How to make a rocket stove to heat your home. Bubafonya and Rocket: do-it-yourself top-loading furnaces Jet furnace from a gas cylinder

This device, despite our brave space achievements, is still not widely known in our country. And for sure, only a few are interested in how to make a rocket furnace with their own hands, because they do not understand the principle of its operation.

This is a relatively new word in the domestic heating environment, which came from Germany. The key to unprecedented popularity in the homeland is a simple cheap design, coupled with high efficiency and with the slightest absence of signs of soot. Considering that it is not difficult to make equipment on your own, we will tell you how to do it, we will give drawings, recommendations from specialists, videos and photos.

Principle of operation

Oddly enough, but the very name "rocket furnace" has nothing to do with space or rockets themselves. The only analogy that can remotely remind of this is a jet of flame rising up in mobile installations.

The design feature of the furnace is the presence of a hood, where flue gases enter and where the final combustion of the sludge takes place. Under the cap, the temperature rises to 1000 0 C already during the first 2 hours, as a result of which everything burns without sediment, and the exhaust is formed only in the form of steam and carbon. In this case, gases circulate freely through the channels without forced draft, which is usually created by a chimney.

This design allows you to use the stove not only for heating the room, but also for heating food or water (on the hood). If the chimney is run through a certain part of the room, up to the sunbed, it will also heat up.

Among the main advantages of rocket furnaces are the following:

• high efficiency - 85%;
• very fast heating of the room - 50 sq.m. in 45-60 minutes;
• the absence of soot and, as a result, soot deposits - at temperatures above 1000 degrees, everything burns out without residue;
• the ability to use any solid fuel;
• minimum consumption - at the same temperature and duration of burning, a rocket furnace consumes 4-5 times less fuel than a conventional furnace.

The simplest rocket works according to the direct combustion formula - these are mobile structures that are easily assembled in field conditions literally from improvised materials and are also easily dismantled.

The simplest design from a barrel or gas cylinder

When it comes to the first stages self-manufacturing rocket furnace (see video), then acquaintance is still worth starting with the simplest design. The camp stove is presented in the form of a bent pipe section, where the fuel chamber and the ash pan are combined.

For fuel, a steel plate is welded to the bottom, at the bottom of which a hole is cut for air suction.

It is possible to use any straight cylindrical container for manufacturing - the drawing of the rocket furnace shows how the direct combustion process takes place.

Video 1 A simple construction of a portable cooking rocket oven

Brick rocket stove in 20 minutes

If you have 20-30 bricks on hand, you can make a simple rocket stove with your own hands in just a few minutes. Moreover, no adhesives are required for masonry.

Lay out of brick, as shown in the photo, a vertical combustion chamber. At the same time, the dishes are placed on the hood in such a way as not to impede the movement of the emitted gases

Do-it-yourself rocket-type brick oven:

For this design to work well, a warm pipe is needed. This term among stove-makers refers to the preliminary run of chips and paper so that the pipe warms up. There will be gas stagnation in a cold pipe, making heating difficult. And if the pipe is warm, then when the firewood is ignited, a powerful draft appears in the channel.

For reference. In the above simple designs from a gas cylinder or pipe, there is a significant drawback - the vertical loading of firewood. Each time you have to move firewood into the chamber when they burn out and only after that put it on. Stationary rocket stoves on coal or long burning provide for a vertical bookmark, which greatly simplifies operation.

Long burning rocket stove

Photo 6 The design of a stationary furnace-rocket

Do-it-yourself rocket jet furnace scheme

In order to make such a unit with your own hands, you need to decide on the dimensions and structural elements.

How a rocket works:

As can be seen from the drawing, the diameter of the cap (D), which covers the top of the pipe, and its cross section (S) are taken as the basis.

Based on these indicators, the dimensions of the rocket furnace are calculated:

• the height of the drum is 2 of its diameter;
• the height of the clay coating is 2/3 of the height;
• coating thickness - 1/3 of the diameter;
• sectional area of ​​the pipe - 7% of its transverse section;
• blower area - 1/2 pipe section;
• the flame tube horizontally and vertically must be the same;
• ash pan volume - 4-6% of the drum height;
• the cross-sectional area of ​​the external chimney is a double cross-section of the pipe.
• thickness of the insulating layer (adobe cushion) under the outer chimney 60 mm;
• the thickness of the coating of the stove bench is 1/4 of the diameter of the drum;
• outer pipe height - 4000 mm;
• the length of the flue directly depends on the diameter of the drum. If for its manufacture they took a metal container with a diameter of 50-60 cm and a volume of 200 liters, then the length of the flue pipe will be at least 6 meters. If the diameter is half as much, then the bed should be made up to 4 meters.

If you are making a stationary rocket furnace with your own hands, be sure to pay attention to the lining of the top of the pipe. This is necessary to isolate the brazier from the walls of the furnace in order to prevent overheating of the walls. Fireclay bricks can be used for lining.

