Rocket stove for a bath. Self-production of a rocket-type furnace
Among the variety of wood stoves special attention deserves such a thermal device as a homemade rocket stove. It is distinguished by its original design, which does not require expensive materials and components in its manufacture. Any person who has at least the slightest understanding of drawings and knows how to work with his hands can make such a stove. Our article should come to the aid of such home craftsmen, where we will talk about the design and operating principle of the rocket stove. Recommendations for its manufacture from various materials will also be given here.
Operating principle of a rocket furnace
Although the design of a rocket stove is quite simple, it successfully uses two operating principles borrowed from other types of solid fuel heating devices:
- the principle of afterburning wood gases released during combustion (pyrolysis);
- the principle of free flow of gases through the channels (without encouragement from the natural draft of the chimney).
Note. In the simplest rocket stoves for cooking, including portable ones, only the second principle operates, since favorable conditions are not created in them for the pyrolysis process to occur.
First, we will analyze the design of direct combustion rocket stoves, intended only for cooking food. Here the firebox is a short horizontal section of pipe, which then turns upward. The design is simple to the point of disgrace, as shown in the figure:
The fuel is placed in the pipe and ignited, resulting in an upward flow of hot gases, tending to rise along the vertical section and exit outside. Here, at the cut of the pipe, a container for food or water is installed. Of course, there is a gap between the pan and the pipe for combustion products to escape. This is achieved through various metal stands.
For reference. The above rocket stove device is one of the first. It is because of the upward-turned nozzle with a flame escaping from it that the device received the name rocket.
Since it is impossible to heat rooms with such a unit, the design of the heating rocket stove was supplemented with a heat exchange device and channels for removing flue gases. To maintain a high temperature in the vertical section of the pipe, it is insulated with any fire-resistant material. Further, for intensive heat extraction, the nozzle is covered from above with a cap, for example, an ordinary metal barrel. At the bottom of the fire horizontal pipe a separate channel is provided for supplying secondary air.
Now the principle of operation of a rocket furnace looks somewhat different. Firstly, at the end of the horizontal fire channel, afterburning of pyrolysis gases occurs due to the supply of secondary air. Secondly, combustion products that have a high temperature accumulate under the top of the bell (barrel), creating some excess pressure. As heat is transferred outward through the metal walls, these gases cool and flow downward.
Since the cooling gases are supported from below by a new hot flow, they cannot descend in the same way, but pass through the space between the walls of the pipe and the barrel, safely exiting into the chimney channel. The flow of processes is well reflected in the diagram of a rocket furnace:
So, thanks to pyrolysis, the efficiency of wood combustion increases, and the use of free flow of gases creates a self-regulating system that limits the flow of fresh air into the firebox. The air mixture is supplied as the combustion products cool under the hood, making room for its new portion. Excessive pressure of hot gases “pushes” the cooled part out, so the operation of the stove depends little on the presence of draft in the chimney.
Efficient heat extraction
The gases entering the chimney duct are still at a high temperature. It is not advisable to simply throw them outside; everyone will understand that the efficiency of such an installation will be too low. Taking advantage of the fact that the rocket stove literally pushes combustion products out, craftsmen have come up with 2 ways to extract heat:
- passing gases through channels arranged under the stove bench;
- installing a water circuit on the stove.
A rocket stove with a water circuit is made without a hood; the force of the upward flow of combustion products is used in a multi-pass heat exchanger made of metal. It is not recommended to introduce a coil with water into the gas flow; it will not last long because it is too high temperature. It would be more correct to make a water jacket with metal fins inside the flue, as shown in the diagram:
Another way is to lay horizontal chimney ducts out of brick directly along the floor surface and place a luxurious heated adobe bench on top, connecting a rocket-type stove to it. What is important here is the correct selection of the length of the channels so that the excess pressure is enough to overcome them, otherwise you will still have to take care of organizing natural draft.
Advantages and disadvantages
Homemade long-burning rocket stoves have many admirers, and for the following reasons:
- simplicity and low cost of installation: to build such a thermal device, you do not need to incur large expenses for the purchase of expensive materials, fixtures and fittings. Experience in furnace business minimum is also required;
- self-regulation and undemanding natural craving chimney;
- The efficiency of the rocket furnace is a variable value and largely depends on the design, the main thing is to extract as much thermal energy as possible from the flue gases;
- fuel can be added on the fly.
Despite the attractiveness and simplicity of the unit, heating with a rocket stove has its negative aspects. It is a mistake to think that you can shove firewood of any quality into the firebox. Wet wood will not provide the required temperature in the chamber, and the pyrolysis process will not proceed. In the worst case scenario, smoke from the furnace can pour into the room. Also, the “rocket” requires constant supervision, especially in terms of fire safety.
Self-made rocket stoves are unsuitable for a bathhouse, since they give off relatively little heat in the infrared range, which is very important for a steam room. The surfaces of the stove that emit heat have too small an area and it will not be possible to heat the bathhouse properly.
For reference. A factory-made metal Robinson rocket stove is often used as a portable heat source. The craftsmen were not at a loss here either and quickly modernized this product, making the same thing, only with a grate.
Stove from a cylinder
This is one of the most simple options, to implement it you can use the drawing below. A propane cylinder with a diameter of 300 mm will serve as an excellent cap, and a steel pipe measuring 150 mm will play the role of a firebox and loading hopper. The internal vertical channel is made of a pipe with a diameter of 70 mm, and the chimney is 100 mm.
The structure is completely welded, the pipes are cut to the required length, and the upper part of the cylinder is cut off. Then the parts are welded according to the drawings, only the opening between the vertical pipes with a diameter of 70 and 150 mm is filled with bulk heat-insulating material. This role can be perlite or vermiculite, or, in extreme cases, ordinary sand.
If there is an opportunity and desire to make a more powerful rocket stove, then a standard 200 liter barrel is used as a hood, then the dimensions of all parts also increase. Working inner tube is accepted with a diameter of 129 mm (or profile 120 x 120 mm), and the outer one is 450 mm in size. It is difficult to find a pipe of this diameter, so usually they find another barrel of smaller capacity and cut off the bottom of it.
The entire assembled rocket stove made from a gas cylinder is not very heavy, so there is no need to build a massive foundation for it. When the unit is placed on the floor, the legs are welded to it, and if a bench is subsequently planned, the structure will have to be coated with a refractory compound, and then the external lining will be done. Then basalt cardboard and a sheet of roofing iron are laid on the floor below.
Brick oven
In terms of its design, a brick rocket stove is not much different from a metal one, but requires a lot of labor. The difference is that all the fire channels of the unit are made of fireclay bricks, and the cap is made from the same barrel.
It is recommended to lower the entire structure, except for the protruding cap, below floor level, for which a shallow hole is dug. Its bottom is compacted, and then a small concrete foundation 100 mm thick. After it hardens, they begin laying, using a solution of refractory clay. After finishing the laying and hardening of the solution, the hole is filled up, and an iron barrel without a bottom is placed on top of the fire channel, the cavity between it and the brick is filled with insulation.
The end of the structure is coated with the same solution, and then the largest barrel - a cap - is put on top. A chimney pipe is welded to its lower part; drawings of a rocket stove are used to clarify all dimensions.
Conclusion
With all its advantages, a home-made rocket stove cannot serve as a full-fledged heat source for heating an entire house. It makes sense to start such construction when it is necessary to organize heating small dacha or another similar building, especially since the “rocket” is not afraid of periodic work.
Today, many types of stoves of various 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 making it. But, as we know, there are no rules without exceptions. In this case, the destroyer of stereotypes is the rocket stove - a very well-thought-out, 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 understand what the highlight of this miracle of technology is and teach how to make it with your own hands from scrap materials.
What is a rocket stove and why is it good?
The rocket stove or jet stove received its impressive names only for the characteristic sound that it makes when the operating mode is violated (excessive air supply to the firebox): it resembles a roar jet engine. That's all, it has nothing more in common with rockets. It works, if you don’t go into details, the same way as all its sisters: wood burns in the firebox, smoke is thrown out into the chimney. Normally, the oven makes a quiet rustling sound.
Reaction furnace arrangement option
Where do these mysterious sounds come from? Let's talk about everything in order. Here's what you should know about the rocket stove:
Design advantages
The operating principle of the rocket stove provides the user with a certain freedom in choosing its design. In addition, the unit can be constructed in such a way that only a small part of it will remain visible and, in terms of aesthetics, minimal damage will be caused to the interior of the room.
