How the long-burning boiler is organized

Knowing how our heating systems operate is crucial to maintaining a warm and comfortable home. The long-burning boiler is an essential part of many homes. This article explores the inner workings of this technological marvel of heating, providing insight into how it keeps our homes toasty warm in the winter.

A long-burning boiler, sometimes referred to as a solid fuel boiler, is a kind of heating system that produces heat by burning solid fuels like biomass, coal, or wood. For those looking for a more economical and environmentally friendly heating option, long-burning boilers provide an alternative to conventional boilers, which run on gas or oil.

A long-burning boiler has a clever, yet comparatively simple, layout. The combustion chamber, which produces heat by burning the solid fuel, is at the center of it. After that, the heat is converted to water, which is then circulated throughout the house via radiators or pipes. This process’s efficiency is influenced by a number of variables, including insulation, combustion temperature, and fuel quality.

The capacity of a long-burning boiler to maintain a gradual and even burn for an extended amount of time is one of its main characteristics. Long-burning boilers can run for hours or even days on a single fuel load, in contrast to conventional boilers that need to be refueled frequently. They are especially well-suited to continuously provide warmth in homes, even during protracted cold spells, because of their sustained heat output.

In addition to being interesting, knowing how a long-burning boiler operates on the inside can help homeowners make the most out of their heating systems. Understanding how these boilers work enables people to choose fuel wisely, take care of them, and increase efficiency, all of which contribute to a comfortable and energy-efficient home.

Device and features of a homemade long-burning boiler

The primary drawback of any solid-fuel boiler for summer cottages is that it requires frequent tossing of the boiler’s fuel, which can be firewood, coal, pellets, etc. And it is really inconvenient as a result. Fortunately, this drawback of a solid fuel long-burning boiler is not experienced by many owners of private country homes.

It enables the loading of coal once every five days and firewood once every thirty hours. Granted that solid fuel boilers with extremely long combustion times exist today, this indicator is average for the great majority of wood-burning boilers. Once a month, fuel is added to them. It goes without saying that their intricate design makes it nearly impossible to create by hand. But anyone with a dacha or private country home can easily build a conventional long-burning wood-fired boiler.

As we examine long-burning boilers, we go deep into the core of energy-efficient residential heating. These clever gadgets are made to use the least amount of fuel possible to consistently provide warmth. Long-burning boilers function primarily on the basis of slow combustion, maximizing the burning process through the use of a regulated airflow system. Their efficient combustion of wood or other biomass materials makes them a sustainable substitute for conventional heating techniques. To ensure longevity and dependability, premium materials and cutting-edge engineering are used in their construction. Proper maintenance can lead to a significant reduction in both heating costs and environmental impact, which makes these boilers an attractive option for homeowners looking for energy-efficient solutions.

Device

The simplest drawing shows the solid fuel boiler’s apparatus as follows:

1. Cylinder body. It is also a combustion chamber.
2. Door for loading firewood.
3. Ash door.
4. Air distributor. It is a large metal circle with a hole in the middle. It presses the wood with its weight and as it burns, it slides downwards.
5. Air supply pipe. It is attached to the center of the air distributor. According to the drawing, it always exits through the top of the wood-fired boilers" body. At the top there is a flap for regulating the air supply.
6. Chimney.
7. Heat exchanger. It can be installed on the chimney, and can be made in the form of a water jacket.

As is evident, the typical long-burning wood boiler for a heating system is made with a straightforward design. But not everything is that easy; there are a lot of little details to consider when building your own solid fuel boiler.

Features of the body

Following these guidelines is required for the cylinder-shaped body to contribute to high efficiency:

1. The ratio of height to inside diameter should be 3:1 to 5:1. In this case, the size of the diameter should vary within 30-80 cm. If the solid fuel boiler will have a too small internal diameter, the air will not be able to react with the fuel properly, because it will be quickly exhausted through the chimney pipe. The efficiency will drop a lot. When the wood boiler will have a very large diameter, the central part of the fuel will burn quickly, and the edges will burn slowly. Because of this, a hole will appear in the center, in which the air distributor will sit, and the combustion of firewood will stop.
2. The enclosure wall should be 4-6 mm. This rule applies to those cases where solid fuel boilers are made of structural steel. If heat-resistant steel will be used for production, its optimum thickness is 2.5 mm.