Photo examples of the original performance

It is noteworthy that not only the walls, but also the lining itself need protection. In order to protect it from combustible gases, you can create a metal sheathing and fill it with river sand. For this purpose, you can use any metal object at hand - a barrel, a bucket, galvanization.

The sand is poured into the bucket layer by layer, with each layer watered abundantly for proper compaction. When the protection is filled with sand to the top, leave for 7-10 days to dry.

The lining of the brazier is done much faster - fireclay bricks are laid on the clay mortar, and the space between the latter and the wall will also have to be covered in layers with sand - with water and drying time.

Pipe lining scheme

All further work on the installation of a jet-type rocket furnace continues only after not only the lining has dried, but also the clay protection, which is applied over the upper cut.

Before making a stationary structure, practice on a traveling sample. After the first experience, it will become clear even if you have not read books for rocket furnaces.

Disadvantages of the heater

1. Often this device is used to heat food or water - indeed, a huge amount of heat, a red-hot cap, why not take advantage of this idea? However, connecting a water circuit in order to heat the whole house, and not a room, is impossible. The design is so simple that any intervention, including the coil, will disrupt the course of work.
2. Surprisingly, such a lightweight mobile heating device is completely unsuitable for either a bathhouse or a garage. Even with its high efficiency, the camping unit will not heat up the air in the steam room to necessary minimum. And in a garage or warehouse, it is not recommended to use appliances with direct open flames.

In this article, we will give an example of a camping installation, for which no masonry or finishing materials are needed.

Necessary materials:

• 2 buckets;
• stainless steel pipe;
• river sand or crushed stone for lining.

Step 1. Cut a hole in the sidewall of one of the buckets along the diameter of the pipe at a height of 5 cm from the bottom. The height should be enough to fill the bucket with gravel or sand.

Step 2. Divide the pipe into 2 parts - a short loading section and a pancake knee-chimney.

Step 2. Insert the pipe into the hole in the bucket.

Step 4. Cut, by analogy with item 1, a hole in the bucket, but already directly in the bottom. The hole diameter corresponds to the pipe diameter. Insert the pipe.

Step 5. Pour sand or gravel into the bucket, which will act as a heat accumulator of the flame tube.

Step 6. Making legs or stands. For this, ordinary reinforcement is suitable, which is bent under pressure and the base is cut out.

Rocket stove from a gas cylinder

This is a sophisticated improved version, for the manufacture of which you will need an already used gas bottle and a rectangular tube 4 mm.

The scheme remains exactly the same with the only exception that combustible gases are discharged from the side through the hole, and not from above, as happens with marching samples.

If there is a need to cook or heat food, the upper part of the cylinder with a tap is cut off, and a flat plate is welded on top.

Video 2 We make a do-it-yourself rocket stove

Imagine the situation: to heat a room at home or cook food, you need to quickly build a simple wood stove. Quality and fuel consumption are secondary. Suitable option- a homemade rocket stove made from improvised materials. We suggest that you familiarize yourself with the heater device and the assembly process at home.

Design and principle of operation

The rocket stove shown in the diagram consists of the following main elements:

• a bunker for laying firewood of a vertical or inclined design;
• horizontal combustion chamber;
• a pipe with a lining - an afterburner (the second common name is a riser);
• a metal cap that plays the role of an air heat exchanger;
• blew;
• chimney channel.

In operation, the stove uses 2 principles: the occurrence of natural draft inside the vertical section and the combustion of wood (pyrolysis) gases. The first is implemented by heating the firebox and the waste products of combustion, tending to rise through the afterburner channel. The released pyrolysis gases burn out in it.

Reference. The name rocket or jet furnace is associated precisely with the principle of operation - a powerful natural thrust arises in a vertical channel, causing intense combustion in the furnace and heat release.

The algorithm for the operation of the stove is as follows:

1. Firewood loaded into the bunker is ignited from below. Air supply is provided through the blower hatch.
2. In the process of combustion, flue gases heat up the insulated walls of the afterburner and rush under the thin metal cap, where they give off most of the heat to the room air.
3. With a sufficient amount of secondary air, the pyrolysis gases have time to burn out inside the riser, releasing additional heat.
4. The products of combustion are discharged directly into the chimney or are first sent to the chimney stacks.

Variants of portable stoves "Robinson"

In a simplified camping version, the stove is made without a cap and insulation. Accordingly, the secondary gases do not burn out completely, because they have time to fly out into the pipe. A small-sized portable heater, called "Robinson", is designed for fast food food on fuel of any quality and degree of humidity.

Element size requirements

The main heat exchange element of the rocket stove is a metal cap, the intensity of heating a room in a house depends on its size. In fixed brick constructions, a 200 liter barrel with a diameter of 60 cm is usually used. Portable versions are made from standard Ø300 mm gas cylinders.