As you can see, the jet stove has something to brag about. But first of all, stove lovers 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 due to the thermal decomposition of organic fuel. When heated, it seems to evaporate - large hydrocarbon molecules break up into small ones, forming flammable gaseous substances: hydrogen, methane, nitrogen, etc. This mixture is often called wood gas.
Small rocket stove
Liquid fuel, for example, waste oil, breaks down into wood gas almost immediately and it burns right there - in the firebox. But with wood fuel the situation is different. The decomposition of solids into a volatile product suitable for combustion - wood gas - occurs in several stages, with intermediate stages also having a gaseous form. That is, we have the following picture: first, a certain intermediate gas is released from the wood, and in order for it to turn into wood gas, that is, to disintegrate even more, it is necessary to prolong its exposure to high temperature.
And the more humid the fuel is, the more “prolonged” the process of complete disintegration 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 soot from heavy hydrocarbon radicals.
In a rocket furnace, on the contrary, all conditions are created for the final disintegration 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 quickly as in a vertical pipe, and the thick heat-insulating coat does not allow them to cool. Thanks to this, the process of decomposition and afterburning is carried out more fully.
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 mode and many other factors. Thus, a rocket stove is a very finely tuned thermal system, when reproducing it it is very important to maintain the correct ratio of the main parameters.
If the manufacture and adjustment of the unit were carried out correctly, the gases will move as expected, while emitting a slight rustling sound; if the regime is violated or the furnace is assembled incorrectly, instead of a stable gas vortex in the gas duct, an unstable one is formed, with numerous local vortices, as a result of which a roaring rocket sound will be heard.
Flaws
One more circumstance should be taken into account. It cannot be considered a disadvantage of the stove; rather, it is 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 money, are not as willing to share their work as was customary, for example, in the Soviet Union. Most of the drawings and diagrams that have become widespread do not display or distort the most important 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 stove making and heating engineering, often end up with a device that absorbs fuel in huge volumes and is constantly overgrown with soot instead of a full-fledged jet stove. Thus, full information about the rocket stove has not yet become public property and overseas pictures should be treated with great caution.
Here, for example, is our popular jet furnace design, which many are trying to use as a model.
Drawing: how the oven works
Drawing of a mobile rocket oven
At first glance, everything seems clear, but in fact, much remains “behind the scenes.”
For example, fire clay is simply labeled with the term Fire Clay - without specifying the grade. The mass ratio of perlite and vermiculite in the mixture from which the body of the furnace (in the diagram - Core) and the lining of the element called Riser is not indicated. Also, the diagram does not specify that the lining should consist of two parts with different function- heat insulator and heat accumulator. Without knowing this, many users make the lining homogeneous, which is why the performance of the furnace drops significantly.
Types of jet furnaces
Today there are only two types of furnaces of this type:
Design of a small rocket stove
As already mentioned, a jet stove is easy to manufacture, so we will consider a full-fledged option.
Design and principle of operation
The stove we will try to make is shown in the picture.
Rocket stove: frontal section
As you can see, its combustion chamber (Fuel Magazine) is vertical and is equipped with a tightly closing lid (prevents the leakage of excess air), as in a top-burning stove (the ash pit is designated the Primary Ash Pit). It was this unit that was taken as the basis. But a traditional top-burning heat generator operates only on dry fuel, and the creators of the “rocket” wanted to teach it to successfully digest wet fuel. To do this, the following was done:
Note. To some of the readers familiar with the device pyrolysis ovens, it may seem that it would be a good idea to supply secondary air to the base of the primary chimney. Indeed, the combustion of wood gas would be more complete, and the efficiency of the stove would be higher. But with this solution, vortices are formed in the gas flow, as a result of which toxic combustion products partially penetrate into the room.
A capacious heat accumulator capable of withstanding such temperatures is fireclay brick (withstands up to 1600 degrees), but the stove, as the reader remembers, was intended for field conditions, so a more accessible and inexpensive material was needed. The leader in this regard is adobe (denoted in the diagram by the term Thermal Mass), but its 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. You can cook food on the cover of this drum (Optional Cooking Surface) - its temperature is about 400 degrees.
To learn more more heat, a horizontal chimney with a stove bench (Airtight Duct) was connected to the stove, and only then an external chimney (Exhaust Vent). The latter was equipped with a view that closes after heating: it will not allow the heat from the gas duct of the stove to evaporate into the street.
So that the pipe inside the stove could be cleaned from time to time, a secondary ash chamber (Secondary Airtight Ash Pit) with a hermetically sealed cleaning door was installed immediately behind the drum. The main part of the carbon deposits, due to the sharp expansion and cooling of gases, settles in it, so 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, instead of a door, a simpler design can be used - a screw-on lid with a gasket made of asbestos or basalt cardboard.
Furnace calculation
Before talking about the dimensions of the oven, we draw the reader’s attention to important point. The square-cube law applies to all solid fuel heat generators. 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. The result is a cube with a side of 2 m, the surface area of which is 24 m 2.
Thus, the surface area has only increased 4 times and now the volume to surface ratio is 1:3. In furnaces, the amount of heat released and its power depend on the volume, and heat transfer depends on the surface area. These parameters are interconnected, so you cannot thoughtlessly scale this or that furnace design, adjusting it to the dimensions you need - the heat generator may turn out to be inoperable altogether.
When calculating a rocket furnace, the internal diameter of the drum D is specified, 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 value - the cross-sectional area of the drum S: S = 3.14 * D^2 /4.
Table: main parameters
Table: maximum permissible length of the flue with a stove bench
Table: volume of the secondary ash chamber
We calculate intermediate values proportionally (interpolate).
Materials and tools
The furnace drum can be made from a standard barrel with a volume of 200 liters and a diameter of 600 mm. The square-cube law allows you to reduce the drum diameter by up to 50%, so for small oven this element can be made from a household gas cylinder or tin buckets.
The blower, firebox and primary chimney are made of round or profile steel pipes. Significant wall thickness is not required - you can get by with a couple of millimeters - combustion in the furnace is weak. The chimney in a stove bench, through which gases flow in a completely cooled form, can generally be made from metal corrugation.
For thermal insulation (lining) of the furnace section, you will need broken fireclay bricks (fireclay crushed stone) and oven clay.
The outer coating layer (heat accumulator) will be made of adobe.
This is what freshly prepared adobe looks like
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 aluminum. Asbestos or basalt cardboard is used as a sealant.
Preparatory work
Within preparatory work it is necessary to cut all available rolled products into blanks required sizes. If you decide to use a gas cylinder as a blank for the cap, you need to cut off the welded upper part from it.
Preparing a gas cylinder for use as a hood
Note! If there is gas left 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 stove is made from a cylinder. Such a unit is capable of heating a room up to 50 m2. A “rocket” from a barrel only has to be used at full power in very rare cases.
From the barrel, if the stove is made from it, it is also necessary to cut off the top part. Next, two openings located opposite each other are cut out in the barrel or in the cylinder, through one of which the fire pipe will be inserted into the primary chimney, and the 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 when making this stove:
Making a firebox
The firebox is welded using steel pipe or sheets. The firebox lid must close tightly. It should be made of a steel sheet, around the perimeter of which a strip of basalt cardboard is fixed with screws or rivets. For a tighter closure, the lid can be equipped with a screw clamping mechanism.
This is what the firebox and ash pan look like in a simple rocket stove
The ash chamber (indicated in the diagram as Primary Ash Pit) is separated from the main part of the firebox by a grate welded from a rod with a diameter of 8–10 mm. The grille should be installed on corner shelves that are welded to the inner walls.
The door of the ash chamber must also be airtight. It is made from a steel sheet, to which a steel strip is welded in two rows along the entire perimeter. An asbestos cord or basalt cardboard is placed in the groove between these strips.
All that remains is to weld the fire tube to the firebox.
Primary chimney
Chimney installation
We weld the horizontal part of the chimney to the outlet of the secondary ash pan, on which the stove bench will subsequently be installed. If the flue is supposed to be made of metal corrugation, then first you need to weld a short pipe to the ash pan, and then attach the corrugation to it using a clamp.
On final stage An external chimney is attached to the horizontal flue.
Furnace lining
The metal part of the stove is ready; now it needs to be properly plastered with heat-insulating and heat-accumulating compounds.
The lining of the combustion part (up to the primary chimney) should be done with a mixture of stove clay and broken fireclay bricks, taken in a 1:1 ratio.
