Coal is first grade. Choosing coal for a solid fuel boiler: which coal is best for heating a house? Coal storage rules

A– anthracite

B– brown

G– gas

D– long-flame

AND– fat

TO– coke

OS– lean sintering

SS– low caking

T- skinny

There may be an abbreviation at the end of the name of the coal brand OK(OK1, OK2), indicating the degree of oxidation.

Also, depending on the degree of enrichment, coals are divided into concentrates, middlings and sludge. Concentrates are typically used in boiler houses and to generate electricity. Industrial products are usually used for the needs of metallurgy. The sludge can be made into briquettes and sold retail to the public for personal use.

Depending on the degree of coalification (metamorphism), there are brown coals, hard coals and anthracites. Brown coals have the lowest calorific value, and anthracite has the highest.

Bituminous coals have the most favorable ratio of price and specific heat of combustion. Coals of grades D, G and anthracite find their use, as a rule, in boiler rooms, because they can burn without blowing. Coals of grades SS, OS, T are used to produce electrical energy, because they have a high calorific value, but the combustion of this type of coal is associated with technological difficulties, which are justified only if a large amount of coal is needed.

In ferrous metallurgy, grades G and Zh are usually used for the production of steel and cast iron.

By marking the coals, you can immediately determine their fraction.

Designation:

P– (slab) more than 100 mm

TO– (large) 50-100 mm

ABOUT– (walnut) 25-50 mm

M– (small) 13-25 mm

WITH– (seed) 6-13 mm

Sh– (piece) 0-6 mm

R– (ordinary) mine 0-200 mm, quarry 0-300 mm

The fraction of a given grade of coal is determined based on the smaller value of the finest fraction and the greater value of the largest fraction indicated in the name of the grade of coal. So, for example, the fraction of the DKOM brand (K - 50-100, O - 25-50, M - 13-25) is 13-100 mm.

The article is devoted to coal grades and their differences. To distinguish types of coals, they are divided into grades:

• A - anthracite
• B - brown
• G - gas
• OS - lean sintering
• SS - low caking
• T - skinny.
• D - long flame
• F - fat
• K - coke

In total, there are 17 grades of coal: “D”, “DG”, “Zh”, “KZh”, “G”, “GZhO”, “GZh”, “K”, “KO”, “KSN”, “KS” "", "OS", "TS", "SS", "T" "AM", "AO", "AS", "AK", "AKO", "ASh" "B1", "B2", "B3 " Based on enrichment, coals are divided into industrial products, a branch of metallurgy. For concentrates - this is our energy, for power plants and sludge - for the population and for coal briquetting. Oxidation is designated OK, OK2, OK1.

Designation of anthracite coal fraction:

• P - plate (≥100mm)
• AK - large (50 - 100mm)
• AKO- fist nut (25-100) ()
• JSC- walnut (25-50mm) ()
• AM— small (13-25mm) ()
• AC- seed (6-13mm) ()
• AS- piece (0-6mm) ()
• R - private (0-200)
• quarry 0–300 mm

There are also mixed brands. If we give an example of the designation of brands, then GKOM (K – 50–100, O –25–50, M – 13-25) is 13–100 mm. When coal is formed, this process is also called metamorphism, the resulting coals are divided into hard, brown and anthracite. Anthracites have the highest calorific value. For the energy industry of Ukarina, hard coals look the most pleasant, because they have the most favorable ratio based on the amount of money spent to the calorific value. As an example, we can cite grade D and grade G coals; they transfer excellent amounts of heat and can burn without blowing; they are often used for combustion in boiler rooms. But SS, T and OS coals are usually used in the energy sector. The justification for using these types of coals is appropriate if a large amount of them is used, since the implementation of the combustion process requires more economic costs. For the production of steel and cast iron, G and Z grades are used.
Grade "A" (anthracite). Large fractions of anthracite are used mainly in the municipal sector of Ukraine. Very popular and widely used among the population of Ukraine. Also, this grade A coal is widely used in the energy sector due to its high combustion heat.

Grade “B” (brown coal). What is characteristic of this brand is that the yield of volatile substances is over 45%. Divided by humidity into: 1 B (above 43%), 2 B (29-45%), 3 B (up to 32%).

Designation of coking coal grades.