Scheme of a rocket heater with a bench

Accordingly, the remaining dimensions dance from the dimensions of the barrel - the diameter and cross-sectional area:

• the height of the cap is provided 1.5-2 times the diameter;
• cross-sectional area of ​​the afterburner is 5-6.5% of the barrel diameter;
• the length of the riser is made such that a minimum gap of 7 cm remains between the upper cut of the pipe and the cover;
• the internal size of the firebox is equal to the cross section of the afterburner, the blower channel is half that;
• the diameter of the chimney is 1.5-2 times the cross section of the afterburner, the height is at least 4 m.

To make it easier for you to calculate the diameters of pipes and linings, we present a drawing for various options rocket furnaces - from a cylinder, barrels and old buckets (the riser is made of round or profile pipe).

We make a furnace - a rocket

The easiest way to make a light camping stove shown in the drawing is to find in household the following materials:

• round steel pipe with a diameter of 133-150 mm and a length of 0.5 m;
• pipe profile section 14 x 20 cm, length 0.4 m;
• metal sheet 2-3 mm thick for grate;
• bar Ø8-10 mm for legs;
• scraps of iron on a stand.

vertical round pipe welded to the profile at an angle of 45 °, then eyelets for legs are attached to the body (they should be easily removed). A grate is placed inside the inclined firebox, a lid is attached outside. For the convenience of cleaning the ash below, it is desirable to install a second door.

Advice. Be sure to weld a stand to the upper cut of the fire channel - gases must penetrate between the bottom of the dish and the body, otherwise there will be no “rocket” thrust.

Drawing of an improved version of a portable furnace

The design of the furnace can be improved by organizing the supply of secondary air inside the flame tube. Modernization will increase the efficiency and duration of burning firewood. Drill holes on the sides on both sides, covering them with rocket "nozzles" according to the drawing. How this stove works is shown in the video:

From a gas bottle

The following materials will be used to make a furnace - rockets with their own hands:

• round pipes with cross-sectional dimensions of 70 and 150 mm; with a wall thickness of 4 mm;
• square corrugated pipe 150-200 mm in diameter;
• chimney pipe Ø10-15 cm;
• low-carbon steel (grade St20) sheet;
• dense basalt wool (80-120 kg / m3) or bulk fire-resistant materials, for example, vermiculite or perlite gravel.

To begin with, cut the rolled metal into blanks in accordance with the drawing. Then you need to saw off the lid of the propane cylinder, after unscrewing the valve and filling the tank to the top with water. The tool is an ordinary grinder with a circle for metal.

Further assembly technology is as follows:

The master will tell you in detail about the manufacture of a rocket stove from a cylinder in a video:

from brick

The simplest rocket stove for cooking can be built from bricks without the use of mortar, as shown in the diagram with orders. Such a structure is easy to disassemble and move if necessary.

A rocket stove with a bench should be placed on a foundation made of concrete or rubble stone. Material - ceramic or refractory bricks, sand-clay or fireclay mortar, respectively. The finished base is covered with roofing material for the purpose of waterproofing, then a solid first row of bricks is laid. The further order of work looks like this:

Important. The construction is carried out in compliance with the rules of oven masonry, painted.

The length of the smoke channels inside the couch is limited by the draft in the rocket furnace and the external chimney. It is better to keep the total length of the flues within 4 m. To prevent the heater from smoking back into the room, raise the top of the chimney to a height of 5 m, counting from the grate. How to build brick oven- a rocket without a barrel, see the video:

In conclusion - the pros and cons of the stove

Such structures are really made quickly, and the performer does not have to be highly qualified. The first and main plus of rocket-type furnaces is simplicity and undemanding to materials. In addition, they perceive a variety of fuels well - raw firewood, branches, brushwood, and so on.

Now for the negatives:

For the above reasons, a rocket heater is extremely inconvenient for a garage where you need to heat the room quite quickly. But the hiking option is indispensable in nature at any time of the year.

Structural engineer with over 8 years experience in construction.
Graduated from East Ukrainian National University. Vladimir Dal with a degree in Electronic Industry Equipment in 2011.

Related posts:

Among a large number of solid fuel heaters, a rocket stove from a gas cylinder deserves special attention. It has a simple design, does not require expensive building materials for the manufacture, but it turns out to be quite effective in heating outbuildings up to 50 square meters. m. Anyone who has at least a little experience with a welding machine can build such a furnace on their own.