The following outcomes will result from incorrect wall thickness:

• If domestic coal-fired boilers will have a too thin wall, the heat will quickly pass through it. That is, too much heat will be released through it. As a result, the exhaust gases after passing through the gap between the body and the air distributor will be colder than 400 ° C, and their combustion will be incomplete. Because of this, the walls of the furnace chamber will begin to be covered with dense soot, and very strong condensation will form on the walls of the chimney;
• If a solid fuel boiler has too thick walls, its thermal inertia will increase greatly. The water in the jacket will begin to boil. Even closing off the air supply pipe will not save the situation.

The following materials work well for creating the enclosure, per a variety of videos and blueprints:

1. Industrial gas cylinder. It has walls with the required thickness. There is no need to make a bottom in it. In addition, the rounded top contributes to better afterburning of flue gases. Solid-fuel long-burning boilers from a cylinder have a capacity equal to 12-15 kW.
2. Pipe with a large diameter. In this case, it is not necessary to bend a sheet of metal with your own hands. However, it is almost impossible to bend metal with a thickness of 4-6 mm at home.

A wood-fired boiler is typically composed of a 90-cm-tall pipe with a 30-cm diameter.

What should be the air distributor

An air distributor for an efficient solid fuel boiler should have the following characteristics:

1. The value of the diameter is 90% of the inner diameter of the body.
2. The presence of ribs welded from the bottom of the U-shaped profile (for wide structures) or strips of metal that diverge from the center and twisted clockwise (for narrow bodies). According to many schemes on the strips of metal should be welded a star with a radius that is equal to a quarter of the radius of the pipe, and a hole with a radius that is equal to a third of the radius of the ductwork. The height of the ribs depends on the diameter of the casing. If the wood boiler has a diameter equal to 60-80 cm, then The height of the ribs should be 10% of the diameter. For a 15-cm radius of the body, the ribs should have a height equal to 4 cm.
3. The bottom of the tube supplying air is at the level of the lower points of the ribs.
4. The thickness of the pancake for small radius cases should be large, and for large radius designs – small.

Schemes and numerous videos suggest that a pancake this thickness should be used for solid fuel heating boilers:

• 6-10 mm, if the internal diameter (D) is 30 cm;
• 6-8 mm, if the long-burning coal-fired boilers will have a D equal to 40 cm;
• 4-6 mm if the D is 60 cm;
• 2.4-4 mm, if long-burning wood boilers will have D = 80 cm;

The nearest larger of the aforementioned values should be used as the basis for the proportional calculation of the metal thickness for the air distributor for intermediate values of D.

Duct features

You must ascertain the element’s height and inner diameter in order to make it by hand. The area of the chimney is used to determine the first indicator. Following is the calculation formula: d = (0,5-0,55) * ((4S/π)^0,5). A chimney that is 175 square feet in area should be installed on wood boilers that have a radius of 15 cm and a height of 90 cm. The chimney opening has a diameter of 15 cm. For the device with these dimensions, an 8 cm diameter pipe should be used to make the air duct.

The height of the tube that supplies air to the system should be higher than the height of the boiler that burns wood. It must also extend 15 centimeters above the collar. There may be variations in the collar’s height. The operational gap between the collar and the pipe determines this. The gap can’t be more than 2.5 mm. The product of the gap and the number 80 determines the collar height. The collar should have a height of 1×80 = 80 mm if the double gap is equal to 2 mm (the multiplicity divided by 2).

It turns out that the coal-fired boiler’s air supply pipe needs to protrude by 8 + 15 = 23 cm. It’s worth noting that wearing the collar that appears in various videos is something you should always do. Efficiency is always increased when it’s present. Consequently, the efficiency of using a solid fuel boiler for home heating increases.

Doors and their dimensions

The easiest way to outfit a homemade solid fuel boiler is with two doors and a layer of sheet asbestos or basalt cardboard in the middle. The neck ought to be rectangular and projecting. This allows you to eliminate the gaps that will inevitably appear if you construct the door by hand from a single sheet of metal. Such gaps are undesirable because, as the video points out, they reduce the efficiency of the wood boiler, making it operate less efficiently.