Grade “D” (long-flame coal). Has poor sinterability. Just like grade A coal can be used both in the energy industry of Ukraine, and in the domestic sphere and in the chemical industry of Ukraine, for molded coke, in the coking process.

Brand "DG" (long-flame gas coal). On the contrary, it has high sinterability and low fragility. But the resulting coke is unsuitable for further use, since it has high reactivity and low strength. This brand has coals of medium and large classes in terms of fractional composition.
Grade "G" (gas coals). It is used in the domestic sector of our state as a cheaper replacement for grade A coal. Due to its properties, it can be used in the process of gasification, coke formation, and semi-coking process. They are divided into the following technological groups: inertinite, vitrinite. Low-ash vitrinite is used to produce synthetic fuel.

The most valuable type of coking coal. Structural strength is one of the distinctive features of coke obtained from the Zh coal grade.

Brand "GZhO" (gas fat lean coal). They make up more than half of the charge and are an excellent product for coking. They can also be used for municipal and domestic needs of the population of Ukraine if they are fusinite. Not suitable for producing coke for metallurgy.

The main purpose is to obtain conditioned metallurgical coke. However, they are not mixed with other types of coals.

Brand “KZh” (coke fat coal). It is widely known that this grade of coal is used in the coke industry in Ukraine. The highest coking rate, which makes it possible to obtain metcoke from this type of coal. They have the following indicators:

• — vitrinite reflections from 1.5 to 1.9%,
• — yield of volatile substances no more than 19.6%,
• — humidity 6-13%,
• — ash content from 6 to 39%,
• — carbon 78-92%,
• - hydrogen 4.2-5.%.

SS - low-caking. Found application at power plants, boiler houses and in the public utility sector of Ukraine. This type of coal is characterized by the following indicators:

• — vitrinite reflections 0.5-1.78%,
• — humidity 8-9%,
• — ash content from 8 to 45%,
• — sulfur no more than 0.8%,
• — carbon from 74 to 90%,
• — hydrogen from 4.0 to 5.0%.

T - skinny. One of the main indicators is the complete absence of caking. Found application in the energy industry of Ukraine, as well as for municipal and domestic needs.

Undoubtedly, it is worth considering options for coal-fired boilers.

The main advantages of solid fuel coal boilers:

• Coal burns longer than wood and, accordingly, requires loading fuel less frequently;
• At fine angles, automatic loading is possible;
• There is a class of boilers that simultaneously operate as stoves for cooking food;
• Most coal boilers are universal and you can get by with other fuel in the absence of coal;
• Easier to store and takes up less space than firewood;
• Due to the heat transfer features, this boiler does not immediately cool down, therefore it retains heat in the house for some time (even when turned off).

Coal marking, coal grades

There are many varieties of this fuel; the main types of coal are brown coal, hard coal and anthracite. In the marking of coal grades, they are designated by the first letter: B (brown) or A (anthracite). Hard coal is more difficult to label: long-flame (D), coke (K), lean (T), fat (F), gas (G). The second letter of the marking is the size of the coal. For example:

• slab, more than 10 cm (P);
• large, 5-10 cm (K);
• nut, 2.5-5 cm (O);
• small, 0.13-0.25 cm (M);
• seed, 0.6-0.13 cm (C);
• piece up to 0.6 cm (W);
• private, different sizes (P).

Main quality indicators for coal

These three indicators will determine which coal is better for heating your home, your personal brand of boiler and, in particular, for your convenience.

The first indicator is calorie content, which is also the heat of combustion. By grade, except anthracite (8600 Kcal/kg), coking coals (8700 Kcal/kg) give a high combustion temperature, but they should not be used for domestic home boilers. Brown coals show the lowest temperature (4500 Kcal/kg). They are also usually not used for heating, since they are ineffective compared to other varieties (but in the absence of other varieties, brown ones are also heated).

The second quality indicator is ash content. This is the percentage of what will not burn during the heating process. The higher this percentage, the worse the quality of coal. Low-grade brands often contain more than half the ash, while high-grade brands contain no more than a quarter. This indicator also tells you how often you will clean your boiler or furnace. Anthracite has the best ash content, followed by low-caking and gaseous ones.

