Bentone B40 - Basic Settings; Pre-Purge Time Calculation; Recommended Excess Air

21
Bentone B 30/B 40 J/K
3. Basic settings
3.1 Calculate prepurge time
V = Fire box size m
3
Q = Burner output at prepurge [kW]
X = Prepurge time seconds Water boilers
100% air rate
50 % air rate
33% air rate
at least 20s prepurge time
at least 40s prepurge time
at least 60s prepurge time
X = Prepurge time seconds Steam generators
at last prepurge 5 times firebox volume
X = Prepurge time seconds Industrial heating process
at least prepurge at least 5 times firebox and
adapted compartments volumes together
Local regulations must be followed
Example A
X = V
.
5
=
2 · 5
= 150 seconds
((Q · 1,2) / 3600) ((200 · 1,2)/3600)
Example B
X = V
.
5
=
9,5 · 5
= 285 seconds
((Q · 1,2) / 3600) ((500 · 1,2)/3600)
Example C
X =
V
.
5
=
25 · 5
= 170 seconds
((Q · 1,2) / 3600) ((2200 · 1,2)/3600)
Calculation example:
Example A: V=2m
3
Q=200
Example B: V=9,5m
3
Q=500
Example C: V=25m
3
Q=2200
3.2 Recomended exsess air
Grade of Oil Excess air flue gases Max. % CO
2
% O
2
% CO
2
Lambda 1.2
Light oil 3–5 ≈12,5 15,4