HP flare and LP flare

[furio2]

Hi all, I’m new in oil & gas engineering and I have to size flares that burn the gas coming from an oil-water-gas separation system.
I read sizing criteria recommended in API RP 521 but I have some doubts: Which is difference between high pressure flares and low pressure flares? Only the gas velocity at the tip? Sizing criteria are the same?

Can you suggest me something to get clear ideas?

Thank you in advance

Angela

 

[ggordil]

Are you refering to the flare system?
From my reading of API 521, for smokless flares, if the system is low pressure, steam or air will have to be added at the tip to keep smoke formation from happening. For high pressure systems, 5-20 psi at the tip, there is enough turbulance that no additional air or steam is needed for smokeless buring.

There are a couple of considerations that you want to take into account when sizing a flare. What is the maximum back pressure you can have on the system? This will affect the kind of flare tip you can use. (Sonic flare tips have a higher back pressure).

Since you do not have much experience, I suggest talking to a vendor. They can supply you with radiation curves and other design information.

Also, you can refernce API RP 537 for more information.

Hope this helps. Gimena