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What kind of miracle is this: a rocket stove? A rocket furnace, a rocket furnace, and even a jet furnace, whatever it is called, however, it has nothing to do with rockets and jet engines. She received such a name, obviously, because of the characteristic "rocket" sound that occurs when the regime fails and excessive air flows through the blower into the furnace. In any case, the developers called it that way: rocket stove, which can be translated as a rocket stove.

Rocket stove principle

The design was first developed in America and was originally intended for use in the field. The main idea is to obtain a furnace with high efficiency with the maximum simplicity of the device. For this, two simple and essentially well-known methods were applied. The first is a more complete decomposition of gases with their afterburning due to a relatively long retention in a heated state. The second is the maximum extraction of heat from the burnt gases.

1. The kindling of the furnace begins with its preheating. To do this, it is best to use any easily combustible materials: wood chips, shavings or paper. The heating bookmark is recommended to be burned in an ash pan.
2. At the same time, the main firewood bookmark is set on fire. The blower was completely open.
3. As the ignition increases, the draft increases and a lot of air begins to flow into the furnace. A characteristic roar appears.
4. Here you should cover the blower damper until an even, quiet sound appears. If the rocket roar reappears, the adjustment should be repeated.

The firebox has good thermal insulation, so it heats up quickly and pyrolysis of firewood begins - the decomposition of solid firewood into gas under the influence of high temperature. Part of the pyrolysis gases decomposes to wood gases and burns. However, some does not decompose enough to burn. In conventional ovens, these semi-decomposed pyrolysis products fly into the chimney in the form of smoke and partially settle in the form of soot. Thus, any smoke is unburned firewood, which not only increases heating costs, but also clogs the chimney.

From this we can conclude that the main task of the furnace, which is used for heating, is to burn the fuel as completely as possible, solving two, albeit secondary, but no less important, tasks. Firstly, to take as much heat as possible from the burnt wood gas and, secondly, after accumulating it, distribute it in a heated room for as long as possible.

The main advantage of the rocket stove is that it perfectly solves all these problems.

After ignition of the main laying of firewood, the firebox warms up almost simultaneously with the horizontal and vertical channel - the so-called burning tunnel - Burn Tunnel. For this, the combustion tunnel, or, as it is also called, the flame tube, as well as the firebox, is insulated with a material that has not only thermal insulation properties, but also low heat capacity. The temperature in the flame tube rises to 900°C and under normal conditions in the upper part can reach 1000°C.

Under such conditions, the gases enter the top of the bell and heat the top to 400°C. Further, going down and cooling down to 250°C, the gases heat the cap and its coating, which acts as a heat accumulator. At the same time, the coating is made of adobe: a mixture of clay and straw - an inexpensive and affordable material.

After pre-cooling in the upper zone of the hood, the gas enters the secondary ash pan. Here the afterburning of wood gases ends and the precipitation of pyrosis residues, which for some reason were not sufficiently decomposed for combustion. Further, the gas moves relatively slowly in a horizontal smoke channel, where it gives off its last remaining heat, heating the lining of the couch, which is also made of adobe.

The main advantages and disadvantages of rocket furnaces

Advantages:

1. High performance, saving up to 90% wood compared to a conventional metal stove, according to their owners. Such savings are achieved due to the afterburning of pyrolysis gases and soot.
2. Uncritical to fuel. Any wood firewood, wood chips, bark, lumber waste will do. Their humidity doesn't matter either.
3. Simplicity and versatility of design. Anyone can assemble such a stove from clay, brick, stone or tile.
4. There is no need to add firewood too often. Firewood as it burns itself moves down and enters the combustion chamber.
5. Comfortable bed. Different stoves have sunbeds, but for example, in a Russian stove, it is located high.

Disadvantages:

1. the need to control combustion and constant manual adjustment of the air supply.
2. the presence of a hot part, due to which you can burn yourself. Although on the other hand it can be used for cooking. Bell temperature approx. 400°C.

Do-it-yourself rocket stove. Blueprints

The rocket stove has a thermally insulated shaped combustion chamber, which causes the fire to move first horizontally and then into the chamber at a 90-degree angle, which causes severe turbulence. Once in the upper part of the bell chamber, hot gases, heated to a temperature of 1000 ° C, give off most of the heat and go down, where they enter the auxiliary ash pan, and there, at a temperature of about 250 ° C, their final pyrolysis occurs along with the afterburning of pyrolysis (wood ) gases. Then, in a horizontal channel, the combustion products give off the rest of their heat and enter the chimney.

Despite the simplicity and accessibility of the design, for the normal operation of the furnace in the planned mode, when it is installed, it is necessary to observe the dimensions and take into account all recommendations.

Engineers and researchers have worked out the best ratio of dimensions to ensure that all processes run optimally. Here are their recommendations:

1. The cap height H must be between 1.5 and 2D.
2. The clay coating of the cap must have the following characteristics: height = 2/3H, thickness = 1/3D.
3. The cross-sectional area of ​​the horizontal and vertical parts of the flame tube is 5-6% of the cross-sectional area of ​​the cap (S).
4. The gap between the upper edge of the flame tube and the cap cover is at least 7 cm.
5. The lengths of the horizontal and vertical sections of the flame tube must be equal. Their cross-sectional areas are also the same.
6. The blower should have a sectional area of ​​50% of the area of ​​the flame tube.
7. The volume of the ash pan is recommended to be at least 5% of the volume of the cap.
8. The thickness of the adobe insulation pad, which is made under the external chimney, is chosen in the range from 50 to 70 mm.
9. The thickness of the bed is recommended 0.25D at D = 600 mm and 0.5D at D = 300 mm.
10. The height of the external chimney is at least 4 meters, the area cross section 9 -12% of the cap area.
11. Length smoke channel in the couch is also calculated from the diameter of the cap. With a diameter of 60 cm (standard 200 liter barrel) - the length of the bed can be up to 6 meters. If the cap has a diameter of 30 cm (the diameter of the gas cylinder), then the length of the bench is no more than 4 meters.
12. The flame channel is recommended to be made of a rectangular pipe, in an aspect ratio of 1:2, with its laying flat. This will ensure more stable operation of the entire furnace.

