How to make a rocket stove for home heating. Wood-burning rocket stoves, their varieties and assembly Pvc rocket pipes

A do-it-yourself rocket stove, the drawings of which most home craftsmen would probably like to have in their archives, can be made, in principle, even within one day, since its design is not complicated at all. If you have the skills to work with tools, read drawings, and have the necessary materials in store, then making a simple stove of this type will not be difficult. It should be noted that it can be made from a variety of materials that are at hand, but much will depend on where the oven is planned to be installed. The rocket stove has a slightly different operating principle from other heating devices, and can be either stationary or portable.

Stationary rocket stoves are installed inside the house along the walls or on the area designated for cooking in the courtyard of the house. If the stove is installed indoors, then it is capable of heating a room with an area of up to 50 sq. m.

Portable versions of the rocket stove are usually quite small and can easily fit in the trunk of a car. Therefore, when traveling, for example, to a picnic or to a summer cottage, such a stove will help to boil the water and cook dinner. Moreover, the fuel consumption in the rocket furnace is very low; even dry branches, torches or bunches of grass can be used as it.

The principle of operation of the rocket-type stove

Despite the simplicity of the rocket furnace device, its design uses two principles of operation, which the developers borrowed from other types of furnaces operating on. So, for its effective work, the following principles are taken:

The principle of free circulation of gases released from the fuel through the created furnace channels, without the forced creation of a chimney draft.
The principle of afterburning of pyrolysis gases released during fuel combustion in the mode of insufficient oxygen supply.

In the simplest designs of rocket furnaces, which are used only for cooking, only the first principle of operation can operate, since it is rather difficult to create the necessary conditions for the flow of pyrolysis and the organization of gas afterburning.

To understand the structures and understand how they work, you need to consider some of them one by one.

The simplest design of a rocket stove

To begin with, it is worth considering the simplest device of a direct combustion rocket furnace. As a rule, such devices are used only for heating water or for cooking, and only outdoors. As you can see from the figure below, these are two pipe sections connected by a right-angle bend.

The firebox for such a furnace design is the horizontal part of the pipe, and the fuel is put into it. Often, the firebox has a vertical loading - in this case, three elements are used to make the simplest stove - these are two pipes of different heights, installed vertically and connected from below by a common horizontal channel. The lower pipe will serve as a firebox. For the manufacture of a stationary version of the simplest design scheme, it is often used installed on a heat-resistant solution.

To achieve higher efficiency, the furnace was improved, and additional elements appeared, for example, a pipe was installed in a housing, which increases the heating of the structure.

1 - outer metal body of the furnace.

2 - pipe - combustion chamber.

3 - a channel formed by a bridge under the fuel chamber and intended for free passage of air into the combustion area.

4 - the space between the pipe (riser) and the body, densely filled with a heat-insulating compound, for example, ash.

The heating of the oven is as follows. A light combustible material, for example, paper, is first put into the firebox, and when it ignites, chips or other main fuel are thrown into the fire. As a result of the intensive combustion process, incandescent gases are formed that rise along the vertical channel of the pipe and go outside. A container for boiling water or cooking food is installed on the open section of the pipe.

An important condition for the intensity of fuel combustion is the creation of a gap between the pipe and the installed container. If its hole is completely closed, then combustion inside the structure will stop, since there will be no draft, which provides air supply to the combustion area and raises the heated gases up. To avoid problems with this, a removable or stationary support for the container is installed on the upper edge of the pipe.

This diagram shows a simple structure, on the loading opening of which a door is installed. And to create thrust, a special channel is provided, which forms the lower wall of the combustion chamber and a plate welded at a distance of 7 ÷ 10 mm from it. Even when the firebox door is completely closed, the air supply will not stop. In this scheme, the second principle is already starting to work - without active access of oxygen to the burning ones, the pyrolysis process can begin, and the continuous supply of "secondary" air will contribute to the afterburning of the released gases. But for a full-fledged process, one more important condition is still lacking - high-quality thermal insulation of the secondary afterburner chamber, since certain temperature conditions are required for the combustion of gases.

1 - air channel in the combustion chamber, through which blowing is carried out when the furnace door is closed;

2 - zone of the most active heat exchange;

3 - ascending stream of incandescent gases.

Video: a variant of the simplest rocket furnace from an old cylinder

Advanced rocket furnace design

The design, designed for both cooking and heating the room, is equipped not only with a fire door and a second body, which serves as a good external heat exchanger, but also with an upper hob. Such a rocket stove can already be installed inside the premises of the house, and the chimney from it is brought out into the street. After carrying out such a modernization of the furnace, its efficiency increases significantly, since the device acquires many useful properties:

Due to the second outer casing and heat-resistant heat-insulating materials, which thermally insulate the main pipe of the furnace (riser), hermetically close the upper part of the structure, the heated air retains the high temperature for much longer.

In the lower part of the body, a channel was mounted for supplying secondary air, which successfully carried out the necessary blowing, for which an open firebox was used in the simplest design.
The chimney in a closed structure is not located at the top, as in a simple rocket furnace, but in the lower rear of the body. Thanks to this, the heated air does not go directly into the chimney, but gets the opportunity to circulate through the internal channels of the appliance, heating, first of all, the hob, and then diverging inside the body, ensuring its heating. In turn, the outer casing gives off heat to the surrounding air.

This diagram clearly shows the whole process of the furnace operation: in the fuel hopper (pos. 1) the fuel is pre-burned (pos. 2) in the mode of insufficient air supply "A" - this is regulated by the damper (pos. 3). The resulting hot pyrolysis gases enter the end of the horizontal firing channel (pos. 5), where they are burned out. This process takes place due to good thermal insulation and the implementation of a continuous supply of "secondary" air "B" through a specially provided channel (item 4).

Further, hot air rushes into the inner pipe of the structure, called the riser (item 7), rises along it to the "ceiling" of the body, which is a hob (item 10), providing it with high-temperature heating. Then the gas flow passes through the space between the riser and the outer casing-drum (item 6), providing heating of the casing for further heat exchange with air in the room. Then the gases go down and only then go into the chimney (pos. 11).

To achieve maximum heat transfer from the fuel and to provide the necessary conditions for the complete combustion of pyrolysis gases, it is important to maintain the highest and stable temperature in the riser channel (pos. 7) For this, the riser pipe is enclosed in another pipe of a larger diameter - a shell (pos. 8 ), and the space between them is tightly clogged with a heat-resistant mineral composition (pos. 9), which will serve as thermal insulation (a kind of lining). For these purposes, for example, a mixture of oven clay with chamotte sand (in a ratio of 1: 1) can be used. Some craftsmen prefer to simply fill this space very tightly with sifted sand.

The design of this version of the rocket furnace consists of the following units and elements:

A top-loading firebox with a lid with a secondary air intake chamber located in its lower part.

The furnace passes into a horizontally located firing channel, at the end of which pyrolysis gas is burned out.

The incandescent gas flow rises along a vertical channel (riser) to the hermetically sealed "ceiling" of the case, where it gives off part of the thermal energy to the horizontal stove - the hob. Then, under the pressure of the hotter gases that follow, it diverges into the heat exchange channels, giving off heat to the surfaces of the drum, and goes down.

In the lower part of the furnace, there is an entrance to the horizontal pipe channels that run under the entire surface of the bed. Moreover, in this space one, two or more turns of a corrugated pipe can be laid, in the form of a coil, through which hot air circulates, heating the bed. This heat exchanger pipe is connected at the end to a chimney that is led out through the wall of the house.

It should be noted that in the case of making a bed of bricks, the channels can also be laid out of this material, without the use of metal corrugated pipes.

The heated stove and stove bench, giving off heat to the room, will themselves serve as a kind of "battery" capable of heating an area of up to 50 m².

The metal drum of the kiln can be made from a barrel, gas cylinder or other durable containers, and also made of bricks. Usually, the material is chosen by the craftsmen themselves as far as financially possible and convenience of work.

A rocket stove with a brick stove bench looks neater, and it is somewhat easier to install than the clay version, but the cost of materials will be about the same.

Video: another original solution to increase the efficiency of heating a rocket furnace

Add upbrickrocket furnacewith a couch

What do you need to work?

The brick heating structure proposed for execution is designed according to the principle of a rocket furnace. The size of the structure with standard brick parameters (250 × 120 × 65 mm) will be 2540 × 1030 × 1620 mm.

Our task is to make such an original rocket stove with a warm stove bench out of bricks.
It should be noted that the design is, as it were, divided into three parts:

The furnace itself - its size is 505 × 1620 × 580 mm;

Furnace compartment - 390 × 250 × 400 mm;

Lounger 1905 × 755 × 620 mm + 120 mm headrest.

The following materials are required for laying the stove:

Red bricks - 435 pcs.;

Blowing door 140 × 140 mm - 1 pc .;

Cleaning door 140 × 140 mm - 1 pc .;

The furnace door is desirable (250 × 120 mm - 1 pc.), Otherwise there is a risk of smoke in the room.

Cooking plate 505 × 580 mm - 1 pc .;

Rear metal panel-shelf 370 × 365 mm - 1 pc .;

Asbestos sheet 2.5 ÷ 3 mm thick to create a spacer between metal elements and bricks.

Chimney with a diameter of 150 mm, with a 90˚ bend.

Clay and sand for mortar or ready-made heat-resistant mixture. It should be noted here that for 100 bricks laid flat, with a joint width of 5 mm, 20 liters of mortar will be required.

The design of this top-loading rocket-furnace is quite simple, trouble-free and efficient in operation, but only if its laying is done with high quality, in full accordance with the order.

In the absence of experience in the work of a bricklayer and a stove-maker, but a great desire to independently install such a heating device, it is worthwhile to play it safe, and to begin with, fold the structure "dry", without mortar. This process will help you figure out the location of the bricks in each of the rows.

In addition, in order for the seams to be of the same width, it is recommended to prepare calibration wooden or plastic slats for masonry, which will be stacked on the previous row before laying the next one. After the mortar has set, it will be easy to remove them.

Under the laying of such a stove, it is necessary to have an even and solid foundation. Despite the fact that the structure is quite compact, and its weight is not as great as, for example, in the Russian stove, a floor made of thin boards is not suitable for its installation. In the case when the floor, although it is wooden, is very durable, before starting laying under the future stove, it is imperative to lay and fix heat-resistant material, for example, asbestos 5 mm thick.

Ordering a brick rocket oven with a stove bench:

Illustration Brief description of the performed operation
The first row is laid out solid, and the brick should lie in exact accordance with the pattern shown in the diagram - this will give the whole base strength.
For masonry, 62 red bricks are required.
The diagram clearly shows the connection of all three sections of the furnace.
The corners on the side bricks of the front of the firebox are cut or rounded off - so the structure will look neat.
Second row.
At this stage of work, internal chimney channels are laid through which gases heated in the firebox will pass, giving off heat to the bricks of the stove bench. The channels connect to the combustion chamber, which also begins to form in this row.
The first brick of the wall dividing the two channels under the stove bench is cut obliquely - this "nook" will collect non-burnt combustion products, and the cleaning door, installed opposite the bevel, will allow you to easily clean it.
For laying a row, 44 bricks are required.
On the second row, the doors of the blowing and cleaning chambers are mounted, which are necessary for periodically putting the ash chamber and internal horizontal channels in order.
The doors are secured with wire, which is twisted on the ears of the cast-iron elements, and then laid in the seams of the masonry.
Third row.
It almost completely repeats the configuration of the second row, but, of course, taking into account the laying in a bandage, and therefore it also requires 44 bricks.
Fourth row.
At this stage, the channels passing inside the bed are overlapped with a continuous layer of brick.
The opening of the furnace is left, and a channel is formed, which will heat the hob and discharge the combustion products into the chimney.
In addition, a rotary horizontal channel is blocked from above, which removes the heated air under the bed.
For laying a row, you need to prepare 59 bricks.
Fifth row.
The next step is to overlap the bed with a second cross layer of brick.
Also, the chimney ducts and the firebox continue to be removed.
60 bricks are prepared for the row.
Sixth row.
The first row of the headrest of the bench is laid out, and the part of the oven, on which the hob will be installed, begins to rise.
The chimney ducts are still led out in it.
For a row, 17 bricks are needed.
Seventh row.
The laying of the headrest is being completed, for which bricks cut obliquely are used.
The second row of the base rises under the hob.
For masonry, 18 bricks are required.
Eighth row.
The laying of the furnace structure with three channels is being carried out.
It takes 14 bricks.
The ninth and tenth rows are similar to the previous, eighth, laid out according to the same pattern, alternately, in a bandage.
Each row uses 14 bricks.
11th row.
Continuation of masonry according to the scheme.
This row will take 13 bricks.
12th row.
At this stage, a hole is formed for installing the chimney.
The hole supplied under the slab is supplied with bricks cut obliquely for a smoother flow of heated air into the adjacent channel leading to the lower horizontal channels located in the bed.
11 bricks were used per row.
13th row.
The base for the slab is formed, and the central and lateral channels are combined. It is through it that hot air will flow under the stove, and then flow into a vertical channel leading under the stove bench.
10 bricks are stacked.
13th row.
On the same row, the base is prepared for laying the hob.
For this, a heat-resistant material - asbestos - is laid along the perimeter of the space in which two vertical channels were combined.
13th row.
Then, a solid metal plate is laid on top of the asbestos gasket.
In this case, it is not recommended to install a hob with opening burners, since when they are opened, smoke can enter the room.
14th row.
The hole for the chimney is blocked and the wall that separates the hob from the stove area rises.
Only 5 bricks are used for the row.
15th row.
This row lifting the wall will also require 5 bricks.
15th row.
On the same row, in continuation of the back wall, next to the hob, a metal shelf is fixed, which can be used as a cutting board.
It attaches to brackets.
15th row.
The schematic picture well simulates how the hob can be used.
In this case, the pan is placed exactly on the part of the stove that will warm up first, since a hot air stream will pass under it.
After completing all the works described in the order, a chimney is embedded in the hole from the back of the stove, which is led out into the street.
From the rear, the structure also looks quite neat, so it can be installed both near the wall and in the middle of the room.
Such a stove is perfect for heating in a country house.
If the stove and chimney are decorated with finishing materials, then the structure can become an original addition, and very functional, for any private house.
As you can see, the corner under the chopping shelf is very convenient for drying and storing firewood.
To fully consider the structure, you need to see its projection from the front side.
And the last figure shows well what should be the result of the work done, if you look at the stove from the side of the stove bench.
In conclusion, I would like to especially note that the design of a rocket furnace can be called one of the simplest and most affordable for self-production, in comparison with other heating devices. Therefore, if a similar goal is set - to acquire a stove in the house, but experience in such work is clearly not enough, then it is best to choose this particular option, since, when building it, it is difficult to make a mistake in the configuration of its internal channels.

