Gas/air ratio control with pneumatic linkage
dreizler A 3001 E - 18.12.2015 | A 2035 - 1.09 | EN - 23.06.2009
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10.3 Instructions for the configuration of the gas/air ratio control
1) A manometer is required, as it allows for a quick and sure determination of air pressure PL, gas nozzle
pressure at the burner head PK, and combustion chamber counter pressure PF.
2) The combustion chamber counter pressure PF is measured directly at the flame tube. Ensure the in-
stallation of the combustion chamber pressure meter in '5 o'clock' position, see chapter 'Flame tube
mounting dimensions'. The installed unit will effectively protect the gas/air ratio controller from conden-
sation in the combustion chamber.
3) Air pressure PL is measured upstream ahead of the swirl plate in the burner head.
4) In burner types M... and MC... up to size 5001, air presetting for QBmax is done at the suction side of
the air box.
5) Gas flow rate is measured at the gas meter in l/min or m3/h. Measurement of the CO2 content allows
for an assessment of the air volume and air/gas ratio.
For natural gas, the CO2 content should be
–
QBmax = 9.5 - 10.5 % (max. burner load)
–
QBmax = 8.0 - 9.5% (min. burner load).
The CO2 content will change if the gas ratio pressure controller PG is manipulated.
NOTICE:
A test log must be kept.
This log will allow conclusions regarding effectiveness, hygienic waste air values and the gas/air mix-
ture settings.
