70 mm strip, we drill one 6-8 mm hole from the edge. We put them on a flat wire pin 6-8 mm long 100-150 mm. We weld the strips in pairs to the door and cuff of the firebox.
9. We make a locking device. This element can be arbitrary - an inventory box lock, a motorcycle chain tensioner, or any type of eccentric with a handle. It is convenient and reliable to use a movable threaded tightening. A lock from a milk can will do. The main task is to ensure that the door is pressed against the cuff of the firebox.
10. In the corner on the door formed by the cuff, we place an asbestos cord on a heat-resistant sealant.
Such a hatch can be installed in any potbelly stove or steel tank, resulting in an effective stove. It should be located 100 mm from the bottom of the firebox. That is, there must be at least 10 cm between the bottom of the loading hatch and the bottom of the oven.
The main and most important rule for operating the BKP: at the bottom of the firebox there must always be a layer of ash at least 80 mm thick. Otherwise, the bottom will heat up and soon burn out.
Simple and convenient chimney
The installation of a horizontal channel for exhaust gases is not always convenient, especially when servicing the furnace. We will give a way to arrange it in a simpler and more convenient form:
- In the back of the upper wall we cut a round or rectangular hole 20-30 mm smaller than the cross-section of the chimney pipe.
- We select a piece of pipe that exceeds this diameter by 20-30 mm and is 40-60 mm long.
- We weld it onto the hole in a centered position.
Now any pipe can be installed in this cuff, and dry clay should be filled and compacted into the bosom (the gap formed by the difference in diameters). This will provide reliable protection against smoke leakage and simplify dismantling for maintenance.
Let us remember that one of the functions of a “basic” potbelly stove is the ability to heat water and cook food on the upper wall of the firebox. The BKP with the Buleryan door retains this property - just load more fuel and fully open the VK.
A furnace bulkhead can be the next stage in the modernization of a grateless potbelly stove. This is a heat sink in the form of a thick (5-8 mm) sheet of metal, located immediately under the chimney and covering 2/3 of the firebox area.
Effect. An even greater slowdown in the flow of hot gas. Additional heat accumulation indoors.
To fully implement a long-burning BCP as a stove, you need to add one more element - an injector. This is a hollow tube (or several) with holes inside the firebox, which is located in the front of the stove at the level of the center of the chimney channel.
1 - combustion bulkhead; 2 - injection tubes
Effect. The injector is needed to feed the flame “tongues” with air and afterburn the fuel. It is located in a place where the combustion process has not yet been completed, and smoke formation is about to begin. By supplying oxygen (air) to this point, we fuel the combustion reaction, the heat from which warms the upper wall. This principle is also used in modern pyrolysis solid fuel boilers.
The injector “automatically” comes into action upon contact with a flame. This becomes possible only if the hearth is located in the front of the firebox. In the long-burning mode (when the hearth is closer to the center of the firebox), it remains unused.
Additional ways to realize the potential of a steel furnace
In this case, one simple rule applies: the more storage material (metal, water, stone), the more heat will remain inside the house:
- If you plan to use the stove even periodically as a stove, you can install additional heat sinks on the upper wall of the firebox. To do this, you need to weld corners or strips on the edge along the entire length from the inside.
- The same ribs on the side walls will provide a 5 to 10% improvement in efficiency. At the same time, they will strengthen the plane of the wall.
- If a chimney made of a steel pipe is provided, it is also possible to weld corners along its length, which will remove some of the residual heat from the exhaust gases. This is another plus of 3-5%.
- Cuttings of a round or profile pipe welded vertically along the side walls will create an effect that is used in modern long-burning stoves. Constant heating ensures continuous movement of air inside the pipe. Up to 20% increase in heat transfer.
- By covering the stove on one or more sides with bricks without mortar, we will get a stone heat accumulator and protect the walls of the room from overheating. A variation of this method - baskets or bunkers with cobblestones around the firebox - is used in baths. Can provide 15 to 20% improvement in efficiency.
- A household fan directed at the stove will protect it from overheating and even out the air temperature in the room by mixing it. Adds 10-20%.
The use of all the described methods together can increase the productivity of the heat exchanger, which in the basic version is the firebox itself, by 50-75%. The described methods, while improving performance characteristics, increase the weight of the product. Keep this in mind when choosing a base for installing the stove.
Stoves without grates have one drawback for all - the absence of an ash pan. Its combined function - accumulated ash serves as protection for the bottom of the firebox from burning out - does not allow cleaning the firebox during operation. On the other hand, prolonged combustion produces less solid waste, which means that cleaning can be done much less frequently. The ash is removed quickly and the room does not have time to cool down during this time.
