With the advent of technologically advanced and economical gas boilers with two heating circuits of traditional solid fuel stove design, a complete exit from the market was predicted. And yet, the usual principles of operation of heating equipment retain their place, actively developing in different directions - both in terms of functionality and in terms of design. This is best evidenced by coal-fired ovens, which are steadily mastering all new technological solutions.
Unit design
The body base of the equipment is usually an all-welded frame made of thick metal. The design provides for the infrastructure of the combustion chamber with conventional pipes through which hot gases circulate. Also, the device of the coal stove has a system of outlet pipes for connection to the chimney, a locking mechanism and doors with a damper. The lower part is formed by an ash collection system with grates and passingblower channels. In some modifications, a cooking floor is provided, which must be heated to high temperatures. Again, depending on the modification and customer requirements, there may be decorative elements - including in the form of a stylistic design of the convector, ash drawer and door.
Types of coal stoves
Design designs may vary depending on the power characteristics, dimensions and diameter of the inlet and outlet pipes, but models made of different case materials will always have fundamental differences.
Metal in most cases is the basis, but which alloy should be preferred? The main competition is between steel and cast iron structures. The former are famous for their high thermal conductivity, can be repaired in case of serious damage by the same welding and almost do not form carbon deposits on their surfaces. On the other hand, steel does not tolerate condensation, which can lead to corrosion in the future.
What does a cast-iron coal stove boast of? This is the traditional and most popular design of solid fuel units, which is explained not only by good thermal conductivity, but also by protection from negative external influence processes - both thermal and hydrochemical like corrosion. But cast iron has a weak point. While the steel hull can be repaired, a crack in the cast iron structure cannot be repaired.
Functional elements
As the designs of heating equipment develop, approaches to the implementation of functional mechanics also change. In modern furnace systems, the following set of working bodies is laid:
- Door. As a rule, it opens to 120 degrees, allowing you to load fuel material and control the combustion process. By the way, the doors with a translucent screen do not require opening at all for visual observation of the processes inside the firebox.
- Convection pipes. It cannot be said that this is a fundamentally new solution, but the optimization of the structural interface with the furnace has made the conventional system more productive in terms of heat transfer.
- Metal grates for coal stoves also increase the efficiency of the heating process, ensuring uniform combustion throughout the entire depth of the furnace.
- The presence of protective sleeves in the design increases the operational life of the unit. These elements take on the thermal impact from burning fuel, thus protecting the basis of the furnace design.
- The damper and overall chimney interaction infrastructure is the most important component of the stove in terms of regulating the combustion process through air draft control, but this operational nuance will be considered separately.
Features of double-circuit ovens
Like modern models of electric and gas boilers, coal-fired stoves support the ability to provide a hot water system.water supply (DHW). To do this, a special channel is provided for heating water and circulating it through pipes to its final destination - a kitchen, a bathroom or other consumers. However, to implement such a system, several technological conditions must be met in advance.
Firstly, a coal-fired stove for a water-heated home can effectively distribute the coolant over two circuits only with the support of a circulation pump. Secondly, in order to reduce the time for hot water to enter the circuit, it is recommended to provide a buffer tank in the system. For a private house, you can use a storage tank with heating circuits of 30-50 liters. The water in this tank will be constantly hot according to the settings of the oven automation.
Features of long burning stoves
In this case, one of the technologies for increasing the energy efficiency of heating equipment by regulating the flow of oxygen is considered. As already mentioned, the gate connecting the design of the furnace with the chimney channel directly affects the intensity of fuel combustion. But the usual mechanical design is largely dependent on the climatic conditions on the street and even with manual control is not able to give the expected result in full.
In a modified form, a long-burning coal stove for the home is additionally provided with a compact fan unit. This is a low-power thermally protected device, the task of which is to artificially regulate traction. HowDoes the function of the fan affect the combustion process? Coal as such, in principle, is distinguished by a long combustion compared to firewood. Intensive air injection can increase heat generation under certain conditions or even reduce it. Support for long burning is also possible with a minimum open damper with a gate, but it is thanks to the fan that the process control does not stop.
This control scheme is completely autonomous, since the operation of the cooler can be controlled by automation associated with temperature and ventilation sensors.