The principle of operation of the rocket-type stove

Despite the simplicity of the rocket furnace, its design uses two principles of operation, which the developers borrowed from other types of solid fuel furnaces. So, for its effective work, the following principles are taken:

The principle of free circulation of gases released from the fuel through the created furnace channels, without the forced creation of a chimney draft.
The principle of afterburning of pyrolysis gases released during fuel combustion in the mode of insufficient oxygen supply.

To understand the structures and understand how they work, you need to consider some of them one by one.

The simplest design of a rocket stove

The firebox for such a furnace design is the horizontal part of the pipe, and the fuel is put into it. Often, the firebox has a vertical loading - in this case, three elements are used to make the simplest stove - these are two pipes of different heights, installed vertically and connected from below by a common horizontal channel. The lower pipe will serve as a firebox. For the manufacture of a stationary version of the simplest design scheme, a brick is often used, installed on a heat-resistant mortar.

To achieve higher efficiency, the furnace was improved, and additional elements appeared, for example, a pipe was installed in a housing, which increases the heating of the structure.

1 - outer metal body of the furnace.

2 - pipe - combustion chamber.

3 - a channel formed by a bridge under the fuel chamber and intended for free passage of air into the combustion area.

4 - the space between the pipe (riser) and the body, densely filled with a heat-insulating compound, for example, ash.

This diagram shows a simple structure, on the loading opening of which a door is installed. And to create traction, a special channel is provided, which forms the lower wall of the combustion chamber and a plate welded at a distance of 7-10 mm from it. Even when the firebox door is completely closed, the air supply will not stop. In this scheme, the second principle is already starting to work - without active access of oxygen to the burning wood, the pyrolysis process can begin, and the continuous supply of "secondary" air will contribute to the afterburning of the released gases. But for a full-fledged process, one more important condition is still lacking - high-quality thermal insulation of the secondary afterburner chamber, since certain temperature conditions are required for the combustion of gases.

1 - air channel in the combustion chamber, through which blowing is carried out when the furnace door is closed;

2 - zone of the most active heat exchange;

3 - ascending stream of incandescent gases.

Video: a variant of the simplest racten oven from an old cylinder

Advanced rocket furnace design

Due to the second outer casing and heat-resistant heat-insulating materials, which thermally insulate the main pipe of the furnace (riser), hermetically close the upper part of the structure, the heated air retains the high temperature for much longer.

In the lower part of the body, a channel was mounted for supplying secondary air, which successfully carried out the necessary blowing, for which an open firebox was used in the simplest design.
The chimney in a closed structure is not located at the top, as in a simple rocket furnace, but in the lower rear of the body. Thanks to this, the heated air does not go directly into the chimney, but gets the opportunity to circulate through the internal channels of the appliance, heating, first of all, the hob, and then diverging inside the body, ensuring its heating. In turn, the outer casing gives off heat to the surrounding air.

Improving the efficiency of heat extraction in rocket stoves

To increase the efficiency of the rocket stove, other designs with more efficient heat extraction were developed, both for using the device in outdoor conditions and for indoor use - for heating premises or heating water.

Stove-stove

For cooking food or blanks for the winter, ovens are made, arranged according to the principle described above, but having an expanded hob, which allows you to install several containers at once.

In this model of a rocket furnace, a vertical tube with a top-loading firebox mounted in it and having a door is located under the hob. Therefore, hot air heats it directly, and in order for the entire panel to be hot, heated gases, collecting under the panel, are directed into a horizontal channel passing under its entire surface and connected to the vertical section of the chimney.

Additionally, the structure is equipped with legs, which gives it stability and reliability. It should be noted that when such a stove is not used for its intended purpose, it may well be used as an ordinary garden table.

In addition to this outdoor model, several types of structures have been developed for indoor use, which make it possible to efficiently heat premises or heat water.

Rocket furnace with water circuit

A rocket furnace with a water circuit consists of the following elements:

The stove is installed on a solid concrete base in order to avoid distortions and deformation of structures.
The lower part of the structure, including the combustion chamber (item 2) and the fire channel, is laid out of fireclay bricks (item 1). The firebox is top-loaded. At the bottom there is an ash pan (pos. 3) with a side door for regular cleaning of the stove from accumulated ash.

The vertical channel (riser) (item 4) is made of a steel pipe, which is put on a thick layer of thermal insulation (item 5) and an outer metal casing.
A heat exchanger unit with a water jacket in the walls (item 6) and horizontal plates that create a kind of labyrinth (item 7) is hermetically fixed on top of the outer casing to ensure the maximum area and time of heat exchange.

Attempts are being made to install a water register in this place. However, as practice shows, this approach is inappropriate - the temperatures here due to the afterburning of pyrolysis gases are very high, and the pipe register has every chance to burn out quickly.

Hot air passing through the heat exchanger, bending around the metal plates, heats up the entire massive block, and the metal gives off heat to the water circulating through the water jacket.
Further, the cooled gas flow goes into the chimney (item 8).
Water circulation occurs through a heat accumulator (item 9), which may well be made from an old boiler or another closed container with valves for connecting cold and hot water. The option of connecting a heating radiator is not excluded, although, in truth, such a stove is unlikely to justify itself in such a role.
Hot water from the heat storage tank through a pipe connected to it (pos. 10) can be directed to the water intake points for domestic needs.

Such a rocket stove is perfect for installation in a country house or in a private house, where it is possible to connect such a heat storage tank to an autonomous water supply system. The stove will help to significantly reduce the cost of heating water and heating, since this model does not require a large amount of solid fuel or connecting it to some additional energy sources.

Rocket stove with stove

Another way to effectively use a rocket stove is to equip a fairly massive structure with a heated stove bench. It should be noted that such a couch can be in the form of a bed or a sofa, successfully replacing these pieces of furniture, since, having laid a mattress on its surface, you can comfortably get a day or night rest. The bed can be made of brickwork or stones and clay mass.

The design of this version of the rocket furnace consists of the following units and elements:

A top-loading firebox with a lid with a secondary air intake chamber located in its lower part.
The furnace passes into a horizontally located firing channel, at the end of which pyrolysis gas is burned out.
The incandescent gas flow rises along a vertical channel (riser) to the hermetically sealed "ceiling" of the case, where it gives off part of the thermal energy to the horizontal stove - the hob. Then, under the pressure of the hotter gases that follow, it diverges into the heat exchange channels, giving off heat to the surfaces of the drum, and goes down.
In the lower part of the furnace, there is an entrance to the horizontal pipe channels that run under the entire surface of the bed. Moreover, in this space one, two or more turns of a corrugated pipe can be laid, in the form of a coil, through which hot air circulates, heating the bed. This heat exchanger pipe is connected at the end to a chimney that is led out through the wall of the house.

It should be noted that in the case of making a bed of bricks, the channels can also be laid out of this material, without the use of metal corrugated pipes.
The heated stove and stove bench, giving off heat to the room, will themselves serve as a kind of "battery" capable of heating an area up to 50 m2.

The metal drum of the kiln can be made from a barrel, gas cylinder or other durable containers, and also made of bricks. Usually, the material is chosen by the craftsmen themselves as far as financially possible and convenience of work.

A rocket stove with a brick stove bench looks neater, and it is somewhat easier to install than the clay version, but the cost of materials will be about the same.

Video: another original solution to increase the efficiency of heating a rocket furnace

We put a rocket oven with a stove bench out of bricks

What do you need to work?

The brick heating structure proposed for execution is designed according to the principle of a rocket furnace. The size of the structure with standard brick parameters (250 × 120 × 65 mm) will be 2540 × 1030 × 1620 mm.

It should be noted that the design is, as it were, divided into three parts:

The furnace itself - its size is 505 × 1620 × 580 mm;
Furnace compartment - 390 × 250 × 400 mm;
Lounger 1905 x 755 x 620 mm + 120 mm headrest.

The following materials are required for laying the stove:

Red bricks - 435 pcs.;
Blowing door 140 × 140 mm - 1 pc .;
Cleaning door 140 × 140 mm - 1 pc .;
The combustion door is desirable (250 × 120 mm - 1 pc.), Otherwise there is a risk of smoke in the room.
Cooking plate 505 × 580 mm - 1 pc .;
Rear metal panel shelf 370 × 365 mm - 1 pc .;
Asbestos sheet 2.5 x 3 mm thick to create a spacer between metal elements and bricks.
Chimney with a diameter of 150 mm, with a 90 ° bend.
clay and sand for mortar or ready-made heat-resistant mixture. It should be noted here that for 100 bricks laid flat, with a joint width of 5 mm, 20 liters of mortar will be required.

The design of this top-loading rocket-furnace is quite simple, trouble-free and efficient in operation, but only if its laying is done with high quality, in full accordance with the order.

In the absence of experience in the work of a bricklayer and a stove-maker, but a great desire to independently install such a heating device, it is worthwhile to play it safe, and to begin with, fold the structure "dry", without mortar. This process will help you figure out the location of the bricks in each of the rows.

In addition, in order for the seams to be of the same width, it is recommended to prepare calibration wooden or plastic slats for masonry, which will be stacked on the previous row before laying the next one. After the mortar has set, it will be easy to remove them.

Under the laying of such a stove, it is necessary to have an even and solid foundation. Despite the fact that the structure is quite compact, and its weight is not as great as, for example, in the Russian stove, a floor made of thin boards is not suitable for its installation. In the case when the floor, although it is wooden, is very durable, before starting laying under the future stove, it is imperative to lay and fix heat-resistant material, for example, asbestos 5 mm thick.

Ordering a brick rocket oven with a stove bench:

Illustration	Brief description of the performed operation
	The first row is laid out solid, and the brick should lie in exact accordance with the pattern shown in the diagram - this will give the whole base strength. For masonry, 62 red bricks are required. The diagram clearly shows the connection of all three sections of the furnace. The corners on the side bricks of the front of the firebox are cut or rounded off - so the structure will look neat.
	Second row. At this stage of work, internal chimney channels are laid through which gases heated in the firebox will pass, giving off heat to the bricks of the stove bench. The channels connect to the combustion chamber, which also begins to form in this row. The first brick of the wall dividing the two channels under the stove bench is cut obliquely - this "nook" will collect non-burnt combustion products, and the cleaning door, installed opposite the bevel, will allow you to easily clean it. For laying a row, 44 bricks are required.
	On the second row, the doors of the blowing and cleaning chambers are mounted, which are necessary for periodically putting the ash chamber and internal horizontal channels in order. The doors are secured with wire, which is twisted on the ears of the cast-iron elements, and then laid in the seams of the masonry.
	Third row. It almost completely repeats the configuration of the second row, but, of course, taking into account the laying in a bandage, and therefore it also requires 44 bricks.
	Fourth row. At this stage, the channels passing inside the bed are overlapped with a continuous layer of brick. The opening of the furnace is left, and a channel is formed, which will heat the hob and discharge the combustion products into the chimney. In addition, a rotary horizontal channel is blocked from above, which removes the heated air under the bed. For laying a row, you need to prepare 59 bricks.
	Fifth row. The next step is to overlap the bed with a second cross layer of brick. Also, the chimney ducts and the firebox continue to be removed. 60 bricks are prepared for the row.
	Sixth row. The first row of the headrest of the bench is laid out, and the part of the oven, on which the hob will be installed, begins to rise. The chimney ducts are still led out in it. For a row, 17 bricks are needed.
	Seventh row. The laying of the headrest is being completed, for which bricks cut obliquely are used. The second row of the base rises under the hob. For masonry, 18 bricks are required.
	Eighth row. The laying of the furnace structure with three channels is being carried out. It takes 14 bricks.
	The ninth and tenth rows are similar to the previous, eighth, laid out according to the same pattern, alternately, in a bandage. Each row uses 14 bricks.
	11th row. Continuation of masonry according to the scheme. This row will take 13 bricks.
	12th row. At this stage, a hole is formed for installing the chimney. The hole supplied under the slab is supplied with bricks cut obliquely for a smoother flow of heated air into the adjacent channel leading to the lower horizontal channels located in the bed. 11 bricks were used per row.
	13th row. The base for the slab is formed, and the central and lateral channels are combined. It is through it that hot air will flow under the stove, and then flow into a vertical channel leading under the stove bench. 10 bricks are stacked.
	13th row. On the same row, the base is prepared for laying the hob. For this, a heat-resistant material - asbestos - is laid along the perimeter of the space in which two vertical channels were combined.
	13th row. Then, a solid metal plate is laid on top of the asbestos gasket. In this case, it is not recommended to install a hob with opening burners, since when they are opened, smoke can enter the room.
	14th row. The hole for the chimney is blocked and the wall that separates the hob from the stove area rises. Only 5 bricks are used for the row.
	15th row. This row lifting the wall will also require 5 bricks.
	15th row. On the same row, in continuation of the back wall, next to the hob, a metal shelf is fixed, which can be used as a cutting board. It attaches to brackets.
	15th row. The schematic picture well simulates how the hob can be used. In this case, the pan is placed exactly on the part of the stove that will warm up first, since a hot air stream will pass under it.
	After completing all the works described in the order, a chimney is embedded in the hole from the back of the stove, which is led out into the street.
	From the rear, the structure also looks quite neat, so it can be installed both near the wall and in the middle of the room. Such a stove is perfect for heating in a country house. If the stove and chimney are decorated with finishing materials, then the structure can become an original addition, and very functional, for any private house. As you can see, the corner under the chopping shelf is very convenient for drying and storing firewood.
	To fully consider the structure, you need to see its projection from the front side.
	And the last figure shows well what should be the result of the work done, if you look at the stove from the side of the stove bench.