Primary chimney lining
Materials used for lining the primary chimney - light fireclay bricks or river sand- are porous, so when open they will quickly become saturated with soot and lose their thermal insulation properties. To prevent this, the lining on the primary chimney is protected with a thin-walled steel casing, and the ends are coated with oven clay.
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 is made differently depending on the size of the furnace. 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 construction sand. If river sand rich in alumina is used, you have to resort to more complex technology:
The last step is to coat all parts of the stove with adobe. It is prepared from the following ingredients:
The straw to clay ratio shown is approximate. In some types of clay, more straw can be added, in others, on the contrary, its amount must be reduced.
Ways to improve the jet furnace
Instead of a couch on a gas duct, you can build a water jacket that will be connected to a water heating system. This part can also be made in the form of a coil made of copper pipe, wound around the chimney.
Scheme of a rocket furnace with a water circuit
Another method of improvement is to organize the supply of heated secondary air to the flame tube.
Drawing of a rocket stove from a cylinder with a secondary air supply
With this design, the efficiency of the stove will be higher, but soot will be more intensively deposited 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 rocket stove from a cylinder
How to fire a rocket stove
A rocket stove, like top-burning heat generators, operates at high performance only if its chimney is hot enough. Therefore, before loading the main fuel into the firebox, the unit must be warmed up well (unless, of course, there has been a long downtime and the stove has had time to cool down). To do this, use any “fast” fuel, for example, sawdust, paper, straw, etc., which is placed in the ash pit.
The subsidence of the hum or a change in its tone indicates that the stove is sufficiently warmed up and the main fuel can be added to the firebox. There is no need to set it on fire - it will flare up from the coals remaining after the burning of the “fast” fuel.
Melt the rocket stove through the firebox
A jet stove, like a Bullerjan, cannot adjust to external conditions and fuel quality. The adjustment must be made by the user. After adding the main fuel, the ash flap must be fully opened, and as soon as the unit begins to hum, close it until a rustling sound appears.
In the future, as the fuel burns, the damper has to be closed 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 fire tube will stop due to the cooling of the intermediate gas mixture. At the same time, the stove will remind you of itself with a “rocket” hum.
Video: how to make a long-burning jet stove with your own hands
They tried to create a jet or rocket stove that was extremely simple and would only benefit the home craftsman. However, as can be seen from our article, it is under no circumstances possible to make this heat generator at random - 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 given parameter ratios and then you will get a productive rocket stove with quite decent characteristics.
Drawings and videos of a rocket stove required for DIY installation
Do-it-yourself jet stove: diagram, drawings, step-by-step instructions for making a rocket stove, etc. + video
The jet stove or rocket stove appeared as a result of a deviation from the traditions of manufacturing equipment for heating a room. It is considered an economical heat generator, the design of which is elementary. Therefore, many people are thinking about building a jet furnace with their own hands.
Description, advantages and disadvantages of the rocket stove
A heat generator for heating the air in a room is called a rocket stove or jet stove, since during operation, in case of excessive air supply, it makes 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.
A rocket stove serves as a device for heating a home and cooking food. 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 a top-burning furnace.
The flame from the jet furnace may burst out
The advantages of the rocket stove include:
- independence from fuel energy;
- simplicity of design consisting of available parts, connected in 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 burns, because the walls of the equipment become extremely hot;
- It is inappropriate to use in a bathhouse, since it cannot be warmed up.
Kinds
A unit that emits a rocket-like hum during operation can be:
- portable (a unit made of metal pipes, buckets or a gas cylinder); Portable rocket stoves are mass-produced by industry
- stationary (made from fireclay bricks and metal containers); Such a unit is more difficult to build than a metal furnace
- equipment for heating air with a stove bench. The stove bench is equipped behind the back wall of the stove
Portable structures are made in large quantities, because they are used for hiking. The basis of these heat generators is a pipe made up of several sections.
True, such structures, unlike units based on fireclay bricks, are not reliable. Walls made of refractory blocks increase the heat transfer of the jet furnace.
If desired, you can add a bed in the form of a sofa or bed, decorated with clay or sawdust.
Parts and operation of a jet heat generator
A basic rocket furnace is a device consisting of two pipe fragments connected by a bend at an angle of 90 degrees.
The combustion chamber in this heat generator is usually a zone in the horizontal part of the structure.
But sometimes fuel is placed in the vertical section of the apparatus, for which a rocket stove is constructed from two pipes of different lengths, mounted vertically and connected by a common horizontal channel.
Primary and secondary air passes through the furnace
The operation of a jet stove is based on two actions: the unhindered passage of wood gases through the pipe and the afterburning of gases produced during fuel combustion.
Wood chips and firewood are placed in the firebox of this heat generator after a highly flammable material such as paper ignites. A container with water or other contents is placed on the open section of the pipe.
In this case, between the structure and the installed container there is left small space necessary to create traction.
The processes occurring inside a stationary reactive furnace resemble the operation of pyrolysis heating units
Calculation of parameters (tables)
The volume of the furnace should be determined wisely, because it is it that affects the power and amount of heat generated by the heating equipment.
When calculating the dimensions of jet heating equipment, use the indicator internal diameter drum D, the value of which can vary between 300–600 mm. You also need to know the cross-sectional area of the drum.
To determine this indicator of the rocket stove, use the formula: S = 3.14 * D2 /4.
The main dimensions of the jet furnace are presented in the table:
Particular importance is attached to the length of the flue with the stove bench. The maximum permissible values 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 non-standard furnace
The production of jet heating equipment will require:
- barrels with a volume of 200 liters and a diameter of 0.6 meters, an empty liquefied gas cylinder or tin buckets to build a furnace drum;
- square or round pipes made of steel 2–3 mm thick, which are needed to create a blower, combustion chamber and primary chimney;
- fireclay crushed stone and oven clay as thermal insulation materials;
- adobe, which serves as the outer coating layer;
- fireclay bricks;
- sand from the bottom of the river;
- pieces of sheets of zinc-coated steel or aluminum for the manufacture of lids and doors;
- asbestos or basalt cardboard, which serves as a sealant.
The tools you will need to build a rocket furnace are: welding machine. And if you plan to make heating equipment from bricks, then you will have to take:
- Master OK;
- mortar spatula;
- hammer-pick;
- jointing;
- sharp-angled sledgehammer;
- level;
- plumb line;
- roulette
Preparation for assembling heating equipment
When choosing a location for a rocket stove, follow some rules:
- jet heating equipment is placed only in a room with an area of at least 16 m²;
- Without floorboards under the stove, installation of equipment will be easier;
- It is prohibited to place wooden beams above a structure that produces heat;
- if it is assumed that the chimney will go through the ceilings, then the heating equipment is placed in the middle of the house;
- the heat generator cannot be installed near the external contour of the house, otherwise the room will lose heated air;
- The jet device must not be placed next to walls and partitions of wooden materials.
To make it convenient to add fuel to jet heating equipment, it is wiser to place it facing the entrance. It is important to leave at least a meter of unoccupied space around the rocket stove.
IN small house builders advise setting aside a place for the stove in the corner. In this case, the firebox should be directed in one direction, and the bed (if it is made) – in the other.
The stove stands on a special platform that protects the floor from high temperatures
Having found a suitable site for the rocket stove, 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. A hole is dug under the exposed floor, the bottom of which is necessarily pressed.
Before construction work, a special solution should be mixed. It consists of sand and clay combined in a 1:1 ratio. You will need enough water so that the construction raw materials have the consistency of sour cream, that is, ¼ of the amount of dry ingredients.
Step-by-step instructions for making it yourself
If you plan to make a rocket stove from a gas cylinder, then you don’t have to be afraid of difficulties. The steps to create equipment from such construction raw materials are quite simple:
- the upper part is cut off from a cylinder with a volume of 50 liters in order to build a kind of cap;
The balloon is cut off at the top and bottom
- Based 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 (internal channel) and another pipe with a diameter of 15 cm (fuel firebox);
Dimensions 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, cleared of organic substances;
- To give the structure stability, the legs are welded.
