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

8.2

Burner operation

D1230
D1986
20024198
Burner calibration
8.2.1

Burner starting

➤ 0 s :
Control device TL closes, the motor starts.
The pump 3) 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 suction and the de-energized solenoid valves 8) -
9) - 16) close the passage to the nozzle.
➤ 5 s :
Servomotor starts: 130° rotation to right, until contact is
made on cam I)(Fig. 21 page 19). The air gate valve is posi-
tioned on MAX. output.
➤ 47 s :
Pre-purge stage with air delivery at MAX. output.
➤ 69 s :
Servomotor rotates to left until contact is made on cam III)
(Fig. 21 page 19).
➤ 106 s :
Air gate valve and pressure regulator are positioned on MIN
output.
Fig. 29
➤ 108 s :
Ignition electrode strikes a spark.
➤ 111 s :
Solenoid valves 8) - 9) - 16) open; the fuel passes through
the piping 10) and filter 11), and 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 regulator 13, then,
through piping 7), it goes back into the tank.
➤ 116 s :
The spark goes out.
➤ 126 s :
The starting cycle ends.
8.2.2

Steady state operation

Burner without output regulator RWF40
At the end of the starting cycle, the servo-motor control then
passes 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).
Fig. 30
Load control TL opens. The servomotor returns to the 0°
angle limited by contact with cam II) (Fig. 21, page 19). The
gate valve closes completely to reduce thermal dispersion
to a minimum.
Every time output is changed, the servomotor automatically mod-
ifies gas oil delivery (pressure regulator) and air delivery (fan gate
valve).
24 GB