The Coal

HU      RU   

| Home | Products | References | Video | Price list | Design | Company | Partners | Contact us

Biomass boilers
         For warm water

  • BIO
    Automated, pellet, wood chips,

  • Farmer
    Automated, pellet,wood chips,
    wood logs, multifuel

  • Automat
    Self-loading, automated,
    pellet, wood chips, multifuel

Steam boilers    

  • Low pressure steam (0,5bar) automated boilers for biomass, pellet, wood chips, multifuel        

Coal boilers

  • Automated brown coal boilers
    For warm water or low pressure steam

Fuel feeder systems

The coal spectrum for the CARBOROBOT

In the green rows are the coal types what can to use for the CARBOROBOT by the USA ranking system.
All type lignite and the lower ranked long flames non-coking sub-bituminous coal type usbale.
For the CARBOROBOT is important parameter the size of the coal pieces . The chunky coal reduce the power and increase the emission. Ideal size range 5-25mm. The dust content of coal possible up to 15%. The ash of fuels may be max. 30%

Using of bituminous coal, antracit, coke not proposed.
According ASHRAE coal stokers for automatic feeding fuel to a furnace can be classified after their coal burning capacity:
CARBOROBOT is Class 1 Stoker - 10 to 100 lbs (4.5 to 45 kg) coal per hour and Class 2 Stoker - 100 to 300 lbs (4.5 to 135 kg) per hour

What coal types can be used?
Firstly brown or young black coal, lignite or coal bricketts (may be made from turf)
Brown coal 10-22MJ/Kg (2000-5000Kcal/Kg) granulate size 5-25mm

The calorific value of brown coals used 12-20MJ/kg (2500-5000kcal/kg). One of the most important conditions of use, the particle size, which is ideal for 5-25mm (culm). If the larger grain size, the rate of burning slows down the boiler capacity is significantly reduced. The increase in size, of the flue gas emission is also wronger, so the use of 5-25mm size for the best values ??of release. The nut size 50mm coal-15 is only good for that, if necessary, until we can get the culm, and not left without heating. The lump coal reduce the boiler power, causes the hopper burn-in, and gassing the tank.

Using bigger size coal pieces, than described, reduces the available power. This severe cases, low smoke and heat to cause premature corrosion.
We recommend that you carry out a test heating, before purchasing large quantities of coal, because the wrong size coal outs, gets stuck in the throat, the boiler will not burn properly, or does not provide adequate power and automatic operation. Test the coal before buying a large quantity.

The dust content of 10-15% to not interfere with operation of the boiler. The boiler capacity 17MJ/kg (4000kcal/kg) calorific limits. This performance is reduced by using inferior fuel, but if using the beter fuel slightly higher. By using higher quality fuel, the filling period of the fuel tank and period of the ash cleaning is better(less frequent). In this case better the retention of spark, and the automatic restart is well secured.

Hard coal, lignite and coal briquettes usability
The black Coals is generally not used except for a few Russian import of coal, with luck though as brown coal is burned due to high gas content in addition to the high calorific value. The Black coals up kb.18-22MJ/kg (4800-5300kcal/kg) worth trying. At higher heating value of coal has surely can not be used in the CARBOROBOT. We recommend that young black coal size should be less than 20mm.

The low calorific lignite or brown coal give poor performance and much of it is consumed. The black coal is not properly chosen not to burn properly, unburned falls off the grate and despite the high heating value also provides a small performance with high power consumption.

Ovoids briqette not useful for large size (40-60mm). It is often blended with bitumen, which blow out the fuel tank and stick together. Previous years, there was a smaller version of what was called perl briquette, e.g.35mm size is more in line with the boiler. The unique firing tests with briquettes can be established the usability.

The black coals, lignites and briquettes user can to try at your own risk. Their Usability tests should be checked prior to purchase to the customer, the manufacturer shall not be liable for such coals usability.

The boilers operate automatically only fuels described in Users manual can do. Getting the right fuel is the responsibility of the operator. Complaints arising from the quality of the fuel is not covered by the Manufacturer's warranty, liability for damages.

How can we tell what kind of coal do we have?
If we scratch a concrete surface with the coal, the brown coal leaves a dark brown mark and the black coal leaves a much harder bluish-black mark.