Always the simplest and most convenient solutions are very popular. Especially when it comes to heating facilities. So, the rocket stove is ideal for use in a private home, as the craftsmen themselves will be able to design it without emptying their wallet too much. Moreover, the principle of the rocket stove makes it possible to adapt to any design of the house. The same principle was used in Korea and China to heat their homes in winter. The advantage is that firewood with this type of heating is spent much less than in a traditional Russian stove.

The operation of this furnace 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 emitted during the combustion of wood (pyrolysis)

A rocket furnace can be fired with recycled materials, tree trimmings, and almost all potentially burning ones, since at the exit from the furnace, due to the high combustion temperatures, almost only carbon dioxide and water vapor are released in the furnace itself. The long chimney ensures complete cooling, resulting in the possibility of water emissions. With the correct design of this furnace, the fuel should burn only in the lower part, gradually settling.

The simultaneous use of a rocket stove for cooking and for heating the room makes it versatile.

Jet stoves have become popular not so long ago. In addition, not everyone knows about the advantages of such a heating system. It is worth noting that they are classified as energy efficient stoves. Their name is heating systems obtained thanks to reactive processes based precisely on heat transfer at significant temperature differences. At the same time, thrust arises in the jet furnace. A similar phenomenon is described in the course of basic physics. And this is thanks to the work without failures.

The design of the furnace "Rocket"

The jet furnace is always equipped with a knee, the angle of which is not more than ninety degrees. This is the main feature of this model. In other words, the chimney in relation to the bottom of the firebox is located at an acute or right angle. In this case, the oven must be equipped with an air duct. It is usually placed through the wall with the firebox.

Advantages of jet furnaces and how they work

Before a do-it-yourself jet furnace is built, it is worth understanding the principle of its operation and evaluating its merits. The main difference of such a design is that the concentration of temperature occurs precisely in the air stream, which is constantly in motion, and not in the furnace. In this case, continuous thrust occurs in the knee - in the place of heating. Air with oxygen for combustion is supplied through the duct, and in the furnace it receives a sufficient amount of thermal energy. In this case, ordinary wood can be used as fuel. In places where there is a temperature difference, it is given. Thus, traction is constantly maintained.

A jet furnace in continuous operation does not require special adjustment of the air supply. After all, the natural balance of all processes provides the necessary traction. In other words, the one that is required to maintain the desired temperature regime in the furnace. As for the exit of all exhaust gases, this process also proceeds naturally, using the pressure of already heated air. It is for this reason that the jet furnace is built with a low chimney.

The first stage of construction: flows only in their pure form

The jet furnace, the scheme of which is not so complicated, consists of several important elements. One of them is the knee. For its manufacture, two pipes can be welded at a right angle. In diameter, these parts must be at least fifteen centimeters. In this case, a ratio of 1 to 2 must be observed. As a result, a ready-made firebox with a chimney pipe should be obtained. The short part of the knee should be horizontal, and the long part vertical. If you make a fire in the pipe, then the heat will go up.

To organize the supply of secondary air, you can use one of the primitive options. To do this, a metal sheet should be installed on the brackets inside the furnace. This will move the hearth away from the duct. But the air that will pass through it will always end up in the corner of the knee. This is what makes it possible to call it secondary. To make the do-it-yourself reactive oven more functional, you can weld the legs to the finished device, and install a grate for the pan on the upper channel.

The second stage of construction: potbelly stove "rocket"

The basis is the design built at the first stage. One more important element needs to be added to it - a horizontal section. The rectangular section of the channels is much more convenient in terms of operation than pipes. A jet furnace, the drawings of which allow you to more accurately imagine the entire structure, may have a different structure. In this case, the duct can be positioned arbitrarily. However, it is worth observing one of the rules. In any case, air must pass through the duct. To do this, you can use plates on the ribs along the bottom wall, parallel side walls of the loading hatch or "brushes".

After that, the steel chimney is attached to the knee. Then you can install the roof. It is very difficult to describe exactly this structure. After all, for its manufacture usually use all sorts of improvised materials. Often a jet furnace is made from a gas cylinder. The main thing is to implement the principle of flow formation.

Third stage of construction: design with vertical heat exchanger

This idea is to create a heat exchanger made of steel with sufficiently thick walls precisely in the path of heat flows. The element built in the second stage must be increased in size. To do this, instead of a vertical pipe, an empty container must be installed, which will be used for dry heat exchange. In this case, a gas cylinder is ideal.

The jet furnace must be built in such a way that the horizontal element is aligned with the chimney channel. This moment is very important. In this case, the firebox - a horizontal element - can be made in several versions. It can be a box, a pipe or a stove body. If this part has sufficient dimensions, then it can be used as a pre-heat exchanger.

In order for the jet furnace, the scheme of which is presented above, to burn continuously for up to 4 hours, it is the fuel compartment that should be increased in size. In height, this element can be up to 60 centimeters. In this case, the loading of logs must be vertical. In such a situation, the combustion of raw materials will occur in the lower part. The logs will gradually burn and sink under their own weight.

The reactive furnace "Shirokov" is quite simple in design. Primary air is usually supplied through a door located in the area of ​​​​the firebox, and secondary air is supplied through a channel or an opening on the knee.

