This document discusses retrofitting a boiler flame scanner system at a 60MW boiler unit to protect the boiler and provide remote monitoring of furnace stability. The flame scanner system uses microprocessor-based scanners to sense the flame at each tier and generate status signals to prohibit oil flow if flame conditions are adverse. The system includes installing scanners, solenoid valves, indication lights, and a dedicated cooling system to prevent overheating of the scanners during operation.

1. Boiler Flame Scanner Retrofitting at Front
Fired ABL make Boiler – 60MW Unit
Prepared by Animesh Dan

2. Purpose:
1. To protect the boiler from explosion
2. To provide oil support from remote for
furnace stability
Prepared by Animesh Dan

3. Protection of Boiler
 Oil Burner Management applications at TGS
 Flame scanner will sense the flame at each tier.
 Generate a status contact according to the flame
condition.
 Status contact is monitored at DCS.
 In flame adverse condition at furnace, DCS logic will
prohibit oil ingress at furnace.
 Status contacts actuating limits can be modified.
Prepared by Animesh Dan

4. What are the basic Functions?
 Prevent firing of oil burners unless a satisfactory Flame
condition is achieved.
 Prohibit start-up of oil burners unless certain permissive
interlocks have been completed.
 Monitor and control the actual Flame condition and generate
annunciation for next action.
 Execute a MFR upon certain adverse unit operating conditions.
Prepared by Animesh Dan

5. Flame Scanner
 Flame Scanner:
The micro processor based flame sensing system is primarily
responsible for sensing the flame by its characteristic fluctuations. The
energy level or intensity of the flame is sensed by the brightness of the
flame and the frequency is sensed by the flickering of the flame.
Prepared by Animesh Dan

6. SCANNER
Prepared by Animesh Dan
Real Life Photo

7. Installation
The scanner head is installed on the air register of the wind box assembly at
the pip hole designated as scanner pipe, at the bottom side.
One Ball flange 2” to 1” (Swivel joint) is installed before the insulator for
proper alignment.
Cooling air line from Cooling air fan (Dual redundant- AC& DC fans)
The respective control & communication cables are routed to the UCR-DCS
panel.
Prepared by Animesh Dan

8. Cooling air line from
Cooling air fan (Dual
redundant- AC& DC fans)
Flame Scanner
Scanner pipe
Scanner
Communication
cable Terminal
Prepared by Animesh Dan

9. Scanner Signal at dedicated PC Monitor
The output signal from transmitter is received in a dedicated PC and
processed with a Flame scanner software.
The user will see the condition of the 15 no flames on the monitor. Each
flame can be further checked with all available condition- frequency & intensity.
The histogram allows the user to trend in real time.
Prepared by Animesh Dan

10. Single Module Screen
Prepared by Animesh Dan

11. Solenoid Oil Valve
Valve Type: Globe type solenoid operated, pneumatic actuator, Open &
Close limit switches, air regulator.
Valve make: Continental Valve
Location: The solenoid operated pneumatic valves are installed at each oil
burner, after the tier isolating manual operated oil valve.
Prepared by Animesh Dan

12. Solenoid valve Continental valve
Air regulator
Prepared by Animesh Dan

13. Modified Oil line Diagram
Prepared by Animesh Dan

14. Indication & Annunciation at Boiler Panel:
A separate Control panel with
LED indications & annunciation
facia with hooter is installed at
UCR.
When the condition of any flame
is ‘Good’ the LED will glow. When
the flame condition is dull or ’Bad
Flame’ the LED will put off.
‘Poor flame’ condition is the
another condition. Scanner O/p
4-20ma is programmed such a
way that it will sense the “poor
Flame’ condition. In the ‘Poor
Flame’ condition the
annunciation will appear.
Prepared by Animesh Dan

15. Operation Control & Logics
Step1:
The purging air line valve will be kept in shut condition. The atomizing air
line valve will be kept in open condition. The gun system will be in retracted
condition.
Shut off valve operation will be remained same, i.e. to be opened after
signal from UCR & master reset at B/F.
Orifice valve will be in bypass condition
Step2:
The oil valve can be opened from DCS or through indicator type Push button
on the back panel.
Valve Open-Close Indication will be available at UCR.
The valve can be closed from DCS only.
Prepared by Animesh Dan

16. Operation Control & Logics
After opening of solenoid operated oil valve;
The operator will insert the retracted gun assembly as soon as possible and
put the orifice in line.
After closing of solenoid operated oil valve;
The operator will extract the retracted gun assembly.
Purge the oil line by opening the purging valve & closing the main oil line valve
for some time
Close the purging valve, open the oil line valve
Prepared by Animesh Dan

17. DC MCB
AC MCB
Scanner
module
Prepared by Animesh Dan

18. Flow-Chart of Control & Logics
Prepared by Animesh Dan

19. Scanner Cooling System
As the flame sensing lens as well as the scanner
is installed at heat zone, a continuous cooling air
is passed through it. For this purpose a
dedicated cooling system is installed at burner
front.
The system comprises two separate blower fans,
one with AC drive & the other with DC drive. The
suction of the fans is from atmosphere with
adequate air filter.
In normal condition, the AC fan will run. In case of failure of AC system,
automatic change over to DC system will occur with annunciation at UCR .
Prepared by Animesh Dan

20. Q&A
Thank you very much for
patient hearing
Prepared by Animesh Dan