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Principle of operation

Despite the fact that the jet furnace from a gas cylinder is quite simple, its operation is based on advanced methods for generating heat from fuel combustion:

• free circulation of heated air and gases. The firewood in its firebox burns due to the natural draft formed by the influx of oxygen through the hole in the lower part of the structure (blower);
• afterburning of wood gases released during the combustion process (pyrolysis). Part of the fuel, converted to a gaseous state, burns out in an additional heat exchange device and a horizontal section of the chimney channel located immediately behind the firebox. Wood gas in it moves more slowly than in a vertical channel, and a thick layer of heat-insulating material does not allow them to cool, which allows the process of decay and afterburning to be carried out in a more complete volume.

The vertical pipe in the cylinder rocket furnace is installed above the furnace, according to the drawing, and is also insulated. The process of pyrolysis when burning firewood significantly increases the efficiency of the stove.

Principle of operation

materials

To make a rocket furnace with your own hands, according to the drawing, you will need the following materials:

No. p / p	Name	Unit measurements	Quantity
1	Pipe section Dn158 mm wall thickness 4 mm	m	0,8
2	Pipe section Dn127 mm wall thickness 3.5 mm	m	1,5
3	Section of a pipe with a section square shape 120x120 mm, wall thickness 4 mm	m	1
4	Empty gas cylinder 50 l	PC.	2
5	Sheet steel	m²	1
6	fittings	m	1
7	Perlite	kg	2
8	Pipe with a diameter of 120 mm for the chimney	m	4
9	asbestos cord	m	1
10	Basalt wool	m²	1

Tools

To work on the construction of a rocket furnace for a garage with your own hands, you will need a set of tools and fixtures, consisting of:

• household apparatus for electric welding with electrodes with a diameter of 3-4 mm;
• grinders or hacksaws for metal;
• hammer - slag separator;
• ordinary hammer;
• pliers;
• chisels;
• metal brushes;
• electric drill;
• measuring instruments: tape measure, level and plumb;
• marker or chalk;
• personal protective equipment: a protective mask, dielectric gloves, overalls made of dense fabric and closed shoes.

Manufacturing instructions

Scheme and dimensions

Scheme of a rocket furnace from a gas cylinder

Balloon preparation

As blanks for the manufacture of a rocket furnace, it is better to use 50-liter cylinders for transporting propane. Their height is 85 cm, diameter is 30 cm.

A rocket stove from a gas cylinder of this size will be able to efficiently burn fuel and heat a room up to 50 m². In addition, such containers are quite often used in everyday life, so finding products that have exhausted their resource will not be difficult.

In a gas cylinder, even if not used for a long time, a small amount of substance remains inside. An attempt to cut it without prior preparation can lead to tragedy. To prevent detonation during cutting, the following manipulations must be performed with both containers:

1. unscrew the valves to release the neck of the cylinders;
2. withstand 2 - 3 days until the rest of the gaseous mixture evaporates;
3. pour water into them and leave them in this position for a day;
4. drain the water and allow to dry.

Such preparation will completely free the containers from gas, eliminating any possibility of an explosion.

Stages of work

• cut off from the profile pipe two segments 30 cm long and one segment for a lounger 35 cm long;
• cut two holes in the lounger - one for the furnace department, the other for installing a vertical pipe;
• cut along one blank from a square pipe and weld one part to the firebox. This detail will contribute to the flow of air masses into the furnace department;
• weld a firebox with a pipe into a single structure;
• manufacture and install a grate from reinforcement. Its basis will be a square-shaped frame made of reinforcement measuring 115x115 mm. Then bars for the grate are welded to it with a step of 8 - 10 mm. It will be laid on the corners welded from the inside of the firebox;
• weld door hinges to the furnace hole and to the ash pan;
• check the quality of the seams for the absence of defects in them, for example, cracks and shells;
• check the operability of the primary combustion chamber with a small amount of fuel;
• cut a piece 10 - 15 cm long from the pipe intended for the manufacture of the chimney;
• cut an opening in the lower part of the remaining pipe and weld the prepared elbow;
• cut an opening for cleaning the chimney just below the knee;
• cut off the top of one cylinder and cut a hole in its bottom;
• on the surface of this cylinder with a tape measure and a marker, mark the location for the chimney and weld the elbow of the chimney pipe with a diameter of 110 - 120 mm to it;
• insert one part of a pipe of a smaller diameter with a length of 0.8 m into a part of a pipe of a larger diameter;
• weld on one side the gaps between the pipes along the entire circumference;
• pour perlite into the space between the pipes for thermal insulation;
• install the pipe in the center of the prepared gas cylinder;
• weld the gaps between the pipes from above along the entire circumference;
• mark another opening on the same cylinder and weld the manufactured firebox to it, and the vertical pipe to the lounger;
• cut off the bottom of the second cylinder;
• clean the places of cuts from burrs;
• weld a hole in it from the valve;
• weld two metal rings to the edge of the cylinder;
• dock the cylinders together in the groove formed by the rings;
• seal the junction of the cylinders with an asbestos cord for maximum tightness;
• put heat-insulating material on the floor at the installation site, and a sheet of thick metal on top.