In a country private house or dacha, the bottom of the furnace door should be positioned at a height equal to the sum of two-thirds of the body’s height. the pancake’s thickness and the height of the air distributor fins. Add 3 cm to the resultant figure.

The firebox door’s measurements should be as follows:

1. Height – one-third of the hull height without pancake thickness, rib height and 2 cm.
2. Width – a quarter of the length of the circumference of the firebox part. For the calculations, the outer diameter of the furnace body of the system is taken as follows.

Ash doors for solid fuel heating boilers should be positioned level with the bottom of the boiler. It ought to be raised sufficiently. This feature should be equivalent to the pancake’s thickness plus the height of the ribs underneath it plus ten to fifteen millimeters. It will be simpler to remove the ash and unburned portions with your hands if it is higher.

Water jacket

A wood boiler needs to have a water jacket that is centered, as the video mentions. This implies that it must always be the same distance from the flame body. The corner makes it feasible to accomplish this outcome. It needs to be welded to the body and formed into a circle with your hands. Naturally, there are two corners in the system: one at the top and one at the bottom.

The following characteristics of the water jacket of a domestic appliance for a private country home or dacha’s heating system are present:

1. The inner distance from the body to its wall should be 4-6 cm.
2. The thickness of the sheet metal can be 2.5 mm. If you want to make the jacket with your own hands more correctly, you need to take into account that 1 mm should account for 1 bar of operating pressure. This is provided that the jacket is not higher than 2 m.

According to the video, sheet metal can be used to make jackets. and look for a fitting pipe.

Manufacturing

In numerous videos, wood-fired boilers for heating are shown to:

1. Cut off the necessary section of pipe for the housing.
2. Cut out holes for the doors and chimney. The latter should be near the top at a distance, equal to the height of the air distributor with ribs plus 2 cm .
3. Cut out the bottom and top. Cut a hole in the center of the top.
4. Cut out the pancake and weld the ribs to it. A hole is made in the center. Weld the pipe for the air supply. Make a flap in it.
5. Weld the bottom, insert the air distributor, weld the top.
6. Fix the corners and the water jacket.
7. Necks and doors are welded on.

Related Articles:

Construction of a long-burning boiler The top-burning boiler’s characteristics Choosing a long-burning solid fuel boiler Building a water circuit boiler that burns for a long time

The principle of operation of a long-burning boiler, made with their own hands with the use of drawings.

It takes less time and effort to heat the house when you install a solid fuel boiler in a country home instead of using a furnace. It also comes with water heating installed. The models with a long burning mode are the most widely used. Craftsmen have experience making these kinds of boilers by hand using ready-made drawings.

Working principle

Prior to becoming an expert with a solid fuel boiler on your own, it’s a good idea to comprehend how industrial production boilers operate. and what explains their higher level of efficiency. Efficiency claims made on boiler passport documentation frequently surpass 90%. This is caused by the fuel burning for a very long time and almost completely.

In models using traditional solid fuels. When using wood, coal, or pellets, the fuel is heated and burned to ash in a common combustion chamber. In this instance, the smoke that is released enters the chimney first, then the pipe. These models have a small area of flame contact with the boiler walls and insufficient time to warm up properly. Consequently, smoke releases a large amount of heat into the atmosphere.

There are phases involved in burning wood in a long-burning boiler. They are first heated to a temperature of roughly 300°C. The process of heating causes the wood’s fibers to separate, smoke to be released, the logs themselves to become charred, and the vapors to become saturated with moisture.

When there is enough oxygen present in the furnace, combustible gases—a mixture of carbon compounds, sulfur, and hydrogen—burn brightly while heat is released. The boilers are specifically designed for this process, which is known as pyrolysis.

The gas generator is the section of pyrolysis units where the wood breaks down. The wood’s access to oxygen is restricted to prevent flue gases from igniting in the gas generator. Gases are burned in the afterburning chamber, a distinct area of the furnace that is accessed by forced blow-up or draught. A heat exchanger encircling the chamber is rapidly heated, and the water it contains then enters the heating system.

