7 replies to this topic

[Amira 55]

Hello dears, 

I am working on recovery of flare gas, I have an HP and then LP separators, the flare lines shall go to a compression station via one trunckline, and I have to either decrease the HP flare pressure or Increase LP flare pressure.

To decrease pressure from HP to LP I can use a Pressure regulating valve.

My question is, can I increase LP pressure to HP pressure via an ejector ? 


Thanks in advance.

[SilverShaded]

Hello dears, 

I am working on recovery of flare gas, I have an HP and then LP separators, the flare lines shall go to a compression station via one trunckline, and I have to either decrease the HP flare pressure or Increase LP flare pressure.

To decrease pressure from HP to LP I can use a Pressure regulating valve.

My question is, can I increase LP pressure to HP pressure via an ejector ? 


Thanks in advance.

Depending on the pressure difference you may need multiple stage ejectors and steam consumption could be quite large.  You could consider a liquid ring pump instead for at least one of the stages if you have multiple stages.  Hijectors may also be an option.

Edited by SilverShaded, 23 September 2021 - 04:38 AM.

[Amira 55]

 

Hello dears, 

I am working on recovery of flare gas, I have an HP and then LP separators, the flare lines shall go to a compression station via one trunckline, and I have to either decrease the HP flare pressure or Increase LP flare pressure.

To decrease pressure from HP to LP I can use a Pressure regulating valve.

My question is, can I increase LP pressure to HP pressure via an ejector ? 


Thanks in advance.

Depending on the pressure difference you may need multiple stage ejectors and steam consumption could be quite large.  You could consider a liquid ring pump instead for at least one of the stages if you have multiple stages.  Hijectors may also be an option.

 

Thank youSilver,
In ejectors, instead of consuming steam, Is there a way to use recovered HP flare gas as motive gas and recovered LP flare gas as entrained gas

[SilverShaded]

 

 

Hello dears, 

I am working on recovery of flare gas, I have an HP and then LP separators, the flare lines shall go to a compression station via one trunckline, and I have to either decrease the HP flare pressure or Increase LP flare pressure.

To decrease pressure from HP to LP I can use a Pressure regulating valve.

My question is, can I increase LP pressure to HP pressure via an ejector ? 


Thanks in advance.

Depending on the pressure difference you may need multiple stage ejectors and steam consumption could be quite large.  You could consider a liquid ring pump instead for at least one of the stages if you have multiple stages.  Hijectors may also be an option.

 

Thank youSilver,
In ejectors, instead of consuming steam, Is there a way to use recovered HP flare gas as motive gas and recovered LP flare gas as entrained gas

 

In theory yes, in pactice what happens if you don't have any HP flare gas?  Just seems to be complicating things but in the right situation might make sense.  Liquid ring pump would be simpler.

[Amira 55]

The idea is to increase LP flare pressure to HP flare with minimum costs.

[Bobby Strain]

You are getting advice based on no data. Maybe you may get something useful with data.

 

Bobby

[SilverShaded]

The idea is to increase LP flare pressure to HP flare with minimum costs.

You wont get LP to HP using HP motive fluid, it's impossible.

[Dacs]

My question is, can I increase LP pressure to HP pressure via an ejector ? 

 

Yes.

In ejectors, instead of consuming steam, Is there a way to use recovered HP flare gas as motive gas and recovered LP flare gas as entrained gas

 

Also yes, but the ejector pressure will be in between LP and HP.

 

You'd want to use a more reliable motive fluid however, so using HP is, as SilverShaded highlighted, unreliable for purpose.

The idea is to increase LP flare pressure to HP flare with minimum costs.

 

If you have an offgas system, you can use it as your motive fluid. 

 

It's hard to speculate beyond the statements above as you have not placed much info. Feed us with some values and we'll see.