Coal briquette: what is it, what raw materials are used. Description of the production process, making it yourself. Coal briquettes for heating: production technology and composition features Press for the production of coal briquettes

More and more people are buying solid fuel stoves and boilers. It's all about the ever-increasing cost of heating utilities. And the lucky ones living in private houses can refuse the central heat supply and switch not just to autonomous heating, but to use heating that does not depend on gas and electricity. However, for such devices you need to buy fuel, of which there are a huge number. To make it easier for you to choose the best option, we will tell you about this type of fuel, coal briquettes.

What are coal briquettes

There are many types of fuel for heating a home. Previously, firewood was the most popular option, and then fuel briquettes began to appear. This material gradually began to displace ordinary firewood from use.

Their main advantage is the ability to be manufactured from various waste materials. This not only reduces the cost of such materials, but is also less harmful to the environment. Also, pressed briquettes burn longer and have high efficiency.

Various materials are pressed into briquettes. Wood waste, agricultural waste and coal, or rather its dust. Such coal briquettes burn without waste and at the same time have high efficiency.

Briquetted coal was already used at the end of the nineteenth century. Then such fuel was made from charcoal waste: its defective particles and dust. To fasten the elements together, resin and a mechanical press were used.

Coal briquettes, which are made nowadays, have a similar production technology. However, briquetting of charcoal waste is mainly chaotic. Such fuel is produced by small enterprises.

What is added to bind coal waste in our time:

Typically, the adhesion of raw materials occurs due to bitumen additives. However, when burned, such components release substances harmful to health.
Another method is to bind coal particles with polyethylene. However, such pressed coal is also harmful to health.
The safest is coal, which is held together with PVA glue. This substance is absolutely harmless, but in this case production has a higher cost.

Only a small part of manufacturers use safe coal production technology. Therefore, you need to be very careful about such fuel.

Advantages of coal briquettes

A boiler for heating a home can operate on different materials. Charcoal briquettes are not the most common option. However, it is quite promising, especially if its production reaches a higher quality level.

Coal in briquettes is not used for grills, barbecues and ovens. It can release carcinogens and has a high combustion temperature, which can ruin such structures.

The advantages that pressed charcoal briquettes have are undeniable. Due to this, this material of dubious quality is used for heating the house.

Advantages of coal briquettes:

Charcoal briquettes burn for a long time and produce a lot of heat. Therefore, they are economical and popular.
The use of such fuel is popular because its briquettes have the same dimensions. This allows you to receive even heat.
In addition to the fact that briquettes burn twice as long as firewood, they are also quite light and compact. Thanks to this, the fuel takes up half the space.
High-quality coal briquettes do not emit carbon monoxide when burned. This makes them safe to use, as long as you have a good ventilation system in your home.
Such briquettes emit more heat than wood, wood and stone charcoal.
During transportation and use, fuel coal briquettes do not crumble. Therefore, they do not generate dust or pollute the room in which they are stored.
If you learn how to light them correctly, then you will only need 15 minutes for this procedure.

Such benefits make charcoal an excellent boiler fuel. If this product begins to be produced in accordance with all safety requirements, then in the future it may become very popular.

Types of coal briquettes for heating

When burning regular coal, a lot of dust remains in the fireplace. The burner in the boiler may become clogged. That is why coal has not found its full application in heating apartments.

Since the quality and safety of coal directly depend on its composition, it is very important to pay enough attention to this factor. You can ask the seller for a quality certificate or contact the manufacturer for a presentation of the production process and see the equipment and raw materials for its production. However, it is best to make such fuel at home with your own hands.

The type of compressed coal fuel is of great importance. They are divided into classes according to several parameters. Let's see why.

By what parameters is pressed coal divided into classes:

The material from which the fuel is produced is of primary importance;
The shape of coal briquettes is only a matter of appearance;
The environmental friendliness of compressed coal fuel depends on its binding material;
The type of packaging is responsible for the safety of raw materials.