Humidity is the third point for coal quality. There is a distinction between surface moisture of coal and internal moisture. And if the surface one can be removed by drying the coal, then the internal one is revealed only during the combustion process. The higher the humidity, the less energy the coal gives off for heating, and the more energy is spent on evaporating moisture during combustion. Sometimes it is advised to wet the coal so that the dust settles, but this is not always advisable.

What type of coal is best for heating a home?

Even if they immediately advise you anthracite as the most profitable, “clean” in combustion (minimum consumption, maximum heat transfer, minimum slag and waste emissions into the atmosphere, only 1% sulfur and 10% ash residues, uniform combustion, etc.), don't rush to buy it right away. So which coal is best for heating a home? Everything is individual. Best - means "best for your boiler". First of all, look at the boiler labeling - it should indicate the types of coal that are suitable for your unit. Indeed, anthracite is the best coal in terms of heat transfer. But due to the characteristics of combustion (it is capable of reaching high temperatures, and only at them it gives its full potential), you are risking: either your boiler (the boiler may simply not withstand the temperature), or your wallet (anthracite simply will not provide the required efficiency) . There are boilers adapted for burning anthracite specifically (their fireboxes are designed for high temperatures), and there are those that are designed for the worst grades, but from them they obtain the maximum useful energy.

If there is no marking, or you are not satisfied with it, try purchasing different varieties for testing and conduct an experiment: record the burning time, release heat, and the amount of ash.

Main varieties and their suitability for heating:

• Anthracite - only for specialized boilers;
• Coke coals are dangerous in everyday life and are not usually heated;
• Brown coals - low efficiency, are not usually heated (unless the brand of the boiler allows it);
• Gas coals are divided into two subtypes, only group 1G of this type of coal is suitable for heating, group 2G is used in industry;
• Fat coals are valuable grades of coals used in industry;
• Long-flame coals are the best choice after anthracite;
• Stone “DPK” (long-flame slab “fist”) is the best type of coal for conventional boilers;
• Stone "DO" - a lower efficiency indicator, but it is easier to automate the fuel supply;
• Stone “DS” (long-flame seed) - similar;
• Stone “TPKO” (skinny “walnut”) - even less efficient, but cheap, used for heating small houses;
• Hard coals “SS” (low-caking) and “TS” (lean, low-caking) are also cheap types of coal used in industrial boiler houses and households.

Some experts advise heating boilers with brands of lower efficiency, but easier to ignite, and then adding brands of coal with greater efficiency to the firebox (for example, start heating with long-flame sunflower seeds, and continue with anthracite). In the case of a stove, it is even recommended to start with firewood (and continue, for example, with seeds).

Grade A (anthracite).
Anthracites include coal with a vitrinite reflectance of more than 2.59%. With a volatile matter release of less than 8%, anthracites also include coals with a vitrinite reflectance of 2.2 to 2.59%. The bulk of anthracite is used for energy purposes. Medium and large classes of them serve as smokeless fuel in the domestic sector. Part of the anthracite is used for the production of thermoanthracite, which, in turn, is used as the main carbon filler in the manufacture of cathode blocks for electrolyzers in the aluminum industry. Anthracites are also used for the production of silicon carbide and aluminum carbide.

Grade D (long flame).
Long-flame coal are coals with a vitrinite reflection index of 0.4 to 0.79% with a volatile matter yield of more than 28-30% with a powdery or slightly caking non-volatile residue. Long-flame coals do not sinter and are classified as thermal coals. The areas of use of these coals are energy and municipal fuels, therefore their most significant characteristic is the heat of combustion. When moving to the next brand of diesel generator, the calorific value of coal increases significantly. Research has shown that long-flame coal with low ash content can serve as a good raw material for the production of synthetic liquid fuels and chemical products, the production of molded coke and spherical absorbents, and low-temperature (up to 700 degrees) coking.

Brand DG (long flame gas).
Long-flame gas coals are coals with a vitrinite reflection index of 0.4 to 0.79% with a volatile matter yield of more than 28-30% with a powdery or slightly caking non-volatile residue. These coals are transitional between grades D and G coals. They differ from long-flame coals by the presence of sinterability (the thickness of the plastic layer is 6-9 mm, and from gas coals with similar sinterability - by less brittleness and increased mechanical strength. The latter circumstance determines the predominance of coarse coals among such coals. - middle classes. DG grade coal is also classified as thermal coal for participation in coke mixtures, since the resulting coke has low mechanical strength and increased reactivity.