In conclusion, I would like to especially note that the design of a rocket furnace can be called one of the simplest and most affordable for self-production, in comparison with other heating devices. Therefore, if a similar goal is set - to acquire a stove in the house, but experience in such work is clearly not enough, then it is best to choose this particular option, since, when building it, it is difficult to make a mistake in the configuration of its internal channels.

Drawings and videos of the rocket furnace required for DIY installation

Do-it-yourself reactive furnace: diagram, drawings, step-by-step instructions for making a rocket furnace, etc. + video

The rocket or jet oven appeared as a result of a deviation from the tradition of manufacturing equipment for heating a room. It is considered an economical heat generator, the design of which is elementary. Therefore, many are thinking about building a jet furnace with their own hands.

Description, advantages and disadvantages of the rocket furnace

A heat generator for heating air in a room is called a rocket oven or a jet oven, since during operation, in the event of an excessive intake of air, it emits special sounds. This noise can be mistaken for the roar of a jet engine. In normal mode, the equipment operates with a barely audible rustling sound.

The rocket stove serves as a device for home heating and cooking. It takes about 6 hours to burn one batch of firewood in such equipment, more than in a standard metal stove. The reason for this is the creation of a heat generator based on an overhead combustion furnace.

The flame from the jet furnace may burst

The advantages of the rocket furnace include:

independence from fuel energy;
simplicity of design, consisting of available parts, connected in a matter of minutes;
the ability to provide a lot of heat, despite the quality of the loaded fuel.

The jet furnace also has some disadvantages:

manual control, which implies constant monitoring of equipment operation;
danger of getting burned, because the walls of the equipment become extremely hot;
inexpediency of using in a bath, since it will not be possible to warm it up.

Views

The unit, which emits a rocket hum during operation, happens:

portable (an assembly of metal pipes, buckets or a gas cylinder); Portable rocket furnaces are mass-produced by industry
stationary (created from fireclay bricks and metal containers); Such an assembly is more difficult to build than a metal furnace
equipment for heating the air with a bench. The bed is equipped behind the rear wall of the oven

Portable structures are made in large batches, because they are used for hiking. The basis of these heat generators is a pipe made up of several sections.

True, such structures, in contrast to units based on fireclay bricks, are not reliable. The walls of the refractory blocks increase the heat transfer from the reactive furnace.

If desired, you can add a couch or bed decorated with clay or sawdust to it.

Details and operation of a reactive heat generator

An elementary rocket furnace is a device of two pipe fragments connected by a 90-degree bend.

The combustion chamber in this heat generator is usually a zone in the horizontal part of the structure.

But sometimes the fuel is put into the vertical section of the apparatus, for which the rocket furnace is built from two pipes of different lengths, mounted vertically and connected by a common horizontal channel.

Primary and secondary air flows through the furnace

The operation of a jet furnace is based on two actions: the unimpeded passage of wood gases through the pipe and the afterburning of gases generated during the combustion of fuel.

Chips and firewood are placed in the firebox of this heat generator after a highly flammable material like paper has ignited there. A container with water or other contents is placed on the open section of the pipe.

At the same time, a small space is left between the structure and the installed container, which is necessary to create traction.

The processes taking place inside a stationary jet furnace resemble the work of pyrolysis heating units.

Calculation of parameters (tables)

The volume of the stove should be determined with knowledge of the matter, because it is he who affects the power and the amount of heat generated by the heating equipment.

When calculating the dimensions of jet heating equipment, use the indicator of the inner diameter of the drum D, the value of which can fluctuate within 300-600 mm. You also need to know the cross-sectional area of the drum.

To determine this indicator of the rocket furnace, use the formula: S = 3.14 * D2 / 4.

The main dimensions of the jet furnace are shown in the table:

Particular importance is attached to the length of the flue with the stove bench. The maximum permissible indicators are shown in the table:

The volume of the secondary ash chamber is also an important indicator, depending on the volume of the drum and the primary chimney.

Construction raw materials for the construction of a custom kiln

The production of jet heating equipment will require:

barrels with a volume of 200 liters and a diameter of 0.6 meters, an empty bottle of liquefied gas or tin buckets to build a furnace drum;
square or round pipes made of steel with a thickness of 2-3 mm, which are needed to create a blower, combustion chamber and primary chimney;
fireclay crushed stone and kiln clay as heat-insulating materials;
adobe, which serves as an outer coating layer;
fireclay bricks;
sand from the bottom of the river;
cuts of zinc-coated steel or aluminum sheets for the manufacture of lids and doors;
asbestos or basalt cardboard, performing the tasks of a compactor.

Of the tools for the construction of a rocket furnace, you will need a welding machine. And if you plan to make heating equipment out of bricks, then you will have to take:

Master OK;
mortar blade;
hammer-pick;
jointing;
acute-angled sledgehammer;
level;
plumb line;
roulette.

Preparation for the assembly of heating equipment

When choosing a place for a rocket stove, they are guided by some rules:

reactive heating equipment is placed only in a room with an area of at least 16 m²;
installation of equipment will be easier without floorboards under the oven;
it is forbidden to place wood beams over a structure that gives heat;
if it is assumed that the chimney will go through the ceiling, then the heating equipment is placed in the middle of the house;
the heat generator cannot be installed near the outer contour of the house, otherwise the room will lose heated air;
it is forbidden to place the jet device near the walls and partitions of their wooden materials.

To make it convenient to put fuel into the jet heating equipment, it is more reasonable to put it with its front side opposite the entrance. It is important to leave at least a meter of unoccupied area around the rocket furnace.

In a small house, builders are advised to set aside a place for the stove in the corner. In this case, the firebox should be directed in one direction, and the stove bench (if made) - in the other.

The oven stands on a special platform that protects the floor from high temperatures.

Having found a suitable site for a rocket furnace, they begin to prepare it for construction work. If boards are laid on the floor in the house, then in the place where the equipment will be installed, they will need to be removed. Under the opened floor, they dig a hole, the bottom of which is necessarily pressed.

A special solution should be mixed before construction work. It consists of sand and clay, combined in a 1: 1 ratio. So much water will be required for the construction raw materials to acquire the consistency of sour cream, that is, ¼ part of the amount of dry ingredients.

Step-by-step instructions for making your own hands

If it is planned to make a rocket furnace from a gas cylinder, then you can not be afraid of difficulties. The steps to create equipment from such construction materials are quite simple:

from a cylinder with a volume of 50 liters, the upper part is cut off in order to build a kind of cap;
The balloon is cut from the top and bottom
focusing on the instructions in the drawing, all parts of the product are welded to each other, that is, a gas cylinder, a pipe with a diameter of 10 cm (future chimney), a pipe with a diameter of 7 cm (inner channel) and another pipe with a diameter of 15 cm (firebox);
Dimensions are in mm
the space between the two pipes is filled with a material that retains heat, for example, sand, which has been thoroughly calcined, that is, cleaned of organic matter;
to give the structure stability, the legs are welded.

To build a rocket stove with a stove bench, which implies the use of bricks, you need to act differently:

The zone for arranging the firebox is deepened by removing 10 cm of soil. The combustion chamber is formed from fireclay bricks. Formwork is created along the contour of the structure being manufactured. To make the base strong, it is recommended to lay reinforcing mesh or metal rods in it;
The platform will harden in about two days
The structure is poured with liquid concrete. Then they wait for the solution to solidify and finish the work. The bricks are laid in a solid line, creating a platform for the oven. After that, the walls of the structure are formed, exposing several rows of brick blocks;
The lower channel of the structure is equipped, while one line of bricks is laid across to block the combustion chamber. The blocks are placed, leaving the vertical channel and the opening of the firebox open;
The two sectors of the furnace at this stage of construction must be open
They find a body from an old boiler and cut off the top and bottom covers on it. At the bottom of the resulting pipe, a flange is installed through which a horizontal heat exchanger will pass. Parts are required to be connected to each other with a continuous weld;
Work requires accuracy
An outlet pipe is inserted into the barrel, after which they take a brush for metal and scrape off rust from the walls of the container. The cleaned barrel is treated with a primer, and a little later - with a paint that is resistant to high temperatures;
The horizontal chimney is welded to a side outlet - the future ash pan. To facilitate its cleaning, a sealed flange is mounted;
The fire tube is laid out from refractory bricks. At the same time, a channel with a height and width of 18 cm is formed inside the structure. In doing this, they constantly use the building level, which allows you to control the verticality of the product;
The height of the pipe is determined in advance
The flame tube is covered with a protective casing, and the resulting gaps are sealed with perlite. The lower area of the vertical channel is sealed with wet clay, the function of which is to prevent the insulation material from spilling onto the floor;
A fuel tank is formed from the boiler, on which the top and bottom have been cut. A handle must be welded to it;
To improve the look, the structure is treated with adobe putty, consisting of sawdust and raw clay. The first component of the composition serves in the same way as crushed stone in concrete, that is, it prevents cracking of the furnace walls. It is recommended to apply adobe putty over the perlite backfill;
They create the facade of the stove, for which the stove contour is laid out of stone, bricks, adobe and sand. The seamy side of the structure is filled with crushed stone, and the front side is filled with adobe mixture, which makes the surface perfectly flat;
A casing made of a metal barrel is placed on the previously created base. The lower branch pipe of the container is directed towards the bed. The bottom of the structure is treated with raw clay, which will ensure its tightness;
A channel from a corrugated pipe is brought to the combustion chamber. It will serve as a link between the firebox and the outside atmosphere;
At this stage, the oven looks almost finished.
Carry out a test kindling of the furnace, watching how the gases are removed from the horizontal chimney. After that, the pipes of the heat exchanger are connected to the lower branch pipe installed on a red brick platform;
The stove is supplemented with a smoke exhaust pipe. The junction of the chimney and the heat generator is sealed with a refractory coating and an asbestos cord;
Using clay and adobe, the couch is given the desired shape. Only the horizontal section of the structure is left unsealed, which will then be used during cooking.
The oven functions as a whole system

Improvement of the design

A couch with a gas flue inside is not the only option for modernizing the rocket furnace. The design can be improved by a water jacket connected to a heating system in which water is circulated. It is desirable to give this part of the structure the appearance of a coil created from a copper pipe twisting on a chimney.

This design gives even more warmth.

Another way to improve the reactive furnace is associated with the organization of the flow of heated secondary air into the fire tube. This will increase the efficiency of the heat generator, but will lead to the deposition of a large amount of soot in the primary chimney. Therefore, it is best to make sure that the drum cover can be removed if necessary.

Subtleties of operation of an unconventional furnace

The rocket furnace is heated by analogy with the upper combustion heat generator. It turns out that the kindling of equipment called a rocket should be carried out according to certain rules:

the main raw material for the furnace of the unit should be laid only after a good heating of the structure, for which, first, sawdust or paper is placed in the blowing sector and set on fire;
they must react to muffling the hum emanating from the furnace - they put a large batch of fuel into the combustion chamber, which will ignite on its own from the red-hot remnants of sawdust;
the process is closely monitored, that is, after laying the firewood, the damper is fully opened, and after a while, when the equipment makes a hum, it is covered to obtain a sound similar to rustling;
as necessary, the shutter is closed more and more, otherwise the firebox will begin to fill with an excess volume of air, which will disrupt pyrolysis inside the flame tube and lead to the creation of a strong hum.

Since the jet furnace was originally designed for use in the field, its design is extremely simple. This allows an ordinary home craftsman to cope with the manufacture of the unit. But, despite the apparent lightness, the rocket furnace is supposed to be assembled, taking into account the correct ratio of parameters. Otherwise, the equipment will turn out to be unproductive.

Ksenia Zubkova
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Source: //legkovmeste.ru/stroitelstvo-i-remont/otoplenie/reaktivnaya-pech-svoimi-rukami.html

Do-it-yourself rocket oven - instructions!

Unfortunately, in our country almost no one knows about the rocket oven. Meanwhile, such a design is extremely useful in a number of cases due to the almost complete absence of soot during operation and a high combustion temperature.

Reactive stove

Rocket furnace

Today we will talk about how a do-it-yourself rocket oven is made.

Principle of operation

Hot gases instead of a chimney enter a special hood, where they burn out (hence the absence of soot). In this case, the temperature rises even more, and the pressure, on the contrary, decreases. The cycle is constantly repeated and soon the furnace goes into combustion mode with maximum thrust (the strength of the latter depends on the design features and the quality of installation).

