4 replies to this topic

[Genii]

Dear All,

How do we calculate the gas flow for the pilot burner of flare.

regards

[JoeWong]

Dear All,

How do we calculate the gas flow for the pilot burner of flare.

regards

Genii,
If you use fuel gas (typically MW ~ 20), you may consider 100 scfh / pilot for estimation purpose. Flare tip vendor can advise exact flow base on fuel gas composition.

JoeWong

[Genii]

Thanx JoeWong

I also like to confirm about the basis of purge gas in flare headers;

Its flow is based on the flash-back velocity of flame ie efflux (flare effluent + purge gas) velocity should be atleast equal or greater than the flame velocity to prevent the back fire. Its flow estimation is also a vendors trade.

With the above basis its regulating valve should be FCV but I have seen PCV on purge lines. please comment.

There is also some criteria about the purge line requirement. This is required on flares which are intermittant. But in case of continuous flow certain minimum flow is required?

Also comment on the location of this purge gas. I have a horizontal flare and purge gas is fuel gas of MWt in between 20 and 22. This purge gas should be some 25 ft away from flare tip or this should be at the start of header?

Regards.

[JoeWong]

Thanx JoeWong

I also like to confirm about the basis of purge gas in flare headers;

Its flow is based on the flash-back velocity of flame ie efflux (flare effluent + purge gas) velocity should be atleast equal or greater than the flame velocity to prevent the back fire. Its flow estimation is also a vendors trade.

With the above basis its regulating valve should be FCV but I have seen PCV on purge lines. please comment.

There is also some criteria about the purge line requirement. This is required on flares which are intermittant. But in case of continuous flow certain minimum flow is required?

Also comment on the location of this purge gas. I have a horizontal flare and purge gas is fuel gas of MWt in between 20 and 22. This purge gas should be some 25 ft away from flare tip or this should be at the start of header?

Regards.

Genii,
I suggest you to open a new post for Flare purging for ease of post search & retriever...i will give some advice...

regards,

JoeWong

[Genii]

Thanx JoeWong

I also like to confirm about the basis of purge gas in flare headers;

Its flow is based on the flash-back velocity of flame ie efflux (flare effluent + purge gas) velocity should be atleast equal or greater than the flame velocity to prevent the back fire. Its flow estimation is also a vendors trade.

With the above basis its regulating valve should be FCV but I have seen PCV on purge lines. please comment.

There is also some criteria about the purge line requirement. This is required on flares which are intermittant. But in case of continuous flow certain minimum flow is required?

Also comment on the location of this purge gas. I have a horizontal flare and purge gas is fuel gas of MWt in between 20 and 22. This purge gas should be some 25 ft away from flare tip or this should be at the start of header?

Regards.

Genii,
I suggest you to open a new post for Flare purging for ease of post search & retriever...i will give some advice...

regards,

JoeWong

OK