Do-it-yourself rocket stoves. Rocket furnace what it is Drawing a rocket furnace from a gas cylinder

Brick rocket stove long burning, despite the simplicity of design, can solve a number of problems for owners of 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.

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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, when burned, has high level heat transfer.

In ordinary solid fuel furnaces 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 reactive heating devices complex design heated air and gas passes 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 blowing. The draft in them is created due to the chimney, and the longer its length, the more intense the upward flow.

Principle of operation

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

Advantages and disadvantages

Rocket long-burning furnaces have the following advantages:

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

There are many advantages to such a furnace, but there are also bad sides.

The disadvantages include:

• manual method of controlling the heating device - fuel burns out quickly, and it is required to report it 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 oven for baths;
• the aesthetic component of such a device is not for everyone and is not suitable for any interior;
• the danger of carbon monoxide penetration into living rooms.

materials

Do-it-yourself building materials for the construction of a long-burning rocket furnace are selected depending on the calorific value of the fuel. For laying the main part of the hull, a simple red is usually used. kiln brick. The firebox and the furnace bunker are lined fireclay bricks.

If it is planned to use high-calorie fuel (for example, coal), then refractory bricks are used for the construction of almost all parts of the structure. The masonry elements are fastened with an aqueous solution of a mixture of sand and clay.

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

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

Tools

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 up and distributing the solution. It is more convenient to work with a tool with a handle slightly shifted to the side;
• picks or hammers - picks for trimming separate parts bricks;
• grinders with a diamond blade for sawing solid blocks into quarters and halves;
• mallets with a rubber tip for leveling bricks in masonry;
• twisted cord - moorings;
• building level;
• square and tape measure;
• shovels.

You also need to stock up on two containers for preparing mortar, concrete and metal mesh for sifting ingredients.

How to do it yourself?

Before you make a rocket furnace, you need to decide on the place of its installation, with the dimensions of the future design, and develop a diagram. The technology of masonry itself is quite simple, any novice builder can master it.

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

Location selection

Before starting construction, the first step is to choose a place. brick ovens missile type is recommended to be placed closer to the front door. In this case, the ash after cleaning will not need to be carried through the entire room, which will positively affect the overall dust content of the room.

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

Solution preparation

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

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 must be soaked, filtered, and then sand is introduced. The resulting solution should have the consistency of thick sour cream. You can check the level of its viscosity in the following way:

• place a wooden stick or trowel handle into the mixture;
• remove the tool and shake well;
• check the thickness of the adhering layer: if less than 2 mm add clay, more than 3 mm - sand.

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

Masonry rocket stove of 20 bricks

Ordering a rocket furnace for 20 bricks

An example of a brick rocket stove

Masonry rocket stove with stove bench

A brick rocket stove, even equipped with a bench, is small. 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 more rounded shapes.

After completing the masonry work, the home-made rocket stove must be dried, carefully, by heating at low intensity. First, no more than 20% of the firewood norm is laid in 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 cleared of damp spots. Drying, depending on the dimensions of the device, may take from three to eight days. During this time, the room should be well ventilated, especially in summer.

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

Ready view

You need to start a brick rocket stove only with a warm chimney. For a small device, this property is not so significant, 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 stove must be heated with paper, dry shavings, straw, etc., placing them in a blower with the door open. When the hum in the stove lowers its tone or subsides, 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 bed is not a fully self-regulating device for external conditions and fuel energy efficiency. Therefore, at the beginning of the furnace with a regular amount of fuel, the blower door is left in the open position. After the stove starts to hum strongly, it is covered to a position where the sound emitted is barely audible.

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

Output

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

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

Why rocket and why jet

Such a stove is often called a “rocket”, but not because the firewood in it burns at high speed, but because of the shape of the structure - the traditional version of the rocket stove is made from two pieces of iron pipes welded together. The unit resembles a rocket on children'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 speed of fuel combustion, but because of the characteristics of combustion - at a certain stage of air supply to the firebox, it starts to hum strongly, as if turbocharging of the nozzles in the engine is turned on.

Furnace humming is an inefficient and consumable combustion mode. During normal operation, it emits a quiet rustle.

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

If a stationary jet stove will heat the house, then it is located along outer wall. Properly designed and equipped, it can heat a house up to 50m2. Also, the oven is installed on open area- on a personal plot, and are used as a summer option for cooking.

How does a rocket stove work?

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

1. The natural circulation of hot gases and smoke through the channels of the stove is a standard solution, as in a potbelly stove.
2. 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 exactly natural combustion firewood - in an open chamber it is impossible to create conditions for maintaining the pyrolysis reaction and afterburning of unburned gases.

Consider a simple construction jet furnace-Rockets of direct combustion, which is traditionally installed in the yard in an open area. It can quickly heat water or cook dinner for the family on vacation. From the figure below, it becomes clear that such a sample will require two pieces of a cylindrical or rectangular iron pipe, which are interconnected by welding at an angle of 90 0.

A horizontal segment 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 a horizontal pipe for loading firewood. Thus, a structure of three pipes or boxes will be obtained, 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 clay mortar.

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

On the diagram:

1. Outer body.
2. A pipe that serves as a firebox.
3. Channel for air outlet to the combustion chamber.
4. Insulated area between hull and riser. The same ash can serve as a heater.

How to heat

The Robinson jet stove is heated according to the principle of kindling a fire - paper, hay, straw or other quickly combustible material is laid first, then small chips or large chips. The last logs are laid in the size of the firebox. Hot combustion products rise along the vertical pipe (2) and go outside. On the open end of the pipe (2) you can put a pot or a tank of water.

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

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. This design will forcibly pump air even if the door closes completely. It can be seen from the diagram that the design is also designed for operation in the pyrolysis mode, while a constant flow of a “secondary” air jet will burn out the exhaust gases. But in order for the afterburning to take place at 100%, it is necessary to equip the thermal insulation of the secondary chamber in which the gas burns out in order to provide the necessary temperature indicators for pyrolysis.

On the diagram:

1. Forced channel for blowing air with the furnace door closed.
2. Area of ​​active combustion.
3. 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 yourself simple option"Rockets" you can add an outer case, 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. Such a minor upgrade significantly increases the efficiency of the model. So, a do-it-yourself rocket stove, the drawings of which are presented below, has the following capabilities:

1. Due to the embedding of the outer casing of a larger diameter pipe and its insulation, which creates a thermal insulation layer for the riser, as well as the ability to hermetically close the top pipe, the hot air cools down much longer.
2. A separate blowing channel has been added in the lower section of the stove, which allows organizing pyrolysis combustion.
3. The chimney in such a scheme is recommended to be placed not vertically at the top, but at the bottom at the back of the body, which will allow organizing additional circulation of hot streams through the internal channels of the stove, providing fast heating hob and the whole 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 burnt out from pyrolysis, gases are fed into the end section of the fire channel (5), in which they are burned. Afterburning provides high-quality thermal insulation and a constant flow of "secondary" air in the "B" mode through the 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 descends to enter the chimney (11) and exit.

