23
20032186
GB
Start-up, calibration and operation of the burner
8.4
Combustion head setting
This is done when fitting the nozzle, with the blast tube removed.
It depends on the output of the burner and is carried out by rotat-
ing the regulating rod, till the terminal plane of the blast tube is
level with the set-point, as indicated in Tab. G, on page 22.
In the sketch (“” on page 23Fig. 19), the combustion head is set
for an output of 3.00 GPH at 12 bar, while the shutter is level with
set-point 3, as required by Tab. G, on page 22.
Combustion head settings indicated in Tab. G, on page 22 are
valid for most cases.
The setting of the fan output according to the installation should
normally be done only through the air damper. Should one sub-
sequently want to retouch also the setting of the combustion
head, with the burner running, operate on the rod 1) with a 6 mm
spanner 2) as follows (Fig. 20):
TURN TO THE RIGHT: (sign +)
In order to increase the volume of air entering the combustion
chamber and thus diminishing its pressure. There is a reduction
of CO2 and the adhesion of the flame to the air diffuser disc im-
proves. (Setting advisable for ignitions at low temperatures).
TURN TO THE LEFT: (sign –)
In order to reduce the volume of air entering the combustion
chamber and thus increasing its pressure. The CO2 improves
and the adhesion of the flame to the diffuser tends to reduce.
(This setting is not advisable for ignitions at low temperatures).
In any case do not bring the combustion head setting more than
one point away from that indicated in Tab. G, on page 22. One
set-point corresponds to 3 turns of the rod; a hole 3)(Fig. 20) at
its end facilitates counting the number of turns.
8.5
Air damper setting
The settings indicated in Tab. G, on page 22 are relevant to a
burner with its cover fitted and the combustion chamber with zero
vacuum.
These settings are purely indicative.
Each system has its own unforeseeable operating conditions:
actual nozzle capacity, pressure or depression in the combustion
chamber, necessary excess air, etc.
All these conditions may require a different air-damper setting.
Therefore we recommend to proceed as follows:
adjust the air damper as shown in Tab. G, on page 22;
fit the cover by simply tightening the upper screw;
check the Bacharach;
if the air output has to be changed, loosen the screw of the
cover, remove it, work on the damper, refit the cover and
then recheck the Bacharach.
2
1
3
5
Fig. 19
D5284
Terminal plane of the blast tube
Blast tube
Regulating rod
Shutter
1
2
3
6
Fig. 20
D8068
WARNING
It is important to take account of the fact that the
air output of the fan differs according to whether
the burner has its cover fitted or not.