Benefits of wood-burning pyrolysis boilers for industrial production

• fuel economy – they can work on one load from 6 hours to 5 days;
• high efficiency, 90-95%;
• environmental friendliness – the smoke contains few gases and soot harmful to the atmosphere;
• safety – the smoke at the outlet has a temperature of 120-160 degrees Celsius;
• high level of process automation.

The following are drawbacks of buying long-burning boilers:

• tendency to condensate on the walls of the heat exchanger and chimney;
• high requirements to fuel moisture content – no more than 16%;
• high price, sometimes 1.5-2 times higher than the cost of conventional solid fuel boilers.

Long-burning boilers’ unique physical characteristics and internal workings are what give them their exceptional efficiency. They can be produced without the use of pricey materials or advanced technology. The majority of boilers are constructed using welding and consist of sheet steel. As a result, if you know how to operate a welding machine, you can create a boiler by hand.

Choice of design

You should think about the long-burning boiler’s typical designs and operation principle before you begin creating drawings by hand. and decide which is the easiest and most economical.

Pyrolysis boilers are separated into two categories based on the kind of apparatus:

• with upper combustion – shaft;
• with bottom combustion.

What do these qualities signify? Everything is very straightforward: the gas generation zone’s location is indicated by the type of combustion.

A door at the top of the furnace is used to load fuel into shaft-type boilers. The entire fuel volume is burned when combustion starts, and the smoke released as a result of this burns through the thickness of the firewood and into the lower part of the furnace where it burns up after being enriched with air thanks to forced supercharging. In this instance, the firewood burns more steadily and with additional heat.

In bottom-burning boilers, the gas afterburning chamber is at the top and the furnace is at the bottom. They move air naturally through draught, so forced air blowing is not necessary. One benefit of these boilers is that they are not dependent on the electrical grid. Minus: lower loading volume and efficiency, which reduces the amount of time that the system can run continuously.

The working principle of a homemade pyrolysis boiler is demonstrated in this video.

The most basic type of boiler is cylindrical in shape. They have a heat exchanger encircling the furnace, and heat is removed from the furnace chamber all the way around. You can construct a boiler like this by hand using two different-diameter metal pipes or sheet iron.

How to make on your own?

Using your own hands, assemble the boiler in accordance with the final drawing displayed in the figure. Although the dimensions shown in the drawing are flexible, it’s crucial to pay attention to the ratios.

The principle of operation of this heating unit is as follows:

The boiler room’s ceiling height needs to be at least 2.8 meters in order to raise the fuel distributor to the point of maximum loading!

• The fuel smolders, releasing flue gases, which finish burning in the upper part of the firebox. Such a boiler can be heated with wood, sawdust, pellets, as well as wood waste – chips, wood shavings, construction waste. For each type of fuel it is necessary to choose a different mode of air supply.

Unlike factory models, the boiler’s design is not airtight, so it needs to be installed in a boiler room with adequate ventilation because burning wood releases harmful carbon monoxide among other gases.

The device’s efficiency is not as high as industrial analogs’, but considering the cost of manufacturing, this is not a major drawback.

Materials and tools needed

Since welding is used to assemble boilers, having a welding machine and the know-how to operate it is a must. To weld with your hands, you’ll also need two to three packs of electrodes with the right diameter.

You will need a Bulgarian machine with cutting wheels for cutting the material, and you will also need grinding wheels for cleaning the seams.

You will also require the following measuring and marking equipment: an angle, a tape measure, a marker, and a circle marker for marking circles.

To press the final product, a compressor will be required.

Materials and purchased products:

Manufacturing of the body and heat exchanger

The body of the boiler is assembled first.

. as the most critical unit subjected to significant thermal loads. The other parts are adjusted in such a way as to create the most airtight construction and avoid smoke leaks and heat loss.

• In the lower part of the inner tube make a rectangular hole for the ash pan door. The door itself can be made of sheet metal or a ready-made cast-iron door can be installed. Thermal insulation of the door is not necessary – there will be no high temperatures at the bottom of the furnace, so the door can be made as a single one. It must necessarily be equipped with a gate valve, tightly closing the door, otherwise there will be an air inflow, which will disrupt the oxygen balance in the boiler.

