5 replies to this topic

[rahul1012]

Hi, 

I am an entry level engineer. I am trying to better understand the design process of the sizing and criteria of selection. So far I have researched a lot of material and most of it says "assume" a value for something or the other. Is that because it has been working for a long time and so people are going with it? I tried asking most of the people here and either they are busy or say I will still have time. It would be really helpful if there is a spreadsheet that sizes both vertical and horizontal seperators. most of the RFQ's we get have oil flow rate, liquid out in barrels per day and to assume 0-100% water out. and the sp gravity of the liquid. I am interested in knowing the process side of the calculations as to how people come with where a oil bucket is placed in the design and where a vane section is placed. Any help would be really helpful and the more knowledge I get, the more I will be able to contribute to this community.

Thanks,

Rahul

[Art Montemayor]

Rahul:
 

Our Forums contain a wealth of information on the design and workings of vapor-liquid separators.  All you have to do is use our SEARCH engine at the top of the Forum page by keying in vapor liquid separator.  For example, go to: http://www.cheresour...rator#entry3506

And you will find a classic discussion on the subject.  You can also peruse through the workbook I attach for your use.

 Art's Liq Vapor SeparatorRev1.xls   147KB   203 downloads

[Bobby Strain]

Rahul,

      It may be that your collegues don't know how to size separators. There are major companies who can't do it, either. Vertical separator design is pretty simple. Sizing horizontal separators is not so simple. The best articulation you will find at red-bag. And there is some useful stuff at my site. Check the links there as well as the software. Just google my name to find it. Art's workbook is well designed, too.

 

Bobby Strain

[rahul1012]

 I do have some knowledge on the sizing of the vessel itself. But what I want to know/learn is the criterion for the internals, like at what distance the oil bucket or the water weir is placed and if a half moon vane is used, what is the criterion to see where it is located and stuff.

Also, is the excel sheet still a work in progress? cuz the last sheet seems to be not complete.

Thanks for the help guys.

-Rahul

[Art Montemayor]

Rahul:

 

Yes, the last page which is an attempt to type in the voluminous paper is still in progress.

 

If you have knowledge of how to design the vessel, you ought to realize that the location of the WEIR and other internals is determined by how much RESIDENCE TIME you are allowing for your 3-phase separator, if that is what you are refering to.   Note that you have not specified WHAT KIND OR TYPE OF SEPARATOR you are referring to.

 

Bobby Strain is correct.  If you know how to design a separator (of whichever type), then you should know what internals are required and where/how they are located within the vessel itself.  Otherwise, it is clear that you don't know how to size one.   Knowing how to design a pressure vessel according to a code is one thing; knowing what process-required internals are also required and why is another totally different thing.

[ali_fz]

May be this new topic be useful for 3-phase drum sizing:

 

http://www.cheresour...ng-spreadsheet/