We also want to tell you about long-burning stoves with vertical loading.
The most common stoves are those that use wood as fuel.
They are conventionally divided into two main types:
- For periodic operation.
- For long burning.
In the second case, we are usually talking about a period of time from about 6 to 10 hours. Note that when using conventional stoves, the fuel used burns out completely within a couple of hours.
The room heats up quickly and then cools down just as quickly. In cold weather this can cause significant inconvenience. To prevent this from happening, you need to periodically load it with fuel.
This solution can be quite inconvenient. At night, this will require a sleepless night or the room will freeze. In such a situation, part of the heat will go into the chimney along with the smoke. Combustion, consuming oxygen in the room, can also create problems.
Long-burning stoves avoid such problems. Their main feature is that they use a slow combustion process, which is created by limiting the supply of oxygen.
This design works as follows: o It is placed separately, in the place required for heating. It usually has two compartments. The supply of air for blowing is regulated by a special design - a damper. A blower is also used.
In some cases, a gas or liquid heat exchange system is additionally installed. It is designed to organize the most rational use of the generated heat. A damper is actually a damper that can completely or partially close the chimney.
Device There are two main designs:
- Rotary design.
- Gate-type design.
In some cases, additional devices may be required to limit the degree of inflation. As mentioned above, to achieve the effect of long-term combustion, the supply of oxygen must be limited in the most optimal way. In addition, smoke removal must be ensured during use.
They operate by loading a large volume of fuel and burning with limited air flow. In this case, rapid combustion of the fuel does not occur and this process continues for a long time at a very low combustion intensity.
The combustion temperature in this case is higher than in a conventional furnace. Also at this time, a special “fuel gas” is formed, which then also burns, providing additional heat.
Self-production
Sawdust stove diagram It is convenient to use the most common type of fuel - firewood. We will tell you in detail how this can be done.
We list the tools and materials needed for this:
- 200 liter barrel;
- 2 small pieces of steel pipe, one of them should be slightly longer than the other;
- piece of metal channel;
- hacksaw which is used for metal work, also requires a hammer, an ax and a mallet;
- measuring devices(roulette, plumb line);
- approximately 50 red bricks;
- reflector;
- Sheet steel(small piece);
- welder;
- mortar for preparing a solution;
DIY process:
- The main part is the barrel. To use it you need to prepare it. First of all, you need to cut off the top cover. This must be done carefully. This detail will be needed a little later. If it was not possible to prepare the side, you can use a piece of large diameter pipe for the same purpose.
- A circle is cut from a sheet of steel, with a diameter slightly smaller than a barrel so that it can be moved freely inside. A hole is cut in it for a longer piece of pipe. Horizontally located channels are welded to the disk from below.
- From the cut off top of a barrel the top cover is made. A hole is cut in it for the pipe to exit.
- 2 holes are made in the lower part. One higher and larger for storing fuel. The other is smaller and at the very bottom for removing ash and coals. Both openings must be equipped with doors with handles.
- A hole is made in the upper part for the chimney and the corresponding piece of pipe is connected. It is placed on the foundation. This is due to high heating during operation.
- In some cases, the oven can be lined with bricks, and the nearby floor and walls - a reflector. But this is not mandatory.
- For chimney It is convenient to take a pipe with a diameter of up to 15 centimeters. It is welded to the upper hole of the furnace being created.
- Using a reflector I can greatly increase efficiency indicators.
- There is no need to cover it with bricks, if the stove will be used in utility rooms.
- You need to free up space near her and do not place objects or materials there that are not fire resistant.
- The chimney must be accessible for regular cleaning.
- Before starting operation, you need to try it in different operating modes and choose the most suitable one.
Advantages and disadvantages
Why is it beneficial to use this variety?
We list the main reasons for this:
- These designs are compact and relatively small in size.
- They have a fairly high efficiency. It can reach 75% - 85%.
- Maximum burning time may be 10 hours.
- Much less fuel consumption than in a normal situation.
- Unlike most types of ovens, you can add a new portion of firewood during the combustion process, without waiting for it to finish.
- Here it is possible to carry out effective adjustment at the intensity of the combustion process.
- It is allowed to use not only wood for burning, but also coal and .
- Cast iron stoves have a long service life. It can reach 50 years.
- They are characterized by a high degree of versatility. They can be installed almost anywhere where it is possible to make a chimney.
- They are not too heavy. Two people can move them to a new location without much effort.