The fourth stage of construction: installation of the injector

At this stage, it is necessary to equip the product with a separate channel, through which oxygen will flow at the stage of fuel burnout. This requires a pipe with a diameter of 1.2-1.5 centimeters, preferably curved in the shape of the channel itself, resulting from individual structural elements. On one side, a plug should be installed and up to eight holes with a diameter of six millimeters should be made in one of the walls. The area with holes made in length should be no more than 100 millimeters. The finished pipe must be installed in such a way that it passes through the entire system. In this case, the edge with the plug should reach the place where the flame still reaches. As for the open side, it should be in the cold part of the structure and have an inflow fresh air. The metal, when heated, will create the necessary traction.

Fifth stage of construction: installation of a turbocharger

Jet furnace on this stage not finished yet. Connect an air pump to the injector. For these purposes, you can use an ordinary old vacuum cleaner. In this case, the injector must have sufficient throughput. After the pump is turned on, not only will the flow of fresh air increase, but an additional one will also be created. At the same time, thrust will increase in proportion to the supplied power. This process will be provided by an increase in the temperature in the heat exchanger.

It is worth noting that this method has been known for a long time. It was used by masters. At the same time, the functions of the air pump were performed by a special blacksmith fur.

Instead of a conclusion

If you are interested in a jet stove, and you decide to install it in your house, remember a few basic rules. First of all, every detail in the system must be harmonious. Each piece of the structure must be balanced. Otherwise, overheating will occur, which will eventually lead to burn-out of metal parts. It is worth noting that it is necessary to install a jet furnace not near the wall, but at some distance from it. So it will heat the room more efficiently.

Rocket stoves are high performance and work great in clay and straw houses. The owners of such stoves claim to reduce wood consumption by 80-90% compared to heating the same space with a conventional metal stove. wood burning stove. This is ensured by the afterburning of combustible gases and soot.

Unlike laying conventional stoves, which require special skills and knowledge, a rocket stove can be assembled by any enthusiast. The only problem with such a project is the difficulty in getting permission for it, because basically, not many officials know what a heater rocket is.

The main difference between a masonry heater and a rocket heater is that the rocket stove has an insulated J- or L-shaped combustion chamber, which causes the fire to move horizontally. The flame then hits the end of the chamber at a 90-degree angle, which causes a lot of turbulence, which raises the heat, creating a strong draft that maintains the intensity of the fire. The heat riser is inside the trunk, or a large secondary chamber that extends a few centimeters above the inner riser. Hot gases rise and enter the upper part of the secondary chamber, give off part of the heat, and then fall down and to the sides through the channels.

The hood then directs the gases through chimneys, as a rule, installed in a bench, which absorbs the last remnants of heat.

Today, clay is often used to create rocket heaters, but you are absolutely free to lay out a bench from brick, stone or tile.

The rocket stove has a high efficiency. At the outlet of the furnace, due to the high combustion temperatures in the furnace itself (900-1200 C), there is practically only carbon dioxide and water vapor. Soot burns at temperatures of 900 C and above. A rocket stove can be fired with secondary materials, wood trimmings, cones, branches, corn stalks - the high combustion temperature with a massive supply of oxygen allows you to burn almost everything potentially burning ...

If the cap is not coated with clay, but left as is, then it will immediately give off heat to the room. If it is overlaid with clay or brick, then it will keep heat longer after burning. permaculturedesign.fr

This rocket stove was made during a large training session on building straw and clay houses in February 2010 in Patagonia, Argentina. www.firespeaking.com

When a jet furnace burns, it draws air in and pulls the flame in. You can toss long logs into the firebox that are sticking out at the top while their other end is burning in the firebox. The wood is consumed gradually and without smoke leakage. This jet oven is from Juured in Estonia. www.juured.ee

This rocket stove was made in house for sale. by Ernie and Erica Wisner.
ernieanderica.info/shop

The combustion chamber runs horizontally, the flames and gases hit at a 90-degree angle, and then, under strong turbulence, they throw out heat and create a rocket effect to throw the heat upwards. The heat in the riser is usually less, the pipe is installed inside a large hood. The internal heat of the riser must be insulated, it creates a thermal differential that again increases traction. The outlets and channels at the bottom are often covered with clay to keep the stove warm and allow the heat to slowly radiate out to warm the room.

Gorgeous rocket stove design made in Brussels. The tabletop is made of refractory cement, with refractory bricks inside. Internal work here: flickriver.com

The firebox for firewood is placed to the right of the sink, the stove is placed to the right of the firebox.

The rocket furnace is made of stone. Written by Ernie and Eric. ernieanderica.blogspot.com

Rocket oven in the center of shamans, France. It will take 3-4 people and about 3-4 days to build such a furnace. ecologie-pratique.org

Rocket oven in wooden house. Juured, Estonia.

Rocket stove in an Oregon samman home.
canadiandirtbags.wordpress.com

A jet stove will heat more than just a clay and straw bench for you. This is a flight of stairs sculpted by Danish architect, mason and reed roof maker Fleming Abrahamsson.

This stylish clay bench with stove is designed by Flemming Abrahamsson, a Danish architect, mason and reed roofer. She is in no less. Such ovens are very efficient, the temperature of the oven is between 1000C and 1100C (this is not the place to keep a vase of flowers).

Rocket stoves are mainly used for cooking, as they do in the mountains of Guatemala. joachim2010.blogspot.com

Rocket stove, France. terre-et-flammes.fr

Rocket stove in the interior poeles-eco-09.com

Antique rocket stove lined with clay. The firebox is on the right, and the heated bench is behind. Ernie and Erica Wisner, more photos: plus.google.com

Sophisticated Rocket Oven by expert Kirk Mobert “Donkey”, sundogbuilders.net, donkey32.proboards.com

Here is another diagram of the principle of operation of a rocket furnace, very accessible.

