Burner Calibration; Burner Firing; Operation - Riello RL 70/M Instrucciones De Instalación, Funcionamiento Y Mantenimiento

8

Burner calibration

8.1

Burner firing

Close load controls and set switch 1)(Fig. 26) to "MAN".
After burner firing a complete burner adjustment should be per-
formed.
Notes on safety for the first start-up
The first start-up of the burner must be carried out
by qualified personnel, as indicated in this manual
and in compliance with the standards and regula-
tions of the laws in force.
WARNING
Check the correct working of the adjustment, com-
mand and safety devices.
WARNING
Set switch 1)(Fig. 26) to "ON".
During the first firing, during the passage from the 1st to the 2nd
stage, there is a momentary lowering of the fuel pressure caused
by the filling of the 2nd stage nozzle tubing. This lowering of the
fuel pressure can cause the burner to lock-out and can some-
times give rise to pulsations.
Once the following adjustments have been made, the firing of the
burner must generate a noise similar to the noise generated dur-
ing operation. If one or more pulsations or a delay in firing in re-
spect to the opening of the light oil solenoid valve occur, see the
suggestions provided on page 27: causes 34 ÷ 42
Burner calibration
1 2
D791
8.2

Operation

The optimum calibration of the burner requires an analysis of the
flue gases at the boiler outlet.
The following settings that have already been made do not re-
quire modification under normal circumstances:
 Combustion head
 Servomotor, cams I - II - IV - V
Contrarily, the settings listed below must be adjusted in se-
quence:
1
2
3
Fig. 26
output.
1 - MAX output
Max output of the burner must be set within the firing rate range
shown on page 9.
In the above instructions we left the burner running in MIN output
operation. Now press button 2)(Fig. 26) "+" until servomotor ar-
rives at 130°.
Adjusting the nozzle flow rate
The nozzle flow rate varies according to the fuel pressure on the
nozzle return.
Diagram (Fig. 27) indicates this relationship for type A3 and A4
Bergonzo nozzles with pump delivery pressure of 20 bars.
Diagram (Fig. 27):
Horizontal axis
Vertical axis
NOTE:
with a pump delivery pressure of 20 bar, the pressure on the
nozzle return must not exceed 17 bars.
The pressure difference between pump delivery and nozzle
return must be at least 3 bars. With smaller pressure differ-
ences, the pressure on the nozzle return can be unstable.
Return pressure
21 GB
MAX burner output;
MIN burner output;
Intermediate outputs between MAX and MIN
: bar, nozzle return pressure
: kg/h, nozzle flow rate
D1228
Fig. 27
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