3 replies to this topic

[Srikrishna Chaitanya]

Dear all
While doing Knock Out drum sizing through
1. Shell DEP we have to check whether its meeting De Foaming criteria or not by using a separate formula
2. API spec 12 J specify different residence times for foaming crudes

my questions are
1. How do we know whether feed having a foaming tendency or not
2. can we predict the foaming tendency in HYSYS/APSEN PLUS/PRO-II softwares
3. what are the fundamentals behind foaming

Thank you

Regards
Satish

[Zauberberg]

The best way to confirm if given service is a foaming one, is to look for the references of similar plants and applications. If possible, conducting laboratory tests can be of much help.

Simulation softwares cannot provide such information - at least from what I have seen so far - and this is quite reasonable to be expected: simply, too many factors are involved. For example, applying foaming factor in design of fractionaton towers is an experience-based rule of thumb, resulting from hundreds or thousands columns where flooding has been observed well below design capacity.

The presence of solids induces foaming - you'll observe it if you put small amount of salt in a boiling water. High pressure operation also induces foaming. Agitation, presence of surface active agents etc.

[Srikrishna Chaitanya]

Dear Zauberberg

Thank you very much for the reply
is there some literature available on this foaming ?
I have tried through GOOGLE but haven't got much

[Zauberberg]

I believe it's hard to find any information related to foaming phenomenon, unless the subject (plant, application, service) is known. What causes foaming is the same in all these cases - as written above. The difference comes from the process/equipment type itself i.e. whether we are speaking about amine/glycol contactors, high pressure separators, 3-phase systems, distillation towers etc. In each of these systems foaming is caused predominantly by one of those factors which I mentioned before. Looking at the specific process application, you'll be able to narrow down the list of possible culprits, and find a way to mitigate or eliminate them.