And this is a store version of the Dragon Heater's 6 metal rocket furnace. The cost of such a furnace is $ 1450. www.dragonheaters.com

To date, quite a lot of varieties and models of wood-burning stoves have been developed and implemented. In this series, the do-it-yourself rocket furnace built with your own hands, the drawings of which will be presented below, fully justifies all expectations. Such a heating structure, of course, deserves close attention, as it has some specific advantages that are indispensable in certain conditions.

This version of the wood stove is simple and original in design and does not require a large number of expensive components and materials for the manufacture. Install such a stove by making it on your own, probably, any person can, even if he does not have experience in the construction of such structures, but who knows how to read the provided drawings and work with some tools.

It is interesting to note that, if necessary, a rocket stove can be made even in 20–30 minutes, for example, from an iron can. However, if you make every effort, it is possible to get a comfortable stationary structure for your home with a heated bench that can even replace an ordinary sofa.

The principle of operation of the rocket oven

The rocket stove was originally conceived as one of the functional survival items in difficult conditions. Therefore, its design had to meet certain criteria:

• Efficient space heating.
• Possibility of cooking.
• High efficiency of the device when using various wood fuels of any quality for heating.
• The ability to report fuel without stopping the combustion process.
• In addition, the oven had to keep warm for at least 6-7 hours to enable the owners to spend the night in comfortable conditions.
• Maximum safety of the structure, in terms of eliminating the possibility of seepage into the room carbon monoxide.
• Another condition that had to be met was the simplicity and accessibility of the design for its manufacture by any non-professional.

Therefore, the basis was taken basic principles several varieties heating appliances operating on wood solid fuel:

• Free circulation of heated air and gases through all channels. The furnace works without forced blowing, and the chimney creates draft, which draws out the products of combustion. The higher the pipe is raised, the more intense the thrust in it.
• The principle of afterburning the gases emitted during combustion from the fuel ( pyrolysis), which is used in devices long burning. This principle of operation is extremely important due to the high efficiency of the device, which is achieved by creating special conditions for the afterburning of pyrolysis gases for the most complete consumption of the energy potential inherent in the fuel.

The term "pyrolysis" means the decomposition of solid fuel into volatile substances, under the influence of high temperatures and simultaneous "oxygen starvation". By creating limited conditions - they are able to burn out, also releasing a large number of thermal energy. At the same time, it is important to know that the pyrolysis of insufficiently dried wood takes place for quite a long time in the gas phase, that is, the released pyrolysis gas will require a lot of heat to create a mixture (wood gas) that can burn completely. Therefore, it is not recommended to use wet fuel for the rocket stove.

A variety of rocket stoves - from simple to complex

The simplest design of a rocket furnace

In a simple design of a rocket stove, heated by bundles of branches or torches, the combustion products almost immediately go into the chimney, without having time to form combustible wood gas in the stove body, so it will not be possible to heat the room with it. Such ovens can only be used for cooking. This model is manufactured in stationary and mobile versions; only the principle of free circulation of heated air operates in it, since it does not create the required conditions for a full-fledged pyrolysis process.

In such furnaces, a small section of pipe is used as a fuel chamber. It can have a horizontal position, as shown in the diagram, or be turned up. In the latter case, fuel is loaded vertically.

After igniting the fuel placed in the pipe, the heated gases released from it rush up the vertical section of the pipe to the outside.

On top of the vertical pipe and install containers for cooking or heating water. In order for the gases to freely escape to the outside, and the bottom of the tank does not completely block the draft in the pipe, a special metal stand is installed on top of the stove. She creates a gap of the right size, which helps maintain traction.

Above - very original stand under the hot water tank

By the way, this simplest type of furnace device was invented first, and because of the furnace opening turned upwards and the flame escaping from it, the furnace most likely got the name rocket. In addition, if the furnace mode is incorrect, the structure emits a whistling “rocket” rumble, but if the furnace is set up correctly, it rustles quietly.

Advanced Rocket Furnace

Since, using the simplest rocket stove with a free exit of gases, it is impossible to heat the room, the design was later supplemented with a heat exchanger and smoke ducts.

After the improvements made, the whole principle of operation of the rocket furnace has changed somewhat.

• To maintain a high temperature of heated air in a vertical pipe, they began to insulate it with a fire-resistant material, and then close it on top with another metal case made from a larger diameter pipe or a metal barrel with a closed top.
• A door was installed on the opening of the furnace, and a separate channel for secondary air appeared in the lower part of the furnace. Through it, blowing began to be carried out (necessary for the afterburning of pyrolysis gases), which previously occurred through an open firebox.
• In addition, the chimney was moved to the lower part of the hull, which forced the heated air to circulate throughout the hull, bypassing all internal channels, and not escaping directly into the atmosphere.

• The high-temperature combustion products first began to rise to the ceiling of the outer case, accumulate there and heat it, which made it possible to use the outer horizontal surface as hob. Then, the gas flow cools down and goes down, turns into a knee and only from there goes into the chimney.
• Due to the inflow of secondary air, afterburning of gases occurs at the end of the lower horizontal channel, which significantly increases the efficiency of the furnace. The free circulation of gases creates a self-regulating system that limits the flow of air into the combustion chamber, since it is supplied only as the hot gases cool down under the "ceiling" of the housing.

A very popular scheme - from a metal profile and an old gas cylinder

The stove model shown in the figure works like a “potbelly stove” and has a chimney brought out to the street. However, it is unsuitable for use in residential premises, since in it, with changes in external pressure, a reverse draft may occur, which will contribute to the entry of carbon monoxide into the premises. Therefore, such a stove should always be supervised, and it is most often used for heating utility rooms or a garage.

