Clayton Steam Generator model EO-100-1M
PAGE 15 / 70
Instruction Manual, doc.nr.: MAN18206 Rev A PSC
3.3
FUEL SYSTEM OIL FIRED UNITS
( DRAWING HE-2673 )
Fuel is delivered to the forced draft burner under pressure. Fuel pressure is governed by an adjustable fuel
pressure regulator
[11].
Burner modulation is achieved by the electrically operated low fire
[Y42]
and high
fire
[Y43]
solenoïd valves. After manual start, oil will enter through the burner nozzle after a prepurge
period and be ignited by an electric spark. Burner operation is fully automatic and all controls are arranged to
fail safe. Flame failure will cause automatic shut-off within one second. A switch
[F81]+[F82]
operated by
combustion air pressure is provided to shut down the generator if the motor or blower fails.
Control of the air is accomplished by electrically operated
[M83]
motor air damper.
3.4
AUTOMATIC BURNER MODULATION
Automatic burner modulation prevents frequent on/off cycling of the burner and provides stable operation
during periods of low load. This is accomplished by controlling the burner by means of the electrically
operated three position
(off, low-fire and high-fire)
main gas valve with an adjustable low fire position.
When steam pressure rises to the adjusted modulation point
[F22]
the gas valve will close to the low fire
position. When the burner modulates, the solenoid operated automatic damper restricts the burner air supply
to maintain oil-fuel ratio. The unit will automatically return to high fire operation if low fire operation will
not carry the steam demand. A manually operated switch
[S1]
on the electrical control box prevents high fire
operation when desired or when making certain burner adjustments.
Control of the air is accomplished by electrically operated
[M83]
motor air damper.
3.5
BURNER MANIFOLD
Air entering the burner volute from the blower, is centrifugally directed at high velocity to the burner
manifold, where it blends with the fuel. Fuel is automatically ignited by an electric spark. A flame detector is
incorporated to detect the flame and maintain safe burner operation.
Steam pressure
(bar)
Steam temp.
(°C)
Steam
pressure
(bar)
Steam temp.
(°C)
1
120
11
188
1,4
126
13
195
1,8
131
15
201
2
134
17
207
2,4
138
19
212
2,8
142
21
217
3
144
23
222
3,5
148
25
226
4
152
27
230
5
159
29
234
6
165
31
237
7
170
33
241
8
175
35
244
9
180
Steam pressure - steam temperature
End Chapter - 3