Review of solid fuel boilers with automatic fuel supply. Automatic coal-pellet boilers Automatic coal boilers

Criteria for choosing a solid fuel boiler

The main criteria for choosing a long-burning coal boiler for your home:

• Energy dependence.
• Availability of fuel.
• Dimensions and weight.
• Availability and functions of the automation system.
• Sufficient power.
• Availability of additional electric heater.
• Price.

If there is no access to a central gas supply, then a coal boiler with automatic fuel supply can become a worthy alternative and completely replace the gas analogue.

1. Automatic boiler "Yamal" long burning
2. Coal boiler "Barin" with automatic feed
3. Solid fuel automatic boiler "Carborobot"

The problem of organizing automatic supply of solid fuel has always worried the developers of solid fuel boilers. If in the case of firewood it is quite problematic to organize it, then when using coal and pellets the situation looks more realistic. Today in our review we will look at the most popular automatic coal boilers, and how they implement a mechanism for delivering fuel to the combustion zone.

Automatic feeding of pellets is most often done using a soft or hard auger. Coal can be delivered to the furnace using a screw conveyor only if its fractions are sufficiently small in size and homogeneous, but most often this is not the case. Today we will look at several coal boilers, in which the mechanism for automatically supplying fuel from the bunker to the combustion chamber is implemented in different ways.

Automatic boiler "Yamal" long burning

Anyone who has heated their home with coal knows about main problem of this fuel, preventing the organization of its automatic supply to the solid fuel boiler. Usually its fractions differ in size, hence automation of supply in the form in which it is implemented, for example, in pellet boilers, becomes impossible. The developers of the Yamal automatic coal boiler solved this problem by using completely new way feeder, capable of working effectively even with fractions of different sizes.

Photo 1: Domestic coal-fired boiler "Yamal" with automatic feed

The essence of this method, like everything ingenious, is extremely simple. Inside the bunker with inclined walls there is a conveyor that picks up pieces of coal and raises them higher and higher. At the highest point there is a gear crusher, which passes fractions of suitable size, and those that are larger either break apart on its teeth or fall back into the hopper. As you can see, the mechanism does not contain complex structures and even if it fails, anyone can get it working with their own hands.

The operation of the Yamal boiler is fully automated. Fuel supply, ignition, slag discharge, power adjustment - all these processes occur automatically under supervision electronic unit management. When the fuel bunker is completely filled and the diesel burner is charged, the coal boiler is capable of independently heating the room for 20 days.

The manufacturing company produces three Yamal models of different power. Below are their main technical data:

Taking into account the fact that pellets have not yet become widespread in our country, a robotic coal heater is perhaps the only affordable way organize autonomous system heating using solid fuel in our country. We talked about it in more detail in one of our previous reviews.

Coal boiler "Barin" with automatic feed

In the Barin solid fuel boiler, the automatic supply is organized in a slightly different way. Here the hopper is located above the boiler and the coal falls into the combustion chamber under the influence of gravity. Its caking on the walls of the fuel tank is prevented by a collapser system.

Having passed through the shaft connecting the firebox and the bunker, surrounded by a water jacket, the coal ends up on water-filled grates, where it is burned. The design of the shaft makes it possible to pre-dry the fuel so that it can be burned more efficiently in the furnace of the Barin boiler. Hollow grates are filled with coolant both to increase the heat removal area and to prevent coal from burning to their surface. Directly below them is the first compartment of the ash pan, in which mostly fine ash accumulates.

The burnt coal is pushed into the second compartment of the ash pan using a scissor mechanism. On a way flue gases, still containing unburned fuel particles, there is a secondary afterburning chamber lined with fireclay bricks. Here, high-temperature afterburning of gases occurs, after which they pass through a tubular heat exchanger system and are discharged into environment through the chimney.

The boiler operation is controlled and monitored by an automatic control system. It maintains the combustion process at the required level, controls temperature and pressure, and also performs many other functions. The owner’s task comes down to setting the necessary operating parameters once, and then only adding coal to the hopper and periodically cleaning the ash pans.

The table below shows some specifications automatic boiler "Barin":

You can learn more about the device, operation, advantages and disadvantages from a special review on our website kotlydlyadoma.ru dedicated to this model.

