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
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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 don’t burn, burn back or produce tar.
Can coke be used?
Definitely not!
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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.
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Coal facts |
The World coal reserves
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