To build a rocket stove with a stove bench, which involves the use of bricks, you need to proceed differently:
- The area 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 ensure a strong foundation, it is recommended to lay it in reinforcing mesh or metal rods;
The platform will harden in about two days
- The structure is poured liquid concrete. Then they wait for the solution to harden and finish the work. The bricks are laid in a continuous line, creating a platform for the stove. After this, the walls of the structure are formed, placing several rows of brick blocks;
- The lower channel of the structure is constructed, with one line of bricks laid across to block the combustion chamber. The blocks are placed, leaving the vertical channel and the firebox opening open;
Two sectors of the furnace at this stage of construction should be open
- Find the body from the old boiler and cut off the top and bottom covers on it. A flange is installed at the bottom of the resulting pipe through which a horizontal heat exchanger will pass. The parts must 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 metal brush and scrape off the rust from the walls of the container. The cleaned barrel is treated with a primer, and a little later with paint that is resistant to high temperatures;
- The horizontal chimney is connected by welding to the side outlet - the future ash pit. To facilitate its cleaning, a sealed flange is installed;
- The fire tube is laid out from refractory bricks. At the same time, a channel 18 cm high and wide is formed inside the structure. When doing this, they constantly use a 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 raw clay, the function of which is to prevent the thermal insulation material from spilling onto the floor;
- From the boiler, on which the top and bottom have been cut off, a fuel tank is formed. A handle must be welded to it;
- To improve the appearance, 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 perlite backfill;
- They create the facade of the stove, for which the stove contour is laid out from stone, bricks, adobe and sand. The back side of the structure is filled with crushed stone, and the front side with adobe mixture, making the surface perfectly flat;
- A metal barrel casing is placed on the previously created base. The lower 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 made of corrugated pipe is connected 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
- A test firing of the stove is carried out, watching how the gases are removed from the horizontal chimney. After this, the heat exchanger pipes are connected to the lower pipe installed on a red brick platform;
- The stove is equipped with a smoke exhaust pipe. The junction of the chimney and the heat generator is sealed with fire-resistant coating and asbestos cord;
- Using clay and adobe, the bed 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
Design improvement
A bench with a gas duct inside is not the only option for upgrading a rocket stove. The design can be improved with a water jacket connected to heating system, in which water circulates. It is advisable to give this part of the structure the appearance of a coil created from a copper pipe twisting onto the chimney.
This design provides even more heat
Another way to improve a jet furnace is to organize the flow of heated secondary air into the flame tube. This will increase the efficiency of the heat generator, but will lead to deposits in the primary chimney large quantity soot Therefore, it is better to make sure that the drum cover can be removed if necessary.
Subtleties of operating an unconventional stove
A rocket furnace is heated in a similar way to a top combustion heat generator. It turns out that the kindling of equipment called a rocket must be carried out according to certain rules:
- the main raw material for heating the unit must be added only after the structure has been well heated, for which purpose sawdust or paper is first placed in the blower sector and set on fire;
- When the hum emanating from the furnace is muffled, they must react by placing it in the combustion chamber. big batch fuel that will ignite on its own from hot sawdust residues;
- the process is closely monitored, that is, after laying the firewood, the damper is fully opened, and after some time, when the equipment makes a hum, it is closed to produce a sound similar to a rustling;
- as necessary, the damper is closed more and more, otherwise the firebox will be filled with an excess volume of air, which will disrupt the pyrolysis inside the fire tube and lead to the creation of a strong hum.
Since the jet stove was originally created for use in the field, its design is extremely simple. This allows the production of the unit to be carried out by ordinary home handyman. But, despite its apparent lightness, the rocket stove must be assembled, taking into account the correct ratio of parameters. Otherwise, the equipment will be unproductive.
- Ksenia Zubkova
Source: //legkovmeste.ru/stroitelstvo-i-remont/otoplenie/reaktivnaya-pech-svoimi-rukami.html
DIY rocket oven - instructions!
Unfortunately, in our country almost no one knows about the rocket stove. Meanwhile, such a design is extremely useful in a number of cases due to the almost complete absence of soot during operation and the high combustion temperature.
Jet stove
Rocket stove
Today we will talk about how to make a rocket oven with your own hands.
Principle of operation
Hot gases, instead of a chimney, enter a special hood, where they burn out (hence the absence of soot). At the same time, the temperature increases even more, and the pressure, on the contrary, decreases. The cycle is constantly repeated and soon the stove reaches the combustion mode with maximum draft (the strength of the latter depends on the design features and quality of installation).
Rocket stove
The temperature in the bell can reach 1200ᵒC, as a result of which all waste burns 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 to heat water, cook food, dry fruits, etc.
Jet furnaces
The advantages include:
- high efficiency;
- no soot;
- high temperature;
- the possibility of using cones, damp branches, dry plant stems as fuel - almost everything burns at a temperature of 1200ᵒ;
- low fuel consumption - approximately four times lower than in the standard design.
Types of rocket stoves
There are several types of rocket (or jet, as they are also called) stoves.
- Portable structures made from tin containers (paint cans, buckets, etc.). Excellent helpers on a construction site or on a hike, which can be made in just a few hours.
- Furnaces made of refractory bricks and metal barrels, intended for heating heat-intensive masses. They are distinguished by a horizontal chimney installed underground and an external riser to provide draft.
- Completely brick structures are used for air-heated floors. They consist of several chimney pipes at once.
Note! Due to the complexity of implementing the third option, only the first two will be considered in this article.
Making a reaction furnace from a brick and a metal barrel
In this case, the work traditionally begins with preparing everything necessary.
Making a reaction furnace from a brick and a metal barrel, drawing
Stage 1. Materials and equipment
For construction you will need:
- fireclay brick;
- steel barrel 200 l;
- chimney pipe;
- metal brush;
- old barbecue;
- fire resistant paint;
- bayonet shovel;
- expanded clay;
- fittings;
- adobe;
- perlite;
- cement mortar;
- trowel. Making a jet furnace from a brick and a metal barrel
Stage 2. Preparation
Step 1. A pit is dug in the floor (if possible) approximately 30-50 cm deep. 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 hood for the furnace. First, the barrel is fired and cleaned of soot with a wire brush, after which it is painted with fire-resistant paint.
Note! 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 are driven into the ground.
Step 3. Steel reinforcement is laid at the bottom.
Step 4. Bricks are laid level around the bottom point of the combustion chamber.
Step 5. The base is filled with concrete mortar.
Making a reaction furnace from a brick and a metal barrel
Stage 4. Masonry
After the solution has dried, you can begin laying the rocket stove.
Note! To do this, you need to use only refractory clay.
Step 1. On the first tier, the masonry rises up, leaving only a hole for the combustion chamber.
Step 2. At the second level, the lower channel of the furnace is formed.
Making a reaction furnace from a brick and a metal barrel
Making a reaction furnace from a brick and a metal barrel
Making a reaction furnace from a brick and a metal barrel
Making a reaction furnace from a brick and a metal barrel
Making a reaction furnace from a brick and a metal barrel
Making a reaction furnace from a brick and a metal barrel
Step 3. On the third, the channel is covered with masonry so that there are two holes - for the combustion chamber and the vertical channel.
Note! The bricks do not need to be hewn after laying - they will 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 approximately 150 liters.
A flange is built into the barrel to connect the chimney. It is also advisable to install a tee here for cleaning the chimney.
Step 5. The ascending part of the structure is placed using the “boot” method. Internal section this part should be approximately 18 cm.
Step 6. A piece of water heater is placed on the ascending part, and the voids between the walls are filled with perlite. The upper part of the perlite is sealed with fireclay clay.
Step 7. The base of the furnace is lined with bags filled with sand, 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 placed on the ascending part.
Step 9. A test run of the furnace is carried out, after which the barrel is painted with fire-resistant paint.
Making a reaction furnace from a brick and a metal barrel, diagram
Stage 5. Chimney lining
Step 1. The chimney is lined with sandbags and filled with expanded clay.
Step 2. The structure is given the appropriate shape using fireclay clay.
Note! A rocket stove requires a large amount of oxygen during operation, so it is recommended to install 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 sealed with clay. That's it, the brick rocket oven is ready for use.
A stove-bed built on the principle of a rocket stove
Stove-bed, built on the principle of a rocket stove, diagram
Stove-bed, built on the principle of a rocket stove, foundation
Stove-bed, built on the principle of a rocket stove, masonry
Stove-bed, built on the principle of a rocket stove, masonry
Stove-bed, built on the principle of a rocket stove, masonry
Stove-bed, built on the principle of a rocket stove, masonry
Stove-bed, built on the principle of a rocket stove, masonry
Stove-bed, built on the principle of a rocket stove, masonry
Stove-bed, built on the principle of a rocket stove, masonry
Making a camping and garden stove
In this design, as in the one described above, the operating principle is to isolate the fire and direct the thermal energy to the right place.