Rocket stove with warm bed

According to the principle of afterburning pyrolysis gases, a rocket furnace with a stove bench is also arranged, but in this embodiment, the heat exchanger is a structure of combined long channels coming from the stove and laid or formed from non-combustible plastic materials under the stove bench surface.

It should be noted that such a heating system is by no means new, and, in fact, such a rocket stove has a rather rich history. It was invented a long time ago, presumably in Manchuria, called " kan", and is still traditional for peasant houses in China and Korea.

Similar stoves called "kan" have long been used to heat homes in East Asia.

The system is a wide couch made of stone, brick and clay, inside which the air heated in the furnace passes through the arranged channels, which are essentially an elongated chimney. Passing through this labyrinth and gradually giving off heat, the gas flow, cooling down, exits into a chimney 3000 ÷ 3500 mm high, located on the street, next to the house.

The stove itself is located at one end of the bench and, as a rule, is equipped with a hob, which allows it to be used for cooking.

From above, the stone-clay construction "kan" is covered with straw or bamboo mats, or a wooden flooring is arranged there. At night, the couches were used as beds, and during the day - in the form of a seat, on which, traditionally for Asian peoples, a special low table 300 mm high was installed - after which a meal was held.

This heating system is quite economical in terms of fuel consumption, since it is enough to use an average thickness of a branch to heat it. Such a rocket oven is capable of long time retain heat, creating comfortable conditions for sleeping throughout the night.

And Korean stoves "ondol" probably became the prototypes of modern "warm floors"

Korean homes use a heating system similar to " kan", which is called "ondol". This heating option, unlike the Chinese one, is not arranged inside the couch, but under the entire floor of the house. In principle, it can be argued that this method of transferring and distributing heat to residential premises seems to have formed the basis for the design modern system"warm floor".

Furnace design with connected pipes to it can be clearly seen in the diagram presented.

In our time, with today's rich variety of materials, the channels in this furnace design can be made of metal pipes laid in a coil and well insulated non-combustible materials. Therefore, the last section of the chimney system can exit from the structure of the bench next to the stove itself or at the end of the bench, and then go through the wall into the chimney pipe installed on the street.

In the presented diagram, you can see the results of design work, which made it possible to achieve a relatively simple circuit with high efficiency, as well as meeting all the requirements for a speech rocket.

Fuel is loaded into the furnace hole vertically. Then it is set on fire, and, burning out, gradually settles down. The air that supports combustion enters the bottom of the combustion chamber through an opening that plays the role of a blower. It must provide sufficient air flow for the afterburning of the released products of the thermal decomposition of wood. But, at the same time, there should not be too much air, since it can cool the initially released gases, and in this case the process of afterburning pyrolysis gases will not be able to take place, and the combustion products will settle on the walls of the housing.

In this variant, the top-loading furnace has on the furnace chamber blank cover, which eliminate the risk of gases entering the room when creating reverse thrust.

In a completely isolated volume of the released gas, thermal energy, temperature and pressure increase, thrust increases. As the fuel burns, the burning gases go through the channels of the furnace body into the heat exchanger, heating the internal surfaces along the way. Since the channels have a complex configuration, gases are retained inside the furnace for a longer time, giving off heat to the body and channel surfaces, which in turn, they heat the surface of the couch and, accordingly, the room itself.

Over time, any furnace and its channels require cleaning from soot deposits. In this design, the problem area is the heat exchanger pipes located inside the bench. In order to carry out these preventive measures without problems, at the level of the heat exchanger turning from the furnace body into the pipes under the bench, a hermetically closing cleaning door is installed (indicated in the diagram as “Secondary Airtight Ash Pit”). It is in this place that all the unburned products of the thermal decomposition of wood concentrate and settle. The door is periodically opened and the passages are cleaned of soot - this process guarantees long-term operation of the chimney. In order for the door to close tightly, asbestos gaskets must be fixed to its inner edges.

How to properly heat a rocket stove?

To get the maximum heating effect, it is recommended to heat up the furnace before laying the bulk of the fuel. This process is carried out using paper, dry shavings or sawdust, which are ignited in a firebox. When the system warms up, it will change the emitted sound - it may die out or change its tone. The main fuel is placed in the heated unit, which will ignite from the heat already created by heating.

Any firewood and even thin branches are suitable for a rocket stove, but the main thing is that they are dry.

Until the fuel flares up well, the door of the combustion chamber or blower must be kept open . But only when the fire becomes intense, and the stove buzzes, the door is covered. Then, in the process of burning, the access of air from the blower is gradually blocked - here you need to focus on the tone of the stove sound. If the air damper is accidentally closed, and the intensity of the flame has decreased, it must be opened again and the stove will flare up with renewed vigor.

Advantages and disadvantages of a rocket stove

Before proceeding to the description of the manufacturing process of the rocket furnace, it is desirable to summarize the information about its advantages and disadvantages.

Rocket stoves are quite popular due to their positive qualities , which include:

• Simplicity of design and a small amount of materials.
• Even a novice master can make any of the furnace designs, if desired.
• The construction of a rocket furnace does not require the purchase of expensive building materials.
• Undemanding to the forced draft of the chimney, self-regulation of the furnace.
• High efficiency of the rocket furnace with a pyrolysis gas afterburning system.
• Possibility of adding fuel during furnace firing.

Despite the large number of advantages of this design, its work has a number of shortcomings :

• Using the simplest design rocket stove, only dry branches and splinter can be used, as excess moisture can give reverse thrust. In more complex system The use of wet wood is also not recommended, because it will not give the right temperature for pyrolysis to occur.
• The rocket stove cannot be left unattended during combustion, as this is very unsafe.
• This type of device is unsuitable for heating a bath, as it does not give enough heat in the infrared range, which is especially important for a steam room. A rocket stove with a stove bench can only be suitable for a rest room in a bath building.

