CIB UNIGAS - M039168CC
21
Combustion head pressure curves depending on the gas flow rate
Curves are referred to pressure= 0mbar in the combustion head!
The curves referred to the gas pressure in the combustion head, depending on the gas flow rate, are referred to the burner properly
adjusted (3% of residual O
2
in the flues and CO in the standard limits). During this stage, the combustion head, the gas butterfly valve
and the servocontrol are at the maximum opening. Refer to Fig. 12, showing the correct way to measure the gas pressure, considering
the values of pressure in combustion chamber, surveyed by means of the pressure gauge or taken from the boiler’s Technical specifi-
cations.
Fig. 12
Key
1
Boiler
2
Gas pressure outlet on the boiler
3
Gas pressure outlet on the butterfly valve
4
Differential pressure gauge
Measuring the gas pressure in the combustion head
In order to measure the pressure in the combustion head, insert the pressure gauge probes: one into the boiler’s pressure outlet (Fig.
12-2) to get the pressure in the combustion chamber and the other one into the butterfly valve’s pressure outlet of the burner (Fig. 12-
3). On the basis of the measured differential pressure, it is possible to get the maximum flow rate: in the pressure - rate curves (showed
on the next paragraph), it is easy to find out the burner’s output in Stm3/h (quoted on the x axis) from the pressure measured in the
combustion head (quoted on the y axis). The data obtained must be considered when adjusting the gas flow rate.
NOTE: THE PRESSURE-RATE CURVES ARE GIVEN AS INFORMATION ONLY; FOR A PROPER SETTING OF THE GAS RATE,
PLEASE REFER TO THE GAS METER READING.
1
2
4
3