- Attractive design. This allows the use of long-burning stoves in a wide variety of cases.
- Relatively low cost.
- Environmentally friendly fuel materials.
Along with the listed positive features, there are also certain disadvantages.
- These devices not suitable for operation on liquid fuel.
- Special requirements for the chimney due to the low speed of smoke movement (the chimney should not be curved).
- Setting it up correctly is quite complex.
- Low outlet temperature, which leads to increased condensation formation.
- Inability to operate in fully automatic mode. Constant supervision is required here.
- Space around the oven location must be protected from fire.
Different kinds
"Buleryan"
One of the popular types of such furnace devices made in Canada. It is shaped like a barrel and made of steel. The firebox has two tiers. There is no ash collector in this design. There are air ducts.
The latter circumstance makes it possible to heat neighboring rooms.
Such furnaces can operate in one of two modes:
- Kindling mode.
- Long burning mode.
In the first case, we are talking about the first half hour of work. At this time, the oven and surrounding area are heated. One bookmark can burn for up to 12 hours. Special requirements are placed on the dryness of firewood placed in the firebox. In this type of furnace, the generator gas does not burn completely. Also, there is a need to ensure insulation of the chimney.
"Breneran"
It is in many ways similar to the Canadian brand described above. But there are some differences. In order to provide heating to adjacent rooms, special aluminum sleeves must be placed on the convection pipes.
But when they are used, a significant leak of thermal energy occurs. There is an alternative option. To do this, you need to purchase a special casing that will reduce heat loss. But its cost approximately corresponds to the cost of the stove itself. The chimney is equipped with a device for collecting condensate. Unfortunately, it cannot be made completely airtight.
On the other hand, many varieties of stoves of this brand are produced. For each specific situation, it is quite possible to choose an oven of suitable volume. Unlike the Canadian model, various types of solid fuel can be used here.
It is also possible to connect water heating. But in the latter case, the long burning time will be reduced due to the additional costs of heating the water.
“Professor Butakov”
Another fairly well-known domestic brand. It has a more thoughtful appearance. Here we use grates (grids on which burning fuel is located).
Convection pipes here are much more efficient than in the previous type of ovens. During combustion, the condensate flows into the furnace and burns completely. When installing, it is necessary to place such a stove on a special pedestal. Long burning is less likely than in Canadian stoves. This is due to the use of grate bars.
Solid fuel boilers sometimes become the only option when you need to heat a room. There can be many reasons for this: the inability or economic infeasibility of connecting to the gas main when you need to heat a temporary structure, or solid fuel is more accessible than all other energy resources.
The most economical are long-burning wood-burning stoves, which, unlike conventional boilers, have a higher efficiency. It is quite possible to make such stoves yourself, if you get acquainted with the recommendations of experienced craftsmen. Thus, you will get double savings: on operation and on manufacturing.
What is the difference from conventional ovens?
First, you can consider what disadvantages the owner of a conventional stove faces:
- very low efficiency, the level of which can be increased to 80 percent, no more;
- You constantly need to ensure that you add a new portion of fuel on time (usually this needs to be done every 2-3 hours);
- there is no way to automate the combustion process and thus reduce labor costs.
There are none of the listed disadvantages in top combustion furnaces. We can say that they have become an improved version of the traditional stove, which has not lost its position for many centuries. In addition, it has a lot of advantages, including the almost complete absence of soot, small dimensions of the boiler, and the ability to regulate the combustion process. There are many designs that you can make with your own hands.
A long-burning furnace is designed so that oxygen supplies the fuel in limited quantities. Firewood (coal, pellets) does not burn, but smolders. At this moment they release so-called pyrolysis gas. It goes into a separate chamber and burns out completely. As a result, efficiency increases by another 10-15 percent, and the fuel loading period extends from 8 to 12 hours.
For such stoves, sawdust, firewood, coal and pellets can be used as fuel. That is, it is not difficult to choose it depending on the region and the availability of any type of fuel. When such advanced stoves use pellets, the fuel loading process is easily automated. You just need to monitor the filling of the bunker.
Reference. Pellets are gradually becoming a popular type of fuel. They are easy to use and allow you to save the Earth’s natural resources, as they make this type of fuel from waste from the wood processing industry.
An automated long-burning stove using pellets can operate without human intervention for several days.