Consistently high temperature in the riser (7) provides maximum heat transfer and creates conditions for complete combustion of gases due to the placement of the riser in a larger pipe - shell (8). The free space is filled with ash or other heat-resistant substance (9) for lining - it can also be a solution of ordinary clay with sand in proportions of 1:3.

The palm of popularity belongs to the industrial model "Robinson" - this 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, draft arises, and the intensity of combustion will only increase as the furnace body heats up. The air supply is controlled by a 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 begins to burn more actively and the chamber and 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 the "Robinson" has a thick heat-insulating layer, which allows you to put large diameter chocks into the firebox.

Stationary oven

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

The hot gas, once at the top, begins to cool and descends into the free inter-chamber volume, and then into the chimney. It happens like this:

1. Gravitational forces cause the colder, and therefore heavier, burnt gases to rush down, where they enter the chimney.
2. This is facilitated by the constantly maintained pressure from the firewood and the consistently high temperature of the gases.
3. 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 keep most of the heat in the house. But the positive qualities make it possible to neutralize the negative points - the high rate of gas outlet allows you 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, it is also possible to equip a warm bench, as shown in the diagram below.

A jet rocket stove is a variant of home heating, which is cheaper only for nothing. A person familiar with the basics of construction can fold a combined brick oven in a design suitable for any home interior. The main task of ennobling the appearance will be decorating the iron cap and the lid of the firebox - everything else will not be visible.

Combined brick-metal barrel oven

It is stationary, because the structure cannot be moved. A fuel chamber and a chimney are laid out of fireclay bricks, valves and doors are made of metal. The brick gives off heat very slowly, so the room will be warmed 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 trying to enter the combustion mode, in which the stove begins to “roar” and “buzz”.

To somehow minimize heat loss when operating this simplest design, many craftsmen build a water circuit into the oven and connect a hot water tank. Also, the construction of a stove bench with a multi-channel horizontal chimney contributes to the preservation of heat in the room. Negative qualities of "rocket" models that cannot be minimized or removed:

1. It is necessary to constantly monitor and adjust the thrust - there are no automation devices.
2. Every 2-3 hours you need to load a new portion of firewood.
3. The iron cap heats up to dangerous temperatures.

The simplest and cheapest option is the Robinson model, which is shown in the drawing below. For its manufacture, cutting pipes or a rectangular profile box are needed, metal corners for legs welding machine. Its dimensions are selected based on the dimensions of the blanks. The main thing is to adhere to the principle of action, not size.

For a home-made design, gas cylinders or barrels of 200 liters are often taken - thick walls and a suitable size are the best fit for what was intended. Both those and others are used to make the outer case, and the internal elements are made from pipes of a smaller diameter or are brought out with 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 circuits 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, for a garage will do gas bottle, for a country house - a two-hundred-liter barrel. An approximate selection of internal elements is shown in the diagram below.

Iron bottle stove

1. Cylinder - gas, oxygen, from under carbon dioxide.
2. Pipe ≥ 150 mm for fuel and loading chambers.
3. Pipes 70 and 150 mm - for an internal vertical chimney.
4. Pipes 150 mm - for the outlet chimney.
5. Insulation of any type, necessarily non-combustible.
6. Blanks sheet metal H = 3 mm.

The upper part of the cylinder is cut off by welding. For safety reasons, it is better to open the stopcock on it and fill it with water before cutting. From 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 channel from the bottom of the cylinder.

After mounting the internal elements, the cut 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 oven can be tested.

Sufficient draft is provided 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 will immediately crack. Masonry 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. A door for ash removal is attached to the front of the firebox. After the clay mortar dries, the trench is filled up, a pipe of the desired 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-flammable material such as asbestos.

Now a cap Ø 600 mm is placed on the masonry - a cut-out cover from metal barrel. Before installation, a hole is cut out in it, into which the pipe for the chimney is inserted. Putting on this cap, the barrel should be turned over, and the nozzle 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.

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The rocket stove was used by many peoples of the world long before the advent of modern home and household stoves. It served, first of all, for heating the dwelling and provided warm sleeping area in the house. Cooking also played an important role. When designing the stove design, it was necessary to come up with a system that could operate at the highest possible efficiency when loaded with low quality wood fuel (in dry and wet form).

Nowadays, it is used for heating, for cooking, and also as an interior element. You can make a rocket stove with your own hands practically from improvised means. It all depends on its purpose and the place where it will be used.

There are many types and designs of a rocket furnace - from the simplest to multifunctional. For effective work it is necessary to observe some rules for the operation of the furnace structure. There are 2 basic principles of operation of a rocket furnace, regardless of its configuration:

• free circulation of released gases from the fuel through the formed furnace channels, without manual chimney draft;
• afterburning of pyrolysis gases released from fuel burnout under conditions of insufficient oxygen supply.

Design, characteristics and application

The rocket stove owes its unique name to the characteristic stove hum that can be heard throughout the entire combustion process. It is remotely similar to the sound of a rocket taking off. The similarity with a rocket is also that in it, in the process of combustion, a jet thrust is created. The conical shape of the furnace can also be associated with the name, but this is not the main characteristic.

There are 2 types of furnace construction (shown in the diagrams):

The simplest rocket oven

The simplest design of a direct combustion rocket furnace is 2 pipes connected by a branch - a Russian rocket furnace.

The down tube is separated by a metal plate. The upper part of the pipe is approximately 2/3 of the total space where the main fuel is directly laid. The lower part serves as a primitive blower, which provides air exchange in the furnace.

The fuel filling in this case is horizontal. When laid vertically, a rocket-type furnace consists of two vertical pipes of different lengths, and a third horizontal one, which serves as a connecting channel. The latter performs the function of a furnace.

Installed simplest form jet stoves are usually outdoors - for the purpose of cooking and heating water.

For the manufacture of a stationary simple brick rocket furnace, a material is used that is installed on a heat-resistant platform.

In order to achieve higher performance, new elements were added to the simplest design of the stove.

The diagram shows a camp jet furnace. The lower pipe is divided by a special jumper into a fuel compartment (2) and a compartment for venting air into the combustion area (3). The upper part of the furnace consists of a riser pipe, around which a heat-insulating composition (4) is laid, which is closed on top by an external metal casing (1).

The operation of the furnace is as follows: fuel (straw, paper) that warms up the furnace is placed in the fuel compartment, after burning through which the main fuel (wood chips, rods, etc.) is added. In the process of active combustion, hot gases are formed that rise along the riser and exit to the outside. A stand for cooking utensils is installed on the pipe cut, taking into account the gap of 7-10 mm. Otherwise, if the necessary clearance is not maintained, the outlet for oxygen draft will be blocked, which, in turn, raises the hot gases up. The combustion process will stop.

