6 replies to this topic

[Engineer87]

Hi Guys,

 

I'm dealing with flare stacks for the first time.I read flame arrestor and the velocity seals are used alternatively somewhere.Is there any reference in API521 related to that?. Any formula calculating purge gas rate with no flame arrester?

[ankur2061]

Engineer87,

 

Purge gas rates with seals (Buoyancy / Velocity) are based on the velocity of purge gas to limit oxygen concentrations below the seal to acceptable limits.

 

Once you know the velocity and the cross-sectional area of the seal / tip, you can calculate the volumetric flow rate of the purge gas.

 

For velocity range for flares with seals, refer Section 6.4.3.6.2 of API STD 521.

 

Regards,

Ankur.

[Engineer87]

Thanks Ankur for quick reply,

 

In AP1 521, its is sated that" Purge-reduction seals are not flame arrestors".Does presence of flame arrestor has any effect on the purge rate calculation?

[gegio1960]

I've never seen flame arrestors in flare systems... so, I'd like to know where you've red of them.

thanks

[vanngoc]

Engineer87.

You can use Husa equation for purge gas flowrate. Sorry thay I can not add the attachment here, but you can try on Google.

Thanks

Edited by vanngoc, 22 August 2014 - 03:33 AM.

[breizh]

http://www.capp.ca/g...px?DocId=137306

 

for information about Husa equation & gas purge flow rate  , take a look at the link above .

 

Breizh

Edited by breizh, 22 August 2014 - 12:40 AM.

[ankur2061]

"Husa" correlation should not be applied when velocity seals are provided.

 

Regards,

Ankur.