Definition Of Woodchip Size Classification According To Qm-Holzheizwerke [Quality Management For Wood Heating Plants] Regulations And En 14961; Woodchip Requirements - Viessmann VIESMANN VITOLIGNO 300-H Technical Manual

Principles of wood combustion
Main proportion
60 to 100 %
Percentage of fines
(incl. finest woodchips)
1
max. 20 %
Definition of woodchip size classification according to QM-Holzheizwerke [quality management for wood
heating plants] regulations and EN 14961
Main fraction
> 80 % of mass
Percentage of fines
< 5 % of mass
Coarse percentage
Max. particle length
< 1 % of mass
Maximum length

Woodchip requirements

For combustion in the Vitoligno 300-H, use woodchips with a maximum
coarse percentage of 20 %, a maximum cross-section of 5 cm
maximum length of 12 cm (5 % up to 16 cm) (G50/P45).
Bulk density S (kg/m³), water content w (%), size G (mm) as per ÖNORM M 7133
and to QM-Holzheizwerke
S 130 w10 to w20
S 130 < w15
S 200 < w15
S 200 w20
S 200 w20 to w35
S 250 < w15
S 250 w20 to w35
S 300 w20 to w35
S 350 w20 to w35
Note
With coarse content limitation < 1 % to a length of up to 125 mm
Fuel
Dry, mixed natural sawdust, woodchips from wood remnants
Briquettes from wood remnants, diameter 40 to 60 mm
Soft natural woodchips
Soft/hard natural woodchips
Soft/hard natural woodchips
Note
With coarse content limitation < 1 % to a length of up to 125 mm
Quality characteristics
Good woodchips:
■ As per ÖNORM M 7133
■ Size G30 or G50
■ Max. 5 % anomalies
■ Smooth surfaces
Values to QM-Holzheizwerke differ from those of EN 14961
*2
VIESMANN
8
(cont.)
Medium sieve nominal mesh
width
Fine sieve nominal mesh width
mm ≥ 3.15
mm
mm
all < 85
mm
See note
G30/G50 P45/P63
G30/G50 P45/P63
G30/G50 P45/P63
G30/G50 P45/P63
G30/G50 P45/P63
G30/G50 P45/P63
G30/G50 P45/P63
G30/G50 P45/P63
G30/G50 P45/P63
mm
mm
Woodchips or shredded wood
P16 P45
*2
≤ 16
≤ 45
< 1 < 1
> 45 > 63
– *2
125
The water content of the woodchips can be up to 30 % (w30/M30).
2 and a
Natural sawdust
Dry, mixed shavings, woodchips from wood remnants
Dry, mixed shavings, woodchips from wood remnants
Soft natural woodchips
Natural sawdust
Dry, mixed shavings, woodchips from wood remnants
Soft natural woodchips
Soft/hard natural woodchips
Hard natural woodchips
Poured weight Max. size (mm) to
S (kg/m 3 ) ÖNORM M 7133
S 130 - S 200 G30/G50
S 200 - S 350 G30/G50
S 200- S 250 G30/G50
S 300 - S 350 G30/G50
S 300 - S 400 G30/G50
Low quality woodchips:
■ Frayed surface
■ More than 5 % anomalies
■ Coarse percentage > 20 %
■ Greater than G30 or G50
2.8 5.6
1 1
P63 P100
*2 *2
≥ 8 ≥ 11.2
≤ 63 ≤ 100
< 1 < 1
> 100 > 200
*2 *2
200 250
EN 14961
See note
P45/P63
P45/P63
P45/P63
P45/P63
P45/P63
VITOLIGNO 300-H
11.2
1
P300
≥ 3.15
≤ 300
< 1
> 400
–
Max. water
content
w (%)
w10 - w20
w10 - w20
< w20
w20 - w35
w20 - w50