26
3.4 Fuel quality requirements
PERMISSIBLE FUEL
Only wood pellets are permissible as fuel for the
HDG Pelletmaster 15/25 boiler.
Wood pellets are pressed into a cylindrical shape. They consist of
untreated shavings and sawdust from the wood processing industry
as well as unprocessed forestry waste. They have a standardised
diameter and length. They are pressed at a very high pressure and
have a very low water content.
DIN 51731 Wood pellets in the size class HP5 are made of pressed, untreated
wood including bark, without any bonding agents. The energy
contained in 2 kg of pellets corresponds approximately to the energy
contained in a litre of heating oil (10 kWh).
ÖNORM M 7135 The Austrian standard contains technical fuel requirements, a test for
suitability, internal and external monitoring and the labelling.
DIN
PLUS The certification to “DINplus” combines the two previously
mentioned standards, taking the stricter value in each case. The
certification procedure is carried out at the pellet manufacturer by a
testing institute approved by “DIN Certco”. Independent tests are
made at regular intervals so that the quality of the pellets can be
ensured.
Standard DIN 51731 ÖNORM M 7135 DINplus
Length max. 50 mm max. 5 x Ø max. 5 x Ø
Diameter Ø 4 – 10 mm max. 10 mm 4 – 10 mm
Thermal value 17.5 - 19.5 MJ/kg min. 18.0 MJ/kg min. 18.0 MJ/kg
Density (spec. gravity)
1.0 – 1.4 kg/dm
3
min. 1.12 kg/dm
3
min. 1.12 kg/dm
3
Piled weight
min. 650 kg/m
3
min. 650 kg/m
3
not specified
Water content max. 12% max. 10% max. 10%
Ash proportion max. 1.5% max. 1.5% max. 0.5%
Abrasion not specified max. 2.3% max. 2.3%
Sulphur content not specified max. 0.04% max. 0.04%
Nitrogen content not specified max. 0.3% max. 0.3%
Chlorine content not specified max. 0.02% max. 0.02%
Pressing additives not specified max. 2.0% max. 2.0%
Table 3/2 - Burning characteristics of wood pellets
To Next Page
Loading...