Coal boiler for heating a private house: traditional, long-burning, pyrolysis

A coal boiler for heating a private home is an excellent alternative to gas boilers. It is often installed in regions where there is no gas main. Coal is a common and therefore affordable fuel. It's easy to buy and the price won't be very high. Modern coal-fired stoves and boilers feature several important technical innovations that make them more efficient and economical to operate.

Coal-fired pyrolysis boilers

Types by combustion method

A coal boiler can be classified in different ways, depending on the method of burning fuel:

• traditional units (combustion occurs from bottom to top);
• long-burning coal boilers;
• pyrolysis

In addition, automatic and semi-automatic coal boilers are popular; they will also be discussed below. Let's consider each type of equipment separately.

Direct combustion - bottom-up

The principle of ignition here is this: fuel is poured into the combustion chamber. The air required for combustion enters through the grate from below, and combustion occurs from the bottom of the fuel pile, spreading upward. These are classic boilers, known to everyone for a long time.

Currently, they are characterized by a long period of fuel filling due to the creation of combustion chambers of a special design, the installation of water jackets, air supply channels to the firebox, as well as many innovations and functions. At the same time, this type of boiler equipment still remains the cheapest due to its simple design and, often, due to the impossibility automatic control.

Long burning coal boiler

Here, fuel combustion occurs in reverse: from top to bottom. The procedure for igniting the unit has also been changed: first, coal is poured in, and then it is burned in top layer heaps. Then, for the purpose of the oxidation process, through a special air supply system, it is supplied not from below, but from above, directly into the combustion zone. In the case of such combustion, fuel loading is needed much less frequently.

Long burning coal boiler Unilux

The only thing that needs to be taken into account is the fastidiousness of long-burning solid fuel boilers on coal to the quality and moisture content of the fuel. If coal is not high-calorie, then no matter how much you want, you will not be able to squeeze out much heat. When using wet fuel, the boiler will go into smoldering mode for a very long time, and will give off practically no heat, since all the energy will be spent on evaporating the water. At this time, a lot of soot is formed, the level of heat output decreases, the boiler and smoke exhaust ducts become clogged.

The situation is aggravated by the accumulation of condensation. Due to the fact that the heating unit does not warm up, the moisture evaporates and turns into condensate, mixes with soot, flows again into the combustion chamber and chimney, often flowing out of the boiler and forming a puddle. With everything you can feel and bad smell. Therefore, if you use wet coal, know that the chances of achieving quality heating are reduced to zero, and you risk simply destroying the structure.

Long-burning coal boilers for private homes are very demanding on fuel; the fuel moisture content should not be higher than 15%!

There are also rules regarding sintering - only low-sintering grades should be used, however, the instructions for all devices contain quality recommendations that should be taken into account. Another difference between a coal-fired boiler is that it cannot be “refueled”. Only after one portion has burned through can you add another portion so as not to disrupt the entire process. Therefore, these are units with a cyclic operating principle.

Although such boilers are quite capricious, they can be an excellent solution due to their energy independence, fuel efficiency, reliability and low maintenance requirements.

Pyrolysis is an effective way to burn fuel

A coal pyrolysis boiler requires adding fuel only once every 20-30 hours; certain models generally heat up to 4-6 days. However, the combustion process itself is much more complicated.

All devices are controlled automatically and require forced air supply to the afterburner. This means that the functioning of the system depends on the electrical network.

The difference between the pyrolysis unit and the design: there are two combustion chambers.

Fuel is placed in the first firebox, and the coal is broken down into coke and gases. In the second there are hot gases, afterburning occurs here.

The principle of operation of such devices is as follows: after the coal is ignited, the automation reduces the air supply, while the fuel does not burn, but smolders. In this mode it is highlighted large volume gases that can also burn. They circulate into another chamber, where they are also mixed with air and burned. As a result, the fuel is almost completely recycled. This can be explained long burning and economical effect (in order to obtain the same amount of heat energy, less coal fuel is required).

One can highlight the disadvantage of a pyrolysis automatic coal boiler - high price. But it is worth saying that the cost pays off quite quickly due to economical fuel consumption. The requirements for coal and firewood in these units are the same as for devices with an upper combustion principle.