Rocket furnace

The temperature in the bell can reach 1200ᵒС, as a result of which all waste is burned almost without residue, and the exhaust consists mainly of carbon dioxide and water vapor.

Note! Thanks to this, the chimney can be laid under the floor or through some kind of heating structure (a couch, for example, or a bench). What's more, the hot hood can be used for heating water, cooking food, drying fruit, etc.

Reactive furnaces

The benefits include:

high efficiency;
no soot;
high fever;
the possibility of using cones, damp branches, dry plant stems as fuel - almost everything burns at a temperature of 1200ᵒ;
low fuel consumption - about four times lower than the standard design.

Types of rocket furnaces

There are several types of rocket (or jet, as they are also called) ovens.

Portable structures made of tin containers (paint cans, buckets, etc.). Great helpers on a construction site or on a hike that can be crafted in just a few hours.
Furnaces made of refractory bricks and metal barrels, intended for heating heat-consuming masses. They are distinguished by a horizontal chimney installed underground and an external riser to ensure draft.
Fully brick structures are used for air heating of the floor. Consist of several chimneys at once.

Note! Due to the complexity of the third option, this article will only consider the first two.

Making a reactive kiln from a brick and a metal barrel

In this case, the work traditionally begins with the preparation of everything necessary.

Making a reactive furnace from a brick and a metal barrel, drawing

Stage 1. Materials and equipment

For construction you will need:

fireclay brick;
steel barrel for 200 l;
chimney pipe;
metal brush;
old barbecue;
fire resistant paint;
bayonet shovel;
expanded clay;
fittings;
adobe;
perlite;
cement mortar;
trowel. Making a reactive furnace from a brick and a metal barrel

Stage 2. Preparation

Step 1. In the floor, a pit is pulled out (if possible) with a depth of about 30-50 cm. This is necessary so that the level of the horizontal chimney does not rise too much.

Step 2. The steel barrel will serve as a lid for the oven. First, the barrel is fired and cleaned of soot with a metal brush, after which it is painted with refractory paint.

Note! The paint is applied only after the chimney outlet flange has been installed.

Stage 3. Foundation

Step 1. Preparing the formwork for the future foundation.

Step 2. In the place where the firebox will be, several bricks go deep into the ground.

Step 3. Steel reinforcement is laid at the bottom.

Step 4. Bricks are laid around the lower point of the combustion chamber.

Step 5. The base is poured with concrete mortar.

Making a reactive kiln from a brick and a metal barrel

Stage 4. Laying

After the solution has dried, you can start laying the rocket oven.

Note! To do this, only use refractory clay.

Step 1. On the first tier, the masonry rises up, leaving only an opening for the combustion chamber.

Step 2. On the second level, the lower oven channel is formed.

Making a reactive kiln from a brick and a metal barrel

Step 3. On the third, the channel is overlapped with masonry so that two holes are obtained - for the combustion chamber and the vertical channel.

Note! After laying the bricks, you can not cut them off - they still have to be hidden with adobe and expanded clay.

Step 4. Preparation for laying the vertical channel. In addition to the barrel itself, this will require an old water heater of about 150 liters.

A flange is built into the barrel for connecting the chimney. It is also advisable to install a tee for cleaning the chimney here.

Step 5. The ascending part of the structure is placed using the "boot" method. The internal section of this part should be approximately 18 cm.

Step 6. A piece of hot water is put on the ascending part, and the voids between the walls are filled with perlite. The upper part of the perlite is sealed with chamotte clay.

Step 7. The base of the furnace is covered with sandbags, the base of the casing is coated with clay. The voids between the bags and the body are filled with expanded clay, after which the base is finished with the same clay.

Step 8. The chimney is connected, an inverted steel barrel is put on the ascending part.

Step 9. A trial run of the furnace is carried out, after which the barrel is painted with fire-resistant paint.

Manufacturing a reactive furnace from a brick and a metal barrel, diagram

Stage 5. Chimney lining

Step 1. The chimney is lined with sandbags and covered with expanded clay.

Step 2. The structure is given the appropriate shape using fireclay clay.

Note! The rocket furnace requires a lot of oxygen during operation, therefore it is recommended to run an air duct from the street.

All that remains is to install the old barbecue in the neck of the firebox and close it with a lid. The seams are filled with clay. That's it, the brick rocket oven is ready for use.

Stove stove, built on the principle of a rocket stove

Stove stove, built on the principle of a rocket stove, diagram

Stove stove, built on the principle of a rocket stove, foundation

Stove stove, built on the principle of a rocket stove, masonry

Making a camping-garden stove

In this design, as in the one described above, the principle of operation is to isolate the fire and direct heat energy to the right place.

Stage 1. Prepare everything you need

To prepare a portable rocket oven, you will need:

two tin containers of different diameters;
a pair of corners;
steel clamps ø10 cm;
stainless steel pipe for chimney;
fine crushed stone;
Bulgarian;
scissors for metal. Making a camping-garden oven for dishes From wire we bend a burner for dishes

Stage 2. Assembly of the structure

Step 1. A lid for the structure is made from a smaller bucket. To do this, a hole is made in it for the chimney (the lid is not removed at the same time). In this case, it is better to bend the "petals" inward - this way the pipe will be more securely fixed.

The lower half of the bucket is cut off with a grinder.

Step 2. A hole is cut at the bottom of the other container to connect the firebox. The tin is cut into "petals" with scissors and bent inward.

Step 3. The forward flow is assembled from a pipe and a pair of corners. The pipe is then inserted into the bucket and connected to the "petals" there with a steel clamp. That's it, the forward flow of the rocket furnace is ready.

Step 4. The space between the forward flow and the walls of the bucket is covered with fine gravel. The latter will perform two functions in the structure at once - thermal insulation and thermal accumulation.

Step 5. The second bucket (lid) is put on the jet oven.

Step 6. A cooking plate is bent from a steel wire.

Note! Instead of a hotplate, you can install three bricks.

Step 7. It remains only to paint the structure with heat-resistant paint (preferably gray or black). For melting, a direct flow outlet pipe will be used.

Reactive mini oven

Reactive mini-oven, kindling

Rules for the operation of rocket furnaces

Rocket furnaces, as well as other long-burning designs, need to be launched onto a warm tube. And if for the second version of the furnace this is not so important, then for the first a cold chimney will only lead to unnecessary combustion of fuel. For this reason, the structure needs preliminary heating - heating with sawdust, paper, etc.

It is also worth noting that the jet furnace is unable to self-adjust, so at first the blower opens completely, and is covered only after the structure begins to hum a lot. In the future, the access of oxygen gradually decreases.

About the rocket oven in the bath

Reactive wood stove with lounger

Many people were probably interested in the question - is it possible to use a jet oven in a bath? It would seem possible, because it is quite easy to equip a heater on a tire.

In reality, such a design is not suitable for a bath. For light steam, you first need to warm up the walls, and only then, after a while, the air. For the latter, the oven must be a hotbed of convection and heat radiation (IR). This is the problem - convection is clearly distributed in the rocket furnace, and the design does not provide for losses due to thermal radiation at all.

Do-it-yourself rocket oven

conclusions

Be that as it may, but today in the manufacture of rocket furnaces there is more intuition than real accurate calculations, therefore, this is an almost limitless field for creativity.

We also suggest that you familiarize yourself with the video instructions for making a rocket furnace.

- DIY jet oven

Source: //svoimi-rykami.ru/stroitelstvo-doma/pechi_i_mangaly/pech-raketa-svoimi-rukami.html

Do-it-yourself rocket furnace made of long-burning brick: drawing, instructions, photo

A rocket stove made of bricks of long burning, despite the simplicity of the design, can solve a number of problems for owners of summer cottages and private houses. These include not only the functions of heating and cooking, but also the creation of an original interior and comfort in the room.

Principle of operation

During the thermal decomposition of solid organic fuel, gaseous substances are released, which also decompose and turn into wood gas in the process, which has a high level of heat transfer during combustion.

In conventional solid fuel stoves, wood gas goes into the pipe along with the gas, where it cools down and settles on the walls in the form of soot. In a rocket-type furnace, due to the horizontal channel, the gases move more slowly, do not have time to cool down, but burn out, giving off a large amount of heat.

In models of jet heating devices of complex design, heated air and gas flows through a series of internal channels. Then they move to the upper part of the body, under the hob, where it burns out completely. For such a rocket, there is no need for additional inflation. The draft in them is created at the expense of the chimney, and the longer its length, the more intense the ascending flow.

Principle of operation

In this diagram, the principle of operation of a rocket oven with a stove bench

Advantages and disadvantages

Long-term rocket furnaces have the following advantages:

high efficiency - at least 85%;
a high speed of heating the room - 50 m² will become warm in less than 1 hour;
the absence of soot - the exhaust during fuel combustion does not form soot, but is formed in the form of steam and carbon;
the ability to operate on any type of solid fuel;
low consumption - fuel consumption of a rocket stove is 4 - 5 times less than that of a conventional stove under the same conditions: the combustion time and heating temperature;
the possibility of arranging a warm bed;
the duration of keeping heat in a well-heated structure without adding fuel - up to 12 hours.

Such a stove has many advantages, but there are also bad sides.

The disadvantages include:

manual way to control the heating device - fuel burns out quickly, and it needs to be reported regularly;
the high heating temperature of some structural elements threatens to burn the owners in case of accidental contact;
the heating rate does not allow the use of a rocket stove for baths;
the aesthetic component of such a device is not suitable for every interior;
danger of carbon monoxide penetration into living rooms.

Materials (edit)

Do-it-yourself building materials for the construction of a furnace for long-burning rockets are selected depending on the calorific value of the fuel. For the masonry of the main body, a simple red oven brick is usually used. The firebox and the furnace bunker are lined with fireclay bricks.

If you plan to use high-calorific fuel (for example, coal), then refractory bricks are used for the construction of almost all parts of the structure. Masonry elements are fastened with an aqueous solution of a mixture of sand and clay.

Regardless of the type of construction for a long-burning rocket furnace, you will need to buy furnace accessories:

blew;
grate grates;
furnace doors;
intermediate cap;
chimney pipe.

Instruments

To build a rocket-type furnace with your own hands, you need to prepare in advance a set of tools for work, which should consist of:

trowels for scooping and distributing mortar. It is more convenient to work with a tool with a handle slightly shifted to the side;
picks or hammer - picks for cutting off individual parts of the brick;
grinders with a diamond disc for sawing solid blocks into quarters and halves;
mallets with a rubber tip for leveling bricks in masonry;
twisted cord - mooring;
building level;
square and tape measure;
shovels.

You also need to stock up on two containers for the preparation of mortar, concrete and a metal mesh for sifting the ingredients.

How to do it yourself?

Before making a rocket furnace, it is necessary to decide on the place of its installation, on the dimensions of the future structure, to develop a scheme. The technology of the masonry itself is quite simple, any novice builder can master it.

The simplest design of a rocket stove can be built from 20 bricks at a summer cottage and used to heat food brought from home.

Seat selection

Before starting construction, first of all, they choose a place. It is recommended to place rocket-type brick ovens closer to the front door. In this case, the ash after cleaning will not need to be carried across the entire room, which will have a positive effect on the overall dustiness of the room.

It is also desirable that at the exit point of the pipe there are no rafters located closer than 40 cm to the chimney. And yet, the stove should not adjoin the outer wall of the house, so that expensive heat does not go to heating the street.

Preparation of the solution

The cement mortar under the influence of high temperatures quickly cracks, therefore, for laying brick heating devices, only a mortar consisting of clay and sand is used.

Their proportions are determined experimentally, depending on the quality of the clay. Most often in a ratio of 1: 2 or 1: 3, and the higher the fat content of the clay, the less it is added to the solution.

First, the clay needs to be soaked, filtered, and then sand is added. The resulting solution should be like thick sour cream in consistency. You can check the level of its viscosity in the following way:

place a wooden stick or trowel handle in the mixture;
take out the tool and shake well;
check the thickness of the adhered layer: if less than 2 mm add clay, more than 3 mm add sand.

The preparation of the mortar must be approached with all responsibility, since only a plastic mixture of the required density can fill in all the irregularities of the bricks and ensure their strong adhesion.

Rocket kiln masonry with 20 bricks

Rocket furnace ordering for 20 bricks

An example of a brick rocket stove

Rocket oven masonry with stove bench

A brick rocket oven, even equipped with a stove bench, is small in size. The order shown in the figures (below) allows you to assemble the structure without the use of metal products. Only the doors will be iron. Subsequently, the body can be coated with clay to give it a more rounded shape.

Row number	Number of bricks, pcs.	Description of masonry	Drawing
1	62	Furnace base formation	(click to enlarge)
2	44	Formation of the base of channels for heating the bench along the entire structure. Fastening mortgages for mounting a cast-iron door
3	44	Repetition of the contour of the second row
4	59	Full channel overlap. The beginning of the formation of the vertical smoke channel and furnace
5	60	Erection of a bed	(click to enlarge)
6	17	Continuation of the laying of the smoke channel
7	18
8	14
9; 10	14	Formation of a smoke channel	(click to enlarge)
11	13
12	11	Beginning of laying the chimney. From here begins the channel through which the air from the hob will go down to move to the stove
13	10	The end of the formation of the surface for the hob. Laying an asbestos gasket that is covered with sheet steel.	(click to enlarge)
14; 15	5	Closing the chimney and forming a low wall between the stove bench and the hob.

After the completion of the masonry work, the homemade rocket oven must be dried, carefully, heating at low intensity. First, no more than 20% of the firewood is put into the firebox, and the device is heated twice a day for 30 - 40 minutes.