• The door of the furnace chamber is placed in the upper part of the housing. Here the temperature regime will be more severe, so the door is better to make with your own hands from sheet metal, and make it double, as in the photo, with a gasket of two layers of asbestos. This, firstly, will create better thermal insulation and will help to avoid burns, and secondly, will increase its rigidity, and during heating the door will not move. The door is similarly equipped with a tight shutter.

• Side or back of the upper part of the body welded flue pipe from a profile pipe with a hole for connection to the chimney. In this case, pay special attention to the quality of the seams on the outside and inside of the jacket – due to the wrong mode can form condensate here, and in combination with flue gases, it contributes to corrosion. Welded seams, which have sinks and not removed scale, are subject to corrosion most strongly.

• In the upper and lower parts of the water jacket, weld spigots for the supply and outlet of the coolant. They are made from scraps of inch pipe of the required length, with a thread on the outer end. It is more convenient to place the pipes on the side of the boiler, away from the flue pipe, so that the smoke exhaust and heating systems can be conveniently maintained.
• The boiler drum is equipped with legs made of scraps of angle or channel – so it will be more convenient to adjust it during installation.
• A removable cover with a diameter of 46 cm and a hole in the center of 6.5 cm is made – it will be installed tightly on the body.
• All parts and seams are cleaned with a bolgar and covered with heat-resistant paint based on siliconorganics, designed for painting stove elements and automotive gas removal systems – it tolerates heating to a temperature of at least 800 degrees Celsius.

Air distributor

A detail that is equally crucial is the air distributor. It is preferable to use thick metal for it, preferably at least 5 mm. First of all, because of its thinner thickness and location in the zone of active combustion, it may eventually deform and burn out. Secondly, the fuel mass will be better compressed by the air distributor if it is thicker.

1. From the metal cut a circle with a diameter of 38 cm with a hole in the center Ø 6 cm. A Ø 6 cm pipe with a length of 120 cm is tightly welded to the opening. This pipe will supply air to the combustion zone.
2. At the bottom of the distributor, weld the impeller – diverging air ducts made of 25 mm angle or channels. Their number can be different, the more channels, the more evenly the fuel will burn.
3. In the upper part of the pipe must install a gate valve or gate valve to regulate the air flow, as well as provide a loop to connect the chain, which the distributor will be raised to the upper position.

The boiler needs to be equipped with forced supercharging in order to run on coal. In this instance, the distributor pipe is telescopic, with a blowing fan located in its upper section.

A long-burning boiler should be leveled and set on a level surface to prevent a strong skew from impairing coolant circulation.

The air distributor is inserted into the furnace, and a cover is placed on top. The cover is secured to the body either by welding or by using asbestos cord to create tension while sealing.

Attach the chimney’s flue pipe. The water jacket’s spigots are connected to the heating system’s pipes.

The boiler can begin heating after the system has been filled. Before it is loaded to its maximum capacity, a test firing is carried out using an incomplete batch of fuel to adjust the modes.

Even though it has a simple appearance, this type of boiler can effectively solve the heating problem by heating a workshop, garage, or village or country house.

Long-burning boilers with their own hands

Classification of long burning boilers

There are numerous manufacturers of various kinds of long-burning boilers on the market today. They are separated based on factors like the kind of solid fuel and the method of combustion.

The fuel type that is appropriate for long-burning boilers is used to categorize them:

1. There are devices that wood-fired. Some of them are heated with pellets (pellets from woodworking waste).
2. Universal solid fuel boilers are also produced, for which it is possible to use different types of fuel coal, briquette, wood and their combination.

Simple combustion is the method of combustion used by the majority of the devices. More efficient gas-generator boilers were created during the improvement process. They are fired using wood gas and firewood. These gadgets are practical; they produce very little ash and don’t produce soot.

In addition to the techniques mentioned above, boilers are classified based on the electricity carrier. They are both reliant and autonomous.

Principle of operation

This kind of boiler works on the top combustion principle, which states that the fire burns from the top to the bottom of the hearth. Many manufacturers currently use the boiler with this system, which was first created in 2000 by the Lithuanian company "Stropuva."