Finished construction

Exploitation

A stove of this type, like any heat generator with top combustion, works with maximum heat transfer only when the chimney is well heated. Therefore, before downloading combustion chamber the main portion of fuel, the device needs:

• warm up the chimney well. For these purposes, you can use any quickly flammable fuel, such as paper lumps, sawdust or shavings. It should not burn in the furnace, but in the blower. The level of heating of the chimney can be judged by the fading of the sound or a change in its tone. Then you can start laying the main fuel in the furnace. It is no longer necessary to set fire to it, it should flare up from the coals left over from the burned-out "fast" fuel;
• regulate manually the flow of air into the furnace section. The rocket stove in the garage is not capable of adjusting itself to changing environmental conditions and the quality characteristics of the fuel, so it must be adjusted manually. After loading the main fuel batch, the blower door should be fully opened, and when a characteristic hum appears in the furnace, it should be closed so much that the tone of the sound in the furnace drops to a rustle. As the firewood burns, the door needs to be covered more tightly, achieving the same rustling sound. If this is not done, then excess air will enter the furnace and cool the intermediate gas mixture. In this case, the pyrolysis process immediately stops, and the oven starts to make a roaring sound.

Only dry wood can be used as fuel for such a stove, since the appearance of an excessive amount of moisture during the burning of wet firewood can provoke a back draft and become an obstacle to creating the temperature necessary to start the pyrolysis process.

To ensure the safety of users during operation, the following rules must be observed:

1. do not use liquid fuels for kindling and do not add them to the stove during the combustion period;
2. avoid contact open areas bodies of contacts with the surfaces of the furnace, since the cylinders and its other metal parts will be very hot during combustion;
3. do not place the device near flammable surfaces;
4. clean the chimney at least once a week, and preferably after each use of the appliance.

Conclusion

A rocket stove from a gas cylinder is an effective heating device utility rooms small area. Such a device can be made by hand. Gas cylinders are made of high quality steel alloy, resistant to impact high temperatures and corrosion. Therefore, such a furnace can last a long time, and the process of its manufacture will not take much time.

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A gas cylinder stove can be placed where heating cannot be arranged in another way: in a garage, country house, change house.

If you have the desire and time, you can do all the work yourself.

This article will help you independently convert a gas cylinder into a heating or heating and cooking stove.

Here you will find drawings and instructional videos with which you can make a waste oil, coal or wood stove.

Varieties of furnaces from a gas cylinder

A do-it-yourself gas cylinder stove is considered the easiest option for manufacturing or working out a heating apparatus.

The cylinder is easily transformed into a stove body. To work, you need a grinder and an inverter or any other welding machine.

The shape of the cylinder allows you to make a furnace with a spherical furnace. Firewood in a stove of this form burns slowly - as a result, a kind of heat generator is obtained, capable of heating the room for hours on one tab of firewood.

A homemade stove from a long-burning gas cylinder can be used in different ways:

• as heating and cooking in residential premises;
• as heating for heating one or two rooms;
• as a cooking for use in the summer in the country;
• as an emergency portable option for use in case of failures in the main heating system.

Advantages of gas cylinder stoves:

• you can get a long-burning apparatus at practically no cost, since the system is assembled from standard inexpensive elements;
• all work can be done independently, no need to look for specialists;
• suitable for heating baths;
• video materials are available with positive experience in creating furnaces of various designs;
• simple operation.

The disadvantages include the moment that the work should be done according to reliable drawings - otherwise the design will not have the required efficiency.

For work, you will need to choose a suitable cylinder. You should opt for an all-metal cylinder with a volume of 12 or 27 liters.

However, for a full-fledged heater, a gas cylinder with a volume of 50 liters and a diameter of 30 centimeters is chosen. Any fuel, including coal, can be burned in a tank of this volume.

Even before the start of work, it is necessary to decide on what type of fuel the furnace will operate. If you need a long-burning furnace, then it is better to provide for the possibility of loading coal into it.

A long-burning stove can be made small, only on wood - for this, it provides for the possibility of regulating draft.

The most difficult thing is to manufacture liquid fuel heating devices: waste oil, diesel fuel. On the other hand, a waste oil furnace allows you to reduce heating costs, since oil is inexpensive.

It is better for a beginner to start with simpler designs, for example, try to convert a gas cylinder into an ordinary potbelly stove.

Solid fuel stove

How can you make a stove from a gas cylinder? The first question that arises even before starting work is: how best to position the tank - horizontally or vertically?

If you want to use the stove for cooking, you will have to place the cylinders horizontally.

IN vertical version inside the cylinder, you will definitely have to install grates; in a horizontal one, this is done as desired.

But in a horizontal structure, it will be necessary to weld a tray for collecting ash, and in a vertical one, when installing the grate to a sufficient height, the ash pan can be omitted.