According to this scheme, the stove is heated until its outer surface is cleaned of damp spots. It may take from three to eight days to dry, depending on the size of the device. During this time, the room should be well ventilated, especially in summer.

Acceleration of drying can lead to cracking of the masonry, that is, the device will become unsuitable for further heating.

Finished view

It is only necessary to launch a brick rocket furnace with a warm chimney. For a small device, this property is not so important, and a larger stove for a cold pipe only uses firewood in vain.

Therefore, before loading the fuel rate after a long break in operation, the rocket must be heated with paper, dry shavings, straw, etc., placing them in a blower with an open door. When the hum in the stove lowers the tonality or dies down, then you can load all the fuel into the furnace, it should ignite by itself from the already existing fire.

A rocket stove with a stove bench is not a fully self-regulating device for external conditions and fuel energy efficiency. Therefore, at the beginning of the firebox with the standard amount of fuel, the blower door is left in the open position. After the stove starts humming strongly, it is covered to a position where the sound made is barely audible.

Only dry wood can be used to warm up the stove, wet wood will not allow the stove to warm up to the desired temperature, which can lead to back draft.

Output

A brick reactive stove is becoming an increasingly popular heating device for small buildings, both temporary and permanent residence. This is explained by the simplicity of execution, the cheapness of the material, the duration of the autonomous operation and the high heat transfer of this design.

A simple heating device, which is not much inferior in popularity to a potbelly stove, is a rocket stove. It runs on wood, and the design scheme is so simple that manufacturing is possible on your own. The stove can also be made economical - many think that looking like a potbelly stove means the gluttony of the combustion chamber, but no. There are schemes that work on smoldering wood (pyrolysis), which means they are economical with the same efficiency.

Why a rocket and why a jet

Such a stove is often called a "rocket", but not because the wood burns in it at high speed, but because of the shape of the structure - the traditional version of the rocket stove is made of two pieces of iron pipes welded together. The unit resembles a rocket in a child's drawing. The use of a simplified form allows you to make it in less than a day. The adjective “reactive” is also used for the stove, but also not because of the rate of fuel combustion, but because of the peculiarities of combustion - at a certain stage of air supply to the firebox, it begins to hum strongly, as if the turbocharging of the injectors in the engine is turned on.

The humming of the furnace is an ineffective and wasteful combustion mode. During normal operation, it emits a quiet rustle.

Any owner of a country or country house has at least a minimum set of carpentry, locksmith and car repair tools in the workshop. Here they will help in the manufacture of a miracle rocket, plus drawings and a minimum supply of materials: pipes or metal boxes, a sheet of iron and - during the construction of a stationary version - brick and mortar on clay. Now it becomes clear that the jet furnace is made portable or stationary, for example, for heating a house or a bath.

If a stationary jet oven will heat the house, then it is placed along the outer wall. Correctly designed and equipped, it can heat a house up to 50m 2. Also, the stove is installed in an open area - on a personal plot, and is used as a summer option for cooking.

How a rocket-type stove works

The device is the simplest - two principles of fuel combustion, borrowed from other stoves:

Natural circulation of hot gases and smoke through the channels of the stove is a standard solution, as in a stove.
Afterburning of unburned gases (pyrolysis) with limited access of oxygen to the combustion chamber.

The scheme of the simplest jet stove, which is intended only for cooking, uses the natural combustion of wood - in an open chamber it is impossible to create conditions for maintaining the pyrolysis reaction and afterburning unburned gases.

Let us consider a simple design of a direct combustion rocket-rocket furnace, which is traditionally installed in a courtyard in an open area. It can be used to quickly heat water or prepare dinner for a family on vacation. From the figure below, it becomes clear that such a sample will require two sections of a cylindrical or rectangular iron pipe, which are connected by welding at an angle of 90 0.

A horizontal section of a metal box acts as a combustion chamber - firewood is laid there. Also, fuel loading can be organized vertically - add a vertical iron cylinder on top of the horizontal pipe for loading firewood. Thus, you get a structure of three pipes or boxes, the lowest of which (horizontal) will work as a firebox. In a stationary scheme, the simplest stove design often uses red brick, which is placed on a clay mortar.

The efficiency of the structure cannot be called satisfactory, so the craftsmen figured out how to increase the efficiency of its work. An additional element is another pipe of a larger diameter (as you can see, all materials are available and cheap), into which the main pipe of the riser stove (primary chimney) is installed. This increases the overall heating and the duration of the heat retention.

In the diagram:

Outer casing.
A pipe that serves as a firebox.
A duct for air outlet to the combustion chamber.
Insulated area between the body and the riser. The same ash can serve as a heater.

How to heat

The Robinson reactive furnace is heated according to the principle of kindling a fire - paper, hay, straw or other rapidly combustible material is laid first, then small chips or large shavings. The last logs are laid in the size of the firebox. Hot combustion products rise along the vertical pipe (2) and go out. A pot or water tank can be placed on the open end of the pipe (2).

In order for the fuel to burn continuously and actively, it is necessary to provide a gap between the outlet pipe (2) and the pan with water using a special lattice metal support.

The diagram below shows a simple device with a door on the fuel loading hole. Air draft is formed due to the presence of a special channel formed by the lower surface of the furnace and an iron plate welded 8-10 mm from the combustion chamber. Such a design will forcibly pump air, even if the door is closed completely. It can be seen from the diagram that the design is also designed to operate in the pyrolysis mode, while a constant flow of a "secondary" air stream will burn the exhaust gases. But in order for the afterburning to be 100%, it is necessary to equip the thermal insulation of the secondary chamber in which the gas burns out in order to provide the required temperature indicators for pyrolysis.

In the diagram:

Forced duct for blowing air with the combustion door closed.
Active combustion area.
Burnt gases.

The improved scheme provides not only the possibility of heating the surrounding space, but also cooking, for which the upper hob is designed. Total: to the simplest version of the "rocket", you can add an outer casing, which will additionally heat the room, the furnace door, blowing air to maintain the pyrolysis mode and a stove for cooking food. This scheme can already be implemented in the house itself, and not in the yard, since the chimney pipe is brought out. This minor upgrade greatly improves the performance of the model. So, a do-it-yourself rocket furnace, the drawings of which are presented below, has the following capabilities:

Due to the embedding of the outer casing from a pipe of a larger diameter and its insulation, which creates a heat-insulating layer for the riser, and also due to the possibility of hermetically closing the upper pipe, hot air cools down much longer.
In the lower section of the stove, a separate blowing channel has been added, which makes it possible to organize pyrolysis combustion.
It is recommended to place the chimney in such a scheme not vertically at the top, but at the bottom behind on the body, which will allow organizing additional circulation of hot streams through the internal channels of the stove, ensuring rapid heating of the hob and the entire insulated body.

In the firebox (1), the fuel does not burn completely (2), since the air supply is not carried out in full, this is the "A" mode, which can be controlled using the damper (3). Hot, but not burned out from pyrolysis gases are supplied to the end section of the firing channel (5), in which they are burned out. Afterburning provides high-quality thermal insulation and a constant flow of "secondary" air in the "B" mode through channel (4).

The hot stream then enters the inner riser (7), rises up to the cooking plate (10) and heats it up. Further, hot air enters the volume (6) between the outer and inner pipes, insulated with a layer of ash (4, 9), heats the furnace body, which gives off heat to the room. Finally, the cooled air goes down to enter the chimney (11) and out.

A stable high temperature in the riser (7) ensures maximum heat transfer and creates conditions for complete combustion of gases by placing the riser in a larger pipe - shell (8). The free space is filled with ash or other refractory substance (9) for lining - this can also be a solution of ordinary clay with sand in a ratio of 1: 3.

The palm of popularity belongs to the industrial model "Robinson" - it is a simple but reliable design. Having such a mobile stove, you can quickly cook food or heat water in the country or on a hike. Structurally, this is an inverted L-shaped pipe, as shown in the diagrams below.

Firewood is laid in the horizontal section of the fuel receiver, and ignition is carried out from the side from which the vertical pipe enters. In the L-shaped pipe, due to the pressure difference between hot and cold air, thrust arises, and the combustion intensity will only increase as the furnace body heats up. The air supply is regulated by a slide damper.

The furnace works on the principle of energy consumption of the natural flow of hot gases. It turns out a closed cycle: as the temperature rises, the fuel starts to burn more actively and the chamber and the hob heat up faster. As a result, "Robinson" is able to heat 10 liters of water in 10 minutes, if you put the tank on an already warm surface. The diagram shows that the hob in "Robinson" has a thick heat-insulating layer, which makes it possible to put large diameter chocks in the firebox.

Stationary oven

Stationary models have a hood to keep the heat in the room longer. In such a stove, fuel combustion occurs according to a different scenario. The beginning of the firewood combustion process is the same - the air supply is limited. This causes the release of pyrolysis gases, which are afterburned in the lower section of a vertical pipe or duct, where the secondary air is supplied separately.

The hot gas, once at the top, begins to cool down and sinks into the free interchamber volume, and then into the chimney. It goes like this:

The forces of gravity cause colder, and therefore, heavier, burnt gases to rush down, where they enter the chimney.
This is facilitated by the constantly maintained pressure from the placed firewood and the consistently high temperature of the gases.
Natural draft in the chimney.

All this creates effective conditions for burning firewood and it becomes possible to attach a smoke channel with arbitrary geometry to the "rocket". Basically, long and complex chimneys are needed in order to better heat the room.

The main disadvantage of all solid fuel stoves is the inability to retain most of the heat in the house. But the positive qualities make it possible to neutralize the negative aspects - the high speed of the gas outlet makes it possible to organize complex vertical or horizontal chimneys with several channels. The implementation of this principle in practice is the Russian stove. In a jet furnace with a horizontal multi-channel chimney, you can also equip a warm stove bench, as shown in the diagram below.

A rocket-rocket stove is an option for home heating, cheaper than which is only a gift. A person familiar with the basics of construction can fold a brick combination stove in a design suitable for any home interior. The main task of ennobling the appearance will be decorating the iron cap and the firebox lid - everything else will not be in sight.

Combined brick-metal barrel oven

It is stationary, because the structure cannot be moved. The fuel chamber and chimney are laid out of fireclay bricks, valves and doors are made of metal. Brick gives off heat very slowly, so the room will be warm for a long time.

High efficiency is not the strong point of such models, but good heat transfer can be achieved by adjusting the air supply to the chamber, without seeking to enter the combustion mode, in which the stove begins to "roar" and "hum".

In order to somehow minimize heat losses during the operation of this simplest design, many craftsmen build a water circuit into the furnace and connect a hot water tank. Also, the construction of a bed with a multi-channel horizontal chimney contributes to the preservation of heat in the room. Negative qualities of "missile" models that cannot be minimized or removed:

Constant monitoring and adjustment of traction is necessary - no automation devices are provided.
Every 2-3 hours you need to load a new batch of firewood.
The iron hood is heated to dangerous temperatures.

The simplest and cheapest option is the Robinson model, which is shown in the drawing below. To make it, you need pipe cuttings or a rectangular profile box, metal corners for legs, a welding machine. Its dimensions are selected based on the dimensions of the workpieces. The main thing is to adhere to the observance of the principle of action, and not the size.

For a home-made design, they often take gas cylinders or barrels of 200 liters - thick walls and a suitable size are as close as possible to what was intended. Both are used for the manufacture of the outer case, and the internal elements are made from pipes of a smaller diameter or brought out in bricks - halves, quarters or whole.

There is no general formula for calculating heat transfer for all models of a rocket stove, so the option of using ready-made calculations based on the principle of similarity of schemes is quite suitable. The main thing is that the size of the future "rocket" should at least approximately correspond to the volume of the heated room. For example, a gas cylinder will do for a garage, a two-hundred-liter barrel for a country house. An approximate selection of internal elements is shown in the diagram below.

Iron cylinder furnace

Cylinder - gas, oxygen, carbon dioxide.
Pipe ≥ 150 mm for fuel and loading chambers.
Pipes 70 and 150 mm - for an internal vertical chimney.
Pipes 150 mm - for the outlet chimney.
Insulation of any type, necessarily non-combustible.
Sheet metal blanks H = 3 mm.

The top of the cylinder is cut by welding. For safety reasons, it is best to open the stopcock on it and fill it with water before cutting. On the sides, you need to cut openings for the fuel chamber and chimney. The pipe for the firebox is connected to the vertical pipe of the chimney from the bottom of the cylinder.

After installing the internal elements, the cut-off top is welded back. The seams are checked visually, the main chimney is connected. If there is a water circuit, it also joins. After that, the rocket furnace can be tested.

Sufficient draft is ensured by the height of the chimney - it must be raised above the firebox by at least 4 meters.

How to lay out a brick firebox

Such a model requires the use of only fireclay (clay) bricks - ceramic or silicate bricks will immediately crack. The laying is carried out on clay mortar, the proportions of the composition are indicated above. A pit is dug under the base of the stove, the soil at the bottom is rammed and poured with concrete. The size of the foundation is 1200x400x100 mm.

After the base has hardened, it is protected with a sheet of basalt cardboard, then they begin to lay out the firebox, vertical chimney and loading chamber. From the front of the firebox, a door for ash removal is attached. After the clay solution has dried, the trench is filled up, a pipe of the required diameter is inserted into the vertical chimney. The cavities between the brick and the pipe should be filled with insulation - basalt wool, ash or other non-combustible material, for example, asbestos.

Now a Ø 600 mm cap is placed on the masonry - a cut-out cover from a metal barrel will do. Before installation, a hole is cut in it, into which a branch pipe is inserted under the chimney. Putting on this cap, the barrel should be turned over, and the branch pipe will be where it is needed. Then the chimney is brought out - either directly to the street, or through the arrangement of a lounger with horizontal chimney channels. The lounger can be laid out with ordinary silicate bricks, since the temperature of the gases will already be low.