Stage 1. Preparing everything you need
To prepare a portable rocket stove you will need:
- two tin containers of different diameters;
- a couple of corners;
- steel clamps ø10 cm;
- pipe from of stainless steel for chimney;
- fine crushed stone;
- Bulgarian;
- metal scissors. Making a camping and garden stove Making a camping and garden stove Making a camping and garden stove In the second bucket - the lower part of the rocket stove, we cut a hole for the pipe. We cut the metal into petals and bend it inside the bucket. for dishes From wire we bend the burner for dishes We heat the rocket stove
Stage 2. Assembling 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 cover is not removed). In this case, it is better to bend the “petals” inward - this way the pipe will be fixed more securely.
The lower half of the bucket is cut off with a grinder.
Step 2. A hole is cut in the bottom of another 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 couple of corners. The pipe is then inserted into the bucket and connected there to the “petals” using a steel clamp. That's it, the forward flow of the rocket furnace is ready.
Step 4. The space between the direct flow and the walls of the bucket is filled with fine crushed stone. The latter will perform two functions in the design at once - thermal insulation and thermal accumulation.
Step 5. The second bucket (lid) is placed on the jet stove.
Step 6. A hotplate is bent from steel wire.
Note! Instead of a burner, you can install three bricks.
Step 7. All that remains is to paint the structure with heat-resistant paint (preferably gray or black). For melting, the direct flow outlet pipe will be used.
Mini jet oven
Mini jet oven
Mini jet oven
Mini jet oven
Mini jet oven
Mini jet oven
Mini jet oven
Mini jet stove, kindling
Operating rules for rocket stoves
Rocket stoves, as well as other long-burning designs, need to be launched onto a warm pipe. And if for the second version of the stove this is not so important, then for the first, a cold chimney will only lead to wasted burning of fuel. For this reason, the structure needs to be preheated - heated with sawdust, paper, etc.
It is also worth noting that the jet stove is unable to self-adjust, so at first the vent opens completely, and closes only after the structure begins to hum strongly. Subsequently, the availability of oxygen gradually decreases.
About the rocket stove in the bathhouse
Jet wood stove with deck chair
Many people are probably interested in the question: is it possible to use a jet stove in a bathhouse? It would seem that it is possible, because it is quite easy to equip a heater on a tire.
In reality, such a design is not suitable for a bathhouse. For light steam, you first need to warm up the walls, and only then, after some time, the air. For the latter, the oven must be a center of convection and thermal radiation (IR). This is the problem - in a rocket furnace, convection is clearly distributed, and the design does not provide for losses due to thermal radiation at all.
DIY rocket oven
conclusions
Be that as it may, today in the manufacture of rocket stoves 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 stove.
– Do-it-yourself jet stove
Source: //svoimi-rykami.ru/stroitelstvo-doma/pechi_i_mangaly/pech-raketa-svoimi-rukami.html
DIY long-burning brick rocket stove: drawing, instructions, photo
A rocket stove made of long-burning bricks, despite its simplicity of design, can solve a number of problems for owners of dachas and private houses. These include not only heating and cooking functions, 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 transform into wood gas during combustion, which has high level heat transfer.
In conventional solid fuel stoves, wood gas goes into the pipe along with the gas, where it cools and settles on the walls in the form of soot. In a rocket-type furnace, due to the horizontal channel, gases move more slowly, do not have time to cool, but burn out, giving off a large amount of heat.
In models of jet heating devices of complex design, heated air and gas pass through a number of internal channels. Then they move to the upper part of the body, under the hob, where it burns completely. For such a rocket there is no need for additional boost. The draft in them is created by the chimney, and the longer its length, the more intense the upward flow.
Principle of operation
This diagram shows the operating principle of a rocket stove with a stove bench
Advantages and disadvantages
Long combustion rocket stoves have the following advantages:
- high coefficient useful action- no less than 85%;
- high speed of heating the room - 50 m² will become warm in less than 1 hour;
- absence of soot - the exhaust during fuel combustion does not form soot, but is formed in the form of steam and carbon;
- possibility of functioning on solid fuel any kind;
- low consumption - the fuel consumption of a rocket stove is 4 - 5 times less than a conventional stove under equal conditions: combustion time and heating temperature;
- the possibility of installing a warm bed;
- Duration of heat retention in a well-heated structure without adding fuel - up to 12 hours.
This stove has many advantages, but there are also disadvantages
The disadvantages include:
- manual method of controlling a heating device - fuel burns out quickly and requires regular reporting;
- the high heating temperature of some structural elements threatens owners with burns in case of accidental contact;
- the heating speed does not allow the use of a rocket stove for baths;
- the aesthetic component of such a device is not for everyone and is not suitable for every interior;
- danger of carbon monoxide entering living rooms.
Materials
Do-it-yourself building materials for the construction of a long-burning rocket stove are selected depending on the calorific value of the fuel. For laying the main part of the body, a simple red one is usually used kiln brick. The firebox and combustion bunker are lined with fireclay bricks.
If you plan 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 stove, you will need to buy stove accessories:
- blower;
- grates;
- firebox 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 and distributing the solution. It is more convenient to work with a tool with the handle moved slightly to the side;
- picks or hammers - picks for trimming individual parts of brick;
- Bulgarian women with diamond blade for sawing whole 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 stove, you need to decide on the location of its installation, the dimensions of the future design, and develop a diagram. The masonry technology itself is quite simple; any novice builder can master it.
The simplest design of a rocket furnace can be built from 20 bricks per summer cottage and use it to heat food brought from home.
Selecting a location
Before starting construction, the first thing is to choose a location. Brick kilns rocket type is recommended to be placed closer to front door. In this case, after cleaning, the ash 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 place where the pipe exits there are no rafters located closer to the chimney than 40 cm. And yet, the stove should not be adjacent to external wall at home, so that expensive heat does not go to heating the street.
Preparation of the solution
Cement mortar will quickly crack under the influence of high temperatures, so for laying heating devices made of bricks, 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 must be soaked, strained, and then sand must be added. The resulting solution should have a consistency similar to thick sour cream. You can check its viscosity level 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 add sand.
The preparation of the mortar must be approached with all responsibility, since only a plastic mixture of the required thickness can fill all the unevenness of the bricks and ensure their strong adhesion.
Laying a rocket furnace of 20 bricks
Ordering a rocket stove for 20 bricks
Example of a brick rocket stove
Laying a rocket stove with a stove bench
A brick rocket stove, 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 made of iron. Subsequently, the body can be coated with clay to give it a more rounded shape.
| Row No. | Number of bricks, pcs. | Description of the masonry | Drawing |
| 1 | 62 | Forming the base of the furnace | (click to enlarge) |
| 2 | 44 | Formation of the base of channels for heating the bed along the entire structure. Fastening mortgages for mounting a cast iron door | |
| 3 | 44 | Repeating the outline of the second row | |
| 4 | 59 | Complete channel blocking. The beginning of the formation of a vertical smoke channel and fireboxes | |
| 5 | 60 | Construction 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 pipe. This is where the channel begins, through which the air from the hob will fall down to move to the stove bench | |
| 13 | 10 | Completion of surface formation under hob. Laying an asbestos pad, which is covered with sheet steel. | (click to enlarge) |
| 14; 15 | 5 | Closing the chimney channel and forming a low wall between the stove bench and the hob. |
After completing the masonry work, the homemade rocket stove must be dried, carefully, heating at low intensity. First, no more than 20% of the required amount of firewood is placed 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 stains. Depending on the size of the device, drying 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.
Finished look
You need to launch a brick rocket stove only when the chimney is warm. For a small device, this property is not so significant, and a larger oven is cold pipe It's just a waste of wood.
Therefore, to bake a rocket before loading the fuel quota after a long break in operation, you need to heat it with paper, dry shavings, straw, etc., placing them in a ash pit with the door open. When the hum in the stove decreases in pitch or subsides, then you can load all the fuel into the firebox; it should ignite by itself from the existing fire.
A rocket stove with a stove bench is not a completely self-regulating device for external conditions and fuel energy efficiency. Therefore, at the beginning of the fire with the normal amount of fuel, the ash door is left in the open position. After the stove begins to hum strongly, it is covered until 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 the required temperature, which can lead to reverse draft.
Conclusion
The brick jet stove is becoming an increasingly popular heating device for small buildings, both temporary and permanent residence. This is explained by the simplicity of execution, low cost of material, long battery life and high heat transfer of this design.