Video: dissenting opinion on rocket stoves

Making a rocket stove with a bench

Rocket ovens come in a variety of sizes and are made using the most different materials- This metal pipes, barrels and gas cylinders, bricks and clay. A combined option is also quite acceptable, consisting of pipes, stones, clay and sand. It is he who deserves special attention.

From a gas cylinder, you can make a stove that is simple in design, including using it for the option with a stove bench.

How to make a simple oven in itself is more or less clear from the above drawings and a description of its work, so it is worth considering the manufacture of a heating unit equipped with a bench.

Video: homemade rocket stove from a gas cylinder

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To make it completely clear what and where is located in the design of the rocket furnace, this scheme will be used to describe the work.

So, the considered furnace-rocket consists of the following elements:

• 1a- a blower with an air supply regulator, with which the stove is adjusted to the desired mode;
• 1b- a fuel chamber (bunker) with a blind cover;
• 1c- a channel for supplying secondary air, which ensures complete combustion of pyrolysis gases emitted by wood;
• 1g– flame tube 150÷200 mm long;
• 1d- primary chimney (riser), with a diameter of 70 ÷ 100 mm.

The flame tube must not be made too long or too short. If this element is too long, then the secondary air in it will quickly cool down and the process of afterburning pyrolysis gases will not reach the end.

The entire design of the flame tube and riser must be thermally insulated as efficiently as possible. The task of this node is to provide complete combustion pyrolysis gases and the supply of hot masses from the riser to other channels, which will already transfer heat to the room and to the bench.

Here it should be noted that in order to obtain the optimal efficiency from the furnace, the diameter R the aizer should be made with a size of 70 mm, and if the goal is to achieve the maximum power of the furnace, then it should be made with a diameter of 100 mm. In this case, the length of the flame tube should be 150÷200 mm. Further, when describing the installation of the furnace, the dimensions will be given for both cases.

It is impossible to immediately let the heated air from the riser into the heat storage, since its temperature reaches 900÷1000 degrees. High-quality heat-resistant heat-accumulating materials have a rather high price, therefore, most often, adobe (clay mixed with chopped straw) is used for these purposes. This material has a high heat capacity potential, but is not heat-resistant, so the design of the secondary furnace (cylinder body) begins with an air temperature converter, which must be heated to only 300 degrees. Part of the generated heat is immediately given into the room and replenishes the current heat loss.

The described functions are performed by the furnace body, made from a standard 50 l gas cylinder.

• 2a- cover of the furnace body. Under it, heated air enters from the riser;
• 2b– hob, which is heated from the inside by heated gases leaving the riser;
• 2c– metal insulation of the riser (shell);
• 2g– heat exchange channels. Heated gas enters them, dispersing under the ceiling of the case;
• 2d– the lower metal part of the case;
• 2nd– exit from the housing to the cleaning chamber.

The main task in the arrangement of these parts of the furnace is to ensure complete tightness of the chimney line.

In the housing (drum), at a height of ⅓ from its "ceiling", the gases cool down and already have normal temperature to enter them into storage. Approximately from this height and to the floor of the room, the stove thermally insulated several layers different formulations This process is called lining.

• 3a- the second cleaning chamber, through which the heat exchanger ("hog"), located under the bench, is cleaned from carbon deposits;
• 3b– sealed door of the second cleaning chamber;
• 4 - "hog", a long horizontal section of the chimney, located under the stove bench.

After passing through the pipes of the "hog" and almost completely giving off heat to the adobe stove, the gases escape through the main chimney channel into the atmosphere.

Having dealt with the device of the rocket furnace in detail, you can proceed to its construction.

Building a rocket oven with a stove bench - step by step

Primarily, you need to prepare lining compositions. Their components will cost quite inexpensively, since they can often be found completely free of charge, literally under your feet:

• 5a- adobe. As mentioned above, this is clay mixed with chopped straw and mixed with water to the density of the masonry mortar. Clay for making adobe is suitable for any, since it will not be influenced by external atmospheric influences;
• 5 B- kiln clay mixed with crushed stone. This will be the main heat insulator. The mortar should have the consistency of a mixture for laying bricks;
• 5v- heat-resistant lining, made of kiln clay and fireclay sand in proportions of 1: 1 and having the consistency of plasticine;
• 5g- ordinary sifted sand;
• 5d - medium-fat clay for kiln masonry.

Step-by-step work on the design is carried out in the following sequence:

Bed for a couch

Having prepared all the necessary compositions, a bed is made - a wooden durable shield of the desired configuration. Its frame is made of timber with a section of 100 × 100 mm. Frame - with cells measuring 600 × 900 mm under the stove and 600 × 1200 mm under the bench. If a curvilinear shape of the couch is planned, then it is brought to the desired configuration with the help of boards and scraps of timber.

Bed - frame base for further construction of the furnace structure

The frame is sheathed with a grooved board 40 mm thick - it is fixed across the long sides of the frame. Later, after the installation of the furnace is completed, the side facade of the bed will be sheathed with drywall. All details wooden structure beds must be impregnated with biocide, and then stained twice with a water-based emulsion.

Further, on the floor, in the place of the room where the stove will be installed, mineral cardboard (cardboard made of basalt fibers) 4 mm thick is laid, the size and shape are fully consistent with the parameters of the bed. Directly under the stove, a sheet of roofing iron is fixed on top of the cardboard, which will come out from under the stove in front of the firebox by 200 ÷ 300 mm.

Then, the bed is transferred and firmly installed on the selected and made location oven, so that the frame stands stably, without play. At the end of the future couch, at a height of 120 ÷ 140 mm above the level of the bed, a hole for the chimney is arranged in the wall.

