Separator Sizing Check

[C26M13]

Dear members,

I am doing a separator sizing check for the separators we have at our plant. I would like to determine the design capacity of the separator and then compare the result to the actual operation to see how far over or under the design capacity.

I am still new to this concept so, I would like to ask for your assistance.
Can somebody help me to work out the calculation? Is there any rules of thumbs to do the calculation?

I would be appreciated if you can provide me some steps to do the calculation.

Thank you,

 

[LittleInch]

You could try this FAQ for starters

http://www.eng-tips.com/faqs.cfm?fid=1153

What are you trying to separate? two phase or three phase?
What level of separation do you need?

Capacity is often limited or affected by downstream equipment capacity so difficult to assess just the vessel itself.

A simple search of this site reveals a lot of useful info, but the GPSA engineering databook book crops up a lot.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[C26M13]

Thanks for your input.

For this case is only focus on two phase separator (vertical and horizontal).

What I am trying to do is just to calculate the flow rate from the known separator size and actual operating conditions to see whether it is above or below the design we operate.

Thanks,

 

[LittleInch]

good luck.

Large number of variables to decide if the separator is working correctly or not.

Unless you have a process problem I'm struggling to see what value you get from this.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[C26M13]

Thank you...

I have the data for the vessel as follows:

Operation conditions:
P = 54 barg
T = 10 deg C
Gas density = 152 kg/m3
Oil density = 788 kg/m3

Vessel dimension:
D = 2520 mm
L = 8944 mm

I would like to know the flow rate base on the data above, then compare to the actual operation?
Hope somebody can help. Thanks

 

[LittleInch]

Horizontal? vertical?

Any de-mister pads

what is process requirement on outlet (presumably liquid in gas?)?

What is proportion of liquid to gas at entry conditions?

Have you tried following the FAQ or the GPSA guidelines?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

To get some idea of separation performance, you need to
a) Get some numbers of the liquid flow that is entrained into the vapor product line
and
b) Get some numbers on gas carryunder flow into the liquid exit stream from this horizontal sep

Both are next to impossible to get in a real world production plant, unless you have some kind of flow meter on each of these exit lines that can tell you the flow for the dispersed phase - dont know if such meters exist - yet.

 

[C26M13]

I have looked at the reference, if I not wrong this for preliminary design.
The vessel configuration is horizontal with mist extractor.

Actually with the data above, I want to know the flow rate based on the known separator size and actual operation condition to see whether the separator capacity can handle the increased in flow rate.

What I am trying now is calculating:
1. maximum allowable vap. velocity
2. cross sectional area occupied by gas
3. gas volumetric flow rate and liq flow rate.

is there any inputs for that steps?

Thank you,

 

[georgeverghese]

Pls read the reference design documentation for each of these steps. For partial cross sectional area occupied by liquid in horizontal vessels, there are reference tables for these, and you can derive these yourself also.

 

[C26M13]

Thank you all for the comments and inputs... I am still working on the calc.?

I will let you know if I have any further help.

Thank you