Nowadays, many stoves have been created that use wood as fuel. A special place among them is occupied by the so-called rocket (rocket) units, which have specific features that are indispensable in certain operating conditions. Let's talk about them.
The rocket is a real miracle unit!
The rocket stove is a heating and cooking system that operates on wood, is famous for its high technical performance and has a simple design. The operating principle of such a long-burning unit is based on the fact that the gases formed during fuel combustion enter a special bell, in which they burn completely. Due to this, the temperature of the stove increases significantly, and the pressure decreases. Moreover, soot does not form in the reactive heating system.
The combustion cycles of heated gases are repeated constantly (while the stove is heating). This causes the system to enter maximum thrust mode. Her specific quantity determined by features homemade unit. If the heating device is assembled truly correctly, the temperature in its hood can reach 1200 °C. In this case, all the fuel used is burned without any residue. It is also important that the heated cap can be used as a hob. You can dry fruits, heat water, and cook food on it.
Initially, the stove we were interested in was designed for use in difficult (for example, camping) conditions. Because of this, special requirements were put forward for its design. The result is a unique unit that:
- makes it possible to cook food in areas where there is no gas or electricity;
- heats the room efficiently;
- retains heat for 6–8 hours (minimum) after the wood burns out;
- It has high coefficient useful action;
- quite safe to use.
In addition, the rocket has a design that allows you to add a new portion of firewood to the firebox without stopping the combustion process. The operation of a unit with such capabilities, of course, appeals to any person. This determines the high popularity of the described heating systems both among lovers of outdoor activities and among ordinary summer residents who need unpretentious and efficient stoves.
Important point. If you plan to create the simplest jet unit with your own hands, it can only be heated with dry wood. Damp wood can cause backdraft. However, it is not recommended to fire more complex rockets with wet wood, since they will not be able to provide the high temperature required for burning heated gases.
The described heating devices must not be thrown away without supervision. Light the stove, wait until the fuel burns out completely. Another disadvantage of rocket equipment is the impossibility of heating private baths (in particular, their steam rooms) with its help. This is due to the fact that the jet unit produces very little infrared heat, which is what is required for bathing procedures. Missiles probably have no other disadvantages.
Types of jet heating systems – what do you need?
The simplest rockets are made from almost any tin container. A portable stove can be made from a bucket, a can in which paint was stored, and so on. Such systems are ideal for an outdoor picnic; they are often used on construction sites. Simple ovens not suitable for heating rooms. They are used exclusively for cooking and heating water. A rocket made from a bucket can be heated with a small splinter, dry cones and leaves, and bunches of branches. In such a stove, combustion products do not have time to form wood combustible gas. They immediately go down the chimney.
More complex heating structures are created from an old gas cylinder or from a metal barrel and brick. These stoves are necessarily equipped with a riser to increase draft and a horizontal smoke exhaust duct. There are also rockets made entirely of brick. They can be equipped with several chimneys at once and used for heating large premises and floor heating. And if you want, you can actually build even a full-fledged stove-bed.
We will tell you how to make all of the indicated types of reactive heating devices yourself. Let’s start our master class with the simplest thing - making a basic garden camping stove from two tin containers (buckets, cans). In addition to them, we will need steel clamps with a cross-section of 10 cm, metal corners, an angle grinder, a stainless steel chimney pipe, scissors for metal, crushed stone. The scheme of work will be as follows:
- 1. Take two buckets. From a container of smaller volume (diameter) we make a lid for our rocket. Cut a hole in the bucket. It is necessary for organizing a chimney.
- 2. In the larger bucket, cut another hole at the bottom. We will connect the firebox to it. We perform all operations with metal scissors, bending the resulting petals (pieces of tin) inward.
- 3. We construct a direct flow from pipes and corners. We insert it into the bucket, and then, using a clamp, connect it with the curved petals.
- 4. Fill the space between the forward flow and the body with crushed stone heating device. This building material will play the role of a heat accumulator and at the same time a heat insulator.
- 5. We put the second bucket on the stove.
- 6. We bend a small burner from wire on which you can place dishes with water and food.
It is advisable to paint the portable rocket with any paint with a high level of heat resistance. After drying, we can use elementary cooking stove. Note! The rocket is ignited through a pipe extending from the forward flow.
A stove made of a barrel and bricks – both cooks and heats!
The construction of a stationary rocket launcher requires significantly more money and time. We prepare the following materials and tools: a metal chimney pipe, red (necessarily heat-resistant) brick, a shovel, an old barbecue, a metal brush, a trowel, cement and sand (it is better to immediately buy a ready-to-use mixture of these materials), reinforcing bars, a little perlite, adobe and expanded clay, heat-resistant paint, 200 liter barrel. Let's start building a stove made of bricks and a metal barrel:
- 1. We dig a hole 0.3–0.5 m deep in the floor. We will hide a horizontal chimney in it, without which the rocket launcher will not work.
- 2. We burn a 200-liter barrel and clean it thoroughly. We install a flange in the container that will connect it to the chimney. After this, apply several layers of heat-resistant paint to the container. We use the barrel prepared in this way as a hood for the heating unit.
- 3. We arrange the foundation. We make a simple formwork from boards, deepen 2-3 bricks into the ground at the furnace installation site. We place reinforcing bars on top. Then we lay bricks in the lower part of the combustion chamber (along the entire perimeter). Fill the structure with cement-sand mortar.
After the filling has dried, we begin laying. It is performed using . We bring the first tier of masonry up. We only need to leave a hole for the firebox. On the second line we form a channel (lower) of the heating structure. It should be covered on the third tier, and in such a way that we have two holes left. One of them is intended for the vertical channel, the second - directly for the combustion chamber.
Next, we install a tee in the barrel to clean the chimney. It is not necessary to install it, but it is advisable if you plan to use the stove for a long time. After this we put in a vertical channel. We lay out the rising section of the structure (we take its diameter to be about 18 cm) using the “boot” technology. Then we put the old water heater on the rising part of the furnace. We fill all the voids that remain after this operation with perlite.
Now we cover the base of the rocket unit casing with clay and surround the base of our structure with sandbags. We fill all remaining free areas with expanded clay. We connect the chimney pipe to the structure, turn the barrel-casing over and pull it onto the ascending part of the stove. The final work is lining the chimney with sand in bags and filling them with expanded clay. Then we give the structure the required shape using clay (fireclay), install a barbecue grill in the neck of the homemade rocket and cover it with a lid.
The last step is to seal the existing seams on the stove. In principle, we can already do a test run of our design. But experts advise additionally connecting a separate air duct from the street to the stove. It is important. The heating rocket requires a lot of air to function properly. It won't be enough indoors. A street air duct is guaranteed to solve this problem.
Rocket heating from a cylinder - let's work with a welding machine
To build a rocket, we choose a heat-resistant and non-explosive cylinder. An all-metal 50-liter tank in which propane is stored is optimal for these purposes. Such a cylinder has standard sizes: height – 85 cm and cross-section – 30 cm.
These parameters are ideal for making your own oven. The modest size and light weight of the cylinder do not make it difficult to work with. At the same time, it is allowed to burn any wood fuel in the finished rocket. You can also take 27 or 12 liter propane cylinders. They make compact portable stoves. But the power indicators of such devices are small. Use them to heat rooms, country houses inappropriate.
To build a furnace, in addition to the cylinder, you will need:
- steel pipes with a cross section of 15, 7 and 10 cm (the first two will be used to organize a vertical internal channel, the third - to the chimney);
- profile pipe product 15x15 cm (we will make a loading compartment and firebox from it);
- 3mm thick sheet of metal;
- dense (100 or more kg/cubic m) basalt fiber (it will serve as a heat-insulating material).
There are various drawings on the Internet for creating a stove from a cylinder. We propose to be guided by this scheme.
The algorithm for manufacturing a rocket launcher is simple. First, we bleed all the gas from the container. Then we turn out the valve, fill the tank with water (to the top) and cut off its upper part along the seam. We cut out the windows on both sides of the gas cylinder, which are required for connecting the chimney and installing the fuel chamber.
After this, we insert the profile tubular product into the container and connect it to the channel (vertical). We remove the latter through the bottom of the tank. Next we do everything necessary actions, focusing on the presented drawing, as well as on the video that we offer home craftsmen for review.
At the end of the work, we weld the cut part of the container in its place and analyze all the resulting seams for permeability. Uncontrolled entry of air into the constructed structure must not be allowed. If the seams are reliable, we connect a chimney to the homemade system. We weld the legs to the bottom of the rocket cylinder. We install the stove on a steel sheet with parameters of 1.5x1 m. The unit is ready for use!
