BCU 560, BCU 565 · Edition 02.16
29
menox® low NOx mode > System structure and function
Flame mode
In order to heat up the furnace, the burner operates in flame
mode.
The ignitable gas/air mixture is ignited using an electrical
ignition spark and combusts inside and outside of the ce-
ramic burner tube. The presence of the flame is monitored in
compliance with EN 746-2.
menox
®
mode
As soon as the combustion chamber temperature is ≥ 850°C,
the burner control unit BCU..D2 can switch to menox
®
mode.
Gas and air are supplied through the same connections as in
flame mode. No ignition takes place in the burner tube. The
combustion process is relocated to the combustion chamber.
The oxidation reactions take place without a visible flame.
Compared to traditional flame mode, the reaction zone is
considerably larger and the reaction density considerably
lower. This prevents the occurrence of peak temperatures
which are responsible for high NO
x
values. Emissions of NO
x
are drastically reduced.
850
1050
1250
1200
1150
1100
900
1000
950
0
100
200
300
400
Furnace temperature [°C]
NO
x [mg/m
3
, ref. 5% O
2
]
Flame mode
Natural gas, air preheating to 450°C
In menox
®
mode, NO
x
values can be reduced to below
150 mg/m³ (reference value of 5% O
2
) even at a furnace tem-
perature of 1200°C and hot air at 450°C – without expensive
additional piping. The high output pulse frequency and rotary
impulse control ensure temperature uniformity which is of
great advantage.
For further information on burner BIC..M,
see www.docuthek.com