If the conditions for creating air draft are met, even with the furnace door closed, the combustion process will not stop. Here, the second principle of operation of a long-burning rocket furnace is partially triggered - the afterburning of pyrolysis gases in conditions of insufficient oxygen supply.

For this principle to work fully, it is necessary to provide the rocket furnace with high-quality thermal insulation of the secondary combustion chamber, because the processes of formation and combustion of gases must comply with temperature requirements.

advanced design

This type of rocket stove in an advanced configuration can be used at home for both cooking and heating rooms. In addition to the fuel compartment and the pipe, there is a second building in it, at the top of which a hob is installed, and the chimney is led to the street. You can heat a room with an area of ​​​​up to 50 sq.m. with such a stove.

As a result of the modernization useful qualities and efficiency is increased due to the fact that the long-burning rocket furnace acquires several unique and important properties:

• in contrast to the simple design of the rocket furnace, the improved one uses a second outer casing, a thermally insulating material around the combustion pipe, a hermetically sealed upper part of the casing, which creates conditions for maintaining a high temperature for a long time;
• an independent opening for secondary air supply in the modernized furnace performs optimal blowing, while in a simple design an open furnace is used for this;
• the chimney system is designed in such a way that the heated gas flow does not immediately rush out of the pipe, but passes through the furnace channels, ensuring high-quality afterburning of the secondary fuel, heating the hob and uniform heat transfer of the air in the room through the heated furnace body.

The improved design uses additional elements, focused on creating high heat transfer and multifunctionality of the rocket furnace. Two principles of operation of the furnace are actively involved here. First, there is a preliminary combustion of solid fuel, which, during combustion, releases pyrolysis gases, which are used as secondary fuel.

The principle of operation of a rocket furnace of this design is shown in detail in the diagram on the left. The fuel compartment (1) is loaded with fuel for pre-combustion. In the zone of the most active heat exchange (2), under conditions of insufficient supply of primary oxygen (A), regulated by a damper (3), pyrolysis gases are released. They rush to the end of the fire channel (5), where they are burned out. Favorable conditions for the combustion of gases are created due to the high thermal insulation of the structure and the continuously incoming flow of secondary oxygen (B).

The hot gas then rises up the internal channel of the riser pipe (7) under the housing cover, which is often equipped under the hob (10), due to the continuous high temperature heating. There, the accumulation of gas diverges through the channels located between the riser and the outer furnace body (6). In conditions of constant heating of the body, its walls accumulate heat, from which the air in the room heats up. After that, the gas flow descends down the channel, and then goes up into the chimney pipe (11).

The burning process can last several hours. For maximum heat transfer of the furnace and complete combustion of pyrolysis gases, it is necessary to maintain a consistently high temperature in the riser. To do this, it is placed in a pipe of a slightly larger diameter, which is called a shell (8). The formed space between the two pipes is tightly filled with a heat-resistant composition, such as sifted sand, to provide thermal insulation in the pipe.

Features of the operation of the rocket furnace

1. Before loading the main fuel, the furnace must be warmed up. This is more about large and multifunctional rocket ovens. In them, without preheating, thermal energy will be used for nothing.
2. To accelerate the furnace, dry paper, wood shavings, and straw are placed in an open blower. Sufficient heating of the furnace can be determined by the hum in the furnace, which subsequently subsides. Then, the main fuel is put into the heated rocket stove, which is ignited by the accelerating fuel.
3. At the beginning of the combustion of the main fuel, the blower door is opened completely. After a while, as the stove rumble appears, the blower is covered until the rumble is replaced by a whisper. In the future, to assess the state of combustion of the furnace, it is also necessary to focus on the “stove sound”, slightly opening the blower door when it subsides and covering it when a rumble occurs.
4. The larger the reaction furnace, the smaller the inflow opening fresh air necessary. It is advisable to use a separate blower in such a furnace.
5. The adjustment of the power of the furnace operation can occur only due to the amount of fuel put in, but not due to the air supply.
6. When making a large rocket furnace on your own, its bunker should be made with a tight-fitting lid, without gaps and cracks. Otherwise, a stable operating mode of the furnace will not be ensured, which is fraught with the consumption of excess fuel energy.
7. Contrary to popular belief, a rocket stove for a bath is not suitable for installation, since the stove does not emit sufficient infrared radiation, which is necessary for heating walls and giving off convection to the air masses in a bath. The rocket stove for a bath, theoretically, can only be installed using the Shirokov-Khramtsov stove type, the characteristics of which are given below.
8. A rocket stove for a garage is a mobile version of a stove design that can quickly heat up a room. The main element is a heating tank from a pipe.

Fuel types

With proper assembly and operation, a rocket stove can be fired with any type of solid fuel, wood and its waste. For example, branches, leaves, firewood, coal, corn stalks, cones, pieces of chipboard, pieces of furniture. It is possible to load fuel into the furnace both in dry and raw form. This is especially true for its use in natural conditions where it is not always possible to find dry raw materials.

Varieties of rocket furnaces

The rocket furnace can be made independently or to order from various materials. Here it is necessary to focus on the possibilities and available resources.

Gas cylinder stove

A used gas cylinder is a common material for making a stove. The convenience of its use lies in the fact that it is, in fact, a ready-made blank of an elongated cone-shaped furnace body. Fuel costs are minimal, and the heat generated will heat a room up to 50 sq.m. The material of the cylinder must be chosen not explosive and resistant to high temperatures and heat. The best option is a solid metal propane tank with a capacity of 50 liters, a diameter of 35 cm and a height of 85 cm. This volume is enough to burn any type of fuel.

Also, for the manufacture of a portable rocket furnace from a gas cylinder, volumes of 12 and 27 liters are used, but with less heat transfer. The cylinder can be purchased at a special gas station.

Before starting the manufacture of the furnace, gas is vented from the cylinder by opening the valve for a while. Then, a simple potbelly stove is made. Next, the upper part of the cylinder is cut off, the hole for the valve remains. A round hole with a welded steel strip is cut out at the top, which serves as the basis for the chimney.

brick oven

It can be both stationary and traveling. Hastily folded, in 15-20 minutes, a dry rocket stove made of bricks, brick fragments or cobblestones will do an excellent job of cooking and heating water. The disadvantage of such a furnace is the low fuel economy and low heat transfer. Heating the bricks in the chimney up to 1000 degrees allows the structure to quickly enter the operating mode. At the same time, the rocket does not smoke due to the fact that at such a temperature all the fuel burns without residue.

Rocket furnace with water jacket

The most commonly used stationary furnace type. The peculiarity of such a furnace is that heat transfer is not only for heating the air in the room, but also for water. To do this, a rocket furnace with a water circuit is connected to a heat storage tank - to create an autonomous water supply system. Perfect option for use in a country house or in private water, because the device helps to reduce the cost of heating and heating water, which is very economical.