Fuel is inserted into the spacious combustion chamber in the form of wood, briquettes, coal, or sawdust. The device’s 500 cubic centimeter volume allows it to operate continuously for several days. The air is forced through the duct by means of an easily adjustable fan. The heat exchanger receives the heat that is released during combustion.

This principle of operation produces a significant amount of heat calories that burn for a long time.

Main advantages

Because they have so many benefits, long-burning boilers are highly sought after by the public.

• A large volume of the furnace, in which solid fuel is laid;
• the possibility of using different types of fuel – pellets, sawdust, firewood, peat, briquettes;
• long period of combustion without adding fuel product;
• high heat output with economical fuel consumption;
• easy operation;
• environmental friendliness – carbon dioxide emission is minimal.

Boiler models powered by solid fuel are continuously evolving. The majority of modern units have air injection fans and electronic automation systems installed. With minimal fuel consumption, they can keep the air temperature at the desired level in reasonably large rooms.

Homemade boilers

Although this heating unit is very popular, it is not inexpensive at all. Many people who wish to purchase it cannot afford its average price of roughly 1000 у.е. A long-burning boiler’s capacity, which controls the air temperature level and the usable area of the heated room, is the primary cause of its exorbitant cost. Contemporary domestic manufacturing companies are developing a lower-power device that will be more reasonably priced.

These devices are assembled by many craftsmen on their own. Reliable and productive units are the product of skilled craftsmen. This technical device is challenging to assemble, and any mistake could result in an explosion, so this kind of work should only be performed by professionals.

Mine boiler

Long-burning boilers are available in a number of varieties and can be manufactured on their own. A homemade boiler with a shaft is one of them.

This kind of boiler runs on sawdust, coal, peat, and wood. The chamber can hold 40–50 kg of firewood for loading. The boiler operates for four to five hours at maximum capacity and load, and for twenty-four hours at minimum power and maximum load. 75 percent of the time, the efficiency is high. 15-20 kW of minimum power. Because it has automatic power regulation, the boiler operates in automatic mode.

Component	Description
Fuel Storage	The long-burning boiler has a storage compartment for the fuel, like wood pellets or logs, which feeds into the combustion chamber.
Combustion Chamber	This is where the fuel burns, producing heat. It"s designed to efficiently burn the fuel, releasing heat energy.
Heat Exchanger	After burning, the heat is transferred to water circulating through pipes in the heat exchanger, heating it up.
Water Circulation System	The heated water is then circulated through the house via pipes to provide warmth to radiators or underfloor heating systems.
Controls	The boiler is equipped with controls to regulate the fuel supply, airflow, and water temperature, ensuring efficient operation.

Gaining knowledge about the functioning of a long-burning boiler can help you design more effective home heating systems. These boilers provide an economical and environmentally friendly way to heat your home during the winter by optimizing fuel consumption and reducing waste.

A long-burning boiler’s combustion chamber, which produces heat through controlled burning of fuel (usually wood or pellets), is its central component. The air supply and fuel feed are controlled to maintain a steady, even burn during the combustion process, which is meticulously supervised to guarantee maximum efficiency.

The capacity of long-burning boilers to store and release heat over extended periods of time is essential to their efficiency. This is accomplished by using thermal mass, which is frequently found in the form of dense materials like stone or ceramics. These materials absorb heat during combustion and release it gradually into the surrounding area as needed.

Long-burning boilers can help with environmental sustainability and overall energy savings in addition to providing heat. They contribute to a decrease in carbon emissions and dependency on fossil fuels by using renewable fuel sources, like wood pellets, in place of conventional heating systems.

Moreover, contemporary long-burning boilers come with sophisticated automation features and controls that enable exact control over fuel consumption and temperature settings. In addition to providing homeowners with increased convenience, this guarantees peak performance and economy all through the heating season.

To sum up, long-burning boilers present a strong case for effectively and sustainably heating and insulating homes. Homeowners can ultimately achieve increased comfort, cost savings, and environmental advantages by making educated decisions about their heating needs by having a thorough understanding of how these boilers are constructed and function.

Video on the topic

Working principle of the long burning boiler "MECHANIC"