Boiler with automatic coal supply

An automatic coal boiler is different from traditional themes that it contains additional devices. Automatic devices do not require the constant presence of the owner nearby, increase system performance and minimize fuel consumption and the amount of remaining ash.

Automation functions:

1. It controls the supply of coal to the combustion chamber. The design involves a filling hopper with an auger (or drum) for automatic fuel supply. However, the user only needs to replenish the fuel supply in the bunker once every few days (from three to ten).
2. Monitors the air supply to the combustion zone. Optimal supply and initial heating of air also contribute to the uniform combustion of coal and the efficiency of equipment operation. The coal boiler with automatic fuel supply has efficiency 90% (this is more compared to other types of structures: a conventional boiler - 70%).
3. Automatically dumps ash with movable grate bars.

The device’s auto operating mode is adjusted by parameters set by the owner. In accordance with the temperature values ​​for heating water and heating indoors, the automation activates combustion or maintains smoldering mode for up to five days. Thanks to continuous combustion, ignition can be carried out powerfully once per heating season.

The principle of automatic fuel supply to a solid fuel boiler

The operating principle of the automation is not complicated. Depending on the degree inside the boiler equipment, liquid capacity, pressure force, commands are sent to the air supply sensor. If the air speed increases or the supply decreases, combustion increases or, accordingly, weakens. This also adjusts the heating temperature of the water inside the heat exchanger.

Electricity is required to operate a coal-fired automatic boiler, which is why such units are classified as energy-dependent. They need the presence of a network (battery, outlet).

Coal-fired equipment is 20-40% more expensive than wood-burning units. But built-in automation makes it possible to reduce heating costs. According to user reviews, fuel savings can sometimes reach 50%. Thus, it can be argued that heating with coal is one of the most profitable for private residential buildings, workshops, workshops...

Types by material of manufacture

Besides different ways Combustion boilers can vary in material, that is, they are made of cast iron or steel. The two options have their own advantages and disadvantages that should be considered when choosing the right device. Let's give brief description:

• steel (a special boiler is used for manufacturing) burns out faster, is less resistant to corrosion processes, but does not cause problems during repairs;
• cast iron is resistant to corrosion and boasts a long lasting operational period. However, it may burst due to temperature changes or shock. Moreover, cracks cannot be welded; it will be necessary complete replacement damaged part.

There is one more nuance: to install equipment made of cast iron, you will need a separate foundation (if its weight with the coolant in the circuit, fuel and chimney exceeds 700 kg). Many people believe excellent option devices made of these two materials: the combustion chamber is made of cast iron, and the body is made of steel.

How are all types of coal boilers heated?

The fuel for this type of equipment also has its differences. Property owners should take care in advance about the selection, delivery and proper storage required quantity fuel. Coal fuel today can be purchased from many companies, but not every person is aware of the difference between one type of coal and another. The market currently offers the following fuel options:

1. Long flame coal. One can guess that this type fuel burns very quickly and generates a lot of heat. It is often installed for heating houses outside the city, as well as country houses.
2. Gas coal - this is the name of coal due to the fact that when burned it emits a large number of gas that can be burned in pyrolysis devices. This is an excellent option for gas generator boilers because a lot of heat is released during combustion.
3. Anthracite is a type of coal with a long burning life. This perfect solution for modern boilers, because anthracite releases a lot of heat energy and burns slowly, without emitting pyrolysis gases.

It is imperative to take care of proper storage of coal. It must be protected from rain and not stored in conditions of high humidity.

It is advisable to protect the fuel from damp, cold winds; it would be a good idea to find a spacious, dry room for storage. This is one of the disadvantages of all solid fuel units: you need to look in advance for where to store coal so that it saves everything beneficial features.

Among the extensive family of heat generators that burn various types of biomass, solid fuel boilers with automatic fuel supply occupy a special place. They are becoming increasingly in demand because, unlike traditional wood-burning units, they fully satisfy one of the main requirements of users - ease of maintenance and operation. IN this material we will review existing boilers with automated loading and figure out what types of solid fuel they can use for their operation.