The potbelly stove will require cast doors for the blower and fuel chamber.

Home craftsmen make them themselves from a piece of metal cut from a cylinder when making a hole for the combustion chamber.

In this case, you only need to purchase hinges and a latch handle. For a purchased door, you will have to weld a frame welded from the corners onto the cylinder around the perimeter of the holes, and bolt the fittings to it already.

Before you start cutting or welding metal, you need to empty the container from the gas. The cylinder is filled to the top with water, then it is drained, and only after that they begin to work.

Stages of manufacturing a horizontal potbelly stove:

1. cut off the top of the container with a grinder;
2. install a grate made of bent reinforcement inside the cylinder;
3. fittings are welded to the tank;
4. a circle is cut out of steel 4 mm thick, equal to the outer diameter of the cylinder;
5. holes-rectangles are cut in a circle - the first under the firebox, the second under the blower;
6. weld a steel circle;
7. fix doors;
8. paste over the doors along the contour with asbestos cement;
9. they begin to re-equip the back of the furnace - they cut out a hole for the chimney equal to the diameter of the pipe;
10. a chimney is welded from a thick-walled pipe.

When the cylinder is located vertically, a design will be obtained that takes up a minimum of space.

Such a cylinder stove is suitable for a bathhouse, a small living space, it can be put in a garage.

Stages of manufacturing a vertical potbelly stove:

1. cut off the top of the cylinder with a grinder;
2. a large hole is cut out on the front of the future furnace for the furnace, below - under the blower, through which the structure will be cleaned of ash;
3. inside the cylinder, a grate of reinforcing bars is lowered and welded to the walls;
4. a border is welded to the holes under the doors and pasted over with an asbestos-cement cord;
5. the top is welded - it was cut off only in order to put a grate;
6. a chimney opening is made from above or from the side.

Bubafonya oven and rocket oven

An ordinary potbelly stove has a significant drawback - low efficiency. A huge amount of heat escapes through the chimney.

In addition, as soon as the fire goes out, the structure immediately cools down. Pyrolysis furnaces, that is, devices capable of maintaining long-term combustion, are deprived of these shortcomings.

The simplest pyrolysis oven can be made from a gas cylinder. Masters call such devices bubaphones.

The bubafonya stove from a gas cylinder was invented by a craftsman from Russia. This happened recently, but bubafonya has already become very popular.

How does the bubafonya type apparatus, converted from a gas cylinder, work? A movable piston is installed inside the container, dividing the balloon into two parts.

Fuel (firewood) burns under the piston, and above it - gases released from firewood as a result of pyrolysis.

This principle of operation leads to the burning of firewood in the "reverse order" - from top to bottom.

Reverse combustion is slower than usual, in which oxygen is supplied to the fuel chamber from below, through the blower holes.

In a bubafon, air is supplied to the furnace by a piston axle, which is a hollow tube. Oxygen enters the pyrolysis chamber through openings cut at the end of the gas cylinder.

The division of the furnace into two compartments allows the wood, even with a lack of oxygen, to burn through to the end without turning into coal.

The system is so effective that a bubafon from a gas cylinder on one tab of firewood works for 4-6 hours.

There are reliable reviews that a bubafonya from a 200-liter barrel works on one tab for a whole day.

Bubafonya can be used for water heating. To do this, the gas cylinder is enclosed in water jacket using another metal case, and connect a water pump to the system.

The rocket stove was developed as a design for survival in extreme conditions. It has high efficiency and maximum safety.

At the same time, a home-made rocket stove is so simple that a non-professional can make it. In rocket furnaces, the principle of pyrolysis is used, that is, fuel decomposes into volatile substances under conditions of oxygen deficiency.

The simplest pyrolysis furnace can be made from any cylindrical metal container, for example, a barrel or a gas cylinder.

Rocket stoves can be equipped with benches. Such structures are still used in China and Korea for heating peasant houses.

Structurally, a rocket stove from a gas cylinder consists of a blower, a fuel chamber with a blind cover, a channel for oxygen supply to the pyrolysis chamber, a flame tube in which gases are burned, and a chimney.

Liquid fuel stove

In individual farms, it is sometimes possible to use used engine oil. In this case, heating costs are drastically reduced.

To burn oil, you need to assemble a special furnace that runs on liquid fuel. A mining heater and a simple wood-burning stove work on a different principle.

At first glance, a working oven is no more complicated than a pan, but complex chemical and thermal processes take place in it.

The furnace for mining from a gas cylinder consists of the following parts:

• oil containers;
• dampers regulating combustion;
• holes for filling oil;
• chimney.

For the manufacture of a furnace from a gas cylinder, tanks with a volume of 50 liters are used.

The balloon is sawn in a ratio of 2:1. The smaller part will go to the manufacture of the tank, the larger one will become the afterburner.