Barrel oven

A common model for home heating. Low-cost in manufacturing and energy-intensive in heat transfer. Often equipped with a warm bed. Able to heat a room of more than 50 square meters. m. For the manufacture of the stove, a standard 200-liter barrel with a diameter of 607 mm is perfect. This diameter can be reduced by almost half, which is convenient for embedding a riser pipe made from a gas cylinder or tin buckets with a diameter of 300-400 mm. In a word, the oven can be made from improvised materials.

Shirokov-Khramtsov oven

Domestic modernization of the rocket furnace. The main material is heat-resistant concrete, which creates excellent thermodynamics in the structure. Due to the stable operation of the furnace and the low thermal conductivity of the material, part of the heat comes out in the form of infrared radiation, which is impossible with other types of furnaces. If you use heat-resistant glass, then the stove can be adapted for a fireplace. The disadvantage of installing such a furnace is the high cost of the material, the preparation of which will require a concrete mixer.

stove-stove

For cooking and preparations at home and outdoors, an improved oven design with a wide hob to install multiple containers. A vertical riser pipe with a firebox welded to it is located directly under the hob, providing high-temperature heating. Accumulating under the cover of the panel, the gases exit through a horizontal pipe, heating the entire area of ​​the panel evenly, and rush to the exit through the vertical chimney channel.

How to DIY

Let's take a closer look at the manufacture of a do-it-yourself rocket stove with a stove bench. Its design is more cumbersome, more difficult to install than the types of furnaces listed above, but thanks to step-by-step instructions and diagrams, it will not be difficult to build it yourself. The main thing is to follow all installation recommendations.

Step by step instructions on how to make a rocket stove:

• First, make a 10 cm deepening for installing the fuel compartment, laying it out with fireclay bricks. Then you need to install the formwork along the construction line. For a stronger foundation, you can use building reinforcement or mesh, laying it on a brick base.
• Using a level, lay out the base for the combustion chamber.
• Then you need to fill the structure with concrete, and allow to dry for a day. After the mortar has set, you can continue to build the furnace.

• Lay out the base of the furnace, laying the bricks in a continuous order.
• Form side walls by laying several rows of masonry.
• Complete the arrangement of the lower channel of the rocket, taking into account the order.
• Then you need to lay a row of transverse bricks so that the riser pipe and the combustion chamber remain open, and the combustion chamber is hidden.

• You need to take the body of the old boiler and cut it off on both sides so that you end up with a pipe that is wide in diameter.
• A flange is installed in the lower part of the body from under the fuel and lubricants, into which the pipe of the horizontal heat exchanger will be installed. To maintain the tightness and safety of the product, it is necessary to provide for the use of continuous welds in the work.

• After that, the outlet pipe crashes into the barrel. The barrel is cleaned of rust, covered with a primer and several layers of heat-resistant paint.
• To the chimney, located horizontally, you need to weld a side outlet to form an ash pan. To facilitate its cleaning, during the operation of the furnace, the channel must be equipped with a sealed flange.
• Next, a fire tube is laid out of refractory bricks, observing the dimensions of 18 × 18 cm square. When laying out the internal channel, it is important to observe strict verticality for the stable operation of the furnace. To do this, you can use a body kit or level.

• It is necessary to put a casing on the flame tube, and place perlite balls in the resulting space. The lower part of the riser must be hermetically covered with a clay mixture to prevent spillage of the heat insulator.
• Then the fuel cap is made - using the previously cut off part from the boiler. For convenience, a handle can be welded to the lid.
• Mix clay with sawdust(do not allow the product to crack), up to 50% of the total volume. The result is the so-called "adobe grease", which needs to be smeared with the appearance of the resulting structure to mask unsightly details and increase thermal insulation.

• Next, the appearance of the furnace is formed. The furnace circuit is laid out. For this you can use different materials: stone, brick, sandbags. The inner part is filled with rubble, and the upper part is smeared with adobe mixture.
• A 200-liter barrel, which serves as an external furnace body, is installed on a previously prepared base. Be sure to install the barrel so that the lower pipe is on the side of the couch. Further, the lower part is covered with clay for sealing.
• Then, from the corrugated pipe, you need to form a channel for supplying air from the street, bring it to the fuel compartment. Without installing such a channel, a do-it-yourself rocket furnace will consume warm air from the premises.

• After the construction of the main part of the furnace structure, a training kindling is carried out to check the free removal of gases through a horizontal chimney.
• The heat exchanger pipes are connected to the lower branch pipe, mounted on a red brick base.
• Next, you need to install the chimney pipe with your own hands, hermetically sealing all connections with an asbestos cord or refractory coating.
• At the end, the couch must be shaped in the same way as before - when forming the main body. If you leave the barrel open, without masking with adobe, then the heat during combustion will instantly enter the room. If the barrel is completely covered with adobe, leaving the lid intact, then the heat will accumulate in the body, which will create excellent conditions for cooking on the hob.

Instead of a barrel, you can use a gas cylinder (rocket stove from a gas cylinder), and instead of a boiler, you can use pipes fitted to the shape, tin buckets. When creating a rocket furnace with your own hands, it is very important to observe accuracy and proportionality in size using drawings. This will guarantee a long and efficient operation of the do-it-yourself long-burning furnace.

The benefits of using homemade rocket stoves in everyday life are significant. The construction of the furnace does not require large economic costs (for materials, heating) and time (it takes a maximum of 3-4 days to manufacture the furnace).

High performance and heat transfer with unpretentious fuel loading is ideal. You can decorate the oven in any way you like, thereby adding a new interior element to the house.

To date, many types of furnaces of a wide variety of designs have been invented. For most of them, the rule applies: the higher the characteristics of the unit, the more skill and experience is required from the craftsman who makes it. But as you know, there are no rules without exceptions. In this case, the destroyer of stereotypes is a rocket stove - a very thoughtful economical heat generator with a simple design that does not require any special skills from the performer. The latter circumstance explains the popularity of the "rocket". Our article will help the reader to understand what is the highlight of this miracle of technology, and teach how to make it with your own hands from improvised materials.

What is a rocket stove and why is it good?

The rocket stove or jet stove got its impressive names only for the characteristic sound that it makes when the operating mode is violated (excessive air supply to the furnace): it resembles the roar of a jet engine. That's it, it has nothing more to do with missiles. She works, if you don’t go into details, just like all her sisters: firewood burns in the firebox, smoke is thrown into the chimney. Normally, the oven makes a quiet rustling sound.

Option for arranging a jet furnace

Where do these mysterious sounds come from? Let's talk about everything in order. Here's what you need to know about the rocket stove:

1. By appointment, it is a heating and cooking.
2. "Rocket" can be equipped with such an important and desired element like a couch. Other types of stoves with this option (Russian, bell-type) are much more bulky and complex.
3. Compared to conventional metal furnaces the operating time on one fuel tab has been slightly increased - from 4 to 6 hours. This is explained by the fact that this heat generator is based on a furnace with upper combustion. In addition, due to the presence of adobe plaster, the stove after the firebox gives off heat for another 12 hours.
4. The furnace was developed for operation in field conditions.