The most important factor in the classification of compressed coal fuel is the type of raw material itself. It is he who determines the characteristics and cost of briquettes. There are three types of raw materials used to create coal briquettes. Let's see which ones.

Types of coal briquettes:

Brown coal has the lowest price. Dust and small particles are used to make briquettes from it. Has the lowest calorie content.
The second most expensive charcoal. However, its calorie content is lower than that of brown coal. It is made from recycled wood.
Anthracite is the highest quality and high-calorie coal. It produces the highest quality briquettes. However, they have the highest cost.

You need to choose coal briquettes based on their raw materials and fastening material. It is these parameters that determine the safety and quality of the fuel.

Coal briquetting technology

You can make coal briquettes for yourself at home. In this case, you don't even need expensive equipment. To do this, you will only have to find forms and purchase the raw materials themselves.

How to make coal briquettes at home:

Mix one part of dry clay with ten parts of coal dust;
Stirring constantly, add water until the desired consistency is obtained;
Spread the mixture into molds and leave until completely dry.

Of course, such material will be inferior in quality to coal briquettes prepared using special equipment. But for home heating they are quite suitable.

What are coal briquettes used for (video)

Coal fuel briquettes are a fuel that will rank first in popularity in the future. However, its production is now at questionable levels. Therefore, many avoid using it.

Content

Affordable price compared to other types of energy resources, no problems with purchase, good heat transfer are the main reasons why many users prefer to use coal briquettes for heating. The price of more conventional energy sources is constantly increasing, which forces us to look for alternative heat sources. Coal dust is an accessible type of fuel, but its use in its pure form is unprofitable: half of the raw material falls into ash through the grate bars, and the other half is sintered, which leads to clogging of the firebox.

Coal briquettes

One of the options for using coal dust, which allows you to get maximum heat from it, is to pour the fraction on firewood, which is used to pre-heat the boiler. But this is very troublesome, since it needs to be poured often in small portions. Adding a large amount of fines will lead to the fact that it will still spill into the ash pan, turning into waste. And the part that still remains on the wood will fill the gaps between them, blocking the air circulation and causing the firebox to fade.

The solution is to produce briquettes from dust with the addition of auxiliary substances by pressing. The fine fraction processed in this way burns well with high heat transfer.

More about briquetting technology

At the beginning of the last century, Russian researcher A.P. Veshnyakov proposed pressing the fine fraction into elements of a certain shape and size, which in terms of heat transfer were not inferior to the coal itself. The idea has found wide application both in everyday life and in industry.

Coal briquettes on a screening belt

Today, pressed coal is classified depending on the material, environmental friendliness, security, shape and type of packaging. But the two main types are:

For production with the addition of binding components.
For home use without additives.

It is important to know that industrial briquettes should absolutely not be used in everyday life. When they burn, a large amount of toxic substances are released, for which special equipment is responsible for removing them under production conditions. Previously, additives in the form of molasses or starch were used in the production of household briquettes. But this technology is a thing of the past.

Industrial production

Distinctive features of dust and fine coal fraction: low specific calorie content and density. But these materials are considered as cheap raw materials that make it possible to organize the production of coal briquettes. The products will have good density and heat transfer at low cost.

To produce briquettes in a factory, a special production line is used, consisting of a crusher, dryer, and press. The movement of semi-finished products between machines is ensured by a conveyor belt.

Pressed coal without additives is produced in several stages:

Grinding raw materials to a particle size of 6 mm and smaller.
Drying the mixture to 15% humidity using steam and gas dryers.
Next, the dust is cooled and fed to a stamp-type press, which acts on the mixture under a pressure of 20-150 MPa (depending on what technology is used). After this processing, the finished briquettes are sent to the finished product warehouse for storage.

