Riello RS 28/E Installation, Use And Maintenance Instructions page 12

Proceed as follows:
 find the correction factor F in the Tab. E, page 10 for the
plant's air temperature and altitude.
 Divide the burner's delivery Q by F in order to obtain the equiv-
alent delivery Qe:
Qe = Q : F (MBtu/hr)
 In the firing rate range of the burner (Fig. 5) indicate the work
point defined by:
– Qe = equivalent delivery
– H1 = combustion chamber pressure
– The resulting point A must remain within the firing rate range
 Plot a vertical line from Point A (Fig. 5), and find the maximum
pressure H2 of the firing rate.
 Multiply H2 by F to obtain the maximum reduced pressure H3
of the firing rate.
H3 = H2 x F (" WC)
If H3 is greater than H1 (Fig. 5), the burner delivers the output re-
quired.
If H3 is lower than H1, the burner's delivery must be reduced.
Above Average barom.
sea level
ft m " WC
0 0 399
329 100 394
658 200 389
987 300 385
1316 400 380
1645 500 376
1974 600 372
2303 700 367
2632 800 363
2961 900 358
3290 1000 354
3947 1200 346
4605 1400 337
5263 1600 329
5921 1800 321
6579 2000 313
20044359
Technical description of the burner
pressure
mbar 0 (0°C)
1013 1.087
1000 1.073
989 1.061
978 1.050
966 1.037
955 1.025
944 1.013
932 1.000
921 0.988
910 0.977
898 0.964
878 0.942
856 0.919
836 0.897
815 0.875
794 0.852
A reduction in delivery is accompanied by a reduction of the pres-
sure in the combustion chamber:
• Qr = reduced delivery
• H1r = reduced pressure
H1r = H1 x
Example, a 5% delivery reduction:
• Qr = Q x 0.95
• H1r = H1 x (0.95)
Steps 2 - 5 must now be repeated using the new Qr and H1r values.
The combustion head must be adjusted in respect
to the equivalent delivery Qe.
WARNING
"w.c.
H2
H3
H1
D2617
CORRECTION FACTOR
Air temperature °F (°C)
41 (5°C) 50 (10°C) 59 (15°C) 68 (20°C) 77 (25°C) 86 (30°C) 104 (40°C)
1.068 1.049 1.031
1.054 1.035 1.017
1.042 1.024 1.006
1.031 1.013 0.995
1.018 1.000 0.983
1.007 0.989 0.972
0.995 0.977 0.960
0.982 0.965 0.948
0.971 0.954 0.937
0.959 0.942 0.926
0.946 0.930 0.914
0.925 0.909 0.893
0.902 0.886 0.871
0.881 0.866 0.851
0.859 0.844 0.829
0.837 0.822 0.808
10
2
( ) Qr
Q
2
A
Qe
F
1.013 0.996
1.000 0.983
0.989 0.972
0.978 0.962
0.966 0.950
0.955 0.939
0.944 0.928
0.932 0.916
0.921 0.906
0.910 0.895
0.898 0.883
0.878 0.863
0.856 0.842
0.836 0.822
0.815 0.801
0.794 0.781
MBtu/hr
Fig. 5
0.980 0.948
0.967 0.936
0.956 0.926
0.946 0.916
0.934 0.904
0.923 0.894
0.913 0.884
0.901 0.872
0.891 0.862
0.880 0.852
0.868 0.841
0.849 0.822
0.828 0.801
0.808 0.783
0.788 0.763
0.768 0.743
Tab. E