Design Benefits

• Energy independence.
• Simplicity of design: the most accessible parts and materials are used, if necessary, a simplified version of the rocket furnace can be assembled in 20 minutes.
• The ability to work with sufficiently high performance on low-quality raw fuel: bark, wood chips, thin raw branches, etc.

The principle of operation of the rocket furnace provides the user with a certain freedom in choosing its design. In addition, the unit can be built in such a way that only a small part of it remains visible and, in terms of aesthetics, minimal damage to the interior of the room will be caused.

As you can see, the jet furnace has something to brag about. But first of all, lovers of the furnace business are attracted by the combination of simplicity of design and good, although not the highest, characteristics when working on waste fuel. These very characteristics are the highlight of the "rocket". Let's try to understand how we managed to achieve such indicators.

The efficiency of a solid fuel heat generator depends on many factors, but perhaps the most determining factor is the degree of afterburning of pyrolysis gases. They appear as a result of thermal decomposition of fossil fuels. From heating, it seems to evaporate - large hydrocarbon molecules decompose into small, forming combustible gaseous substances: hydrogen, methane, nitrogen, etc. This mixture is often called wood gas.

Small Rocket Furnace

Liquid fuel, such as waste oil, decomposes into wood gas almost immediately and it burns right there - in the furnace. But with wood fuel, the situation is different. Decay solids to combustible volatile product- wood gas - occurs in several stages, and the intermediate stages also have a gaseous form. That is, we have the following picture: first, some intermediate gas is released from the wood, and in order for it to turn into wood gas, that is, it decays even more, it is necessary to extend the exposure to high temperature.

And the wetter the fuel is, the more “protracted” the process of complete decay becomes. But gases tend to evaporate: in a conventional furnace, the intermediate phase is mostly sucked out by draft into the chimney, where it cools down without having time to turn into wood gas. As a result, instead of high efficiency, we get carbon deposits from heavy hydrocarbon radicals.

In a rocket furnace, on the contrary, all conditions are created for the final decay and afterburning of the released intermediate gases. In essence, a very simple technique was used: immediately behind the firebox there is a horizontal channel with good thermal insulation. The gases in it do not move as fast as in a vertical pipe, and a thick heat-insulating coat does not allow them to cool. Due to this, the process of decay and afterburning is carried out in a more complete manner.

At first glance, this solution may seem primitive. But this simplicity is deceptive. Engineers and researchers had to tinker a lot with calculations in order to link the required thrust force with the optimal combustion regime and many other factors. Thus, the rocket furnace is a very finely tuned heat engineering system, in the reproduction of which it is very important to observe the correct ratio of the main parameters.

If the manufacture and adjustment of the unit were performed correctly, the gases will move as expected, while emitting a slight rustle; in case of violation of the regime or incorrect assembly of the furnace, instead of a stable gas vortex, an unstable one is formed in the gas duct, with numerous local vortices, as a result of which a roaring rocket sound will be heard.

Flaws

1. The jet furnace is manually operated, and the user has to constantly monitor and adjust it.
2. The surface of some elements is heated to high temperatures, so that if accidentally touched, the user may be burned.
3. The scope is somewhat limited. For example, a jet stove cannot be used in a bath, as it is not able to quickly warm up the room.

One more circumstance should be taken into account. It cannot be considered a disadvantage of the furnace, it is rather important feature. The fact is that the “rocket” was invented in the USA. And the citizens of this country, where any idea can bring good earnings, are not so willing to share their best practices, as was customary, for example, in the Soviet Union. In most drawings and diagrams that have become widespread, it is not displayed or distorted essential information. In addition, we simply do not have access to some of the materials used in it.

As a result, home craftsmen, especially those who do not know the intricacies of furnace business and heat engineering, instead of a full-fledged jet furnace, often get some kind of device that absorbs fuel in huge volumes and is constantly overgrown with soot. Thus, complete information about the rocket furnace has not yet become public property, and overseas pictures should be treated with great caution.

Here, for example, is our popular jet furnace scheme, which many are trying to use as a model.

Drawing: how the oven works

Drawing of a mobile furnace-rocket

At first glance, everything seems clear, but in fact, much remains “behind the scenes”.

For example, refractory clay is simply designated by the term Fire Clay - without specifying the grade. The mass ratio of perlite and vermiculite in the mixture from which the furnace body (in the diagram - Core) and the lining of the element called Riser are laid out is not indicated. Also, the diagram does not specify that the lining should consist of two parts with different functions - a heat insulator and a heat accumulator. Unaware of this, many users make the lining homogeneous, causing the performance of the furnace to drop significantly.

Varieties of jet furnaces

To date, there are only two types of furnaces of this type:

1. A full-fledged stationary heating and cooking rocket stove (it is also called a large one).
2. Small rocket stove: used for cooking during the warm season. Unlike the first option, it is portable and has an open firebox (it is supposed to be used outdoors). It is very popular among tourists, as it has a compact size and at the same time is able to develop power up to 8 kW.

The device of a small furnace-rocket

As already mentioned, the jet furnace is easy to manufacture, so we will consider a full-fledged option.

Design and principle of operation

The stove that we will try to make is shown in the figure.

Rocket oven: frontal section

As you can see, its combustion chamber (Fuel Magazine) is vertical and equipped with a tight-fitting lid (prevents excess air from being sucked in), like in a top-burning stove (the ash pan is designated by the term Primary Ash Pit). It was this unit that was taken as the basis. But the traditional top-burning heat generator works only on dry fuel, and the creators of the “rocket” wanted to teach it how to successfully digest wet fuel as well. For this, the following was done:

1. Was picked up optimal size blew (Air Intake), so that the amount of incoming air was sufficient for the afterburning of gases, but at the same time they did not cool down beyond measure. In this case, the principle of upper combustion provides a kind of self-regulation: if the fire flares up strongly, it becomes an obstacle to the incoming air.
2. A well-insulated horizontal channel was installed behind the firebox, called the Burn Tunnel or fire tube. To hide the purpose of this element, it was indicated on the diagram with a meaningless flame icon. Thermal insulation (Insulation) must have not only low thermal conductivity, but also low heat capacity - all thermal energy must remain in the gas stream. In the flame tube, the intermediate gas decomposes into wood (at the beginning of the section), which then burns out completely (at the end). In this case, the temperature in the pipe reaches 1000 degrees.
3. Behind the flame tube was installed vertical section, called the internal or primary chimney (Internal or Primary Vent). On the diagrams, secretive Americans often designate this element with the meaningless term Riser. In fact, the primary chimney is a continuation of the flame tube, but it was placed vertically to create an intermediate draft, and at the same time to reduce the horizontal part of the furnace. Like the flame tube, the primary chimney has a heat-insulating coating.

