Pellet Quality Characteristics; Types Of Pellet Delivery; Principles Of Woodchip Combustion For Generating Heat; What Are Woodchips - Viessmann VIESMANN VITOLIGNO 300-H Technical Manual

Principles of wood combustion
Requirement
Diameter mm
Length mm
Bulk density
kg/m
Net calorific value (when MJ/kg
free of water) kWh/kg
Water content %
Percentage of fines %
(particles shorter than the
specified length of
3.15 mm)
Mechanical strength %
Abrasion resistance %
Ash content %
Ash softening temperature °C
Chlorine content %
Sulphur content %
Nitrogen content %
Copper content %
Chromium content %
Arsenic content %
Cadmium content %
Mercury content %
Lead content %
Nickel content %
Zinc content %
Compression additive %
External production control

Pellet quality characteristics

High quality pellets:
■ Smooth, shiny surface
■ Uniform length
■ Low proportion of dust
■ Sink in water

Types of pellet delivery

In their loose form, pellets are transported by silo tanker and pumped
into the storage room via a hose system.

1.3 Principles of woodchip combustion for generating heat

What are woodchips?

Woodchips are made from 100 percent natural wood from forests and plantations. This raw material comes from tree trunks or branches. The
wood is then processed with high speed cutting tools in accordance with ÖNORM M 7133.
Definition of woodchip size classes according to ÖNORM M 7133
Total mass
100 %
Coarse percentage Max. cross-section
up to 20 % Max. length
Coarse sieve nominal mesh
width
*1 The essential properties of wood pellets are described in European Standard 14961-2. EN 14961-2 will be superseded in 2014 by international
standard ISO 17225. Once ISO 17225-2 is published in 2014, the values in brackets will replace the previous values.
VITOLIGNO 300-H
(cont.)
*1
ENplus-A1
3.15 ≤ L ≤ 40
A maximum of 5 % may be lon-
ger than 40 mm, but no longer
than 45 mm.
3 ≥ 600 (600 to 750)
≥ 4.58 (4.6 to 5.3)
≤ 0.03 (≤ 0.04)
DINplus
6±1
≥ 16.5
≤ 10
≤ 1
≥ 97.5
—
≤ 0.7
≥ 1200
≤ 0.02
≤ 0.3
≤ 10
≤ 10
≤ 1
≤ 0.5
≤ 0.1
≤ 10
≤ 10
≤ 100
—
—
Low quality pellets:
■ Cracked rough surface
■ Widely varying length
■ High proportion of dust
■ Float in water
Careful handling of pellets ensures a low proportion of dust, trouble-
free boiler charging and a constant heating output by the solid fuel
boiler.
Woodchip size classification
G 30
Fine
cm² 3
cm 8.5
mm 16
ÖNORM M 7135
—
—
—
≥ 18
≥ 5
≤ 10
—
—
≤ 2.3
≤ 0.5
—
≤ 0.02
≤ 0.04
≤ 0.3
—
—
—
—
—
—
—
—
≤ 2
Yes
G 50
Medium
5
12
31.5
VIESMANN
—
—
1
—
≥ 18
≥ 5
≤ 10
—
—
≤ 2.3
≤ 0.5
—
≤ 0.02
≤ 0.04
≤ 0.3
—
—
—
—
—
—
—
—
≤ 2
—
G 100
Coarse
10
25
63
7