Nozzle Assembly; Secondary Air Adjustment - Riello RL 70 HS Manual

D8262
(A)
(C)
D8264
(D)
(E)
Example with the RL 70 HS Model:
Boiler output = 635 kW - efficiency 90 %
Output required by the burner =
635 : 0,9 = 705 kW;
705 : 2
therefore, two equal, 60°, 12 bar nozzles are re-
quired:
1° = 7.0 GPH - 2° = 7.0 GPH,
or the following two different nozzles:
1° = 6.0 GPH - 2° = 8.0 GPH,
or:
D8263
1° = 8.0 GPH - 2° = 6.0 GPH.

NOZZLE ASSEMBLY

At this stage of installation the burner is still dis-
(B)
assembled from the blast tube; it is therefore
possible to fit the two nozzles after removing the
flame disk 1)(A) and the plastic plugs 2)(A). Do
not use any sealing products such as gaskets,
sealing compound, or tape. Be careful to avoid
damaging the nozzle sealing seat. The nozzles
must be screwed into place tightly but not to the
maximum torque value provided by the wrench.
The nozzle for the 1st stage of operation is the
D693
one lying beneath the firing electrodes Fig. (B).
Make sure that the electrodes are positioned as
shown in Figure (B).
Finally remount the burner 3)(C) to the slide bars
2) and slide it up to the flange 5), keeping it
slightly raised to prevent the swirler disk from
pressing against the blast tube.
Tighten the screws 1) on the slide bars 2) and
screws 4) fixing the burner to the flange.
If it proves necessary to change a nozzle with the
burner already fitted to the boiler, proceed as
outlined below:
- Retract the burner on its slide bars as shown
in fig. (B)p.5.
- Remove the nuts 1)(D) and the disk 2).
- Use spanner 3)(D) to change the nozzles.

SECONDARY AIR ADJUSTMENT

Loosen screw (1) to be able to turn the ring nut
(2) that opens / closes air flow to the secondary
swirler.
Adjust with secondary air fully open. When the
secondary air is closed, the main swirler speed
increases and therefore, the flame width is
reduced.
With full cone nozzles, close the secondary air
Attention
When the secondary air is fully closed, the max-
imum burner output is reduced by about 10%.
1
2
D8270
6
= 352 kW per nozzle;