Note. It may seem to some of the readers familiar with the design of pyrolysis furnaces that it would be nice to supply secondary air to the base of the primary chimney. Indeed, the combustion of wood gas in this case would be more complete, and the efficiency of the furnace would be higher. But with such a solution, vortices are formed in the gas flow, as a result of which the toxic combustion products partially penetrate the room.

A capacious heat accumulator capable of withstanding such a temperature is fireclay brick (can withstand up to 1600 degrees), but the furnace, as the reader remembers, was intended for field conditions, therefore, a more accessible and inexpensive material. The leader in this regard is adobe (indicated by the term Thermal Mass in the diagram), but for it the temperature limit is 250 degrees. To cool the gases, a thin-walled steel drum (Steel Drum) was installed around the primary chimney, in which they expand. On the cover of this drum (Optional Cooking Surface) you can cook food - its temperature is about 400 degrees.

To absorb even more heat, a horizontal chimney with a bench (Airtight Duct) was attached to the stove, and only then - an external chimney (Exhaust Vent). The latter was equipped with a view, which closes after heating: it will not allow the heat from the gas duct of the couch to evaporate into the street.

So that the pipe inside the couch could be cleaned from time to time, a secondary ash chamber (Secondary Airtight Ash Pit) with a hermetically closing cleaning door was installed immediately behind the drum. The main part of the soot, due to the sharp expansion and cooling of gases, settles in it, therefore, cleaning the external chimney has to be done extremely rarely.

Since the secondary ash chamber has to be opened no more than twice a year, a simpler design can be used instead of a door - a screw-on lid with an asbestos or basalt cardboard gasket.

Furnace calculation

Before talking about the size of the furnace, let's draw the reader's attention to an important point. For all solid fuel heat generators, the square-cube law applies. Its essence can be explained with a simple example.

Imagine a cube with a side of 1 m. Its volume is m 3, and its surface area is 6 m 2. The ratio of volume to surface area is 1:6.

Let's increase the volume of the body by 8 times. It turned out a cube with a side of 2 m, the surface area of ​​\u200b\u200bwhich is 24 m 2.

Thus, the surface has increased only 4 times and now the ratio of volume to surface is 1:3. In furnaces, the amount of heat generated and its power depend on the volume, and heat transfer depends on the surface area. These parameters are interconnected, therefore, it is impossible to thoughtlessly scale one or another furnace scheme, adjusting it to the dimensions you need - the heat generator may even turn out to be inoperable.

When calculating a rocket furnace, the inner diameter of the drum D is set, which, as mentioned above, can vary from 300 mm (15 kW furnace) to 600 mm (25 kW furnace). This "fork" is precisely due to the square-cube law. We will also use a derived quantity - the area cross section drum S: S = 3.14 * D^2 /4.

Table: main parameters

Table: Maximum permitted flue length with bed

Table: secondary ash chamber volume

Intermediate values ​​are calculated proportionally (interpolate).

Materials and tools

The furnace drum can be made from a standard barrel with a volume of 200 l and a diameter of 600 mm. The square-cube law allows you to reduce the diameter of the drum up to 50%, so for a small oven this element can be made from a domestic gas cylinder or tin buckets.

The blower, firebox and primary chimney are made of round or shaped steel pipes. A significant wall thickness is not required - a couple of millimeters can be dispensed with - combustion in the furnace is weak. A chimney in a couch, through which gases follow in an already completely cooled form, can generally be made from metal corrugations.

For thermal insulation (lining) of the furnace part, fireclay bricks (fireclay crushed stone) and furnace clay will be required.

The outer coating layer (heat accumulator) will be made of adobe.

This is what freshly made adobe looks like

The thermal insulation of the primary chimney is made of light fireclay bricks (ShL grade) or river sand rich in alumina.

Parts such as lids and doors can be made from galvanized steel or aluminium. Asbestos or basalt cardboard is used as a sealant.

Preparatory work

As part of the preparatory work, it is necessary to cut all the available rolled products into blanks the right sizes. If it is decided to use a gas cylinder as a blank for the cap, the welded upper part must be cut off from it.

Preparing the gas cylinder for use as a cap

Note! If gas remains in the cylinder, it may detonate during cutting. For safety reasons, such containers are cut only after filling with water.

Note that in most cases, a rocket furnace is made from a cylinder. Such a unit is able to heat a room up to 50 m 2. The "rocket" from the barrel only in very rare cases has to be used at full capacity.

From the barrel, if the oven is made from it, it is also necessary to cut off the upper part. Further, two openings located opposite each other are cut out in a barrel or in a cylinder, through one of which a flame tube will be started, passing into the primary chimney, and a gas duct with a stove bench will be connected to the second.

Step-by-step instruction

Here is an approximate procedure that should be followed in the manufacture of this furnace:

Firebox manufacturing

The firebox is made welded using a steel pipe or sheets. The firebox lid must be hermetically sealed. It should be made from steel sheet, along the perimeter of which a strip of basalt cardboard is fixed with screws or rivets. For tighter closing, the lid can be equipped with a screw clamping mechanism.

This is how the firebox and ash pan look in the simplest rocket stove

The ash chamber (marked as Primary Ash Pit in the diagram) is separated from the main part of the furnace by a grate welded from a rod with a diameter of 8–10 mm. The grate should be installed on the shelves from the corner, which are welded to the inner walls.

The door of the ash chamber must also be airtight. It is made of steel sheet, to which a steel strip is welded in two rows around the entire perimeter. An asbestos cord or basalt cardboard is placed in the groove between these strips.

It remains to weld the flame tube to the firebox.

primary chimney

1. A 90-degree bend and a small piece of pipe must be welded to the pipe that serves as the primary chimney, after which this L-shaped structure is placed inside the barrel or cylinder, that is, the future drum.
2. The outlet with a piece of pipe welded to it should be led out into one of the openings in the lower part of the drum so that the primary chimney is located strictly in the center. Recall that the upper cut of the pipe must be located at least 70 mm below the upper edge of the barrel (cylinder).
3. After centering the primary chimney, its horizontal shank, which was brought out into the opening in the drum, is welded to its edges with a continuous seam around the entire perimeter.
4. After that, the shank of the primary chimney is welded to the flame tube, and a tire is welded to the top of the drum.
5. A short piece of pipe should be welded to the second opening in the drum, which will play the role of a secondary ash pan. In it you need to perform a window for cleaning. Studs must be butt welded along its edges, to which the lid will be screwed (recall that we decided not to install the door in this place, since it is rarely necessary to open it).
6. A strip of basalt cardboard should be fixed around the perimeter of the lid with screws or rivets.

Chimney installation

We weld the horizontal part of the chimney to the exit of the secondary ash pan, on which a stove bench will subsequently be arranged. If the gas duct is supposed to be made of metal corrugation, then first a short pipe must be welded to the ash pan, and already to it - attach the corrugation with a clamp.

At the final stage, an external chimney is attached to the horizontal flue.

Furnace lining

The metal part of the furnace is ready, now it needs to be properly plastered with heat-insulating and heat-accumulating compounds.