What size of coal granulate can be used?
Ideal size is 5-25mm. Larger, 30-40mm pieces burn badly, and the power is low.
Even larger pieces donít burn, burn back or produce tar.

Can coke be used?
Definitely not!

The coal ranking

According to the International Coal Classification, there are two types of coals: hard coals and low-rank coals.
Hard Coal
The term "hard coal" (as used in the international classification system) is defined as coal with a gross calorific value of more than 5,700 Kcal/kg (10,260 Btu/lb or 23.86 MJ/kg) on a moisture, ash-free basis. The American Society of Mechanical Engineers (ASME) classifies anthracite, bituminous, and higher rank subbituminous in the hard-coal category.
Low-Rank Coal
The term "low-rank coal" (as used in the international classification system) is defined as coal with a gross calorific value of less than 5,700 Kcal/kg (10,260 Btu/lb or 23.86 MJ/kg) on a moisture, ash-free basis. The American Society of Mechanical Engineers (ASME) classifies medium and lower rank subbituminous, lignities, and brown coals are included in the low-rank coal category.

-- Peat soil material consisting of partially decomposed organic matter; found in swamps and bogs in various parts of the temperate zone. One type of peat is fuel peat, which is most widely used in regions where coal and wood are scarce, e.g., Ireland, Scandinavia, and parts of Russia. Peat is the earliest stage of transition from compressed plant growth to the formation of coal. Large deposits of peat in the United States are found in Michigan, California, and the Florida Everglades.
-- Lignite - or brown coal, carbonaceous fuel intermediate between coal and peat , brown or yellowish in color and woody in texture. It contains more moisture than coal and tends to dry and crumble when exposed to the air; the flame is long and smoky and the heating power low. It is found in the United States, Canada, Germany, and elsewhere chiefly in formations formed in the Tertiary period.
- - Sub-bituminous coal - is a coal whose properties range from those of lignite to those of bituminous coal It may be dull, dark brown to black, soft and crumbly at the lower end of the range, to bright, jet-black, hard, and relatively strong at the upper end. Subbituminous coal contains 20 to 30 percent inherent moisture by weight. The heat content of sub-bituminous coal ranges from 17 to 24 million Btu per short ton (20 to 28 MJ/kg) on a moist, mineral-matter-free basis. The heat content of sub-bituminous coal consumed in the United States averages 17 to 18 million Btu/ton (20 to 21 MJ/kg), on the as-received basis (i.e., containing both inherent moisture and mineral matter). A major source of sub-bituminous coal in the United States is the Powder River Basin in Wyoming. Relatively low density and high water content renders some types of sub-bituminous coal susceptible to spontaneous combustion if not packed densely during storage in order to exclude free air flow.
-- Bituminous coal - is usually black, sometimes dark brown, often with well-defined bands of bright and dull material.The carbon content of bituminous coal is around 60-80%; the rest is composed of water, air, hydrogen, and sulphur, which have not been driven off from the macerals.
The heat content of bituminous coal ranges from 21 to 30 million Btu/ton (24 to 35 MJ/kg) on a moist, mineral-matter-free basis.
-- Anthracite - coal is the highest of the metamorphic rank, in which the carbon content is between 92% and 98%. The term is applied to those varieties of coal which do not give off tarry or other hydrocarbon vapours when heated below their point of ignition. Anthracite ignites with difficulty and burns with a short, blue, and smokeless flame. It is the highest rank; a harder, glossy, black coal used primarily for residential and commercial space heating.
-- Briquette A block of compressed coal dust. Some briquettes are compressed and dried brown coal (lignite) extruded into hard blocks. This is a common technique for low rank coals. They are typically dried to 12-18% moisture, and are primarily used in household and industry. In Ireland, peat briquettes are a common type of solid fuel after coal. Although often used as the sole fuel for a fire, they are also used to begin a coal fire quickly without hassle. A fire burning peat briquettes is, similarly to a turf fire, slow burning. For the CARBOROBOT the size of the briquette is the most important parameter. Usable the small size "perl" briquette or fraction max. piece size 30mm.











Coal facts

The World coal reserves


Copyright © 2016 CARBOROBOT
Contact informations     tel/fax:+36-13852-862