Stove-bed - for lovers of special comfort
The heating unit with a place to sleep and rest is equipped with a special heat exchanger. Its channels are interconnected. They are made from non-flammable materials. The heat exchanger is installed under the plane of the bed. The design of such a furnace is very thoughtful and relatively complex. The bed itself is a surface made of brick or stone and clay. When the stove burns, the heated gas moves through the heat exchange channels, gives off heat upward, and then is removed through the smoke exhaust duct outside the house. The height of the chimney is made within 3–3.5 m. The stove is mounted at the edge of the stove bench (on one side). In most cases, it is equipped with a surface for cooking food. A detailed drawing of this system is presented below.
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Elements of the furnace in the diagram:
- blower - 1a;
- fuel bunker – 1b;
- channel for secondary air - 1c;
- flame tube – 1g;
- riser (primary chimney) – 1d.
The fuel chamber is equipped with a blind cover, and the blower is equipped with a special regulator for adjusting the amount of air supplied. The flame tube has a length of 15–20 cm. The secondary air channel is necessary for complete combustion of gases. The riser cross-section is 7–10 cm. A chimney with a diameter of 10 cm is recommended for cases when we want to obtain the greatest rocket power. A riser with a cross-section of 7 cm provides an optimal indicator of the efficiency of the stove. The fire pipe and the primary chimney require high-quality thermal insulation.
We will make the rocket body from a gas cylinder, although a metal barrel can also be used. Under the housing cover (2a), the primary chimney supplies heated air, and the heated gases leaving the riser heat the cooking device (2b). Other body elements:
- lower part (2d);
- heat exchange channels (2g);
- shell – metal chimney insulation (2c);
- exit to the cleaning chamber (2e).
The smoke exhaust line must be absolutely sealed throughout. At a height of 1/3 from the upper end of the drum (housing), the gases are already at a low temperature. They have time to cool down. From approximately the specified height, the rocket-bed is lined (all the way to the floor). This process refers to the thermal insulation of the furnace with special compounds. The second cleaning chamber in diagram (3a) is needed to remove carbon deposits from the hog (4) - the heat exchanger. It must be equipped with a sealed door (3b). Now that we have figured out the design of the bed, we can begin to build it.
Building a rocket with a place to sleep - the first steps are the most important!
Before starting work, mix all the necessary ingredients:
- Kiln clay (designation 5b in the diagram), which is combined with crushed stone. This composition plays the role of the main heat insulator.
- Saman (5a). It is a composition of straw and any clay at hand, diluted with water to a relatively thick consistency.
- Seeded sand (5g).
- Heat-resistant lining (5v). It is made from equal parts of fireclay sand and clay.
- Medium fat clay (5d). It is used for rocket laying.
We are making a bed for our bed. Basically, we need to bring down the shields high strength under the bed and directly under the stove. The frame of the buildings is made from wooden blocks 10x10 cm. We make frame cells with dimensions of 60x120 cm (for a bed) and 60x90 cm (for heating installation). Then we sheathe the resulting skeleton with 4 cm. And the façade of the couch can be finished later with sheets of plasterboard.
Before installation, it is advisable to treat wood products with Biocide, and then apply two layers of water emulsion to them.
We lay 4 mm thick basalt cardboard on the floor where we will place the heating rocket. In shape and geometric parameters, it must be similar to the characteristics of the bed. We install an iron roofing sheet on top of the basalt lining. Before the firebox, it will extend about 25 cm from under the unit. We install the previously made bed in the place prepared for it. We punch a hole on the wall at a height of 13 cm above the level of the couch (at one of its ends). It is needed for the installation of a chimney.
The next stage is installation of formwork around the perimeter of the bed and pouring installed structure adobe. Carefully level the surface of the mixture using the rule. We wait 14–20 days until the adobe hardens. During this time, you can make the body of the heating structure from a gas cylinder according to the previously described scheme. We weld the combustion components of the rocket (blower, flame duct, chamber) into a single structure with a gas container and coat it with a heat-resistant lining. Important! Apply the composition in a continuous layer only at the bottom. We do not treat the top and sides of the structure with the solution.
Next, we install another formwork under the area where the rocket will stand. It will allow us to make heat-resistant thermal protection for the stove. The height of the formwork structure is about 10 cm. Fill it with a mixture of crushed stone and oven clay. Then we do one by one:
- 1. Shell. We bend it from a sheet of steel or use a ready-made pipe with a cross-section of 15–20 cm.
- 2. Furnace structure.
- 3. Cleaning chamber. This element is made from 1.5 mm galvanized steel. We cut an opening on the side with a cross-section of 16–18 cm. The chimney pipe will subsequently fit into it.
Completion of work - the warm bed will turn out great!
We put a drum from a gas cylinder on the primary chimney. We lay oven clay on the bottom of the installed housing, using a spatula to form an inclined surface (about 7°), which is directed towards the cleaning compartment window. Then we put a metal round timber on the chimney. It should be pressed into the clay composition. Then we pull the shell over the riser and coat it with medium-fat clay. The next steps are:
- 1. We line the chimney from the inside. We use sand. It should be filled up separate layers. We wet and tamp each of them. The total number of layers is 7. Place 5 cm of medium-fat clay on top of the sand.
- 2. Place a cleaning box, coating its bottom and side surfaces with clay. We install the opening of the transition channel into the hole of the drum and press it as hard as possible. We fill all remaining gaps with clay. It is necessary to achieve complete tightness of this stove unit.
- 3. We install another formwork along the (external) contour of the bed. It should rise about 9 cm above the edge of the hole for the hog. Fill the formwork with adobe mixture.
- 4. We stretch the corrugated pipe along the entire length of the rocket-bed. We connect one end of the corrugated product to the cleaning compartment.
- 5. We lay the fixed corrugated pipe in a spiral and insert its second end into the chimney outlet opening, securing the joint with a clay compound.
- 6. We treat the entire length of the bur with adobe solution and compact this coating.
- 7. We fix the housing covers and cleaning chambers with bolts, under which we install rubber gaskets.
- 8. Coat the drum with adobe (don’t touch only the top part) with a layer of about 10 cm.
After about 17 days, the adobe will dry out. We will be able to remove the formwork and apply a special enamel to the drum that can withstand heating up to 750 °C. Then experts advise treating the adobe surface with acrylic-based varnish (preferably in two layers). This coating will protect the structure from moisture and make the stove very attractive in appearance.
The heated bed is done. We test our structure before starting its full operation. The check is carried out simply. We put some paper in the firebox, set it on fire, and monitor the behavior of the rocket. If everything is fine - there are no frightening sounds, we add firewood. After a while the unit will begin to hum. At this moment, close the oven vent. We wait. When the humming gives way to a gentle whisper (the soft sound of a working stove), open the vent. Next, we use the heating installation for its intended purpose.
The jet stove or rocket stove appeared as a result of a deviation from the traditions of manufacturing equipment for heating a room. It is considered an economical heat generator, the design of which is elementary. Therefore, many people are thinking about building a jet furnace with their own hands.
Description, advantages and disadvantages of the rocket stove
A heat generator for heating the air in a room is called a rocket stove or jet stove, since during operation, in case of excessive air supply, it makes 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.
A rocket stove serves as a device for heating a home and cooking food. 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 a top-burning furnace.
The flame from the jet furnace may burst out
The advantages of the rocket stove include:
- independence from fuel energy;
- simplicity of design, consisting of accessible 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 burns, because the walls of the equipment become extremely hot;
- It is inappropriate to use in a bathhouse, since it cannot be warmed up.
Kinds
A unit that emits a rocket-like hum during operation can be:
- portable (unit made of metal pipes, buckets or gas cylinder);
Portable rocket stoves are mass-produced by industry
- stationary (made from fireclay bricks and metal containers);
Such a unit is more difficult to build than a metal furnace
- equipment for heating air with a stove bench.
The bench is equipped behind the back wall of the stove
Portable structures are made in large quantities, because they are used for hiking. The basis of these heat generators is a pipe made up of several sections. True, such structures, unlike units based on fireclay bricks, are not reliable. Walls made of refractory blocks increase the heat transfer of the jet furnace. If desired, you can add a bed in the form of a sofa or bed, decorated with clay or sawdust.