Brand G (gas).
Gas coal has two technological groups. Vitrinite coals (vitrinite reflectance index from 0.5 to 0.89%) with a volatile matter yield of 38% or more, with a plastic layer thickness of 10 to 12 mm form group 1G, vitrinite and inertinite coals with a vitrinite reflectance index of 0.8 - 0.99%, a yield of volatile substances of 30% and above and a thickness of the plastic layer from 13 to 16 mm form group 2G. The moisture content of gas coal usually does not exceed 10%, the ash content varies from 7 to 35% with a predominance of ash content of 10-15% . Gas coals are used mainly as energy and municipal fuel. Coal of group 2G with a plastic layer thickness of more than 13 mm is sent for coking. The limited possibility of using gas coals in the batches of coke plants producing metallurgical coke is due to the fact that during layer coking they cause the formation of microcracks in the coke, which significantly reduce its strength. Gas coal with a plastic layer thickness of 8-12 mm is used for the production of molded coke and spherical absorbents, and coals with a plastic layer thickness of less than 8 mm are used for gasification and semi-coking. Vitrinite low-ash coals of grade G with a volatile matter yield of more than 42% are a good raw material for the production of synthetic liquid fuel.
Brand B (Brown).
Brown coal is characterized by a low vitrinite reflectance (less than 0.6%) and a high yield of volatile substances (more than 45%). Brown coals are divided depending on humidity into technological groups: 1B (humidity over 40%), 2B (30-40%), 3B (up to 30%). Brown coals of the Kansk-Achinsk coal basin are represented mainly by group 2B and partially by 3B (vitrinite reflection index 0.27-0.46%), brown coals of the Moscow region belong to group 2B, coals of the Pavlovsk and Bikinsky deposits (Primorsky Territory) belong to group 1B. Brown coal is used as an energy fuel and chemical raw material.

Brand GZhO (gas fatty lean).
Gas fatty lean coals in terms of the yield of volatile substances and the thickness of the plastic layer occupy an intermediate position between coals of the G and GZh grades. There are two technological groups. The 1GZhO technology group includes coal with a vitrinite reflection index of less than 0.8% and a volatile substances yield of less than 38%, with a plastic layer thickness of 10 to 16 mm. Group 2GZhO includes coals with a vitrinite reflection index of 0.80-0.99%, a volatile matter yield of less than 38%, with a plastic layer thickness of 10-13 mm, as well as coals with a vitrinite reflection index of 0.80-0.89% with the yield of volatile substances is 36% or more with a plastic layer thickness of 14-16 mm. The humidity of the GZhO brand ranges from 6-8%, ash content - 6-40%. The carbon content varies between 78-85%, hydrogen - from 4.8 to 6.0%, sulfur 0.2-0.8%. GZhO grade coal is characterized by a wide variation in properties, which does not allow us to recommend any one direction for their use. Coal of the 1GZhO group with a plastic layer thickness of less than 13 mm can make up no more than 20% of the batches of coke plants, and only on the condition that the rest of the batch contains well-caking coals with a vitrinite reflection index of 1 to 1.5%. Coal of the 2GZhO group is a good raw material for coking (especially with a vitrinite reflection index of at least 0.85%) and can account for more than half of the charge. Fusinite coal of group 1GZhO (subgroup 1GZhOF) is completely unsuitable for the production of metallurgical coke, and can be used in the municipal (large classes) or energy (small classes) sectors.

Brand GZh (gas fatty).
Fatty gas coals occupy an intermediate position between the G and Zh coal grades and are divided into two groups. Group 1GZh combines coal with a vitrinite reflectance of 0.5-0.79%, a volatile matter yield of 38% or more, and a plastic layer thickness of more than 16 mm. Group 2GZh combines coal with a vitrinite reflectance of 0.8-0.99%, a volatile matter yield of 36% or more, and a plastic layer thickness of 17-25 mm. The GZh grade differs from gas coals in its higher sintering ability, and from Zh grade coals - in a higher yield of volatile substances. GZh grade coals are mainly used in the coke industry and are included in the group of coal grades that are especially valuable for coking. In most cases, they can completely replace high-fat coals in the batches of coke plants. It is advisable to use GZh grade coal concentrates with an ash content of less than 2% as a binder in the production of electrode and carbon-graphite products; GZh grade coals are also suitable for the production of synthetic liquid fuel.

