Technical description of the burner
11
20036952
GB
3.8
Firing rate
MAXIMUM OUTPUT
must be selected in area A (Fig. 4).
MINIMUM OUTPUT
must not be lower than the minimum limit
shown in the diagram:
NOTE:
The firing rate area given in Fig. 4 have been reduced by 10% with
respect to the maximum range that can be reached.
3.8.1
Procedure to refer burner operating condition
in high altitude plants
Find the
CORRECTED BURNER CAPACITY
for the plant’s alti-
tude in chart
1
and the
CORRECTED PRESSURE
in chart
2
.
Check in the firing rate graph of the burner (Fig. 4), if the working
point defined by the values above is within the range limits.
If not, higher burner size is needed.
Note
Charts are based only on altitude variation (reference temper-
ature = 68°F, 20°C)
To get the combined correction in case of different air temper-
ature, a compensation of 1000 ft each 20°F (305 m each
11°C) is applicable (100 ft = 2°F).
Example
Rated capacity = 3000 MBtu/hr - Rated air pressure = 1 “WC
Real altitude
= 3000 ft - Real temperature = 88 °F
= 88 °F - 68°F (reference temp.) = 20°F (equiva-
lent 1000 ft variation)
Proceeding as descripted above and considering a “virtual altitude”
of (3000 + 1000) ft:
–
the corrected capacity is 3425 MBtu/hr
–
the corrected burner air pressure is 1.14
Model
MBtu/hr
GPH
RLS 68/E
682
5
RLS 120/E
1023
7.3
WARNING
The firing rate area values have been obtained con-
sidering an ambient temperature of 68 °F, and an
atmospheric pressure of 394” WC and with the
combustion head adjusted.
Fig. 4
Co
m
bustio
n ch
amber
p
ressure
-
“W
C
D11360
Combust
ion chamb
er
p
res
su
re
-
“WC
RLS 68/E
RLS 120/E
