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# Purge For Burn Pit Flare

flare purge

6 replies to this topic
|

### #1 Sue N

Sue N

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Posted 06 December 2017 - 02:23 PM

One of our older plants has a burn pit ground flare, and we are trying to validate the purge rate for it.

How does one calculate a purge rate for a flare with this configuration?  API521 6th Edition has guidelines for purging the stack, but a burn pit doesn't have a stack - it is just an open pit.  The equations in  API521 (46 & 47) reference a variable "y" called "column depth at which the O2 concentration is predicted".   In the case of a burn pit, would "y" be the depth of the pit, the height of the pilot tip, or some other value?

Eqns 46 & 47 also reference a variable "D", the flare stack diameter.  In the case of the burn pit, would this be the flare header diameter?

Are there different methods in another reference or standard that I should use instead?

Are there different equations in another reference or standard that I should use instead?  If the API calculations are appropriate, what would I base the value of "y" on - the depth of the pit, the height of the pilot tip, or something else?

### #2 fallah

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Posted 07 December 2017 - 06:13 AM

One of our older plants has a burn pit ground flare, and we are trying to validate the purge rate for it.

How does one calculate a purge rate for a flare with this configuration?  API521 6th Edition has guidelines for purging the stack, but a burn pit doesn't have a stack - it is just an open pit.  The equations in  API521 (46 & 47) reference a variable "y" called "column depth at which the O2 concentration is predicted".   In the case of a burn pit, would "y" be the depth of the pit, the height of the pilot tip, or some other value?

Eqns 46 & 47 also reference a variable "D", the flare stack diameter.  In the case of the burn pit, would this be the flare header diameter?

Are there different methods in another reference or standard that I should use instead?

Are there different equations in another reference or standard that I should use instead?  If the API calculations are appropriate, what would I base the value of "y" on - the depth of the pit, the height of the pilot tip, or something else?

Sue N,

Do you think a liquid burning system has to be purged during operation like a gas burning flare?

### #3 Sue N

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Posted 07 December 2017 - 10:02 AM

The flare is for a gas plant, so it isn't really a liquid burning flare.  I think a way to describe it is like a horizontal flare stack that exits into a pit.

### #4 fallah

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Posted 07 December 2017 - 10:48 AM

The flare is for a gas plant, so it isn't really a liquid burning flare.  I think a way to describe it is like a horizontal flare stack that exits into a pit.

Might you mean a ground flare?

### #5 Sue N

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Posted 07 December 2017 - 11:01 AM

I don't know the exact manufacturer, but this Zeeco link has something that looks like the burn pit.

https://www.zeeco.co...nd-burn-pit.php

### #6 Sue N

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Posted 07 December 2017 - 11:05 AM

I apologize for my lack of knowledge and my trouble describing the system.  Most of the plants I work with have elevated flares.

### #7 Bobby Strain

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Posted 07 December 2017 - 11:35 AM

I would contact Zeeco for help.

Bobby