The lining of the furnace part (up to the primary chimney) should be carried out with a mixture of furnace clay and fireclay bricks, taken in a 1: 1 ratio.

Primary chimney lining

The materials used for lining the primary chimney - light fireclay bricks or river sand - are porous, therefore, in the open state, they will quickly become saturated with soot and lose thermal insulation properties. To prevent this, the lining on the primary chimney is protected with a thin-walled steel casing, and coated with kiln clay from the ends.

In accordance with the square-cube law, the ratio of the volume and surface area of ​​the drum depends on its diameter, therefore, the lining of the primary chimney, depending on the size of the furnace, is made differently. Three options are shown in the figure.

Primary chimney lining options

If the lining is made with fireclay bricks, the cavities between its fragments must be filled up building sand. If river sand rich in alumina is used, one has to resort to more complex technology:

1. The sand is cleaned of large debris (careful preparation is not required).
2. A layer of small thickness is poured into the casing, it is rammed and moistened so that a crust forms.
3. The subsequent layers are poured in the same way. There should be 5 to 7 in total.
4. The sand lining is dried for one week, then its top is covered with kiln clay and the kiln manufacturing is continued.

The last step is to coat all parts of the oven with adobe. It is prepared from the following ingredients:

• clay;
• straw (14–16 kg per 1 m 3 of clay);
• sand (in a small amount);
• water.

The stated ratio of straw to clay is approximate. In some varieties of straw clay, more can be added, in others, on the contrary, its amount has to be reduced.

Ways to improve the jet furnace

Instead of a stove bench on the flue, you can build a water jacket that will be connected to the water heating system. This part can also be made in the form of a coil from a copper pipe wound around a chimney.

Scheme of a rocket furnace with a water circuit

Another way to improve is to organize the supply of heated secondary air to the flame tube.

Drawing of a rocket stove from a cylinder with secondary air supply

With this design, the efficiency of the furnace will be higher, but soot will be deposited more intensively in the primary chimney. To make it easy to remove, the drum cover must be made removable. Naturally, it must be equipped with a seal.

An improved version of the balloon rocket furnace

How to heat a rocket stove

A rocket stove, like top burning heat generators, only works at high performance if its chimney is hot enough. Therefore, before loading the main fuel into the furnace, the unit must be warmed up well (unless, of course, there has been a long downtime and the furnace has had time to cool down). For this, any “fast” fuel is used, for example, sawdust, paper, straw, etc., which is placed in the blower.

The fading of the hum or a change in its tone indicates that the stove is warm enough and the main fuel can be put into the furnace. It is not necessary to set it on fire - it will flare up from the coals left after the “fast” fuel burns out.

Melt the furnace-rockets through the firebox

A jet furnace cannot adjust to external conditions and fuel quality, like, for example, Bullerjan. The adjustment must be made by the user. After laying the main fuel, the blower damper must be fully opened, and as soon as the unit hums, it must be closed until a rustling sound appears.

In the future, as the fuel burns, the damper has to be covered more and more, still achieving a quiet rustle. If you miss the right moment, an excess amount of air will begin to enter the furnace and pyrolysis in the flame tube due to the cooling of the intermediate gas mixture stop. At the same time, the stove will remind you of itself with a “rocket” rumble.

Video: how to make a long-burning jet furnace with your own hands

They tried to create a jet or rocket stove as simple as possible, and this only plays into the hands of a home craftsman. However, it is by no means possible to make this heat generator at random, as can be seen from our article - instead of a rocket, the master will receive an ordinary potbelly stove, very voracious and constantly overgrown with soot. It is important to observe all the above ratios of parameters and then you will get a productive rocket furnace with quite decent characteristics.

Simple stove options for heating a room, heating food and water are always popular, especially with home craftsmen who tend to make such units on their own. Such designs include a rocket stove that runs on wood, and does an excellent job of the tasks assigned to it, while not requiring complex materials for manufacturing. Today we will take a closer look at the design of such an interesting heater, as well as provide drawings and videos in order to make a do-it-yourself rocket stove.

Principle of operation

Before proceeding with the manufacture of the unit, you should consider in detail the principle of its operation. I would like to clarify right away that a rocket stove for a home has nothing to do with a jet engine and space flights. A similar name for the furnace was given by the people due to its unusual appearance: the unit is very similar to an inverted rocket and emits a characteristic buzz during operation.

The buzz appears at the stove only during a certain mode of operation, when too much oxygen is supplied to the firebox. Please note that if your oven hums too loudly or makes an unusual roar, this indicates incorrect, uneconomical and inefficient operation. The correct operation of the rocket furnace is accompanied by a barely audible rustle.

A portable rocket stove is very often taken with you on a hike to heat food.

Thermal units of this type, depending on the scope of application, can be divided into:

• Portable;
• Stationary.

The former are mainly used in field conditions They are mobile, easy to transport and do not take up much space. The second type of construction is more capital. It is used for indoor installation, for heating a room or for heating food.

The principle of operation of a rocket furnace is easiest to show by the example of the simplest tourist firebox "Robinson". The design is an inverted pipe in the form of the letter "G".

In that part of the pipe, which is in a horizontal position with respect to the surface of the earth, solid fuel(firewood, chips), then the fuel is ignited from the side of the vertical part of the pipe.

A thrust is created in the transition channel, which increases as the fuel warms up, and therefore, for efficient operation, it is necessary to shut off the air supply from the outside. If the air supply is not limited, the wood will burn out in vain, and no heat energy will be obtained as a result.

Even the simplest rocket stove is capable of heating water in a large container in a matter of minutes. If the upper part of the pipe is properly insulated, it will be possible to burn thick logs in the device and heat a large area.

Types of rocket furnaces

Depending on the type of construction, rocket furnaces are divided into:

• Rocket furnace with water circuit (with proper arrangement can replace a full-fledged solid fuel boiler);
• Rocket stove from a gas cylinder;
• Rocket furnace "Ognivo - Boss";
• A simple brick rocket stove with a bench;
• Hiking options from metal pipes.

General view of a rocket furnace made from a gas cylinder

Advantages and disadvantages

The advantages of a rocket-type furnace include:

• High heat output, which in some cases reaches 18 kW;
• High efficiency;
• Super-efficient work, which is characterized by complete burnout of firewood, coals and soot loaded inside;
• To ensure combustion, even waste from the woodworking industry (chips, leaves, twigs, branches, leaves, regardless of the degree of humidity) is suitable;
• Economical combustion and low consumption of wood;
• Tall temperature regime at the exit (heating of a large container of water is carried out in a few minutes).

Along with the advantages, furnaces of this type also have disadvantages:

• Installing a water heating coil reduces the thermal efficiency of the furnace;
• The continuous combustion cycle makes it impossible to install a rocket stove in garages and baths;
• The small size of the firebox does not allow loading a large amount of fuel at once; to ensure long-term burning, a constant lining of firewood is made.

