Burner Operation; Burner Starting; Steady State Operation; Firing Failure - Riello RL 190/M Installation, Use And Maintenance Instructions

7.5

Burner operation

7.5.1

Burner starting

Control device TL closes, the motor starts.
0 s:
The pump 3)(Fig. 32) sucks the fuel from the tank
through the piping 1) and the filter 2) and pumps it
under pressure to delivery.
The piston 4) rises and the fuel returns to the tank
through the piping 5) - 7).
The screw 6) closes the by-pass heading towards suc-
tion and the de-energized solenoid valves 8) - 9) - 16)
close the passage to the nozzle.
Servomotor starts: 130° rotation to right, until contact is
5 s:
made on cam I)(Fig. 27 at page 22).
The air gate valve is positioned on MAX. output.
Pre-purge stage with air delivery at MAX. output.
47 s:
Servomotor rotates to left until contact is made on cam
69 s:
III)(Fig. 27 at page 22).
106 s: Air gate valve and pressure regulator are positioned on
MIN output.
108 s: Ignition electrode strikes a spark.
Solenoid valves 8) - 9) - 16) open; the fuel passes
111 s:
through the piping 10) and filter 11), finally it enters the
nozzle.
A part of the fuel is then sprayed out through the nozzle,
igniting when it comes into contact with the spark: flame
at a low output level, point A; the rest of the fuel passes
through piping 12) at the pressure adjusted by the regu-
lator 13), then, through piping 7), it goes back into the
tank.
116 s: The spark goes out.
126 s: The starting cycle ends.
7.5.2

Steady state operation

Burner without output regulator RWF40
At the end of the starting cycle, the servomotor control then pass-
es to load control TR for boiler pressure or temperature, point B.
 If the temperature or pressure is low (and the TR load con-
trol is consequently closed), the burner progressively
increases output up to MAX (section B-C).
 If subsequently the temperature or pressure increases until
TR opens, the burner progressively decreases output down
to MIN (section D-E). And so on.
 The burner locks out when demand for heat is less than the
heat supplied by the burner in the MIN output (section F-G).
Load control TL opens.
The servomotor returns to the 0° angle limited by contact
with cam II)(Fig. 27 at page 22).
The gate valve closes completely to reduce thermal disper-
sion to a minimum.
Every time output is changed, the servomotor automatically mod-
ifies gas oil delivery (pressure regulator) and air delivery (fan gate
valve).
Burner with output regulator RWF40
See the handbook enclosed with the regulator.
Start-up, calibration and operation of the burner
D1230
D1986
7.5.3

Firing failure

If the burner does not fire, it goes into lock-out within 5 s of the
opening of the gas oil valve.
7.5.4 Firing failure
If the flame should go out for accidental reasons during operation,
the burner will lock out in 1 s.
25
GB
Fig. 31
Fig. 32
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