19
20148049
GB
Installation
5.8
Choice of nozzles for the 1st and 2nd stage
Both nozzles must be chosen from among those listed in Tab. I.
The first nozzle determines the delivery of the burner at the 1st
stage.
The second nozzle works together with the 1st nozzle to
determine the delivery of the burner in the 2nd stage.
The outputs of the 1st and 2nd stage have to be within the value
range indicated in Tab. C on page 8.
Use nozzles with a 60° spray angle at the recommended
pressure of 12 bar.
Generally the two nozzles have the same flow rate but the nozzle
of the 1st stage can have an output that is 50% lower than the
total output, when you want to reduce the back pressure peak on
ignition (the burner provides good combustion values also with
40 - 100% ratios between the 1st and 2nd stage).
Example:
Boiler power = 1630 kW - efficiency 90 %
Burner requested output = 1630: 0.9 = 1812 kW;
1812: 2
= 906 kW per nozzle
so two equal nozzles of 60°, 12 bar are required:
1° = 18 GPH
2° = 18 GPH
or the following two different nozzles:
1° = 16 GPH
2° = 20 GPH
Tab. I
GPH
kg/h
kW
12 bar
10 bar
12 bar
14 bar
10.0
10.5
11.0
12.0
12.3
13.0
13.8
14.0
15.0
15.3
16.0
17.0
17.5
18.0
19.0
19.5
20.0
21.5
22.0
22.5
23.0
23.5
24.0
24.5
25.0
25.5
26.0
26.5
27.0
27.5
28.0
38.4
40.4
42.3
46.1
47.3
50.0
53.1
53.8
57.7
58.8
61.5
65.4
67.3
69.2
73.0
75.0
76.9
82.7
84.6
86.5
88.4
90.4
92.2
94.2
96.1
98.0
99.9
101.9
103.8
105.7
107.6
42.4
44.6
46.7
50.9
52.2
55.1
58.5
59.4
63.6
64.9
67.9
72.1
74.2
76.4
80.6
82.7
84.8
91.2
93.3
95.5
97.6
99.7
101.8
104.0
106.0
108.2
110.3
112.4
114.5
116.7
118.8
46.1
48.4
50.7
55.3
56.7
59.9
63.3
64.5
69.2
70.5
73.8
78.4
80.7
83.0
87.6
89.9
92.2
99.1
101.4
103.7
106.0
108.3
110.6
112.9
115.3
117.6
119.9
122.2
124.5
126.8
129.1
502.9
529.0
553.9
603.7
619.1
653.5
693.8
704.5
754.3
769.7
805.3
855.1
880.0
906.1
956.0
980.9
1005.8
1081.7
1106.6
1132.6
1157.5
1182.4
1207.3
1233.5
1257.2
1283.2
1308.2
1333.1
1358.0
1384.1
1409.0
