Setting The Combustion Head - Riello GAS 9/2 Installation, Use And Maintenance Instructions

SETTING THE COMBUSTION HEAD

(A)
(B)
GAS
(C)
D49
D3439
AIR
S8058
9
SETTING THE COMBUSTION HEAD
Combustion head adjustment depends exclu-
sively on MAX output generated by the burner in
stage 2.
This value must therefore be set before adjusting
the combustion head.
Two head settings are available, i.e. the gas set-
ting and the air setting.
Gas setting is done with the burner open (fig. B)
page 8, when securing the burner to the boiler;
while air setting is done after burner closing.
Gas side adjustment
- Loosen screw 1)(A).
- Rotate the ring nut 2) so that indicator 3) coin-
cides with the required notch 4).
- Fasten screw 1).
Air side adjustment
The combustion head adjuster (air side) is locat-
ed under the control panel cover.
The adjustment shall be according to the setting
graph. Proceed as follows (see fig. B):
- Loosen the fixing bolt 3)(B).
- Rotate the sector 1) to the reference position,
defined by the chart, this moving rod and shut-
ter mounted inside the combustion head.
- Positioning can be read by the index on the
sector itself or on the graduated cylinder (2)
which refers to the surface (4).
- Fasten the belt (3) to fix the reached position.
The notch number for gas and
air are taken from graphs (C)
according to the output at which
the burner is set in stage 2.
WARNING
Example:
a GAS 9/2 burner is installed on a 2250 kW boil-
er. If a 90% efficiency rate is considered, the
burner should deliver approximately 2500 kW in
stage 2.
Graphs (C) indicates that for this capacity, the
gas and air should be set on notch 4 and 5 re-
spectively.
The graph indicates the opti-
mum ring nut 2)(A) setting. If
mains pressure is very low and
does not permit the required
WARNING
pressure (and so the required
output), the ring nut may be
opened by a further 1-2 notch-
es. See also the note on
page 13.