B&C Technologies IM Series Industrial Ironer User Manual
Page 132
6
GAS PRESSURE
The adjacent tables are used to calculate manifold pres-
sure taking into account combustion chamber pressure.
Column 1
Pressure loss at combustion head.
Gas pressure measured at test point 1)(B), with:
• Combustion chamber at 0” WC
• Burner operating at maximum output
•
A
= Gas ring 2)(B)p.8 adjusted as indicated in dia-
gram (C)p. 8.
•
B
= Gas ring 2)(B) adjusted to zero.
Column 2
Pressure loss at gas butterfly valve 2)(B) with maximum
opening: 90°.
Calculate the approximate maximum output of the
burner as follows:
- subtract the combustion chamber pressure from the
gas pressure measured at test point 1)(B).
- Find the nearest pressure value to your result in col-
umn 1A or B of the table for the burner in question.
- Read off the corresponding output on the left.
Example - RS 28/M:
• Maximum output operation
• Natural gas
• Gas ring 2)(B)p.8 adjusted as indicated in diagram
(C)p.8.
• Gas pressure at test point 1)(B)
= 2.36“ WC
• Pressure in combustion chamber
= 0.79“ WC
2.36 - 0.79 = 1.57“ WC
A maximum output of 795 MBtu/hr shown in Table RS
28/M corresponds to 1.57” WC pressure, column 1A.
This value serves as a rough guide, the effective deliv-
ery must be measured at the gas meter.
To calculate the required gas manifold pressure at test
point 1)(B), set the maximim output required from the
burner operation:
- find the nearest output value in the table for the burner
in question.
- Read off the pressure at test point 1)(B) on the right in
column 1A or B.
- Add this value to the estimated pressure in the com-
bustion chamber.
Example - RS 28/M:
• Required burner maximum output operation:
795 MBtu/hr
• Natural gas
• Gas ring 2)(B)p.8 adjusted as diagram (C)p.8.
• Gas pressure at burner output of 795 MBtu/hr,
taken from table RS 28, column 1A = 1.57” WC
• Pressure in combustion chamber
= 0.79” WC
1.57 + 0.79 = 2.36” WC
pressure required at test point 1)(B).
(A)
RS 28/M
RS 38/M
RS 50/M
MBtu/hr
kW
∆
p (“ WC)
1
2
A
B
624
699
795
891
986
1078
1174
1232
183
205
233
261
289
316
344
361
0.98
1.22
1.57
1.85
2.17
2.48
2.76
2.95
0.98
1.3
1.69
2.05
2.28
2.68
3.07
3.58
0.039
0.039
0.039
0.079
0.079
0.12
0.12
0.12
MBtu/hr
kW
∆
p (“ WC)
1
2
A
B
870
979
1099
1211
1327
1440
1552
1665
255
287
322
355
389
422
455
488
1.02
1.22
1.46
1.69
1.89
2.13
2.36
2.6
1.02
1.38
1.77
2.28
2.72
3.11
3.54
4.21
0.079
0.079
0.12
0.12
0.16
0.16
0.2
0.23
MBtu/hr
kW
∆
p (“ WC)
1
2
A
B
1099
1249
1402
1552
1706
1856
2006
2197
322
366
411
455
500
544
588
644
0.87
1.14
1.42
1.69
1.97
2.2
2.48
2.83
0.87
1.3
1.61
2.01
2.36
2.76
3.15
3.78
0.12
0.16
0.2
0.23
0.28
0.35
0.39
0.47
D2786
(B)
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