Formwork and pouring the first level of adobe mixture

A solid formwork is installed along the entire contour of the bed, having a height (A -40 ÷ 50 mm) and a smooth upper edge.

An adobe mixture (5a) is poured into the formwork and its surface is leveled using a rule. Formwork sides serve as beacons for leveling.

Production of the furnace body

• While the adobe filling will dry, and this process will take 2-3 weeks, you can start making the furnace body from a cylinder. It should be noted that a rocket stove is made from a barrel in the same way.

Cutting a gas cylinder and making a cap with a "skirt"

• The first step is to cut off the top from an empty cylinder to obtain a hole with a diameter of 200 ÷ 220 mm. Further, this hole is closed with a 4 mm thick steel round timber prepared in advance - this surface will play the role of a hob. After that, another cut is made below the hob by 50 ÷ 60 mm in order to get a lid.
• On the outer perimeter of the resulting cover is welded, so-called"skirt" made of thin sheet steel. The width of the skirt should be 50 ÷ 60 mm, the seam of this strip is welded. If there is no experience in welding work, then it is better to entrust this process to a professional.
• After that, along the entire circumference of the skirt, stepping back from the lower edge of 20 ÷ 25 mm, holes are evenly drilled into which the bolts will be screwed.
• Further, the lower empty part of the cylinder is cut off at a height of approximately 70 mm from the bottom. Then, a hole is cut in the bottom of the cylinder for the riser to enter the body.
• After that, it is necessary to fix a well-woven asbestos cord on the inner edge of the lid with Moment glue, and then immediately put it on the cylinder body and press it down with a load of 2.5 ÷ 3 kg from above. The cord will serve as a sealing gasket. Further, through the holes in the metal “skirt”, through holes are drilled in the cylinder body, in which the threads for the bolts are cut.
• After that, you need to measure the depth of the hull, since it is necessary to determine the height of the riser.
• Then the cap is removed from the cylinder to protect the gasket from being completely impregnated with glue, otherwise the asbestos will lose its elasticity.

Production of the furnace part of the furnace

The next step from square pipe(or channel) with a section of 150 × 150 mm, elements are made: 1a - blower, 1b - combustion chamber; 1d - flame channel.

Raiser (1d) is made from round pipe with a diameter of 70÷100 mm.

The angle of insertion of the combustion chamber (bunker) into the blower and flame tube can vary within 45 ÷ 60 degrees from the horizontal. Its upper edge is placed flush with the protruding blower element, as shown in the diagram.

In the lower part of the blower and flame tube, it is necessary to separate the secondary air channel (1c). It is separated by a metal plate 3 ÷ 4 mm thick. Its rear edge should end exactly at the level of the front wall of the riser, and the front edge should go ahead of the blower by 25÷30 mm. The plate is pinpointed in four places by welding inside the pipe.

Then, at the end of the flame tube, a hole is cut from above, into which the riser is welded at a right angle, and the end of this channel is closed with a metal square, also fixed by welding.

Must be installed on the blower door - latch to help regulate the air supply. The cover for the combustion chamber is made of galvanized metal. The hopper does not require hermetic closure - the main thing is that the lid fits snugly against the inlet.

After that finished construction smeared with a solution of 5v. A solid lining is made only at the bottom, and the sides and top of the blower are left free from the lining. In order for the coating mixture to dry out faster, the structure is put on the pole with a blower chamber. It is necessary to ensure that the mixture from the surfaces does not slip and does not opal, since the lining plays a big role in retaining heat. If this happens, then the coating must be done again, using a fatter clay.

Rocket Furnace Insulation

After the adobe layer has dried, a formwork is installed to equip the heat-resistant thermal insulation for the furnace. It is done only under the location of the furnace. The height of the formwork will be 100÷110 mm together with the adobe layer.

The installed formwork is filled with composition 5b and leveled along the beacons, which will serve as the sides of the formwork. On the main diagram, this layer is marked with the letter B.

Production of the bottom part of the drum and shell

The shell is made from a round pipe with a diameter of 150 ÷ ​​200 mm or it is rolled from a steel sheet.

The bottom round timber, which will fit inside the drum, is cut out from sheet metal 1.5 ÷ 2 mm thick, and in the middle it is cut out round hole. The circumference of this element must be 4 mm smaller inner size cylinder, and the diameter of the middle cutout for the shell is 3 mm larger than its outer diameter.

Installation of the furnace structure

After the thermal insulation layer has dried in the formwork, a furnace structure is mounted on it. It is installed by controlling the level vertically and horizontally, and then fixed on the heat-insulating layer with the help of pegs. Then, around the furnace, formwork is installed with a height of 350 ÷ 370 mm from the floor. Here it should be taken into account that the cleaning chamber (3a) and its door (3b) must be installed next to the solidified mixture (5b) with which the formwork will be filled. The connection (2e) of the cleaning chamber with the heat exchange channel (2g) will pass over the lining composition poured into the formwork. The mixture is also aligned to the ideal, level with formwork, with regulations.

cleaning chamber

While the mixture is drying in the formwork, you can start manufacturing a cleaning chamber with a door and a transition to a heat exchanger. It is made of galvanized steel, 1.5 ÷ 2 mm thick, and its front part is made of metal 4 ÷ 6 mm. A hole with a diameter of 150 ÷ ​​180 mm is cut out in the side part of the cleaning chamber to install the end of the chimney pipe, which will pass under the lounger.

The door of the cleaning chamber is made with a size of 160 × 160 mm, also from steel of 4 ÷ 6 mm. Before its installation, a sealing gasket made of mineral cardboard is installed along the perimeter of the inner surface. The door itself is screwed to the chamber box with fixing bolts, for which threads are cut in the drilled holes.

