HP seperator volume design

[wangduyu]

Hi, I am working on a HP seperator for LNG feed gas, I wonder what is the input and how to decide the volume and width/longth of HP seperator(vapor and liquid).

Anyone have good answer?

Thanks a lot.

 

[BigInch]

Get the dimensions off a vendor

http://www.surfaceequip.com/two-three-phase-vertical-horizontal-separators-gas-scrubbers.html

 

[wangduyu]

good answer~

 

[LittleInch]

As BI says, and from the tables it is dependant on:
Flowrate,
Inlet pressure,
volumes of liquid, both steady state and slugs or surge volumes you want to cater for
Degree of liquid separation you want / need 9 the more the bigger the vessel on average
Single phase liquid or two phase (water/ condensate)

Lots of variables so lots of possible sizes...




My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[wangduyu]

Thanks BI & LI.

Yes, to save cost, perform pre-treatment is important, make the 2-phase flow stable.

 

[mbt22]

As much as I am unwilling to disagree with either of the eminent posters above, I would argue that you need to be able to at least do a back of the envelope sizing before going to vendors. Perhaps it might not be necessary if you've specified dozens before and have an instinctive feel for what is reasonable, but I find it helps me to understand what factors are driving the design.

I don't have it to hand right now, but from memory the GPSA manual has some guidelines.

Matt

 

[BigInch]

Later when you have time, you can calculate the actual volume of gas at the average pressure within the separator, calculate it's velocity over the liquid and make the vessel long enough, or tall enough to remain within the vessel for the required time such that entrained liquid droplets fall out.

 

[weldstan]

First you need to define the quantity of C2, C3, C4, CO2, H2O, etc. the feed gas. If anything like the gas plant that is being designed to treat incoming sales gas for LNG production and export, multiple separators will be required.

 

[wangduyu]

Thanks, with example from surfaceequip website, I believe that, giving Feed gas property, including pressure, temp. Flow rate, percentage of content, experience vendoer procvide solution, including PSV etc.
Maybe manufacturer can do more than that.