The purpose of the fuel and the equipment used are the main factors influencing the size of the particles, the level of humidity and the amount of pressure under which they are turned into briquettes. At the same time, the energy intensity of the finished product directly depends on the quality of the raw materials. It is important to use the fine fraction of anthracite, and not brown or other types of coal. For strength, it is permissible to add mineral or organic additives.

Coal Briquetting Press

Coal briquettes can be compressed in two ways depending on what briquetting equipment is used:

Stamp press. The heated coal mixture is filled into special molds, in which it is compressed with a force of 100-120 MPa. After cooling, the briquettes are packaged. The finished product looks like bricks or cylinders with holes, and may look like “tablets” or “pads.” This manufacturing method is suitable for the production of briquettes in large quantities due to the high energy and financial costs.
Extrusion machine. In this case, the plastic coal mass is pressed through the matrix by a press. A screw-pressed briquette (pini-key) made from coal dust has a cylindrical shape, resembling a “sausage”, with a calibrated hole in the middle. The technology is less expensive, but also less productive.

The technology for producing briquettes for industrial use involves the addition of cement, oil-bitumen mixture, liquid glass and others. The use of these substances in metallurgy is permitted. But you cannot buy coal briquettes with oil bitumen for heating a living space according to the requirements of the SES.

Briquetting coal at home

Industrial technology is not suitable for briquetting coal at home. The high price of equipment for the production of coal briquettes, high energy costs, and the need to obtain a huge number of permits from government agencies significantly increase the cost of the finished product. But for the purpose of heating a small private house, there is no need to organize large-scale production. To make 3-4 tons of briquettes (winter stock), it is quite possible to make do with improvised means.

Equipment for briquetting at home

The simplest method, which was well known to our great-grandfathers:

Coal dust is mixed with clay in a ratio of 10:1 with the addition of a small amount of water to form a thick mass. Clay is a safe binding component that will prevent the briquettes from falling apart. It is important to thoroughly mix all the components of the mixture. A construction mixer is often used for this purpose.
Next, the solution is poured into molds. These can be either special containers or used equipment (old pots, buckets, boxes). If there are no containers, coal cakes can be formed by hand, as our ancestors did.
After complete drying, the briquetted coal can be sent for storage.

Despite the fact that, according to production technology, the mixture is dried, during the home preparation of briquettes the mixture is moistened. In this case, homemade coal briquettes have the following distinctive features:

Imperfect shape.
Different levels of humidity and, therefore, heat transfer.
Low strength, which does not allow briquettes to be transported.

Homemade coal briquette

But these properties do not prevent low-cost products from burning well, especially compared to sintered dust. This option is much more convenient and practical.

And if you still want to automate the process somehow, then you can follow the example of home craftsmen and independently make equipment similar to production equipment:

A machine that allows you to make briquettes manually. Instructions on how to make a machine can be easily found on the Internet. A unit designed for home brick production is well suited for manual pressing. The materials that allow welding the frame are a profile pipe and a 40*40 mm corner. A receiving hopper is mounted on top. A manual mechanism is attached to the side for briquetting the mixture into rectangular or cylindrical products. Technology:
- The raw materials are crushed as much as possible. The fine fraction ensures the strength and quality of the briquette.
- Adding water will create a sticky mixture. It is acceptable to add clay in small quantities to slightly increase the ash content of the fuel.
- Next, the mixture is poured into a hopper, from where the mold is filled. The briquette is extruded by pressing a lever.
- The reverse movement of the lever causes the briquette to be pushed out of the mold. It is removed and placed in the sun to dry.
Screw press, where products are briquetted by extrusion. In this case, the financial costs of assembling the machine, as well as its productivity, will be greater. You will need:
- Thick-walled steel pipe for making the body. It is machined inside according to the desired screw size.
- Auger made from high-strength carbon steel.
- A matrix with one or more holes made of the same material.
- Electric motor with a power of 4 kW.
- Belt drive (minimum 3 belts).
- Reception bunker.

