Why should CO2 not be discharged directly into the engine exhaust?

Why should CO2 not be discharged directly into the engine exhaust?

• A. Because it may damage the engine.
• B. Because it is illegal.
• C. Because it will not extinguish the fire.
• D. Because CO2 cannot reach the fire.

Answer: (C)

CO2 works by displacing the oxygen around the flame and cooling the fuel, so it has to reach the actual fire zone to be effective. In an engine, the fire is located in the nacelle and ducts, while the exhaust is a fast, hot flow pushing gases out of the engine. If CO2 is released into the exhaust, it’s carried away by that strong exhaust stream before it can contact the flame, so it won’t reach or suffocate the fire. Therefore, discharging CO2 into the engine exhaust would not extinguish the fire.

CO2 works by displacing the oxygen around the flame and cooling the fuel, so it has to reach the actual fire zone to be effective. In an engine, the fire is located in the nacelle and ducts, while the exhaust is a fast, hot flow pushing gases out of the engine. If CO2 is released into the exhaust, it’s carried away by that strong exhaust stream before it can contact the flame, so it won’t reach or suffocate the fire. Therefore, discharging CO2 into the engine exhaust would not extinguish the fire.