PART II: NOTES FOR THE INSTALLER
12
Combustion head gas pressure curves
Combustion head gas pressure depends on gas flow and combustion chamber backpressure. When backpressure is subtracted, it
depends only on gas flow, provided combustion is properly adjusted, flue gases residual O2 percentage complies with “Recommended
combustion values” table and CO in the standard limits). During this stage, the combustion head, the gas butterfly valve and the
actuator are at the maximum opening. Refer to , 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 specifications.
.
Matching the burner to the boiler
(
low NOx burners)
The burners described in this manual have been tested in combustion chambers complying with standard EN676. If the burner is to be
matched to boilers with combustion chambers of a smaller diameter or shorter length than those indicated in the Standard, contact the
Manufacturer to check that it is suitable for the application for which it is intended.
To correctly match the burner to the boiler:
Check that the required power and the pressure in the combustion chamber are within the working range.
Also check that the length of the combustion chamber is greater than the combustion head.
Verify that the neutral section of the head exceeds the refractory. The application does not always meet this requirement, so it may
be necessary to use a spacer of a suitable size, which serves to retract the burner to meet the above measurements.
The neutral section of the combustion head must be protected against high temperatures. A specially shaped panel for applications
with operating temperatures up to 1200° C is supplied.
If the above requirements cannot be met, the choice of burner must be reviewed in consultation with the manufacturer.
1
2
4
3
Note: the figure is indicative only.Key
1 Generator
2 Pressure outlet on the combustion chamber
3 Gas pressure outlet on the butterfly valve
4 Differential pressure gauge
ATTENTION: THE BURNED GAS RATE MUST BE
READ AT THE GAS FLOW METER. WHEN IT IS NOT
POSSIBLE, THE USER CAN REFERS TO THE
PRESSURE-RATE CURVES AS GENERAL
INFORMATION ONLY.
30° max
1
2
3
1 - Burner insulation
2 - Burner head
3 - Boiler door
Summary of Contents for C70N US
Page 43: ......