Let's say right away: a rocket stove is a simple and convenient wood-fired heating and cooking device with good, but not exceptional parameters. Its popularity is explained not only by its catchy name, but more so by the fact that neither a stove-maker nor even a bricklayer can make it with their own hands; if necessary - literally in 15-20 minutes.

And also by the fact that, having invested a little more work, you can get an excellent stove bench in the house without resorting to building a complex, expensive and cumbersome Russian or bell-type stove. Moreover, the very principle of the rocket furnace gives great freedom to design and the manifestation of creativity.

Rocket stove - wood-fired device

But the "jet furnace" is perhaps more remarkable for the huge number of associated, at times completely absurd inventions. For example, here are a few pearls snatched at random:

"The operating principle of the furnace is the same as that of the MIG-25 ramjet engine." Yes, the MIG-25 and its descendant MIG-31, as they say, did not sit down in the bushes near the ramjet engine (ramjet). On the 25th and 31st there are by-pass turbojet engines (turbojet engines), the four of which then pulled the Tu-144 and still pulls other machines. And any furnace with any jet engine (RD) is technical antipodes, see below.
Reverse jet furnace. Is the stove flying tail first, or what?
"How can she blow such a pipe?" The naturally aspirated stove does not blow into the pipe. On the contrary, the chimney pulls from it, on natural draft. The higher the pipe, the better it pulls.
"The rocket stove is a combination of a Dutch bell-type stove (sic!) With a Russian stove bench." First, there is a contradiction in the definition: a Dutch stove is a channel stove, and any bell stove is anything but a Dutch stove. Secondly, the bed of the Russian stove warms up in a completely different way than the rocket stove.

Note: in fact, the rocket stove was called so because in the wrong mode of the furnace (which will be discussed later), it emits a loud whistling rumble. A properly tuned rocket furnace whispers or rustles.

These and similar inconsistencies, of course, are confusing and prevent you from making a rocket furnace properly. So let's figure out what the truth is about the rocket stove, and how to use this truth correctly so that this really good stove shows all its merits.

Stove or rocket?

For complete clarity, we still need to figure out why a furnace cannot be a rocket, and a rocket cannot be a furnace. Any RD is the same internal combustion engine, only the outflowing gases act as pistons, connecting rods with a crank and transmission. In a piston internal combustion engine, already at the moment of combustion, the high temperature of the working fluid creates a lot of pressure, which pushes the piston, and it already moves the entire mechanics. The movement of the piston is active, the working fluid pushes it where it itself seeks to expand.

When fuel is burned in the combustion chamber of a jet engine, the thermal potential energy of the working fluid is immediately converted into kinetic energy, as in a load falling from a height: since the incandescent gases have an outlet to the nozzle, they rush there. In the taxiway, the pressure plays a subordinate role and nowhere exceeds the first tens of atmospheres, this, for any conceivable nozzle section, is not enough to accelerate the flashlight to 2.5M or launch a satellite into orbit. According to the law of conservation of momentum (momentum), an aircraft with a taxiway receives a push in the opposite direction (recoil momentum), this is jet thrust, i.e. thrust from recoil, reaction. In a turbojet engine, the second circuit creates an invisible air envelope around the jet stream. As a result, the recoil momentum seems to be pulled in the direction of the thrust vector, therefore turbojet engine is much more economical than a simple turbojet engine.

The furnace does not convert types of energy into each other, therefore it is not an engine; the furnace simply distributes potential thermal energy in a proper way in space and time. From the point of view of the furnace, an ideal RD has an efficiency of 0%, since it only pulls at the expense of fuel. From the point of view of the jet engine, the furnace has an efficiency of 0%, it only dissipates heat and does not pull at all. On the contrary, if the pressure in the chimney rises to or above atmospheric (and without this, where will the jet thrust or active effort come from?), The stove will at least smoke, or even poison the residents or start a fire. Chimney draft without pressurization, i.e. without energy consumption from the outside, it is provided due to the temperature difference along its height. Potential energy is here again, it is not transformed into any other.

Note: in a rocket taxiway, fuel and oxidizer are fed into the combustion chamber from the tanks, or they are immediately refueled into it if the taxiway is on solid fuel. In a turbojet engine (TJE), the oxidizer - atmospheric air - is pumped into the combustion chamber by a compressor driven by a turbine in the exhaust gas stream, the rotation of which consumes a certain fraction of the energy of the jet stream. In a turboprop engine (TVD), the turbine is calculated so that it takes 80-90% of the power of the jet, which is transmitted to the propeller and compressor. In a ramjet engine (ramjet engine), air supply to the combustion chamber is provided by a high-speed hypersonic pressure. There have been many experiments in the ramjet, but there were no serial aircraft with it, and is not expected, the ramjet is too capricious and unreliable.

Kan or not kan?

Among the myths about the rocket furnace, there are some that are not entirely absurd, and even somewhat substantiated. One such misconception is the identification of the "racket" with the Chinese Kan.

As a child, the author had a chance to visit the Amur region in winter, in the Blagoveshchensk region. There were many Chinese people living there in the villages, and then they scampered in all directions from the Cultural Revolution of the Great Chairman Mao and his completely frostbitten Red Guards.

Winter in those parts is not Moscow's; frost at -40 is a common thing. And what amazed and aroused interest in stoves in general was how Chinese fanzas were heated by kangs. Firewood is being carried to Russian villages in carts, smoke from chimneys is a pillar of smoke. And all the same, in the hut of logs, not in a child's girth, by morning the corners from the inside froze over. And the fanza is built like a country house (see fig.), The windows are covered with a fish bubble or even rice paper, bunches of chips or twigs are placed in the canal, but the room is always warm.

However, there are no subtle heat engineering wisdom in the cana. This is an ordinary, only small, kitchen stove with a lower outlet to the chimney, and most of the chimney itself is a long horizontal channel, a hog, on which the bed is arranged. Chimney, for the sake of fire safety - outside the building.

The effectiveness of the kan is determined, first of all, by the heat curtain it creates: the bed goes around, if not the entire perimeter from the inside, except for the door, then 3 walls for sure. Which once again confirms: the design and parameters of the furnace should be linked to those of the heated room.

Note: the Korean Ondol stove works on the principle of a warm floor - a very low bed takes up almost the entire area of the room.

Secondly, in the very cold, the Kans were drowned with argal - the dried droppings of ruminants, domestic and wild. Its calorific value is quite high, but argal burns slowly. In fact, the argal fire is already a long-burning furnace.

It is not in the Russian custom to stick twigs into the oven every now and then, and our peasants disdained to cook food on animal feces. But travelers of the past highly valued argal as fuel, collected it along the way and carried a supply with them, carefully protecting it from getting wet. N.M. Przhevalsky in one of his letters asserted that without argal he would not have been able to carry out his expeditions across Central Asia without losses. And the Englishmen, who disdained argal, returned to the base 1 / 3-1 / 4 of the personnel of the detachments. True, he was recruited from sepoys, Indian soldiers in the British service, and pandits - spies recruited from the local population. One way or another, but the highlight of the rocket stove is not at all in the stove bench on the hog. To get to it, you will have to learn to think in American: all the primary sources on the rocket furnace are from there, and utter speculations are generated only and only by misunderstanding.

How to deal with missiles?

From our point of view, it is necessary to study the original technical documentation of rocket furnaces with caution, but not at all because of inches-millimeters, liter-gallons and the subtleties of American technical jargon. Although they also mean a lot.

Note: The textbook example is "Naked conductor runs under the carriage." Literary translation - a naked conductor runs under the carriage. And in the original article from the Petroleum Engineer, it meant "Bare wire runs under the crane trolley."

The rocket stove was invented by members of survival societies - people with a peculiar way of thinking, even by American standards. In addition, they were not bound by any standards and norms, but, like all Americans, mechanically everything was always converted into money, taking into account their own benefit; a person with a different outlook in America simply will not get along. And instinctive self-interest inevitably gives rise to egocentrism. He by no means excludes good deeds, but not out of emotional impulse, but on the basis of dividends. Not in this life, so in that one.

Note: How much the average inhabitant of the greatest empire in history fears everything, you can understand only after talking to them for a long time. And the sociopsychologists there go out of their way, convincing that living languishing in fear is normal and even cool. The rationale is clear: the intimidated biomass is easily predictable and manageable.

Without heating and cooking, of course, you cannot survive. What is the stove for? For the time being, the survivors were content with camping stoves. But then, according to the confessions of the Americans themselves, in 1985-86. they were greatly impressed by two films that were released with a short interval and triumphantly bypassed all the screens of the world: the Soviet fantastic parody of the entire human race "Kin-dza-dza" and Hollywood's "The Day After", about the global nuclear war.

The survivors realized that after the nuclear winter there would be no extreme romance, but there would be the planet Plyuk in the Kin-dza-dza galaxy. The newly-minted plukans will have to be satisfied with "ka-tse" in small quantities, bad, expensive and difficult to obtain. Yes, all of a sudden someone hasn't watched "Kin-dza-dza" - ka-tse, in Plukan, a match, a measure of wealth, prestige and power. It was necessary to invent their own furnace, none of the existing ones was designed for a post-nuclear pluck.

Americans are very often endowed with a sharp mind, but a deep one is the rarest exception. A completely normal and with an IQ higher than the average US citizen may sincerely not understand how it does not reach the other what he himself has already "caught up" and how someone else may not like what suits him.

If the American has already grasped the essence of the idea, then he brings the product according to it to possible perfection - what if there is a buyer, you cannot sell raw iron. But technical documentation, seemingly beautiful and neat, can be drawn up in essence extremely carelessly, or even deliberately distorted. And what's wrong with that, it's my know-how. Maybe I'll sell it to someone. Pluck will be, or not, but for now the know-how costs money. In America, such an attitude to business is considered quite honest and dignified, but there a clinical alcoholic at work will never miss a stoper and will not pull a couple of bolts home to the farm. On that, in general, all America is.

And the Russian broad-mindedness is also a double-edged sword. Our master most often just from the sketch immediately understands how this thing works, but in the little things he turns out to be careless and overly gullible to the source code: how is it that a skilled bro deceives his own. If something is not, well, it is not necessary. It seems clear how everything is spinning there - even your hands are itching. And there, perhaps, while it comes to the hammer, chisel and accompanying literature, still count and count. Moreover, important points can be omitted, veiled or deliberately incorrect.

Note: an American acquaintance once asked the author of this article - how is it that we, really stupid, chose the very smart Reagan as president? And you, really smart, tolerate a slobbering senile with dyed eyebrows in the Kremlin? True, then in America, no one would even dream in a bad dream that in the next century a black citizen with a Muslim name would settle in the Oval Office, and his first lady would dig a vegetable garden near the White House and start growing turnips there. Times is changing, as Bob Dylan once sang on a completely different occasion ...

Sources of misunderstanding

There is such a thing in technology - the law of the square-cube. Simply, when the size of something changes, its surface area changes in a square, and its volume in a cube. Most often this means that the overall dimensions of the product must be changed according to the principle of geometric similarity, i.e. just keeping the proportions is impossible. With regard to solid fuel stoves, the square-cube law is doubly valid, since fuel also obeys it: it emits heat from the surface, and its supply is contained in the volume.

Note: a consequence of the square-cube law is that any specific furnace design has a certain permissible fork of its size and power, within which the specified parameters are provided.

Why, for example, it is impossible to make a potbelly stove the size of a refrigerator and a capacity of about 50-60 kilowatts? Because the potbelly stove, in order for it to somehow warm up, must be heated inside itself to at least 400-450 degrees. And in order to warm up to such a temperature the volume of the refrigerator with a given heat transfer, firewood or coal is needed as much as it does not fit into it. There will be no sense from a mini-stove either: the heat will escape through the outer surface of the stove, which has grown relative to its volume, and the fuel will not give up more than it can.

The square-cube law acts threefold on the rocket furnace, because she is "licked" in an American professional manner. It is better to stay away from her with our nashensky kondachkom. For example, here in fig. American development, which, judging by its relevance, many of our craftsmen take as a prototype.

Original blueprint for a mobile rocket oven

With the fact that the exact grade of fire clay is not indicated here, ours will still figure it out. But, to be honest, who noticed that, judging by the absence of an external chimney and the presence of carrying pipes, this stove is mobile with an open firebox? Most importantly, the fact that a 20-gallon keg with a diameter of 17 inches (431 mm with small change) went to her drum?

Judging by the constructions from the Runet - no one at all. They take this stuff and fit it on the outside according to the principle of geometric similarity to a domestic 200-liter barrel with a diameter of 590 mm. Many people guess to arrange a blower, but the bunker is left open. Are the proportions of vermiculite and perlite for lining the riser and molding the furnace body (core) not specified? We make the lining homogeneous, although it will be clear from what follows that it should consist of insulating and accumulating parts. As a result, the stove roars, the fuel eats only dry, and a lot, and even before the end of the season, it grows inside with fumes.

How was the rocket oven born?

So, already without fiction with futurology, the survivors needed a stove to heat a house, working with high efficiency on low-quality random wood fuel: wet chips, twigs, bark. Which, in addition, will need to be reloaded without stopping the furnace. And most likely it will not be possible to dry it in a wood log. Heat transfer after heating takes at least 6 hours to get enough sleep; getting fired up in a dream on Plyuk is no better than in America. Additional conditions: the design of the furnace should not contain complex metal products, non-metallic materials and assemblies that require production equipment for the manufacture, and the furnace itself should be available for construction by an unskilled worker without the use of power tools and complex technologies. Of course, no pressurization, electronics and other volatility.

