3 replies to this topic

[mbeychok]

Ram:

Since you didn't furnish any details, I will assume that your question concerns a separator for (1) a vapor phase, (2) a liquid hydrocarbon phase and (3) a liquid aqueous phase. If that is the case, the following article has been recommended in prior postings to this forum:

Monnery, W.D and William Y. Svrcek, "Successfully Specify Three-Phase Separators", Chemical Engineeirng Progress (CEP), September 1994, Pgs. 29-40.

If you cannot find it in your library, try contacting the American Institute of Chemical Engineers (AIChE) who publish the CEP journal.

[ShaunHill]

The GPSA (Gas Processing Suppliers Association) Engineering Databook also contains some excellent guidelines on designing and sizing three phase separators. Basically you need a section of the vessel that provides gas/ liquid separation and a section to provide sufficient liquid retention time to get liquid/ liquid separation.

There are different ways of doing this, but a common design is to use a horizontal vessel with an internal weir and a liquid "boot" off the bottom of the vessel to catch the heavy liquid (usually water). You will need to include appropriate level guages and controls to run the separator.

Standard gas/ liquid separation features should be used: inlet diverter, vortex breakers, misteleminators.

Of course you should also apply mechanical design practices that you would use for any pressure vessel.

[avsp]

Ram,

If you can get hold of the Shell DEP 31.22.05.12, which is an excellent guideline on sizing of 3 phase separator, it would be great!..............I myself have used them for sizing several separators, while working for PDO, and found them to give reasonable design results. In fact, this standard is a "live" standard which keeps getting updated (like any one of Shell's Standards) based on Shell's own plant experience and their in-house research results.