CleaverBrooks FLX Operation, Service And Parts Manual page 42

Chapter 2
COMBUSTION AND HIGH CO EMISSIONS WILL
RESULT. Monitor O
2
The introduction of FGR into the combustion chamber
will lower the flue O
2
induce high levels of CO in the flue gas. It may be nec-
essary to adjust the air damper blades to raise the O
proper low-fire values. If the proper NOx values can not
be reached by adjusting the cam screw, the FGR linkage
will have to be adjusted as well. Please see the section
on linkage adjustment for details.
4. Once the low-fire setting is complete, continue with the
instructions above, adjusting the cam at each screw, to
obtain the proper NOx values. Verify the values modu-
lating back to low-fire, and adjust accordingly.
OIL BURNERS
The oil burner adjustments consist of the oil metering valve
and air shutters. The firing rate is regulated by a metering
valve in the nozzle return line. At low-fire, the arrow on the
valve points to approximately number 7, and at high-fire it is
in the closed position (no return flow), approximately at
number 2. The oil metering valve position will vary the oil
pressure to the nozzle. An oil pressure gauge should be
installed in the return line to monitor the oil pressure. Oil
pressure at low fire is approximately 80 to 100 PSI and 300
PSI at high-fire. Size 1 V10 to 25 uses a simplex nozzle, sizes
2 & 3 use a return flow nozzle.
1. Set the Manual-Auto switch on the "Manual" position.
2. Place the manual flame control potentiometer in the
CLOSED (low-fire) position.
3. Turn the burner switch to the "On" position.
4. The burner will start and be in the low-fire position.
5. Adjust low-fire with the metering valve position to have
approximately 80 to 90 PSI, and adjust the low-fire air
shutter for a clean fire. Record the combustion reading
from the flue gas analyzer, normally 4.5% to 6.5% O
and less than No. 1 Smoke (Bacharach).
6. Operate the boiler at low-fire until it is up to operating
pressure (steam) or temperature (hot water). Then
increase the fuel input to the boiler by turning the man-
ual flame control potentiometer towards OPEN in small
increments. This will cause the metering valve to close,
resulting in an increase in the oil pressure feeding the
burner nozzle.
7. At each point, allow the burner to operate for a few min-
utes before recording the O
readings. Observe that the O
within an acceptable limit. Adjust the oil pressure as
necessary, to correct this situation. For burners with the
cam trim option, adjust the cam screws throughout the
range to obtain correct O
this until the burner reaches high-fire (the potentiometer
2-30
and CO levels during this process.
levels. Too much FGR may
, CO, Smoke, and pressure
2
and CO levels remain
2
and CO levels. Continue to do
2
is at the OPEN position).
8. Adjust the high-fire fuel input to match maximum oil
pressure. At high-fire, the metering valve should be in
the fully closed position and the pressure should be 300
PSI. Verify and record the readings and pressures. High-
to
fire is typically 3.5% to 4.5% O
2
Smoke. Adjust the high-fire excess air rate using the
high-fire shutter adjustment.
9. Modulate the burner to low-fire. Verify the readings
once again. The burner should be adjusted to provide
correct fuel flow at a constant rate, at the low-fire and
high-fire positions as indicated on the burner data plate.
10. Tighten all linkages and marked settings. Complete the
Startup report at the end of this section.
11. Turn the Manual-Auto switch to "Auto." The burner
will now modulate according to the load demand to the
boiler.
COMBINATION GAS-OIL BURNERS
In general, the combination fueled system is to be started first
using oil, because as a fuel, oil has a greater combustion air
requirement than natural gas.After being completely adjusted
for oil combustion, the burner is re-started and adjusted using
natural gas as fuel. Combustion adjustment of the
combination burner for natural gas involves balancing the
input rate only against the existing flow of combustion air, as
established initially for oil
Do not readjust the air shutter when tuning the
combination burner for combustion of natural gas.
1. Set the Manual-Auto switch to the "Manual" position.
2. Position the manual flame control potentiometer in the
CLOSED (low-fire) position.
3. Turn the fuel selector switch to the "Oil" position.
4. Turn the burner switch to the "On" position.
5. Proceed with startup and adjustments using the same
2
procedures defined in the Oil Burners section.
6. After the system has been completely adjusted for oil
firing, place the burner switch OFF, and position the fuel
selector switch to "Gas."
7. Proceed with startup and adjustments using the same
procedures defined in the Gas Burners section. Do not
alter the air setting set for oil. Correct the O
adjusting the butterfly valve.
Profire V Burner
with less than No. 1
2
levels by
2
750-177