Kostrzewa Twin Bio Manual De Uso página 66

66 5. Design guidelines
Tip:
Connect the fl ue ducts without any loads and stresses
• seal the fl ue duct
• the fl ue must be opened upwards and lead horizontally at
least 1 metre over the roof surface (with a rain cap)
• fl ue diameter must be selected in accordance with the fl ue
liner manufacturer's requirements
• estimate cross sectional area of a circular fl ue is calculated
using Redtenbacher's equation:
A = 2,6 * Q / (n * H^0,5)
where:
A – fl ue cross section [m
Q – boiler heat output [kW]
n – coeffi cient within the following range 900 – 1880
(n = 900 for wood)
H – fl ue height [m]
CAUTION!
The installed fl ue system requires the commissioning
consisting in the inspection of the following:
• fl ow capacity;
• gas tightness;
• draught;
• connection and conformity with the design;
• standard height above the roof;
• environmental protection standard requirements;
• installation conformity with the design and as-built
documentation;
• valid certifi cates for structural, insulation and
mounting materials used for installation.
The device has to be commissioned by an authorized
personnel with a report.
Experts in heating
2
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5.F. Fuel quality requirements
Pellets
Sawdust granulate (pellets) made to EN 14961-2:2011
– Class A1 are the basic type of fuel used in the Twin Bio boiler
• diameter: 6 ± 1 mm; 8 ± 1mm
• length 3,15 ≤ L ≤ 40
• moisture content ≤ 10%
• ash content ≤ 0,7%
• calorifi c value 16,5 – 19 MJ/kg
• density ≥ 600 kg/m
Oats / Pellets
The Twin Bio boiler may be fi tted with an optional burner
grate for the combustion of oats and wood pellets mixture
(50:50 ratio) and low quality pellets (high ash content, lower
calorifi c value). Oats moisture content ≤12%. The burner grate
replacement for the oats grate is included in section 7.J.
Wood
Additionally, the Twin Bio boiler may be fi tted with cast iron
grates for burning pieces of wood. Wood grate installation is
described in 7.K.
In order to achieve the nominal power of the boiler, use dry
wood with the max. humidity of up to 20%, which is equivalent
to 18 months of drying the wood under cover. Using larger
elements (chopped into thick pieces) will prolong the burning
of one load to up to 8 hours.
CAUTION!
Use the fuels from reliable sources only.
The fuels must have suitable moisture content and
low proportion of fi nes. They should not contain
mechanical impurities (stones etc.) which may affect
the combustion process and damage the device.
Kostrzewa shall not be held liable for any damage
or incorrect combustion process as a result of using
unsuitable fuels.
Failure to comply with the fuel quality requirements may result
in damage to the heating system components (e.g. boiler,
feeder) and is not covered by the warranty. It may invalidate
the warranty and result in additional charges in case an
authorised service centre is involved.
User Manual Twin Bio - PLV 09.13