Air Eductor Pilot Burners
AIR EDUCTOR PILOT BURNERS
Air Eductor Pilots are used when a flare’s relief gas and/or purge gas is inert and flowing at higher than the recommended rate. When the surrounding atmosphere is oxygen-deficient, a standard pilot can be starved of the air it needs, leading to pilot flame stability problems. To solve this, the pilot is fitted with an air eductor: a factory-set assembly that, when supplied with compressed air at the required pressure, delivers enough combustion air to keep the pilot flame stable and reliable.
How an Air Eductor Pilot Works
A conventional NAO flare pilot is an inspirating (aspirating) burner, the fuel gas jet draws in surrounding air through a venturi to create a stable air/fuel mixture. That design depends on the air around the pilot containing sufficient oxygen. In applications where inert relief or purge gases (nitrogen, carbon dioxide, or fuel gas) displace the ambient air, there may not be enough oxygen present for dependable combustion.
The air eductor overcomes this by using compressed air as the motive medium. Instead of relying only on the fuel jet to pull in ambient air, the eductor entrains and delivers a controlled, guaranteed supply of combustion air to the pilot. Because the eductor is factory set for the specific application, the pilot receives the correct air volume every time the compressed-air supply is at the required pressure, independent of the composition of the gas surrounding the flare tip.
When to Specify an Air Eductor Pilot
Air eductor pilots are the right choice when the flare system operates with:
- Inert or oxygen-deficient purge gas around the flare tip
- Relief and/or purge rates higher than the recommended values for a standard pilot
- Process conditions that make ambient combustion air unreliable, where flame stability is critical
In these conditions, the eductor removes the pilot’s dependence on ambient air and provides the stability needed to keep the flare reliably lit.
Engineered Reliability
Like every NAO flare pilot, air eductor pilots have no problem meeting or exceeding the requirements of API-521. NAO pilots have been proven rainproof and windproof at wind speeds up to 250 MPH (400 km/hr), and design features developed in demanding steel-mill and coke-oven service help prevent fallout from fouling or plugging the pilot piping and venturi. With over 100 years of experience, NAO has earned a worldwide reputation for reliability and trouble-free performance.