HDG Compact 25, Operation Manual

Page: 35 / 188

3 Mode of operation – Fuel quality requirements
35
W
OOD PELLETS
Wood pellets are pressed into a cylindrical shape. They consist of un-
treated shavings and sawdust from the wood processing industry as
well as unprocessed forestry waste. They have a standardised dia-
meter and length. They are pressed at a very high pressure and have
a very low water content. The energy contained in 2 kg of pellets cor-
responds approximately to the energy contained in a litre of heating
oil.
In accordance with DIN EN 14961-2, the fuel specifications for wood
pellets are separated into categories A1 and A2. The diameter of the
employed pellets must be in accordance with D06.
• A1/D06
The diameter of the pellets must be 6 mm +/- 1 mm. The length of
the pellets must measure between 31.5 mm and 40 mm. A maximum
of 1% by weight of the pellets may be longer than 45 mm. The water
content must be less than 10% (M10), the ash content must be less
than 0.7% by weight (A0.7).
• A2/D06
The diameter of the pellets must be 6 mm +/- 1 mm. The length of
the pellets must measure between 31.5 mm and 40 mm. A maximum
of 1% by weight of the pellets may be longer than 45 mm. The water
content must be less than 10% (M10), the ash content must be less
than 1.5% by weight (A1.5).
With regard to the quality standards for wood pellets, DIN EN
14961-2 "Solid biofuels - fuel specifications and classes - wood pel-
lets for non-industrial use" applies.
Standard A1 wood pellets A2 wood pellets
Length 3.15 - 40 mm 3.15 - 40 mm
Diameter Ø D06: 6 mm +/-1 mm D06: 6 mm +/-1 mm
Thermal value 16.5 - 19 mJ/kg or
4.6 - 5.3 kWh/kg 16.3 - 19 mJ/kg or
4.5 - 5.3 kWh/kg
Density (spec. gravity)
1.0 – 1.4 kg/dm
3
min. 1.12 kg/dm
3
Bulk weight
min. 600 kg/m
3
min. 600 kg/m
3
Water content max. 10% max. 10%
Ash content max. 0.7% max. 1.5%
Fine material max. 1.0% max. 1.0%
Sulphur content max. 0.03% max. 0.03%
Nitrogen content max. 0.3% max. 0.5%
Chlorine content max. 0.02% max. 0.02%
Additive max. 2.0% max. 2.0 %
Table 3/5 - Burning characteristics of wood pellets