9
20024198
GB
Technical description of the burner
(1)
Average barometric pressure
Tab. B
To check it, proceed as follows:
1
Find the corrective factor F (Tab. B) relating to the air tem-
perature and altitude of the system.
2
Divide the burner’s delivery Q by F in order to obtain the
equivalent delivery Qe:
3
In the firing rate range of the burner, (Fig. 4), indicate the
work point defined by:
Qe = equivalent delivery
H1 = combustion chamber pressure
The resulting point A must remain within the firing rate
range.
4
Trace a vertical line from point A, (Fig. 4), and find the maxi-
mum pressure H2 of the firing rate.
5
Multiply H2 by F to obtain the maximum lowered pressure
H3 of the firing rate
If H3 is greater than H1, as in (Fig. 4), the burner can produce the
delivery requested.
If H3 is lower than H1, the burner’s delivery must be reduced. A
reduction in delivery is accompanied by a reduction of the pres-
sure in the combustion chamber:
Qr
= reduced delivery
H1r = reduced pressure
Example, a 5% delivery reduction:
Qr
= Q x 0.95
H1r = H1 x (0,95)
2
With the new values - Qr and H1r - repeat steps 2 - 5.
4.3.1
Test boiler
The firing rates were set in relation to special test boilers in ac-
cordance with the methods defined in EN 267 standards.
Fig. 5 indicates the diameter and length of the test combustion
chamber.
Example:
delivery 200 kg/hour:
diameter = 80 cm; length = 3,5 m.
Whenever the burner is operated in a much smaller commercial-
ly-available combustion chamber, a preliminary test should be
performed.
m a.s.l.
(1)
F
AIR
°C
M
mbar
0
5
10
15
20
25
30
40
0
100
200
300
400
500
600
700
800
900
1000
1200
1400
1600
1800
2000
1013
1000
989
978
966
955
944
932
921
910
898
878
856
836
815
794
1,087
1,073
1,061
1,050
1,037
1,025
1,013
1,000
0,988
0,977
0,964
0,942
0,919
0,897
0,875
0,852
1,068
1,054
1,042
1,031
1,018
1,007
0,995
0,982
0,971
0,959
0,946
0,925
0,902
0,881
0,859
0,837
1,049
1,035
1,024
1,013
1,000
0,989
0,977
0,965
0,954
0,942
0,930
0,909
0,886
0,866
0,844
0,822
1,031
1,017
1,006
0,995
0,983
0,972
0,960
0,948
0,937
0,926
0,914
0,893
0,871
0,851
0,829
0,808
1,013
1,000
0,989
0,978
0,966
0,955
0,944
0,932
0,921
0,910
0,898
0,878
0,856
0,836
0,815
0,794
0,996
0,983
0,972
0,962
0,950
0,939
0,928
0,916
0,906
0,895
0,883
0,863
0,842
0,822
0,801
0,781
0,980
0,967
0,956
0,946
0,934
0,923
0,913
0,901
0,891
0,880
0,868
0,849
0,828
0,808
0,788
0,768
0,948
0,936
0,926
0,916
0,904
0,894
0,884
0,872
0,862
0,852
0,841
0,822
0,801
0,783
0,763
0,743
Qe =
Q : F
(kg/h)
H3 =
H2 : F
(mbar)
Qe
kg/h
mbar
D388
Fig. 4
WARNING
the combustion head must be adjusted in respect
to the equivalent delivery Qe.
H
1
r = H
1
x
(
)
Qr
Q
2
D688
Fig. 5
combust
ion chambe
r
p
ressure
mb
ar