Technology for producing coal briquettes without a binder

It is better to entrust the manufacture of the body, matrix, and auger to a good turner. It is important that the pulley diameters ensure a screw rotation speed of no more than 200 rpm. The motor must be grounded before connecting it to the household electrical network.

Production technology:

The raw materials are crushed and mixed with water.
With the engine running, the mixture is loaded into the hopper.
The emerging “sausages” are cut into pieces of the desired length and laid out on a rack to dry.

It is important to know that the presence of through holes in finished briquettes promotes better combustion and greater heat transfer.

conclusions

If you believe the manufacturers of coal briquettes, the calorific value of this type of solid fuel is even greater than that of other varieties. Theoretically, this statement may be quite realistic due to the fact that only by burning 1 kg of anthracite can 7.7-8 kW be obtained. In terms of specific heat, firewood and wood briquettes lag significantly behind, releasing only 5 kW/kg.

However, an analysis of reviews from owners of solid fuel boilers on thematic forums shows that the demand for coal dust briquettes is lower than for wood for several reasons:

With their help, it is difficult to light a boiler and when burned, coal gives off little heat.
Before and during combustion, an unpleasant odor remains in the room.
Briquettes lose their shape and crumble heavily during transportation.
Lots of ash.

Combustion of coal fuel in briquettes

A large number of negative reviews (about 70% of the total) can be explained by the fact that manufacturers use low-quality raw materials in order to make more profit. They briquet charge, sludge and other types of coal that are unsuitable for heating premises, and add extra substances to the mass. Briquettes truly made from anthracite are difficult to find. The main feature is the deep black color of the products.

The conclusions are obvious:

It is better to make coal briquettes yourself.
For production it is necessary to buy high-quality raw materials.
If it is possible to purchase only low-calorie grades of coal, pressing is not economically feasible. Although burning low-quality briquettes along with firewood will reduce heating costs.

Yes, home-made coal briquettes are very different from their factory-made counterparts: they crumble during transportation, are wet, and produce less heat. But this way you can control the quality of the raw materials used, the presence and quantity of additives. Both in a boiler and a stove, “homemade” briquettes burn well, much better than dust, which is simply baked into a cake. In addition, in terms of price, homemade cylinders, bricks or “sausages” are much more profitable.

While various wood wastes in the form of sawdust and wood chips are quite easy to burn in long-burning boilers specially adapted for this, the situation is different with fine coal and dust. Anyone who has ever tried to fire a stove or boiler with small fractions of coal knows that half of the fuel is wasted, spilling through the grate into the ash pan, and the other half is sintered and blocks the access of air to the firebox. Because of this, the intensity of combustion is sharply reduced. At the same time, it is stupid to throw away such fuel, because it contains a lot of thermal energy. In such a situation, coal briquetting can help, which will be discussed in this article.

About coal briquetting technology

One of the ways to burn coal fines is to light the boiler with wood, and then pour the dusty fraction of fuel on top of the burning logs. But this is too troublesome, since coal dust must be added in small portions, and therefore often.

If you load a large portion, then some of the fuel will definitely spill into the ash pan and go to waste, and the rest of the fuel will fill the cracks between the wood. Air will stop flowing into the combustion zone and, as a result, the firebox will begin to fade.

The best way is to use the pressing method to form briquettes from the fine fraction, which then burn very well, releasing a large amount of heat. Such a solution as coal briquetting was proposed at the beginning of the century before last in Russia by the inventor A.P. Veshnyakov is still successfully used both for industrial purposes and in everyday life. Its essence is that the compaction of fine coal using high pressure on special equipment makes it possible to obtain fuel whose calorific value is no less than that of high-quality coal.

Without going deeply into the intricacies of the technological process and the classification of different brands of fuel, we note that such briquettes are produced in two types:

with binders for industrial purposes;
without binders, intended for combustion in domestic boiler systems.

