Table of Contents
Advertisement
7.3.3
MAX power
Max output of the burner must be set within the firing rate range
shown on page 11.
In the above instructions we left the burner running in MIN output
operation. Now press button 2)(Fig. 23 at page 22) "+" until ser-
vomotor arrives 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.
With a pump delivery pressure of 20 bar, the pres-
sure on the nozzle return must not exceed 17 bar.
The pressure difference between pump delivery
WARNING
and nozzle return must be at least 3 bars. With
smaller pressure differences, the pressure on the
nozzle return can be unstable.
The nozzle return pressure value is indicated by the pressure
gauge 1)(Fig. 28).
The output and the pressure of the nozzle are at maximum when
the servomotor is positioned on 130°.
The fine adjustment of the pressure in the return line may be car-
ried out by changing the setting of the eccentric 6), of the nut and
lock-nut 4).
–
The eccentric setting should be carried out by loosening
screws 7);
–
turning the screw 5) to obtain the desired eccentricity.
–
Turn clockwise the screw 5) to increase the eccentricity, in-
creasing the difference between the min. and max. capacity
of the nozzle;
–
turn counter-clockwise the screw 5) to decrease the eccen-
tricity and, consequently the difference between the min. and
max. capacity of the nozzle.
•
The proper setting of the eccentric 6) is possi-
ble when its operation field follows the servo-
motor operation field (20° ... 130°): so, that
CAUTION
every variation of the servomotor position cor-
responds to a pressure variation.
•
Do not let the piston beat repeatedly: the stop
ring 3)(Fig. 28) determines the max. stroke.
•
When the setting is carried out, verify manual-
ly that no slow-down occurs between 0° and
130° and that the maximum and minimum
pressures correspond to those chosen as per
diagram (Fig. 27).
–
If you wish to check the delivery capacity of the nozzle, open
the burner, attach the nozzle, simulate the start-up and then
proceed with weighing of the maximum and minimum pres-
sures of the fuel.
–
If at the maximum capacity of the nozzle (maximum pressure
in the return line) pressure fluctuations are detected on the
manometer 1), slightly decrease the pressure in the return
line until they are completely eliminated.
Adjusting air delivery
Progressively adjust the end profile of cam 2)(Fig. 29) using ad-
justment screws 5).
– Turn the screws clockwise to increase air delicery.
– Turn the screws counter-clockwise to reduce air delicery.
Start-up, calibration and operation of the burner
D1228
D1227
Key (Fig. 28)
1
Pressure gauge for pressure on nozzle return
2
Oil pressure switch
3
Ring for piston stop
4
Nut and lock-nut for piston setting
5
Eccentric adjusting screw
6
Variable eccentric
7
Eccentric locking screws
D1229
Key (Fig. 29)
1
Servomotor
2
Adjustable profile cam
3
Adjustment screws for cam profile
4
Adjustment fixing screws
5
Adjustment screws for cam profile
23
GB
Return pressure - bar
Fig. 27
Fig. 28
Fig. 29
20033333
Advertisement
Table of Contents