Brand J (bold).
Fat coals are divided into two groups. The first group (1G) includes coal with a vitrinite reflectance of 0.8-1.19%, a volatile matter yield of 28-35.9% and a plastic layer thickness of 14-17 mm. The second group (2G) includes coals with a vitrinite reflectance of 0.8-0.99%, a volatile matter yield of 36% or more, and a plastic layer thickness of 26 mm or more. This group also includes coals with the same values ​​of the vitrinite reflectance index, but with a release of volatile substances from 30 to 36% with a plastic layer thickness of 18 mm and above. Also included in group 2G are coal with a vitrinite reflection index of 1-1.19% with a release of volatile substances of at least 30% with a plastic layer thickness of at least 18 mm. Zh grade coal is a particularly valuable coking coal and is used mainly in the coke industry, making up from 20 to 70% of coke mixtures. Coke produced from Zh grade coal has high structural strength.

Brand KZH (coke fat).
Fatty coke coals are distinguished as coal with a vitrinite reflection index of 0.9-1.29%, a plastic layer thickness of 18 mm, and a volatile matter yield of 25-30%. The main consumer of KZh grade coal is the coke industry. Of all the grades of coal used to produce coke, they have the highest coking properties. High-quality metallurgical coke is obtained from them without mixing with other grades of coal. In addition, they are capable of accepting up to 20% of filler coals of KO, KS and OS grades without changing the quality of coke.

Brand K (Coke).
Coke coal is characterized by a vitrinite reflection index of 1 to 1.29%, as well as good sinterability. The thickness of the plastic layer is 13-17 mm for coals with a vitrinite reflection index of 1.0-1.29% and 13 mm and higher with a vitrinite reflection index of 1.3-1.69%. The yield of volatile substances is in the range of 24-24.9%. Without mixing them with coals of other brands, they ensure the production of standard metallurgical coke. The quality of coke can increase significantly when mixing grade K coal with 20-40% of grade Zh, GZh and KZh coals.

Brand KO (Coke lean).
Lean coke coal is a coal with a yield of volatile substances close in values ​​to coking coals, but with a smaller thickness of the plastic layer - 10-12 mm. The reflectivity of vitrinite is 0.8-0.99%. KO grade coal is used mainly for the production of metallurgical coke as one of the filler coals for the GZh and Zh grades.

Brand KSN (coke low-caking low-metamorphosed).
Low-caking, low-metamorphosed coke coals are characterized by a vitrinite reflection index of 0.8 to 1.09%. When coked without mixing with other coals, they produce mechanically weak, highly abrasive coke. They are used both in the coke industry, as well as in the energy and household sectors. KSN grade coal can also be used to produce synthetic gas.

Grade KS (Coke low-caking).
Low-caking coke coals are characterized by low caking (plastic layer thickness 6-9 mm with a vitrinite reflection index of 1.1-1.69%. KS grade coal is used mainly in the coke industry as a lean component. Part of the coal is used for layer combustion in industrial boiler houses and in the domestic sector. Low-caking coke coals are characterized by low caking (plastic layer thickness 6-9 mm with a vitrinite reflectance of 1.1-1.69%. KS grade coal is used mainly in the coke industry as a lean component. Part of the coal used for layer combustion in industrial boiler houses and in the domestic sector.

OS grade (lean sintering).
Lean sintering coals have vitrinite reflection indices from 1.3 to 1.8% and a yield of volatile substances of no more than 21.9%. The thickness of the plastic layer for the 2OS group is 6-7 mm, and for the 1OS group - 9-12 mm with a vitrinite composition and 10-12 mm with a fusinite composition. The moisture content of mined OS grade coals does not exceed 8-10%. Ash content ranges from 7 to 40%. The sulfur content in the Kuznetsk basin does not exceed 0.6%, in the Karaganda basin it sometimes reaches 1.2%, in the Donbass 1.2-4.0%. The carbon content is 88-91%, hydrogen 4.2-5.%. The main consumer of OS grade coal is the coke industry; these coals are one of the best lean components in coke mixtures. Some OS grade coals, even without mixing with other grades of coal, produce high-quality metallurgical coke; but during coking, they develop a large expansion pressure on the walls of coke ovens; coke is released from the ovens with great difficulty, which leads to rapid failure of the ovens. Therefore, OS grade coal is usually coked in a mixture with G and GZh grade coals, which have a high degree of shrinkage.