Types of automatic boilers

The main disadvantage of a solid fuel heat generator is the frequent loading of wood or coal. To eliminate it, you need to automate the fuel supply, but this is not so simple; a device for loading logs has not yet been invented. But if the fuel has a free-flowing structure, then it is much easier to solve the problem, which was done in the corresponding heating units. Based on the types of bulk biomass burned, they are divided into the following types:

• pellet boilers with automatic fuel supply;
• coal automatic heat generators;
• units operating on wood chips;
• universal boilers.

Let's consider each of the presented types in more detail.

Pellet boilers

Pellets are a universal biofuel produced in the form of solid cylindrical granules. It is universal because a variety of wood waste and agricultural products are used as raw materials for its production: sawdust, wood chips, sunflower husks, straw, and so on. In turn, a pellet boiler is a perfect, fully automated unit that requires human attention no more than 1-2 times a week. In addition to this advantage, the heat generator has others:

• the highest operating efficiency among all solid fuel boilers – up to 90%;
• high degree of automation, including ignition;
• complete absence of inertia and danger of coolant overheating. After the supply of fuel and air to the combustion zone is stopped, the flame dies out almost immediately;
• environmental friendliness and cleanliness in the furnace room.

Of the shortcomings, only two significant ones should be noted: this high price equipment and service, as well as the need to store the granules in a dry room so that they do not become damp and crumble.

All the advantages that a pellet boiler has stem from the successful design of the fuel supply system and burner device. The unit itself is nothing special - a steel or cast iron combustion chamber with a two- or three-pass heat exchanger, surrounded by a water jacket. Various sensors are built into the body of the boiler, operating together with the controller and transmitting to it information about the presence of draft, temperature, pressure, water level in the boiler block, and so on.

Note. Units of some foreign manufacturers designed to work with various types flare burners. A burner for natural gas, diesel fuel or your choice can be built into the same housing.

Of much greater interest is how the automatic fuel supply into the combustion chamber of a pellet boiler works. Here the main element is the screw conveyor, which moves the granules into the combustion zone.

Fuel is poured into the auger under its own weight from the loading hopper, and is dosed depending on the temperature of the coolant. It is monitored by the controller using a corresponding sensor and regulates the pellet consumption by controlling the electric motor of the auger and fan - air blower, thereby changing thermal power unit. If the loading hopper is close to empty, then based on a sensor signal, the controller informs the homeowner about this, and then stops operation.

Many automated systems pellet feeds can be controlled remotely via GSM communication or mobile app for smartphone. This depends on whether the controller has the corresponding function.

Automatic boilers for coal and wood chips

The design and principle of operation of these units is not much different from pellet units. The screw conveyor in the same way supplies coal to the firebox at the command of the control unit, air injection and ignition work in the same way. The difference is in the design of the auger itself; for coal it is made more massive, and accordingly, the power of the electric motor is increased. In addition, a coal solid fuel boiler with automatic fuel supply requires fuel of a certain quality and humidity. This is due to the design features of the retort burner used in such heat generators.

Heating units that burn wood chips have one additional function– wood chopping. After all, the length of the chips can be different and it is impossible to provide an auger for it. To make the chips the same size, a rotary chopper knife is built into the supply pipe between the hopper and the auger. Both the conveyor and the knife are driven by one powerful electric motor. Many people offer such products European manufacturers, for example, the Austrian automatic solid fuel boiler using FROLING wood chips.

A little about universal units. Their convenience is that if there is a shortage of any type of bulk fuel, you can switch to regular firewood at any time. For this purpose, the design provides an additional combustion chamber for loading wooden logs. Of course, the efficiency in this case is significantly reduced (from 90 to 80%), since the heater operates in idle mode. solid fuel boiler. One more circumstance should be noted: every manufacturer of automatic boilers is trying to expand the range of fuel burned by modernizing the supply system. Therefore, some products, in addition to pellets, can use coal dust, eco-peas and even seed husks. An example of this is the Polish universal boilers DEFRO DUO UNI.

Conclusion

We are already accustomed to the idea that the operation of a solid fuel boiler requires constant supervision, frequent loading and maintenance. But progress does not stand still; every year new models of automatic units appear at exhibitions and the market, relieving us of the duties of a home fireman.