The principle of operation of such a furnace system is as follows:

1. oil is poured into the fuel bunker and set on fire;
2. air is fed into the chamber through an air throttle and thus greatly limit the intensity of combustion;
3. as a result, the fuel does not burn, but evaporates, that is, the pyrolysis process begins;
4. oil "steam" rises to the upper chamber and burns completely there.

In other words, the fuel is used twice - first the oil burns, and then its vapors burn out. As a result, no waste remains, and the efficiency of such a furnace is as high as 80%.

Waste oil is a heavy, heavily polluted and poorly burning mass of complex composition. Two-stage combustion allows you to fully use the entire resource of this fuel. The structure is vertical.

On top of it, you can install a lattice-stand for placing buckets, pans and other utensils.

Drawings that must be strictly adhered to and training videos will help to make a furnace for testing from a cylinder.

The disadvantage of liquid fuel stoves can be attributed to increased safety requirements. Fuel reserves have to be stored away from the boiler room.

A waste oil-powered structure cannot be used as a sauna stove, but it is useful for heating workshops, change houses and residential premises.

In the latter case, it is better for her to build a separate boiler room in the form of an extension to the house.

So, now you know how to make any oven from a metal gas cylinder with your own hands.

Having the necessary drawings, a grinder and an inverter, you can easily make a mobile and efficient heating device that will help out in winter time when other types of heating are turned off or unavailable.

This unusual type of heating systems is not familiar to ordinary developers. Many professional stove-makers have also never encountered such designs. This is not surprising, since the idea of ​​a rocket stove came to us from America relatively recently, and today enthusiasts are trying to bring it to the mass consciousness of citizens.

Due to the simplicity and low cost of construction, thermal comfort and high efficiency, rocket furnaces deserve a separate article, which we decided to devote to them.

How does a rocket oven work?

Despite the loud space name, this heating structure has nothing to do with missile systems. The only external effect that gives some resemblance is a jet of flame that breaks out of a vertical pipe near the camp version of the rocket stove.

The work of this hearth is based on two basic principles:

1. Direct combustion - the free flow of fuel gases through the furnace channels without being stimulated by the draft created by the chimney.
2. Post-combustion of flue gases released during the combustion of wood (pyrolysis).

The simplest jet furnace works on the principle of direct combustion. To achieve thermal decomposition of wood (pyrolysis), its design does not allow. To do this, it is necessary to perform a powerful heat-accumulating coating of the outer casing and high-quality thermal insulation of the inner pipe.

Despite this, portable rocket stoves perform their functions well. They don't require a lot of power. The generated heat is enough for cooking and heating in the tent.

Rocket furnace designs

To begin acquaintance with any design should be with its simplest options. Therefore, we present a diagram of the operation of a mobile rocket stove (Fig. 1). It clearly shows that the firebox and the combustion chamber are combined in one piece of steel pipe, bent up.

For laying firewood, a plate is welded in the lower part of the pipe, under which there is an air hole. Ash, which plays the role of a heat insulator, helps to enhance heat transfer in the cooking zone. It is poured into the lower part of the outer casing.

The secondary chamber (casing) can be made of metal barrel, bucket or old gas cylinder.

In addition to metal, the simplest rocket furnace can be built from several dozen bricks even without the use of mortar. A firebox and a vertical chamber are laid out of them. Dishes are placed on its walls so that there is a gap under the bottom for the exit of flue gases (Fig. 2).

A prerequisite for the good operation of such a design is a “warm pipe”, as the stove-makers say. In practice, this means that before laying firewood, the rocket stove must be warmed up for several minutes, burning wood chips and paper in it. After the pipe is warmed up, the firewood is stacked in the firebox and set on fire, in furnace channel there is a powerful upward flow of hot gases.

Bookmark fuel in simple designs rocket furnaces horizontal. This is not very convenient, because it forces you to periodically push the firewood into the firebox as it burns out. Therefore, in stationary systems, a vertical bookmark is used, and air is supplied from below through a special blower (Fig. 3).

Burning out, the firewood itself falls into the oven, saving the owner from manual feeding.

Main dimensions

A visual representation of the configuration of a stationary long-burning rocket furnace is given by drawing No. 1.

Anyone who wants to build a stationary rocket furnace, without being distracted by simplified modifications, must know its basic dimensions. All dimensions of this design are tied to the diameter (D) of the cap (drum) covering the vertical part of the flame tube (riser). The second dimension required for calculations is the cross-sectional area (S) of the cap.