Brand TS (skinny low-caking).
Lean, low-caking coals are characterized by a yield of volatile substances of less than 22% and very low caking (plastic layer thickness less than 6 mm. The moisture content of mined TC grade coal is low - 4-6%. Ash content is in the range of 6-45%. Carbon content is 89-91%, hydrogen 4.0-4.8%. Sulfur content in coals of Kuzbass is 0.3-0.5%, Donbass 0.8-4.5%. Coal of the TS grade is used both in the coke and chemical industry. mainly in the energy sector; large-medium classes of coal of this grade are a good smokeless fuel for small boiler houses and individual household use.

Grade SS (low-caking).
Low-caking coals are characterized by a vitrinite reflectance in the range of 0.7-1.79%, a plastic layer thickness of less than 6 mm and the release of volatile substances characteristic of well-coking coals of the Zh, KZh, K, KS and OS grades. The moisture content of mined coal reaches 8-9%. Ash content ranges from 8 to 45%. The sulfur content usually does not exceed 0.8%. The carbon content ranges from 74 to 90%, hydrogen from 4.0 to 5.0%. They are mainly used in large power plants, industrial boiler houses and the domestic sector. In limited quantities, certain varieties of SS grade coals are used in the batches of coke plants.

Brand T (skinny).
Lean coal is characterized by the release of volatile substances from 8 to 15.9% with a vitrinite reflectance from 1.3 to 2.59%; there is no caking. They are used mainly in the electric power industry and in the public utility sector; provided they have a low ash content, they can be used to produce carbon fillers in electrode production.

Solid fuel boilers of individual manufacturers and brands operate without problems on various fuels, however, before purchasing a large amount of coal, it would not hurt to find out which type is best suited for use. As a rule, information about recommended products allowed for kindling is contained in the instructions for the unit. If for some reason it is not possible to obtain reliable information from the boiler manufacturer, then it is enough to purchase a bag of fuel of different grades and fractions, and then experimentally select the most effective one.

Qualitative parameters

Hard coal is a sedimentary rock that can contain a variety of elements that can greatly influence the choice of fuel depending on the application. Basically, when determining a suitable brand, they are guided by a number of characteristics. Thus, when choosing coal for coking, as many as 30 parameters are assessed. Of course, if you buy charcoal with delivery for household purposes, then there are not so many requirements, but you still need to know the properties of the fuel.

Caloric content or calorific value

The unit of measurement is Kcal/kg, the indicator reflects how much heat will be obtained during fuel combustion. Brown coals give off the least amount of heat – up to 4,500 Kcal/kg; the most heat comes from anthracite and coking coal – 8,600 and 8,700 Kcal/kg, respectively.

Ash content

One of the most important indicators of coal quality. The less ash is formed during fuel combustion, the more heat can be obtained. The resulting residue consists of various non-flammable impurities that reduce the efficiency of heat transfer. The parameter is indicated as a percentage. For high-grade coal, the figure does not reach 25%, while for low-grade coal it can be 40% or even higher. It is necessary to take into account the amount of remaining ash not only due to heat transfer from the fuel, but also due to contamination of the boiler itself, pipes and channels that ensure its operation. Constantly appearing soot and ash require regular removal.

Humidity

There are two types: superficial and internal. The first can be eliminated when the fuel is exposed to air, and the second can be eliminated directly during the combustion process. The damper the coal, the less heat it will give off. In winter, it is sometimes possible to notice the amount of moisture content even upon inspection: if individual particles are stuck together, the fuel is caked, then there is a lot of water. It is not recommended to specifically wet the coal except in cases where it is too dusty. Water promotes the formation of lumps, thereby providing better air circulation.

Solid fuel brands

The best fuel for domestic use is anthracite (marked with the letter “A”). It has a long combustion life, does not form a large amount of soot, and low ash content. However, you need to know how to use such coal, since it is difficult to ignite, and also costs a lot of money.

