Settings for marathon
®
burners with mechanical linkage
dreizler A 3001 E - 18.12.2015 | A 2070 - 1.12 | EN - 09.11.2012
40
NOTICE:
Modern systems can also operate with a control ratio of up to 1:5, but that would mean more adjustments.
Close air dampers L90 and L130 via cam 2 of the servomotor until rotating the gas damper allows a
throughput setting of less than 30%.
In this air damper position, the gas damper is then adjusted in small increments until the CO
2
content
is set to between 9 and 10%, and no CO occurs.
Run the system repeatedly to position MAX and check your measurements.
12.7 Fine tuning the gas and air volume
Connect a U tube manometer on the measuring nipple downstream of the gas damper.
If settings are correct, it will power from
.
head pressure (measuring nipple downstream of the gas damper) will display a pressure ratio of approx.
100/33 = 3:1
NOTICE:
Gas pressure decreases squared to linear capacity.
Tab. 12-1 Burner pressure ratio
Example: At a control ratio of 1:4,46 = 22.4%, the pressure ratio is 1:20.
NOTICE:
Only a few burners are able to handle this, as only 1/20 of the 'mixed energy' will be available at the burner
head in position MIN.
12.7.1 Setting intermediate positions
Monitor the burner flame.
The flame can burn with a slightly yellow flame at MIN load, during start-up, however, it should always
burn in a visible blue range.
NOTICE:
A CO
2
content in the waste gas of 8 - 10.5% between MIN and MAX load is desirable.
MAX
to
MIN
100%
to a value of
33%
e.g. Gas pressure (mbar)
Pressure ratio
Burner output ratio
12,0
100% = 1
1 = 100%
6,0
50% = 1/2
1/2 = 70,0%
3,0
25% = 1/4
1/4 = 50,0%
2,4
20% = 1/5
1/5 = 44,7%
1,2
10% = 1/10
1/10 = 31,6%
0,6
5% = 1/20
1/20 = 22,4%