Parts and operation of a jet heat generator
A basic rocket furnace is a device consisting of two pipe fragments connected by a bend at an angle of 90 degrees. The combustion chamber in this heat generator is usually a zone in the horizontal part of the structure. But sometimes fuel is placed in the vertical section of the apparatus, for which a rocket stove is constructed from two pipes of different lengths, mounted vertically and connected by a common horizontal channel.
Primary and secondary air passes through the furnace
The operation of a jet stove is based on two actions: the unhindered passage of wood gases through the pipe and the afterburning of gases produced during fuel combustion. Wood chips and firewood are placed in the firebox of this heat generator after a highly flammable material such as paper ignites. 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 occurring inside a stationary reactive furnace resemble the operation of pyrolysis heating units
Calculation of parameters (tables)
The volume of the furnace should be determined wisely, because it is it that affects the power and amount of heat generated by the heating equipment. When calculating the dimensions of jet heating equipment, use the indicator of the internal diameter of the drum D, the value of which can range from 300–600 mm. You also need to know the cross-sectional area of the drum. To determine this indicator of the rocket stove, you should use the formula: S = 3.14 * D^2 /4.
The main dimensions of the jet furnace are presented in the table:
| Parameter | Meaning |
| Drum height H | From 1.5D to 2D |
| Height of drum insulating coating | 2/3H |
| Thickness of drum insulating coating | 1/3D |
| Cross-sectional area of the primary chimney | From 0.045S to 0.065S (optimally - from 0.05S to 0.06S). The higher the primary chimney is, the better. |
| Minimum clearance between the top edge of the primary flue and the drum cover | 70 mm. With a lower value, the aerodynamic resistance of the gap for gases passing through it will be excessively large. |
| Flame tube length and area | Length and area of the primary chimney |
| Blower cross-sectional area | Half the cross-sectional area of the primary chimney |
| Cross-sectional area of the external chimney | From 1.5S to 2S |
| The thickness of the adobe cushion under the flue with a stove bench | 50–70 mm (if there are wooden floors under the bed - from 25 to 35 mm) |
| The height of the coating above the flue with a stove bench | 150 mm. It is not recommended to reduce it, otherwise the oven will accumulate less heat. |
| External chimney height | not less than 4 m |
Particular importance is attached to the length of the flue with the stove bench. The maximum permissible values 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.
| D (diameter) | Volume | |
| 300 mm | 0.1x(Vk - Vpd) | Where Vk is the volume of the drum, Vpd - volume of the primary chimney. |
| 600 mm | 0.05x(Vk - Vpd) | |
Construction raw materials for the construction of a non-standard furnace
The production of jet heating equipment will require:
- barrels with a volume of 200 liters and a diameter of 0.6 meters, an empty liquefied gas cylinder or tin buckets to build a furnace drum;
- square or round steel pipes 2–3 mm thick, which are needed to create a blower, combustion chamber and primary chimney;
- fireclay crushed stone and oven clay as thermal insulation materials;
- adobe, which serves as the outer coating layer;
- fireclay bricks;
- sand from the bottom of the river;
- pieces of sheets of zinc-coated steel or aluminum for the manufacture of lids and doors;
- asbestos or basalt cardboard, which serves as a sealant.
When constructing a rocket stove, you will need a welding machine. And if you plan to make heating equipment from bricks, then you will have to take:
- Master OK;
- mortar spatula;
- hammer-pick;
- jointing;
- sharp-angled sledgehammer;
- level;
- plumb line;
- roulette
Preparation for assembling heating equipment
When choosing a location for a rocket stove, follow some rules:
- jet heating equipment is placed only in a room with an area of at least 16 m²;
- Without floorboards under the stove, installation of equipment will be easier;
- It is prohibited to place wooden beams above a structure that produces heat;
- if it is assumed that the chimney will go through the ceilings, then the heating equipment is placed in the middle of the house;
- the heat generator cannot be installed near the external contour of the house, otherwise the room will lose heated air;
- The jet device must not be placed next to walls and partitions of wooden materials.
To make it convenient to add fuel to jet heating equipment, it is wiser to place it facing the entrance. It is important to leave at least a meter of unoccupied space around the rocket stove.
In a small house, builders advise setting aside a place for the stove in the corner. In this case, the firebox should be directed in one direction, and the bed (if it is made) – in the other.
The stove stands on a special platform that protects the floor from high temperatures
Having found a suitable site for the rocket stove, 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. A hole is dug under the exposed floor, the bottom of which is necessarily pressed.
Before construction work, a special solution should be mixed. It consists of sand and clay combined in a 1:1 ratio. You will need enough water so that the construction raw materials have the consistency of sour cream, that is, ¼ of the amount of dry ingredients.
Step-by-step instructions for making it yourself
If you plan to make a rocket stove from a gas cylinder, then you don’t have to be afraid of difficulties. The steps to create equipment from such construction raw materials are quite simple:
- the upper part is cut off from a cylinder with a volume of 50 liters in order to build a kind of cap;
The balloon is cut off at the top and bottom
- Based 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 (internal channel) and another pipe with a diameter of 15 cm (fuel firebox);
Dimensions 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, cleared of organic substances;
- To give the structure stability, the legs are welded.
To build a rocket stove with a stove bench, which involves the use of bricks, you need to proceed differently:
- The area 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 reinforcement mesh or metal rods in it;
The platform will harden in about two days
- The structure is filled with liquid concrete. Then they wait for the solution to harden and finish the work. The bricks are laid in a continuous line, creating a platform for the stove. After this, the walls of the structure are formed, placing several rows of brick blocks;
- The lower channel of the structure is constructed, with one line of bricks laid across to block the combustion chamber. The blocks are placed, leaving the vertical channel and the firebox opening open;
Two sectors of the furnace at this stage of construction should be open
- Find the body from the old boiler and cut off the top and bottom covers on it. A flange is installed at the bottom of the resulting pipe through which a horizontal heat exchanger will pass. The parts must 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 metal brush and scrape off the rust from the walls of the container. The cleaned barrel is treated with a primer, and a little later with paint that is resistant to high temperatures;
- The horizontal chimney is connected by welding to the side outlet - the future ash pit. To facilitate its cleaning, a sealed flange is installed;
- The fire tube is laid out from refractory bricks. At the same time, a channel 18 cm high and wide is formed inside the structure. When doing this, they constantly use a 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 raw clay, the function of which is to prevent the thermal insulation material from spilling onto the floor;
- From the boiler, on which the top and bottom have been cut off, a fuel tank is formed. A handle must be welded to it;
- To improve the appearance, 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 perlite backfill;
- They create the facade of the stove, for which the stove contour is laid out from stone, bricks, adobe and sand. The back side of the structure is filled with crushed stone, and the front side with adobe mixture, making the surface perfectly flat;
- A metal barrel casing is placed on the previously created base. The lower 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 made of corrugated pipe is connected 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
- A test firing of the stove is carried out, watching how the gases are removed from the horizontal chimney. After this, the heat exchanger pipes are connected to the lower pipe installed on a red brick platform;
- The stove is equipped with a smoke exhaust pipe. The junction of the chimney and the heat generator is sealed with fire-resistant coating and asbestos cord;
- Using clay and adobe, the bed 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
Design improvement
A bench with a gas duct inside is not the only option for upgrading a rocket stove. The design can be improved with a water jacket connected to the heating system in which water circulates. It is advisable to give this part of the structure the appearance of a coil created from a copper pipe twisting onto the chimney.
This design provides even more heat
Another way to improve a jet furnace is to organize the flow of heated secondary air into the flame 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 better to make sure that the drum cover can be removed if necessary.
Subtleties of operating an unconventional stove
A rocket furnace is heated in a similar way to a top combustion heat generator. It turns out that the kindling of equipment called a rocket must be carried out according to certain rules:
- the main raw material for heating the unit must be added only after the structure has been well heated, for which purpose sawdust or paper is first placed in the blower sector and set on fire;
- they must react to the muting of the hum emanating from the stove - they put a large batch of fuel into the combustion chamber, which will ignite on its own from the hot remains of sawdust;
- the process is closely monitored, that is, after laying the firewood, the damper is fully opened, and after some time, when the equipment makes a hum, it is closed to produce a sound similar to a rustling;
- as necessary, the damper is closed more and more, otherwise the firebox will be filled with an excess volume of air, which will disrupt the pyrolysis inside the fire tube and lead to the creation of a strong hum.
Since the jet stove was originally created 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 its apparent lightness, the rocket stove must be assembled, taking into account the correct ratio of parameters. Otherwise, the equipment will be unproductive.