Fuel Oil Combustion Adjustment - CleaverBrooks FLX Operation, Service And Parts Manual

Adjustment Procedures
MODEL NO.
Fuel Consumption Gas (cfh)
A. Natural Gas @ 1000 Btu/cu-ft.
REGULATOR INLET
PRESSURE (PSIG)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Table 6-2: Pressure Correction Factors
T. FUEL OIL COMBUSTION
ADJUSTMENT
After operating for a sufficient period of time to assure a
warm boiler, adjustments should be made to obtain efficient
combustion.
Burner efficiency is measured by the amount or percentage of
O present in the flue gas. O
2
amount or excess air in the combustion process, above the
point of stoichiometric combustion or perfect combustion.
Stoichiometric combustion however, is the reference point
used when setting fuel/air ratios in a boiler.
There must always be excess air in the combustion process to
account for changes in boiler room conditions and to ensure
the combustion is on the proper side of the combustion curve .
Proper setting of the air/fuel ratios at all rates of firing must
be established by the use of a combustion gas analyzer.
Efficient combustion cannot be solely judged by flame
750-177
150 200 250 300
A
1500 2000 2500 3000
Table 6-1: Fuel Consumption (Natural Gas)
PRESSURE FACTOR
1.05
1.11
1.18
1.25
1.32
1.39
1.45
1.53
1.59
1.66
1.72
1.81
1.86
1.93
2.00
readings determine the total
2
350 400 450 500
3500 4000 4500 5000 5500
MODEL NO.
FLX-150
FLX-200
FLX-250
FLX-300
FLX-350
FLX-400
FLX-450
FLX-500
FLX-550
FLX-600
FLX-700
FLX-800
FLX-900
FLX-1000
FLX-1100
FLX-1200
Notes:
1. Table is based on 1,000 Btu/cu.ft natural gas and elevation to 1000
feet.
2. Minimum gas pressure also applies to 200 fuel series.
3. As an option, the standard gas train can be replaced with an
oversized design to reduce inlet gas pressure requirements.
4. Use this column for all U.S. Installations.
5. Use this column for all Canadian Installations.
Table 6-3: Minimum Required Gas Pressures
condition or color, although they may be used in making
approximate settings. Combustion settings should be done so
that there is a bright sharp flame with no visible haze.
Most flue gas analyzers in use today measure the content, by
percentage, of oxygen (O
Carbon dioxide (CO
gas analyzers, but may be displayed as a calculation.
The O levels through the entire firing range of the burner,
2
low fire to high fire should be tested. Cleaver-Brooks
recommendations on turndown should also be followed and
the turndown range of the burner should not be exceeded.
It is required to set the burner to operate with a reasonable
amount of excess air to compensate for minor variations in
the pressure, temperature, or burning properties of oil. Fifteen
to 20% excess air is considered reasonable. This would result
in an O reading of 3% to 4%, at high fire.
2
550 600 700 800 900
6000 7000 8000 9000 10000 11000 12000
MIN. GAS MIN. GAS
STD GAS
PRESSURE PRESSURE
TRAIN SIZE
(IN.W.C.) (IN.W.C.)
(IN.) Note 3
Note 4 Note 5
1 11.2 12.5
1 19.4 21.7
1.5 12.4 15.7
1.5 15.9 20.7
1.5 15.5 22.0
1.5 18.7 27.2
2 16.0 26.7
2 17.6 21.0
2 22.9 27.1
2 20.0 24.9
2 25.2 31.9
2.5 19.9 22.2
2.5 24.7 27.7
2.5 31.6 31.6
2.5 37.3 37.3
2.5 38.2 38.2
) and in some cases, smoke.
2
) is not normally measured with modern
2
Chapter 5
1000 1100 1200
BURNER
MODEL
PFVG-15
PFVG-20
PFVG-25
PFVG-30
PFVG-35
PFVG-40
PFVG-45
PFVG-50
PFVG-55
PFVG-60
PFVG-70
PFVG-80
PFVG-90
PFVG-100
PFVG-110
PFVG-120
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