This diagram shows the dimensions of all elements and the place of installation and connection of the chamber with the drum (cylinder). Further, after fitting the elements, a 70 mm window is cut out in the lower part of the furnace drum, into which the connecting channel (2e) will be mounted by welding.

The corrugated pipes under the bench can be located arbitrarily, depending on the configuration of the lounger, it is only important to adhere to the dimensions indicated on the drawing for the manufacture of the cleaning chamber, indicated under the letters A, B and C. How to properly connect the "boar" pipe will be discussed below.

Drum mounting

When the solution in the formwork dries, it is removed. On the riser, on top of the frozen thermal insulation, they put on a combustion system drum made of a gas cylinder. The drum is currently mounted without a cover - its installation is shown in the diagram.

Solution 5b is laid out on the bottom part of the installed drum, and with the help of a spatula, a surface inclined by 6–8 degrees is formed from it, towards the outlet window of the cleaning chamber. Then, on the riser, a round timber from a metal sheet is put on and lowered to the bottom of the drum and pressed against the laid mortar. From the middle hole around the riser, the solution is selected, otherwise it will not be possible to install the shell pipe. After that, the pipe itself is put on the freed space on the riser and slightly screwed into the solution. All gaps formed along the outer and inner contours are smeared with clay (5d).

Fuel structure lining from the inside

After installing the shell and hearth, it is not necessary to wait for the thermal insulation solution to dry, you can immediately proceed to the riser lining. The composition (5g) is poured into the shell, around the riser, in 6÷7 layers. Each of the layers must be compacted as much as possible, while wetting the dry mixture with water from a spray bottle. From above, this space filled with sand is closed with a clay layer (cork) 50 ÷ 60 mm thick, using a solution of 5d.

Cleaning chamber installation

After mounting the drum, you need to install a cleaning chamber. Installing the box is not difficult - for this, a layer of solution 5d is applied to the transition channel and the hole in the drum, as well as to the side and bottom of the box, which has a thickness of 3 ÷ 4 mm. The box is put in place, and the transition channel window (2e) is inserted into the prepared opening of the drum and is well pressed and pressed down. The solution that comes out on the sides is immediately smeared. The entrance of the cleaning chamber to the drum must be well sealed, therefore, if there are gaps left, they must be sealed well.

Laying the thermal insulation layer

Formwork for level G

Further, a formwork is installed along the outer contour of the bed, just as in the manufacture of level A. The height of this level G must be displayed, focusing on the hole for connecting the “hog”. Above the upper edge of the hole, the level should be raised by about 80÷100 mm.

Formwork filling

The next step is filling the formwork with adobe mortar (5a) to the bottom edge of the hole prepared for the installation of the "hog" in the cleaning chamber one side, and at the end of the bed - to the lower edge of the outlet for the chimney.

The mixture is laid out and leveled by hand, while making sure that the mass is as close as possible to the previous layer. Thus, from the cleaning chamber to the chimney outlet rise is formed for pipes "hog", the height difference of which should be 15 ÷ 30 mm. This design is necessary so that the couch warms up evenly.

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Installation of a corrugated pipe

Stretching is the next step. corrugated pipe for the entire length of the bed. One end is connected to the cleaning chamber, inserted into the hole to a depth of 20÷25 mm and flaring inside the chamber with a flathead screwdriver through the cleaning door. Then the entrance of the pipe to the ash pan is coated with a solution of 5d, and the beginning of the pipe 150 ÷ ​​200 mm is coated with adobe. This will fix the rub well in the desired position and prevent it from slipping out of the hole during further work.

After that, the pipe in the formwork is laid in the form of a coil, but it must always be at a distance of about 100 mm from the edges of the formwork and the wall. During the laying process, the pipe is pressed into the adobe layer laid under it. Having laid the pipe along its entire length, its second end is fixed on a clay solution in the outlet chimney.

After that, the entire "hog" is plastered with adobe mortar, which must be well compacted, especially between the bends of the pipe, so that no voids form in it. After the adobe mass fills the space flush with the top of the corrugated pipe, a more liquid solution of adobe is poured into the formwork, and at the end the surface is smoothed out by a rule that is carried out along the walls of the formwork, which act as beacons ..

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Cover installation

After that, the covers of the cleaning chamber and the drum are fixed with bolts. They need to be tightened tightly so that they press the gaskets installed inside.

Furnace drum coating

Further, the oven drum is coated with adobe by ⅔ from the bottom of the body. top the drum is left free from the adobe layer. Thermal insulation is applied with a thickness of at least 100 ÷ 120 mm, and the configuration of the coating is chosen by the master himself.

Furnace finish

After two or two and a half weeks, the adobe layer should dry out and the installed formwork can be removed. Then, if necessary, the right corners of the structure are rounded. In addition, the drum is covered with heat-resistant enamel that can withstand temperatures up to 450÷750 degrees. The adobe surface of the couch is covered with acrylic varnish in two layers, each of which should dry well. The varnish will hold the surface material together, preventing it from dusting, protect the adobe from moisture and give the glazed clay the aesthetics.

If desired, a wooden flooring made of thin boards can be laid on the surface of the couch - it is quite often made removable. The side parts of the couch are sometimes trimmed with drywall or lined with stone. decorative trim carried out to the taste of the owner of the house.

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Carrying out a furnace test

A dry oven must be tested. To do this, it is necessary to warm up the structure by laying light fuel in the form of paper in the blower and replenishing it during the combustion process. When heat is felt on the surface of the bed, you can put the main fuel into the combustion chamber. When the stove starts to hum, the blower closes until the sound changes to a “whisper”.

In conclusion, it must be said that the rocket stove can also be made of brick or stone - it all depends on the financial capabilities and creative abilities of the master. The main thing that can attract in this design Save so as not to lose!