no flaring system

[moberton]

Have you ever designed or have you any feedback about flare systems purged in normal operation and lighted only in case of flare gas discharge?

Pilots in this case are not required to be in operation and they are lighted only in case of discharge.

Please let me know your opinion about the above.

 

[Flareman]

As it happens, more people are asking this question. There's either someone out in the market selling something connected with the idea or there's an increased interest in the environment. Or both.

My direct experience of flameless operation is limited by virtue of the fact that few operators have chosen this mode of operation in previous times. However, it is not entirely unknown

In my own case, I have been directly involved with flares intended for such service on at least three specific occasions and there may have been other actual cases but none for which I was directly responsible.

One aspect of performance would be the inclusion of an automated "instant" Ignition system. This might be to light a gas pilot or to light the flare directly. (Slightly different mechanical considerations for each)

The current favorite here would be direct High Energy electrical ignition available from most convntional flare vendors but there's also the pellet gun which fires an incendiary pellet up a tube to strike a plate and produce a big "spark" (I'm personally wary of this for on-shore service).

In ALL cases, the key issue to be resolved, in my view, are
- can the operator determine, ahead of a relief, that a relief is probable
- if so can this be reliably instrumented
- what sort of lead time is possible
- are gas-fed pilots needed/used during periods of flare operation
- is an electrical supply available
- how is the flare rendered "safe" when out of service / purged or not
- how is sudden "sweep" (pre-purge) of flammable gas reliably managed at any start-up condition (sudden massive discharge of water from a seal/rapid valve opening ?)
- how is flammable gas removed from the stack after a relief case (post purge)
- how are pilots returned to their dormant condition
- what are the potential ramifications of ignition system failure (risk analysis)
- what are the local regulations concerning no pilots
- what are the local regulations regarding potential venting of unburned gas.

I cetainly would not like to give a blanket recommendation to this manner of operating without walking through the full design considerations ... but it is possible.


David

 

[MortenA]

Take a look at this tread.

thread124-45267 a link to a ABB no-flaring system.

Best regards

Morten

 

[MortenA]

I have to complement myself ;-)

Because the tread that i reference is actually quite good with many good observations re. flares/pilots and igniting of the same especially if you follow the other references around.

Best regards

Morten