Most often, long-flame coal is purchased for lighting household boilers. It burns long enough, ignites easily, the flame is long and produces a large amount of heat. You can recognize the fuel by the “D” marking. It is also possible to heat private houses using “SS” and “T” grade coal, but their characteristics leave much to be desired.

In addition to the brand, coal also differs in fraction size. So, for a slab the size of the pieces ranges from 100 mm, for a large one it varies from 50 to 100 mm, a nut is sold at 25-50 mm, a small one - 13-25 mm, a seed - 6-13 mm, a piece - up to 6mm. There are no standard sizes for raw coal.

All coal is marked by the first letter of its name. However, the name may contain several letters, which indicate additional characteristics of the fuel. For example, DPK is slab coal with a fraction of 50-100 mm, DS is long-flame seed. As for raw coal, it does not have an approved composition. It can contain 70% large elements, and 30% shtyba, or vice versa.

It is impossible to say with 100% accuracy what fuel should be purchased in each individual case, since the choice depends directly on the type of boiler and the manufacturer’s requirements for operating the product. If the documentation indicates a certain type of coal, for example, anthracite, then replacing it with another is not recommended, as this can lead to large financial costs along with a decrease in thermal efficiency.

Those who primarily focus on the cost of fuel need to look beyond the price tag and characteristics. Suppliers often charge extra for delivery and may charge different prices depending on the volume purchased.

Which coal is better for the stove and boiler?

If there are no instructions for the boiler or a conventional brick oven is used as a heating unit, then you will have to select coal experimentally or by listening to the advice of “experienced people”.

As for household boilers, it is better to light them with long-flame “walnut” coal. As it burns, anthracite is added on top in an even layer. It allows you to provide heat throughout the day due to its long combustion. In the evening, it is already possible to pour a “seed” into the boiler; it will be enough to keep the temperature at the same level until the morning. However, do not forget about the type of installed device. The described instructions are not universal, so in some cases the fuel use pattern may be different.

Brick stoves are best heated with wood. When they burn out, it’s time to add coal briquettes; it is also possible to use a “seed”, ideally a long-flame one. Until the fire completely engulfs the coal, the furnace dampers must not be closed to ensure the flow of oxygen. When the stove flares up, you can use coarse coal; “fist” or “nut” are suitable for these purposes. Another scheme is also allowed: first, a “nut” is used, and in the late evening and at night – a “seed”.

How much coal is needed for the winter?

In order not to be left without fuel in severe frosts and not to think about where to put coal in the summer, it is necessary to evaluate a number of parameters before purchasing this or that volume.

These include:

• room area, wall material and insulation thickness;
• type of windows, doors, degree of ventilation;
• type of fuel, boiler, coal laying scheme;
• temperature changes in the region, duration of cold weather.

As practice shows, heating a brick house requires 35% more fuel than heating a wooden or aerated concrete block building. This is due to the fact that brick, due to its characteristics, takes away some of the heat. Approximately for a house with an area of ​​90 square meters, built of slag concrete with a wall thickness of 45 cm, with stove heating you will need from 2.5 to 3.5 tons of coal (2/3 of the volume is “seed”, the rest is anthracite “nut”) depending on changing temperature. If such a structure does not have additional insulation, then the amount of fuel purchased will already be at least 6-7 tons. Wooden house made of timber with an area of ​​80 sq.m. at a minimum temperature in winter of up to -40 °C (about 1.5 months and up to -20 °C the rest of the time), you will have to heat it with 5 tons of coal and 5 tons of firewood.

Coal storage rules

The shelf life of coal depends on the brand, deposit and environmental conditions. The best chance of preserving all the properties of the fuel is when storing anthracite and semi-anthracite. With sizes from 70 cm to 100 mm, this coal is stored without loss of quality for up to 36 months, and with sizes from 100 mm - about a year. If you order coal for delivery, then plan the volumes you use to avoid loss of quality.

It is best to place coal in a covered room (barn, dry basement), where the rays of the sun do not penetrate. Coal oxidation begins at a temperature of 20-25 °C. At 40 °C weathering begins, which can be seen by a decrease in the size of the pieces. It is also necessary to periodically check the condition of the coal, since, for example, brown and porous stones are capable of spontaneous combustion. The combustion temperature for brown is 40-60 °C, fatty - 60-70 °C, lean and anthracite - from 70 °C.