Fired heaters are used to provide heat through the combustion of fuel. They involve combustion fundamentals like the reaction of methane and oxygen. Fired heaters have a furnace design and use draft systems and air preheaters. They employ different types of burners like those used in hot oil heaters and regeneration gas heaters. The start-up process involves inspection, purging, lighting pilots and burners, and adjusting temperatures and flows. Operation requires monitoring air adjustment, temperatures, and addressing potential issues like deposits, failures, or flame-outs. Control strategies manage variables like temperatures, fuels, and flows.

1. Fired Heaters
Petroskill course
Hector Nguema Ondo

2. Fired Heaters
Combustion fundamentals
𝐶𝐻4 + 2𝑂2 → 𝐶𝑂2 +2𝐻2 𝑂 + 𝐻𝑒𝑎𝑡
BTU’s
Amount of work needed to raise the
temperature of one pound of water by one
degree Fahrenheit
1𝐵𝑇𝑈 = 1055 𝐽

3. Fired Heaters
Furnace Design

4. Fired Heaters
Draft Systems

5. Fired Heaters
Typical Natural Draft Profile

6. Fired Heaters
Air preheaters

7. Fired Heaters
Types of burners

8. Fired Heaters
Burner examples
Hot Oil Heater #4 Regen Gas Heater

9. Fired Heaters
Burner and Flame Patterns

10. Fired Heaters
• Inspection
– Clean up, check for damages
– Ensure all burners and pilot valves are closed
• Purge
– Remove any flammable vapors present in the heater
• Light-off Pilots
– Remove the blind in the pilot header
• Light-off burners
– Remove blind in the main fuel header
– If burners does not light within a few seconds, you should turn the fuel off
• Normal Operations
– Increase Temperature and process stream flow
– Check balance through the passes and check outlet temperatures
Start-up

11. Fired Heaters
Air Adjustment

12. Fired Heaters
Troubleshooting
&
• Cause overheating and coke formation
• Use of a pyrometer
• Build-up of deposits inside tubes
• Monitor tube skin temperatures
• Remove Ash outside the tubes
• Do not required shutdown

13. Fired Heaters
Equipment Failure
• Feed Pump failure
 Try to start again or use the back-up pump
• Fan failure
 Steam Ring or air doors
• Control Valve failure
 No flow control Shutdown
• Burner failure
 Burner tips plug
• Instrument failure
 Readings comparison
• Flame out
 Burner flames go out and fuel is still entering the burner.
 Shutdown and purge the heater

14. Fired Heaters
Operation Variables
• Gradient temperature
from convection tubes to
atmosphere

15. Fired Heaters
Fuel and Flow Variables control

16. Fired Heaters
Control strategy
FF