Note. Briquettes pressed with binders cannot be used in everyday life. When burned, these substances form harmful or toxic compounds, which are captured in industry in various ways. Previously, starches or molasses were also added to household fuel as binders, but this technology is outdated.

Since we are interested in the technology for producing coal briquettes without any additives for household purposes, it is worth considering this. So, the sequence of the process is as follows:

first, the coal undergoes a grinding operation, with a maximum fraction size of 6 mm allowed;
the next operation is drying in order to achieve an optimal humidity of 15%. For this purpose, special equipment is used for the production of coal briquettes - steam or gas dryers;
After drying, the composition is cooled and supplied for pressing. The operation takes place at a pressure of 100-150 MPa in the so-called stamp press;
final cooling and shipment to the warehouse.

Note. The traditional technological process is described here, but the requirements for the fraction size and moisture content of the raw materials may vary depending on the equipment used. For example, a modern mini-plant of the Russian company UNITEK requires particle sizes of up to 0.25 mm with a moisture content of 6 to 16%. That is, in this case, the coal briquetting technology should provide for better grinding, but the pressing pressure is applied much lower.

The output is a coal briquette whose ash content does not exceed 15-20%, the maximum permissible mechanical load is 3 kg/cm2, and when dropped from a height of up to 2 m, the product loses no more than 15% of its mass as a result of impact. The heat of combustion depends on the grades of coal from which the briquette is pressed.

Making coal briquettes at home

It is clear that industrial equipment for coal briquetting is inaccessible to the average homeowner due to its high cost. However, our grandfathers also knew how to make briquettes without any equipment. To do this, coal dust and crumbs were mixed with water in such a ratio that a thick mass was obtained, and then cakes were molded from it by hand. After drying, such products were successfully burned in a home stove. That is, contrary to production technology, the mixture for the production of coal briquettes is not dried, but, on the contrary, moistened.

At home, briquettes are made in 2 ways:

using a hand press;
on a homemade screw extruder.

The first method is good because you can buy a pressing machine inexpensively or make it yourself. Its disadvantage is low productivity; in order to make yourself a fuel briquette for the whole season, you will have to work very hard. In the second case, briquetting of coal dust occurs quite quickly, since the entire process is mechanized. But here the cost of the unit comes to the fore; even a homemade installation will require significant costs. You will need to purchase a powerful electric motor, gearbox and other parts.

The algorithm according to which you can make coal briquettes yourself is as follows:

You must try to grind the coal chips in any available way. The smaller the fraction, the better the quality of the product;
mix the resulting composition with water. It is not possible to indicate exact proportions, since they depend on the dust content. The main thing is that the mixture is very thick and molded by hand. There is no need to add clay, this will only increase the ash content;
fill the mold with the composition and operate the manual mechanism;
Remove the briquetted coal from the mold and leave to air dry.

As a result, we get fragile products that are unsuitable for transportation, but burn well in the stove. One of the ways to briquet coal at home can be found by watching the video:

When a screw press is available, production is greatly simplified and accelerated. Turning on the electric motor, the above mixture is loaded with a shovel into the receiving hopper of the extruder. The output is cylindrical “sausages” of excellent quality. It is worth noting that such briquettes made from coal dust have good strength and can even be transported.

For more information about the operation of the extruder, watch the video:

Conclusion

Of course, home-made briquettes are far from ideal. They have low density and high humidity, and therefore provide less heat than factory products. However, in a stove or boiler they burn well, it’s not like burning coal dust that bakes into a cake. And in terms of cost, homemade coal briquettes will be cheaper.