They immediately took a couch from the kan, but what about the fuel? For a bell furnace, it needs high quality. Long-burning furnaces operate at least on sawdust, but only dry, and do not allow stopping with additional loading. They were nevertheless taken as a basis, very attracted by the high efficiency achieved by simple methods. But in attempts to make the "long stoves" work on poor fuel, one more circumstance emerged.

What is wood gas?

The high efficiency of long-burning furnaces is achieved largely due to the afterburning of pyrolysis gases. Pyrolysis is the thermal decomposition of a solid fuel into volatile combustible substances. As it turned out (and the survivors have their own research centers with highly qualified specialists), the pyrolysis of wood fuel, especially wet, continues for a long time in the gas phase, i.e. The pyrolysis gases that have just escaped from the tree still need a lot of heat to form a mixture that can burn out completely. This mixture was called wood gas, woodgas.

Note: in runet woodgas has created more confusion, because in American vernacular gas can mean any fuel, cf. ex. gas station - gas station, gas station. When translating the original sources without knowing the American technical, it turned out that woodgas is just wood fuel.

Before that, no one had seen wood gas: in ordinary stoves, it is formed immediately in the furnace, due to the excess energy of fiery combustion. The designers of long-burning furnaces came to the conclusion that the primary air must be heated, and the exhaust gases must be retained in a significant volume over a large mass of fuel, simply by trial and error, so they overlooked wood gas.

It turned out not so when heating with bundles of twigs: here the primary pyrolysis gases were immediately dragged into the chimney by the draft. Wood gas could have formed in it at some distance from the firebox, but by that time the primary mixture had cooled down, pyrolysis stopped, and heavy radicals from the gas settled on the walls of the chimney as carbon deposits. Which quickly tightened the channel completely; this phenomenon is well known to amateurs who build rocket furnaces at random. But the survivors eventually figured out what it was, and still made the right oven.

Who are you, the Rocket Stove?

There is an unspoken rule in technology: if it seems that it is impossible to create a device according to the given requirements, then read, smart guy, school textbooks. That is, go to the basics. In this case, to the basics of thermodynamics. Survivors do not suffer from sick vanity, they turned to the basics. And they found the main principle of operation of their furnace, which has no analogues in others: slow adiabatic afterburning of pyrolysis gases in a weak flow. In long-burning furnaces, afterburning is equilibrium isothermal, requiring a large buffer volume, subject to the square-cube law, and a supply of energy in it. In pyrolysis gases in the afterburner, they expand almost adiabatically, but practically into a free volume. And now - we are learning to think in the American way.

How does a rocket oven work?

The scheme of the final fruit of the labors of the survivors is shown on the left side of Fig. The fuel is loaded vertically into the hopper (Fuel Magazine) and burns, gradually settling down. Air enters the combustion zone through a blower (Air Intake). The blower must provide an excess of air so that it is enough for afterburning. But not excessive, so that the cold air does not cool the primary mixture. With vertical loading of fuel and a blank bunker lid, the regulator, however, is not very effective, the flame itself acts: if it is too hot, it pushes the air away.

Rocket furnace device

Then things begin that are already non-trivial. We need to warm up, and with good efficiency, a large oven. The square-cube law does not allow: the scanty heat will immediately dissipate so much that the pyrolysis will not reach the end, and the thermal gradient from the inside to the outside will not be enough for heat transfer into the room; everything will whistle into the pipe. This law is harmful, you cannot break through it. Okay, let's see in the basics, if there is anything that is beyond his control.

But of course, there is. The same adiabatic process, i.e. thermodynamic without heat exchange with the environment. There is no heat exchange - the squares are resting, and the cubes can be reduced even to a thimble, even to a skyscraper.

Imagine a volume of gas completely isolated from the whole. Let's say energy is released in it. Then the temperature and pressure will begin to rise until the energy release stops and solidify at a new level. Great, we burned the fuel completely, hot flue gases can be released into a heat exchanger or heat accumulator. But how can you do this without technical difficulties? And most importantly - how, without breaking the adiabat, to supply air for afterburning?

And we will make the adiabatic process non-equilibrium. How? Let the primary gases go directly from the combustion source into a pipe covered with high-quality insulation with a low intrinsic heat capacity (Insulation). Let's call this pipe for ourselves a fire or a combustion tunnel (Burn Tunnel), but we will not sign it (know-how! not accused of "opacity", let us designate it with a flame.

Along the length of the flame tube, the adiabatic index changes (this is a nonequilibrium process): the temperature will first drop slightly (wood gas is formed), then it will rise sharply, the gas will burn out. You can release it into the storage, but we have forgotten - and what will pull the gases through the fire tube? Aspiration means volatility, and there will be no exact adiabat, but something mixed with isobar, i.e. efficiency will drop.

Then we will lengthen the pipe twice, preserving the insulation, so that the heat does not go away in vain. Bend the "blank" half upwards, making the insulation on it weaker; how to keep the heat seeping through it, we will think about a little later. A temperature difference in height will appear in the vertical pipe, and, therefore, draft. And good: the thrust force depends on the temperature difference, and with an average temperature in the fire tube of about 1000 degrees, it is not difficult to achieve a difference of 100 at an altitude of about 1 m. So, while we have made a small economical stove-stove, now we need to think about how to use it warmly.

Yes, it doesn’t interfere with additional encryption. If we call the vertical part of the fire tube the primary or internal chimney (Primary or Internal Vent), then they will guess the main idea, we are not the smartest in the world. Well ... let's call the primary chimney the most common technical term for vertical pipes with an upward current - riser (riser). Purely American: correct and incomprehensible.

Now let's remember about heat transfer after heating. Those. we need a cheap, always available and very capacious heat accumulator. There is nothing to invent here, adobe (Thermal Mass) was invented by primitives. But it is not fire-resistant, it does not hold more than 250 degrees, and we have about 900 at the mouth of the riser.

It is not difficult to convert high-grade heat into medium-grade heat without losses: you need to give the gas the opportunity to expand in an isolated volume. But, if you leave the expansion adiabatic, then the volume will be too large. This means that it is material and labor-intensive.

I had to again bow to the basics: immediately after leaving the riser, let the gases expand at constant pressure, isobaric. This requires the removal of heat to the outside, about 5-10% of the thermal power, but it will not disappear and will even be useful for quickly warming up the room during the morning firebox. And further along the course of gases - isochoric cooling (in constant volume); this way, almost all the heat will go to the battery.

How to do it technically? We will cover the riser with a thin-walled iron drum (Steel Drum), it will also prevent heat loss from the riser. "Drum" turns out to be too high (the riser sticks up strongly), but it doesn't matter: we will coat it 2/3 of the height with the same adobe. We attach a stove bench with a sealed chimney (Airtight Duct), an external chimney (Exhaust Vent), and the stove is almost ready.

Note: The riser and the drum covering it look like an oven hood over an upward-stretched high. But thermodynamics here, as we see, is completely different. It is useless to try to improve the bell-type stove by building on the hailo - only the extra material and work will go away, and the stove will not get better.

It remains to solve the problem of cleaning the channel in the bed. For this, the Chinese have to break the kan from time to time and mutate it again, but we are not in the 1st century. BC. we live when the kan was invented. We will arrange a Secondary Airtight Ash Pit immediately after the drum with a sealed cleaning door. Due to the sharp expansion and cooling of flue gases in it, everything in them that has not burned out immediately condenses and settles. The cleanliness of the external chimney is guaranteed by this for years.

Note: the secondary cleaning will have to be opened once or twice a year, so you don't have to fool around with the latch hinges. Let's just make a cover from a metal sheet on screws with a mineral cardboard gasket.

Small rocket

The next task of the designers was to create, on the same principle, a small continuous combustion oven for cooking in the warm season. During the heating season, the Optional Cooking Surface of a large oven is suitable for cooking, it heats up to about 400 degrees. The small rocket furnace was supposed to be portable, but it was permissible to make it with an open firebox, because when it's warm, you can cook outdoors or under a canopy.

Here the designers took revenge on the square-cube law, forcing it to work for themselves: they combined the fuel bunker with the blower, see Fig. at the beginning of the section on the right. It is impossible to do this in a large furnace; accurate adjustment of the furnace mode as the fuel settles (see below) will be impossible.

Here, the volume of the incoming primary air (Primary Air) turns out to be small relative to the heat release area and the air can no longer cool the primary mixture until the pyrolysis stops. Its supply is regulated by a slot in the cover of the hopper (Cover Lid). The hopper, inclined at 45 degrees, optimizes the automatic adjustment of the oven power for standard culinary procedures, but makes it more difficult.

Secondary air for afterburning wood gas in a small furnace enters through additional holes in the riser mouth or simply leaks under the burner if there is a cooking pot on it. If a small furnace is close to the size limit (about 450 mm in diameter), then an optional Secondary Woodgas Frame may be needed for complete afterburning.

Note: it is not possible to supply secondary air to the riser mouth of a large furnace through holes in the drum (which would increase the efficiency of the furnace). Although the pressure in the entire flue gas duct is lower than atmospheric pressure, as it should be in the furnace, due to strong turbulence, flue gases will be thrown into the room. Here their kinetic energy, harmful to the furnace, affects; this is, perhaps, the only thing that makes a rocket oven with a jet engine in common.

The small rocket stove revolutionized the class of camp stoves, especially tourist stoves. A wood chip stove (a Bond stove in the West) will help to cook a stew or wait out a blizzard in a one-two-person tent, but a group caught in a spring hike by a belated storm will not save them. And the small rocket furnace is only slightly larger, it can be quickly made from nowhere from nothing, but it is capable of developing power up to 7-8 kW. However, we will talk further about rocket stoves from just about anything.

Also, the small rocket furnace has spawned many improvements. For example, Gabriel the Apostle provided her with a separate blower and a wide bunker. The result is a stove suitable for a compact and rather powerful water heater, see the video below. The large rocket furnace has also been modified, we will talk about this a little at the end, but for now we will dwell on more significant things.

Video: a water heater based on a rocket furnace designed by Gabriel Apostol

How to sink a rocket?

A rocket furnace with long-burning furnaces has a common property: they only need to be launched on a warm pipe. For a small one, this is insignificant, but a large one on a cold chimney will only burn fuel in vain. Therefore, a large rocket furnace before loading the standard fuel into the bunker after a long break in the furnace and kindling requires acceleration - firing with paper, straw, dry shavings, etc., they are placed in an open blower. The end of the acceleration is judged by a change in the tone of the hum of the furnace or its decay. Then you can load the fuel into the bunker, and its ignition will happen by itself from the accelerating fuel.

The rocket stove, unfortunately, does not apply to stoves that are completely self-adjusting to the quality of the fuel and external conditions. At the beginning of the combustion of standard fuel, the blower door or the bunker cover in a small furnace is opened completely. When the stove hums strongly, cover it up "to a whisper." Further, during the heating process, it is necessary to gradually cover the air access, focusing on the sound of the stove. Suddenly the air damper slammed shut for 3-5 minutes - it's okay, if you open it, the stove will ignite again.

Why such difficulties? In the process of burning out the fuel, the flow of air into the combustion zone increases. When there is too much air, the furnace explodes, but do not rejoice: now the excess air cools the primary gas mixture, and the sound is amplified because the stable vortex in the riser is knotted into a disorderly lump. The gas phase pyrolysis is interrupted, no wood gases are generated, the furnace consumes too much fuel, and a bituminous soot-cemented soot settles in the riser. This, firstly, is fire hazardous, but most likely it will not come to a fire, the riser channel will quickly be completely overgrown with carbon deposits. But how to clean it if you have a non-removable drum cover?

In a large furnace, a spontaneous change of mode occurs abruptly, when the top of the sticks drops to the lower edge of the bunker, and in a small furnace - gradually, as the fuel mass settles. Since the experienced hostess does not leave her for a long time when cooking on the stove, the designers considered it possible, for the sake of compactness, to combine a bunker with a blower in it.

With a large furnace, such a trick will not work: a high riser pulls very strongly, and the air gap is needed so thin (and it also needs to be regulated) that it is impossible to achieve a stable furnace mode. It is easier with a separate blower: it is easier for air to flow around a mass of fuel, rounded in cross-section, from the sides, an overly flared flame squeezes it out there. The stove turns out to be self-regulating to some extent; however, within very small limits, so you still have to manipulate the blower door from time to time.

Note: to make the bunker of a large furnace for the sake of simplicity without a tight lid, as is often done, is impossible. Due to the unregulated additional air flow through the fuel mass, it will hardly be possible to achieve a stable operation of the furnace.

Materials, sizes and proportions, lining

Now let's see what a homemade rocket stove should be from the materials available to us. Here, too, we need to look back: not everything that is at hand in America is with us, and vice versa.

Of what?

For a large stove oven with a stove bench, more or less reliable experimental data is available for products with a drum from a 55-gallon barrel with a diameter of 24 inches. 55 gallons is 208 with a small change, and 24 inches is almost exactly 607 mm, so our 200-liter will do just fine. Keeping the parameters of the furnace, the diameter of the drum can be reduced by half, to 300 mm, which makes it possible to make it from 400-450 mm of tin buckets or a household gas cylinder.

Pipes of different sizes will go to the blower, bunker, firebox and riser, see below, round or shaped. So it will be possible to make the insulating lining of the furnace part from a mixture of equal shares of furnace clay and chamotte crushed stone, without resorting to brickwork; we'll talk more about the riser lining below. Combustion in a rocket furnace is weak, therefore, the thermochemistry of gases is gentle and the thickness of the steel of all metal parts, except for the gas pipeline in the stove bench, is from 2 mm; the latter can be made of thin-walled metal corrugated metal, here the flue gases have already completely exhausted both in terms of chemistry and temperature.