Based on the two indicated values, the remaining dimensions of the furnace structure are calculated:

1. The cap height H is between 1.5 and 2D.
2. The height of its clay coating is 2/3H.
3. Coating thickness - 1/3D.
4. The cross-sectional area of ​​the flame tube is 5-6% of the cap area (S).
5. The size of the gap between the cap cover and the upper edge of the flame tube should not be less than 7 cm.
6. The length of the horizontal section of the flame tube must be equal to the height of the vertical one. Their cross-sectional areas are the same.
7. The blower area should be 50% of the cross-sectional area of ​​the flame tube. To ensure a stable operation of the furnace, experts recommend making a flame channel from a rectangular metal pipe with an aspect ratio of 1:2. She is laid flat.
8. The volume of the ash pan at the exit from the furnace to the external horizontal smoke channel must be at least 5% of the cap (drum) volume.
9. The external chimney must have a cross-sectional area between 1.5 and 2S.
10. The thickness of the adobe insulation pad, which is made under the external chimney, is chosen in the range from 50 to 70 mm.
11. The thickness of the adobe coating of the couch is chosen equal to 0.25D (for a drum with a diameter of 600 mm) and 0.5D for a cap with a diameter of 300 mm.
12. The external chimney must be at least 4 meters high.
13. The length of the flue in the bed depends on the diameter of the cap. If it is made from a 200-liter barrel (diameter 60 cm), then you can make a bed up to 6 meters long. If the cap is made of a gas cylinder (diameter 30 cm), then the bench should not be longer than 4 meters.

When building a stationary rocket furnace, special attention must be paid to the quality of the lining of the vertical section of the flame tube (riser). To do this, you can use refractory bricks of the ShL brand (light fireclay) or washed river sand. To protect the lining from flue gases, it is made in a metal shell, using old buckets or a galvanized sheet for this.

Sand filling is done in layers. Each layer is compacted and lightly sprayed with water. After making 5-6 layers, they are given a week to dry. Thermal protection from fireclay is easier to make, but the space between the outer shell and the brick will also have to be covered with sand so that there are no empty cavities (Fig. 4).

Figure No. 4 scheme of the lining of the flame channels of rocket furnaces

After the backfill has dried, the upper edge of the lining is coated with clay, and only after that the installation of the jet rocket furnace is continued.

Advantages and disadvantages of rocket stoves

An important advantage of a properly constructed structure is omnivorousness. Such a stove can be fired with any kind of solid fuel and wood waste. Moreover, the moisture content of wood does not play a special role here. If someone claims that such a stove can only work on well-dried wood, then this means that gross mistakes were made during its construction.

The heat output of the rocket furnace, which is based on a barrel drum, is very impressive and reaches 18 kW. A gas cylinder stove is able to develop thermal power up to 10 kW. This is quite enough for heating a room with an area of ​​16-20 m2. We also note that the adjustment of the power of rocket furnaces is carried out only by changing the volume of loaded fuel. It is impossible to change the heat transfer by supplying air. The blower adjustment is used only to enter the furnace into operating mode.

Since the amount of heat generated by a rocket furnace is very large, it is not a sin to use it for such household needs, like heating food (on the drum lid). But it is impossible to use such a hearth to heat water used in a radiator heating system. Any introduction of coils and registers into the furnace design adversely affects its operation, worsening or stopping the pyrolysis process.

Useful advice: before you start building a stationary jet furnace, make a simplified camp structure from metal or clay. So you will work out the basic assembly techniques and get useful experience.

The disadvantages of rocket stoves include the impossibility of their use in baths and garages. Their design is designed for energy storage and long-term heating. Therefore, it cannot give a lot of heat in a short period of time, as is necessary in the steam room. For garages that store fuels and lubricants, an open flame oven is also not the best option.

We assemble a rocket stove with our own hands

The easiest way is to assemble a camping-garden version of a jet stove. To do this, you do not have to purchase masonry materials and prepare adobe for coating.

A few metal buckets, a stainless steel pipe for the flame channel and small gravel for backfilling - that's all you need in order to make a do-it-yourself rocket furnace.

First step- cutting holes in the lower bucket with scissors for metal to pass the flame tube. It must be done at such a height that there is room under the pipe for crushed stone backfill.

Second step- installation in the lower bucket of a flame tube, consisting of two elbows: a short boot and a long one for the outlet of gases.

Third step- cutting a hole in the bottom of the upper bucket, which is put on the lower one. The head of the frying pipe is inserted into it so that its cut is 3-4 cm above the bottom.

Fourth- backfilling with small gravel in the lower bucket at half its height. It is needed for heat accumulation and thermal insulation of the flame channel.

Last step- production of a stand for dishes. It can be welded from round reinforcement with a diameter of 8-10 mm.

A more complex, but at the same time durable, powerful and aesthetic version of the rocket stove requires the use of a gas cylinder and a thick rectangular steel pipe.

The assembly scheme does not change. The exhaust gas here is organized on the side, and not at the top. For cooking, the upper part with a valve is cut off from the cylinder and a flat round plate 4-5 mm thick is welded in its place.