Materials and tools
To decide how to make a long-burning stove yourself, you need to prepare all the tools in advance and stock up on materials:
- for the furnace body you will need a metal container of at least 200 liters in volume (sometimes they take an empty, broken gas cylinder for this purpose);
- two pieces of pipe with a diameter of 10 cm;
- metal channel; for body legs;
- approximately 60 pieces of refractory bricks (if it is decided to line the stove with bricks);
- sheet of metal with a thickness of 60 to 80 cm diagonally;
- mixture for masonry (preferably ready-made, but you can make the solution yourself);
- hinges for doors;
- necessary tools that are used when working with metal (for example, a grinder);
- electric welding equipment, electrodes;
- level and plumb lines,
- construction tape and other marking tools.
After all materials and tools have been prepared, you can begin the process of making the stove.
How to make a stove with your own hands
When choosing a room where you can make a long-burning stove with your own hands, you need to keep in mind that for welding work you will need access to 220 V electricity.
The body can be made of stainless steel, cast iron or steel. When you make it yourself using welding, you need to take steel sheets with a thickness of at least 4 mm. The most convenient and stable design will be obtained if the body is shaped like a rectangular parallelepiped. But the main thing is to make it airtight.
However, it is easier and more reliable to choose a ready-made container. For example, even a used fire extinguisher is suitable for a low-power oven.
Important! If a used gas cylinder is used for the housing, special procedures must be followed for safety reasons. An empty cylinder always contains gas vapors, which can lead to an explosion. Therefore, before cutting off the “top” of it, the balloon must be filled to the very top with ordinary water.
Separately, another circle is cut out of a sheet of iron with a diameter 2-2.5 cm larger than the diameter of the body itself. You need to cut a hole in it for a pipe with a diameter of 10 cm. The pipe is immediately welded into place.
The legs are made of metal channel. They will not only support the base, but also “push” the fuel during the combustion process.
The lid is made separately. They also cut a hole in it for a pipe 10 cm in diameter. A “skirt” is provided along the edges for a tighter connection between the lid and the body.
Holes for the firebox and ash pan are cut out on the body. Metal doors are hung on them, to which handles (from a corner or channel) are welded. The firebox and ash pan are separated by a grate on which fuel must be placed.
Oven base
When making a coal stove with your own hands, you need to take care of a reliable foundation. This must be done, even if the stove is not heavy in design.
There is no need to make a recess for the foundation. It is enough to make a smooth concrete “pillow”.
In order to mark the base of the stove, you can use building materials such as ceramic tiles or bricks. In this case, straightness must be strictly observed, controlling the surface of the base using a mounting level.
Chimney device
When it comes to heating equipment that runs on solid fuel, it is imperative to install a chimney. In this case, the chimney is made from a pipe with a diameter of 100 mm.
At a distance of 50–100 mm from the upper edge of the stove, a chimney pipe is cut in. This is a length of steel pipe into which the chimney will fit tightly. The smoke channel is made with a small horizontal section - 50 - 60 cm of a straight pipe is enough to weaken the draft. A large number of knees before leaving the premises is not allowed.
A chimney made of several sections is easy to use. This way you can clean it without any problems.
Important! Sections of the prefabricated chimney pipe are assembled in the direction opposite to the movement of gases.
Final stage
After the stove is assembled and installed in a permanent place, it can be given an aesthetic appearance using refractory bricks. As practice has shown, this does not affect the performance of the boiler in any way. There is an opinion that due to a decrease in heat losses, the fuel burnout period increases. However, this has not yet been proven.
Therefore, the owner of the stove can choose whether it is worth spending additional money on covering the stove with bricks, or doing without this step. Sometimes in this way they make a stove for a long-burning greenhouse with their own hands, which is very convenient and practical.
Whatever fuel is used in a long-burning furnace, the operating principle is the same. The pyrolysis process, with minimal access to oxygen, significantly increases the efficiency of the furnace and increases the burnout period of the fuel.
There are some rules for the manufacture and installation of a stove, compliance with which is important for further operation:
- For safety reasons, there should be no furniture, objects, or other things for a meter around the stove to avoid a possible fire.
- If you install the stove on a small pedestal, then, if necessary, you can easily remove and disassemble the chimney.
- Not much ash is formed in a long-burning furnace, but from time to time it needs to be removed, leaving a small layer for thermal insulation of the bottom (thus reducing the intensity of its burning).
To improve performance characteristics, a heat reflector - a metal or foil sheet - is attached to the wall behind the stove. It not only protects the wall from fire, but also returns heat from the wall back into the room.
Of course, gas is currently the most cost-effective and less problematic to operate. But its connection is not always possible. Many regions are forced to make do with other types of fuel. Electricity, although a convenient energy resource, is very expensive. In such a situation, long-burning solid fuel stoves will help out.