Operating restrictions
The use of coal fuel and in general solid fuel stoves involves some restrictions associated with elementary fire safety rules. Among them, it is worth noting the following norms:
- The unit must not be used in areas where flammable materials are present. At the same time, it is recommended to store coal in bags made of heat-resistant material. Another thing is that fuel cells have their own requirements in terms of storage, and the main danger in relation to coal will not be temperature, but humidity.
- Only materials approved by the manufacturer should be used as fuel. It should be noted that a coal stove for a home usually allows the use of pellets with firewood, if they are suitable in size. However, liquid fuels such as kerosene, diesel and gasoline are prohibited.
- Operation of the equipment is possible only after a major installation in a room prepared for heating. ATmobile houses, tent structures and trailers, such units are not used.
Which coal is suitable?
For domestic use, experts advise using anthracite grades. It sustains combustion for a long time, emits little smoke and leaves behind a small amount of ash waste. By the way, in terms of the amount of heat released, anthracite is adjacent to coking coal - about 8500 Kcal / kg. In this regard, the least attractive option will be brown coal, the heat release of which is at the level of 4500 Kcal/kg. On the other hand, anthracite often causes problems during ignition and is not cheap. For example, coal in bags of 50 kg will cost 500-600 rubles. As the volume of a one-time purchase increases, the price tag logically decreases, but relative to the same brown coal, this is a higher cost.
Installing the oven
The unit is installed on a flat surface with a heat-shielding base. It will not be superfluous to pre-prepare a 5-10 cm thick screed for the structure. As a rule, massive equipment does not require special fixation - it is enough to correctly position the body in terms of optimal connection with adjacent communications and the chimney.
Lightweight coal stoves are additionally attached to the floor with metal brackets or heat-resistant anchors. Again, the possibility of installing the latter should be thought out in advance when installing a screed or preparing a rough floor surface. When choosing the location of the furnace, it should also be borne in mind that, according to the installation rulesboiler equipment, the distance from their surface to combustible objects and wall decoration should be from 15 to 50 cm, depending on the type of material and its ability to sustain combustion.
Chimney installation
For the organization of the output of combustion products in private homes, it is recommended to use modular pipes. Manufacturers of such equipment offer complex sandwich structures with the necessary attachment and connection points. An essential feature of this type of modular chimney is the presence of a heat-insulating layer and the ability to withstand temperatures of hot gases of the order of 1000 ° C.
As for installation, from coal stoves in one-story buildings, output up to 5 m high is usually calculated. The assembly is carried out by means of clamp and lock joints, which are provided for in the design of the elements. The main task of the contractor is to think over in advance the points of attachment of the contours to the walls and prepare a technological hole in the roofing. For this, special outlets with deflectors and draft regulators are also provided.
Preparing for workflow
Immediately after installation, it is necessary to check the reliability of the structure, the condition of the working parts, the presence of the grate and the ash box. The first warming up is desirable to be carried out with the ventilation running and the windows open. This is important so that not only the products of combustion are weathered, but also the harmful factory oils that covered the structure under conservation conditions.
Test intensive burning modeshould be maintained for about 1 hour, after which the unit should be left to cool completely. It is not necessary to touch its internal surfaces at this stage, since after heating, the internal heat-resistant paint will become stable for a while.
How to heat the stove?
There are special operating modes for coal-fired heating stoves and boilers. The main feature of this process is the metered loading of the combustion chamber relative to one heating session. For example, how to heat the stove in standard mode for several hours? A series of bookmarks is performed, each of which should form a layer of no more than 15 cm. As it decreases by about 50-60%, the volume of fuel can be replenished. If there are difficulties with ignition, then you should always have thin wood for kindling in stock. From above, they are also covered with a layer of fine coal 5-7 cm high.
Conclusion
The design of furnace units has advanced significantly in recent years. In addition to the possibility of providing domestic hot water and autonomous traction control, new functions have also appeared - pyrolysis combustion and automatic control. But are the new advantages so significant compared to the advantages of laying a coal-fired brick oven? After all, traditional furnace structures are superior to factory-made metal equipment in terms of heat transfer and heat retention.
In practice, the mass transition to optimized designs is driven by practicality, ergonomics and functionality. Preference is givensmall size and ease of maintenance of the equipment, and in terms of heat output, cast-iron coal-fired units are able to heat large houses, also supporting the function of water heating.