Requirements for environmental conditions at the installation site

Installation height	up to 1000 m
Design for operation	indoors
Temperature
On mechanical equipment	min. 5 °C
On control cabinets	min. 5 °C, max 40 °C
Air humidity	Max. 75%
Electrics
Execution	DIN/IEC
Low voltage
Nom. voltage	400 V, ± 5%
Network frequency	50 Hz, ± 5%
Control voltage
Rated voltage	24V DC current/110V
Network frequency	50 Hz
Raw materials data:
Feed material:	Coke breeze
Bulk density	0.9 g/cm³
Particle size Temperature	up to 6 mm Environment
Max. permissible water content	4%
Binder	Bentonite approx. 5% Starch approx. 2%

Received product:

Description of equipment. Specifications

Frame

The press frame is a welded structure, manufactured in such a way that pressing forces are absorbed inside the frame and are not transferred to the foundation.

To facilitate the replacement of rolls, the end cheeks of the frame are connected to the upper/lower chords with hinge bolts. When the upper bolt is loosened, they (the cheeks) can be tilted to a horizontal position; they are used to remove the rolls.

Rolls

The rollers with axial journals are made of forged steel.

Press forms

Molds made of wear-resistant material are used, the molds are mounted on the roll body.

Setting the roll gap

The distance and clearance of the rollers is adjusted through intermediate parts inserted between the rolling bearing housing.

If desired, the gap can be controlled with an inductive displacement sensor by monitoring the parameters on the control panel.

Lubricated support

The rolls are mounted on ball bearings with bushings, the housings of which are sealed with labyrinth seals and rings. The bearings are filled with lubricant during installation.

Hydraulic pressing system

The roller is supported by the bearing housing on a hydraulic pressing device, which is necessary for uniform pressing force, as well as for uniform distribution of the load on the frame and protects the press from overload.

Includes:

Pressure cylinder
Nitrogen battery
Pressure gauge
Remote pressure sensor
Safety valves
Oil tank with pump
Drive motor 3 kW
Armature
Fill level controller
Thermometer

The hydraulic system maintains the set pressure and ensures constant pressing force.

Roll casing

To prevent dust, the rollers are surrounded by a casing, which is sealed in the rotating parts with labyrinth seals. The casing has a flange at the end for connection to the tray. Holes are provided for connection to the dust removal device.

Material supply

The gravity feed device is mounted on the press frame and consists of:

Floor slab with loading funnel
Hopper

main drive

The drive consists of:

Gearbox with two outlet pins
Safety coupling between motor and gearbox
Two double gear couplings between the gearbox and the press roll

Instrumentation and A

Instrumentation devices are connected in terminal boxes (transfer point) with metric cable glands on terminal panels. The cable to the press is laid in flexible hoses. Cable designation according to DIN/IEC.

The following devices are installed on the press:

proximity sensor with speed change relay on the main drive motor, 24V DC signal. current
pressure sensor on the hydraulic pressing system for measuring oil pressure passive signal 4 - 20 mA
Oil pressure solenoid valve
Pressure gauge for monitoring hydraulic system pressure

On-site control panel (wall mounting)

To service the roller press during the production process, a control panel is installed next to the press.

The remote control is equipped with the following devices:

Painting- standard

Miscellaneous

1 set of tools for installing roller supports

1 set for checking and filling the hydraulic system

Material execution

All parts in contact with the product are made of structural steel unless otherwise specified.

The scope of supply includes the above equipment, except where specifically marked. Also included are drawings, necessary documentation for startup, operation, and a list of spare parts.

Optional

Organization of the installation site, including cleaning and leveling, topographic studies, soil analysis, infrastructure organization
Permits required by state and government authorities
Construction and supply of buildings and internal construction of platforms for operation and maintenance
Manufacturing and supply of mechanical connections to the Customer’s equipment in the installation
Dust removal of pipelines
Insulation and measures for its installation
Consumables such as oils and lubricants
Spare and wearing parts
Transportation and storage of raw materials
Materials, auxiliary devices (tools, cranes) and personnel for installation and commissioning
Programming device
Electrical equipment between low voltage distributors, control panels and electrical units, instrumentation, safety devices (fire protection, etc.)
Departmental acceptance and start-up
Transportation, storage and packaging of other finished products
Other services and equipment not specified in the offer