For external coating, the best heat accumulator is adobe. If the dimensions indicated below are observed, the heat transfer of a rocket furnace in adobe after heating can reach 12 hours or more. The rest of the parts (doors, covers) are made of galvanized metal, aluminum, etc., with sealing gaskets made of mineral cardboard. Ordinary stove fittings are not very suitable, it is difficult to ensure its tightness, and the slotted rocket stove will not work properly.

Note: it is advisable to equip the rocket furnace with a view in the outer chimney. Although the gas view in the high riser locks the common flue gas duct tightly, strong winds outside can draw heat out of the bed prematurely.

Dimensions and proportions

The basic calculated values, to which the rest are tied, are the drum diameter D and its cross-sectional area along the inside S. Everything else, based on the size of the available gland, is determined as follows:

Drum height H - 1.5-2D.
Drum coating height - 2 / 3H; for the sake of design, the edging of the design can be made oblique curvilinear, then 2 / 3H must be sustained on average.
Drum coating thickness - 1 / 3D.
The cross-sectional area of the riser is 4.5-6.5% of S; it is better to keep within 5-6% of S.
Height of the riser - the more, the better, but the gap between its edge and the drum cover must be at least 70 mm; its minimum value is determined by the viscosity of the flue gases.
The length of the flame tube is equal to the height of the riser.
The cross-sectional area of the flame tube (fire conduit) is equal to that of the riser. It is better to make a fire conduit from a square professional pipe, so the oven mode will be more stable.
The sectional area of the blower is 0.5 from its own firebox and riser. A more stable oven mode and its smooth adjustment will give a rectangular professional pipe with sides 2: 1, laid flat.
The volume of the secondary ash pan is from 5% of the initial volume of the drum (excluding the volume of the riser) for the furnace from the barrel to 10% of the same for the furnace from the cylinder. Interpolation for intermediate drum dimensions is linear.
The cross-sectional area of the external chimney is 1.5-2S.
The thickness of the adobe cushion under the external chimney is 50-70 mm; if the channel is round, it is considered from its lowest point. If the bed is on wooden floors, the pillow under the chimney can be cut in half.
The height of the bed over the external chimney is from 0.25D for a 600 mm drum to 0.5D for a 300 mm one. Less is possible, but then the heat transfer after heating will be shorter.
The height of the outer chimney is from 4 m.
The permissible length of the gas duct in the bed - see next. sect.

The limiting thermal power of the rocket furnace from the barrel is about 25 kW, the furnace from the gas cylinder is about 15 kW. Power adjustment - only by the size of the fuel load. By supplying air, the oven is put into operation, and nothing more!

Note: In the original survivor furnaces, the riser section was taken at 10-15% S, based on completely wet fuel. Then in the same place, in America, there were rocket stoves with a stove bench for bungalows, designed for air-dry fuel and more economical. In them, the riser section is reduced to the recommended ones and here 5-6% S.

Riser lining

The efficiency of the rocket furnace largely depends on the thermal insulation of the riser. But, alas, American lining materials are not available to us. In terms of reserves of high-quality refractories, the United States has no equal, where they are considered a strategic raw material and are even sold to trusted allies with caution.

From our available materials for heating engineering, they can be replaced with light fireclay bricks of the SHL brand and ordinary self-excavated river sand with a large admixture of alumina, correctly laid, see below. However, these materials are porous; in the oven, they will quickly become saturated with carbon deposits. Then the stove will start roaring with any supply of air, with everything that comes out. Therefore, we need to surround the riser lining with a metal shell, and the end of the lining must be covered with oven clay.

Lining schemes for 3 types of furnaces are shown in Fig. The bottom line is that with a decrease in the size of the drum, the proportion of its direct heat transfer through the bottom and the non-lined part increases according to the square-cube law. Therefore, while maintaining the desired thermal gradient in the riser, the lining power can be reduced. This makes it possible to correspondingly increase the relative cross-section of the annular lowering of the flue gases in the drum.

Riser Lining Schemes in Rocket Furnaces

What for? Firstly, the requirements for an external chimney are reduced, because the external link pulls better now. And since it pulls better, then the permissible length of the hog in the bed falls more slowly than the dimensions of the oven. As a result, if a stove from a barrel heats up a stove bench with a hog up to 6 m long, then half the size of a cylinder is 4 m.

How to lining with sand?

If the lining of the riser is chamotte, then the residual cavities are simply covered with construction sand. A self-dug river lining entirely of sand does not need to be thoroughly prepared for lining, it is enough to select large debris. But it is poured in layers, in 5-7 layers. Each layer is tamped and sprayed until a crust forms. Then the entire backfill is dried for a week, the upper edge is covered with clay, as already mentioned, and the construction of the furnace continues.

Balloon rocket

From the above, it is clear that it is more profitable to make a rocket oven from a gas cylinder: less work, fewer unsightly parts in sight, and almost the same heats the bed. A heat curtain or underfloor heating in Siberian frost will heat a room of 50 sq. m and more, so here, too, a balloon rocket turns out to be more profitable, a large barrel will rarely have to be launched at full power with maximum efficiency.

The craftsmen, apparently, understood this too; at least some. For example, here in fig. - drawings of a balloon rocket furnace. On the right is the original; the author, it seems, was wisely versed in the original developments and in general everything turned out right for him. On the left - the necessary improvements, taking into account the use of air-dry fuel and warming up the bed.

Drawings of a rocket furnace from a gas cylinder

A fruitful idea is a separate supply of heated secondary air. The oven will be more economical and the flame tube can be made shorter. The cross-sectional area of its duct is about 10% of the riser cross-section. The furnace always works with a fully open secondary. Initially, the mode is set by the primary valve; precisely adjusted by the hopper cover. At the end of the firebox, the stove explodes, but here it is not so scary, for cleaning the riser the author of the design provides a removable drum cover. She, of course, should be sealed.

Rockets from anywhere

Canning

Diagram of a rocket furnace from cans

Tourists, hunters, and fishermen (many of them members of survival societies) soon adapted the small rocket furnace to be used as a camping stove made from empty cans. It was possible to minimize the influence of the square-cube by using a horizontal fuel supply, see the diagram on the right. True, at the cost of some inconvenience: the sticks, as they burn out, need to be pushed inward. But the mode of the furnace began to be held firmly. How? Due to the automatic redistribution of air flows through the blower and above / through the fuel. The power of the canned rocket furnace is in the range of 0.5-5 kW, depending on the size of the furnace and is regulated by about three times the amount of fuel loading. The basic proportions are also simple:

The combustion chamber diameter is 60-120 mm.
The height of the combustion chamber is 3-5 diameters.
The blower section is 0.5 from its own combustion chamber.
The thickness of the thermal insulation layer is not less than the diameter of the combustion chamber.

These proportions are very approximate: changing them by half does not prevent the furnace from working, and the efficiency during the campaign is not so important. If the insulation is made of wet sandy loam, as described above, the joints of the parts can simply be coated with clay (left position in the figure below). Then the stove after 1-2 fireboxes will acquire strength, allowing it to be transported without special precautions. But in general, any of the available non-combustible materials will be used for insulation, trace. two pos. A burner of any design must provide a free flow of air, 3rd pos. A rocket furnace welded from a steel sheet (right position) with sand insulation is twice lighter and more economical than a stove of the same power.

Compact rocket furnaces

Brick

Brick debris rocket kiln

We will not dwell on large stationary rocket furnaces: in them all the original thermodynamics is sprayed, and they are deprived of one of the main advantages of the original furnace - the simplicity of construction. We will tell you a little about rocket furnaces made of bricks, clay or stone fragments, which can be made in 5-20 minutes, when there are no cans at hand.

Here, for example (see the video below), a rocket-oven of 16 bricks laid on a dry basis is quite complete in thermodynamics. The voice acting is English, but everything is clear there even without words. A similar one can be folded from fragments of bricks (see fig.), Cobblestones, molded from clay. For 1 time, a stove made of greasy earth is enough. All of them are not very economical, the height of the combustion chamber is too small, but enough for pilaf or urgent heating.

Video: rocket oven made of 16 bricks (eng)

New material

Scheme of the Shirokov-Khramtsov furnace

Of the domestic developments, the Shirokov-Khramtsov rocket-furnace deserves attention (see the figure on the right). The authors, not caring about survival in the pluck, used a modern material - heat-resistant concrete, adjusting all thermodynamics to it. The components of refractory concrete are not cheap; a concrete mixer is needed for mixing. But its thermal conductivity is much lower than that of most other refractories. The new rocket furnace became more stable, and it became possible to release some of the heat outside in the form of infrared radiation through heat-resistant glass. The result is a rocket stove - a fireplace.

Do rockets fly in the bath?

Isn't a rocket stove suitable for a bath? It seems that a stove can be arranged on the drum cover. Or flowing instead of a couch.

Unfortunately, the rocket stove is not suitable for the bath. To get light steam, the sauna stove must immediately warm up the walls with thermal (IR) radiation, and immediately, or a little later, the air, by convection. For this, the oven must be a compact IR source and a convection center. The convection from the rocket furnace is distributed, and it gives little IR at all, the very principle of its design excludes significant radiation losses.

In conclusion: rocket stove-makers

In successful designs of rocket furnaces, there is still more intuition than accurate calculation. And therefore - good luck to you! - the rocket oven is a fertile field for craftsmen with a creative streak.

Illustration	Brief description of the performed operation
	The first row is laid out solid, and the brick should lie in exact accordance with the pattern shown in the diagram - this will give the whole base strength. For masonry, 62 red bricks are required. The diagram clearly shows the connection of all three sections of the furnace. The corners on the side bricks of the front of the firebox are cut or rounded off - so the structure will look neat.
	Second row. At this stage of work, internal chimney channels are laid through which gases heated in the firebox will pass, giving off heat to the bricks of the stove bench. The channels connect to the combustion chamber, which also begins to form in this row. The first brick of the wall dividing the two channels under the stove bench is cut obliquely - this "nook" will collect non-burnt combustion products, and the cleaning door, installed opposite the bevel, will allow you to easily clean it. For laying a row, 44 bricks are required.
	On the second row, the doors of the blowing and cleaning chambers are mounted, which are necessary for periodically putting the ash chamber and internal horizontal channels in order. The doors are secured with wire, which is twisted on the ears of the cast-iron elements, and then laid in the seams of the masonry.
	Third row. It almost completely repeats the configuration of the second row, but, of course, taking into account the laying in a bandage, and therefore it also requires 44 bricks.
	Fourth row. At this stage, the channels passing inside the bed are overlapped with a continuous layer of brick. The opening of the furnace is left, and a channel is formed, which will heat the hob and discharge the combustion products into the chimney. In addition, a rotary horizontal channel is blocked from above, which removes the heated air under the bed. For laying a row, you need to prepare 59 bricks.
	Fifth row. The next step is to overlap the bed with a second cross layer of brick. Also, the chimney ducts and the firebox continue to be removed. 60 bricks are prepared for the row.
	Sixth row. The first row of the headrest of the bench is laid out, and the part of the oven, on which the hob will be installed, begins to rise. The chimney ducts are still led out in it. For a row, 17 bricks are needed.
	Seventh row. The laying of the headrest is being completed, for which bricks cut obliquely are used. The second row of the base rises under the hob. For masonry, 18 bricks are required.
	Eighth row. The laying of the furnace structure with three channels is being carried out. It takes 14 bricks.
	The ninth and tenth rows are similar to the previous, eighth, laid out according to the same pattern, alternately, in a bandage. Each row uses 14 bricks.
	11th row. Continuation of masonry according to the scheme. This row will take 13 bricks.
	12th row. At this stage, a hole is formed for installing the chimney. The hole supplied under the slab is supplied with bricks cut obliquely for a smoother flow of heated air into the adjacent channel leading to the lower horizontal channels located in the bed. 11 bricks were used per row.
	13th row. The base for the slab is formed, and the central and lateral channels are combined. It is through it that hot air will flow under the stove, and then flow into a vertical channel leading under the stove bench. 10 bricks are stacked.
	13th row. On the same row, the base is prepared for laying the hob. For this, a heat-resistant material - asbestos - is laid along the perimeter of the space in which two vertical channels were combined.
	13th row. Then, a solid metal plate is laid on top of the asbestos gasket. In this case, it is not recommended to install a hob with opening burners, since when they are opened, smoke can enter the room.
	14th row. The hole for the chimney is blocked and the wall that separates the hob from the stove area rises. Only 5 bricks are used for the row.
	15th row. This row lifting the wall will also require 5 bricks.
	15th row. On the same row, in continuation of the back wall, next to the hob, a metal shelf is fixed, which can be used as a cutting board. It attaches to brackets.
	15th row. The schematic picture well simulates how the hob can be used. In this case, the pan is placed exactly on the part of the stove that will warm up first, since a hot air stream will pass under it.
	After completing all the works described in the order, a chimney is embedded in the hole from the back of the stove, which is led out into the street.
	From the rear, the structure also looks quite neat, so it can be installed both near the wall and in the middle of the room. Such a stove is perfect for heating in a country house. If the stove and chimney are decorated with finishing materials, then the structure can become an original addition, and very functional, for any private house. As you can see, the corner under the chopping shelf is very convenient for drying and storing firewood.
	To fully consider the structure, you need to see its projection from the front side.
	And the last figure shows well what should be the result of the work done, if you look at the stove from the side of the stove bench.