How to make a DIY rocket stove

Many decide to install a rocket stove due to the ability to make it from improvised means. Such a furnace does not require expensive materials and components, while it stands out among others. wood stoves original design.

To make a furnace, it is enough to understand at least a little the drawings and be able to work with your hands. Especially for home craftsmen, we will consider several options for making a rocket stove.

Marching from a profile pipe

This design stands out for its maximum simplicity, so it is with it that you can begin work on mastering the technology of building rocket furnaces. At right approach The entire production process will take no more than 3-4 hours.

The manufactured oven will have small dimensions and weight, which is why it is convenient to take it with you on hikes and fishing trips.

We will consider a slightly more complicated version of the rocket furnace, due to the additional part, the process of further use of the unit will be greatly facilitated. We are talking about a small metal plate with a grate that can be removed for easy loading of firewood.

To make an oven, you need to prepare the following items:

• Two pieces of a square pipe measuring 15 by 15 cm (metal thickness - 3 mm). The length of one pipe is 45 cm, the other is 30 cm;
• 4 strips of steel 3 mm thick and 30 by 5 cm in size;
• 2 steel strips 3 mm thick and measuring 14 by 5 cm.
• A metal grate with dimensions of 30 by 14 cm. If a grate of suitable dimensions could not be purchased, you can make it yourself from steel bars.

The camping stove-rocket is made in the form of a bent pipe section

The production of the furnace includes the following steps:

1. We mark two pipes for further cutting with a grinder at an angle of 45 degrees;
2. We connect the pipes to each other with cut sides and weld;
3. At the top of the vertical pipe, we make 4 cuts at the corners, insert prepared strips of steel into them to form a cross, weld the structure;
4. We make a frame for a retractable grate from the remaining steel strips, put a grate on the frame and weld;
5. We check the oven for operability;
6. When the unit is completely cool, paint it with heat-resistant paint to give an attractive appearance.

The design can be slightly improved by welding a handle to the retractable grate.

Some craftsmen make a rocket stove right in the field from two soda cans. Such an oven gives a minimal amount of heat, but it will be enough to heat dinner or a glass of water.

From a gas bottle

For the manufacture of a rocket furnace from a gas cylinder, the scheme of which is shown in the figure, you will need:

• 80 cm steel pipe with a diameter of 158 mm and a metal thickness of 4 mm;
• 150 cm steel pipe with a diameter of 127 mm and a wall thickness of 3.4 mm;
• Profile pipe 100 cm long, 12 by 12 cm in size and 4 mm thick wall;
• 2 empty gas cylinders;
• Sheet metal;
• Steel bars;
• Material for thermal insulation;
• Metal pipe with a diameter of 12 cm for the chimney.

Scheme of a gas cylinder furnace with dimensions

The production process includes the following steps:

1. We cut the profile pipe into two parts. One should have a length of 30 cm, the second - 35 cm. In the second pipe, we cut a hole for the firebox and for the vertical pipe of the future stove;
2. We cut the remaining piece of the profile pipe along, weld it to the firebox (it will serve as an air supply hole);
3. We weld the firebox to a vertical pipe;
4. We make doors for the furnace and ash pan;
5. We check the performance of the manufactured structure (primary chamber), wait for it to cool;
6. With the help of a grinder, we cut a hole for the firebox in the lower gas cylinder. We weld a pipe with a diameter of 120 mm, which will serve as a chimney, in the lower part of the pipe we make a hole for cleaning the chimney;
7. We weld a piece of a pipe of a slightly larger diameter to the chimney, weld a firebox to the cylinder;
8. In the space formed in the cylinder between the pipe and the surface of the cylinder, we pour perlite, which acts as a thermal insulator;
9. At the second cylinder, we cut off the bottom with a grinder, weld a hole near the valve, the design will act as a container for igniting gases;
10. We connect all the parts of the stove together.

A more detailed process of manufacturing a rocket furnace from a gas cylinder is discussed in the video.

Video: rocket stove from a gas cylinder

From bricks

The diagram of the simplest rocket furnace is shown in the figure.

The simplest design involves the presence of 21 bricks

To build an improved structure, you will need about 20-30 bricks and dry clay.

From the bricks we add the structure, as in the picture. By appearance it resembles a rocket that is ready to launch.

Clay is used to give the structure strength and stability.

We check the oven for operability, wait until the bricks cool down, and coat them with prepared clay. The manufacturing process has been completed. Once the clay is completely dry, the oven can be used.

Video: oven rocket of twenty bricks

Long burning design

The best option for a long-burning stove is a stove with a stove bench. This design is perfect for heating a small room.

A long-burning rocket stove is a great option for heating your home.

The manufacturing process includes the following steps:

1. The place where the firebox will subsequently be located is deepened into the ground by 10 cm, a refractory stone is placed in the resulting recess;
2. A formwork is installed along the perimeter of the masonry, a reinforcing mesh is laid on the bottom;
3. The lower part of the future working chamber is laid on the same level with the installed formwork, the structure is poured with concrete;
4. The constructed part is left for a day until the concrete is completely solidified, then the base of the furnace and the combustion chamber are formed;
5. The walls of the future furnace gradually rise along the perimeter;
6. The lower channel of the rocket furnace is being laid;
7. The constructed structure is sheathed with bricks, except for the places where the firebox and raiser will be located;
8. A metal container (an iron barrel or a gas cylinder is suitable) is cut off with a grinder on both sides, coated with a primer and painted with heat-resistant paint, a pipe cuts into the lower part;
9. A branch is welded to the chimney pipe, which will play the role of an ash pan;
10. A fire tube is laid out of brick in the form of a square;
11. In the resulting gap between the metal container and the masonry, heat-insulating material is poured;
12. The body of the future furnace is being formed, all brick surfaces are cleaned with clay, the future contour of the stove-bed is being laid;
13. The operation of the furnace is checked;
14. All gaps are sealed, the shape of the couch is formed, and adobe is covered on top.

How to heat the stove correctly

If no special preparation is required for the firebox of mobile rocket furnaces, then in order for the long-burning furnace to work at the limit of its capabilities, it is necessary to preheat it. Such an event also reduces the degree of pollution of the chimney.

It is most convenient to warm up the oven with paper sheets, wood chips and sawdust. The degree of heating is estimated by the emerging hum in the channel. Initially, the hum will be strong, this indicates high traction and low temperature, according to the degree of noise reduction, we can talk about an increase in temperature in the furnace.

To warm up the rocket stove, it is best to use small chips and sawdust.

As soon as the noise began to decrease, the main fuel is loaded into the furnace. After 15 minutes, the damper begins to gradually close. The gap must be adjusted so that a barely audible rustling comes from the oven.

There are plenty of successful designs of rocket furnaces on the net, while the authors are often guided more by intuition than technical calculations. The main thing is to stick to the "L-shaped" type of design, and then everything depends only on your imagination.

Be sure to check the operation of the furnace at a preliminary stage.