6 replies to this topic

[sheryl]

l am working on a gas-liquid horizontal demister separator,i very confuse about demister mat specification,i dont know how to calculate and size it.where can i get more information about demister mat specification?

[JoeWong]

l am working on a gas-liquid horizontal demister separator,i very confuse about demister mat specification,i dont know how to calculate and size it.where can i get more information about demister mat specification?

sheryl,

Please find below articles link that can leads to have better idea of demister.

1. Demystifying the Selection of Mist Eliminator
2. Mesh and Vane Mist Eliminator

There is a datasheet in article 1. Data required would probably sufficient for Demister specification.

Please raise specific question (if you still have) after you have read them.

[superdaigle]

Try contacting one of the following:

Koch Industries - http://www.koch-glitsch.com
ACS Industries - http://www.acssepara...rs/default.html
Amistco - http://www.amistco.com

You will need to supply the following:

Operating Pressure
Operating Temperature
Operating Flow Rate
Gas Type
Gas Density
Gas Viscosity
Liquid Type
Liquid Density
Liquid Viscosity
Quantity of Liquid
Effluent Quality Desired

[Zauberberg]

Good info can be found in GPSA Databook. Detailed information is available in process design standards - go to Iranian Petroleum website and look for separator vessel design document. It is free for download.

And one practical tip - avoid vane packs at pressures above 15 bar.

[djack77494]

And one practical tip - avoid vane packs at pressures above 15 bar.

Zauberberg,
I've never heard of that one before. Can you tell me why?

[Zauberberg]

Hello Doug

Vane packs are highly susceptible to relative density changes of vapor phase, showing rapid decline in performance at pressures ~10-15bar. Actually if you look in several process design standards (e.g. Shell, Total) you'll see that usage of vane packs is discouraged at elevated pressures. The same has been confirmed by the LNG process licensor in Equatorial Guinea (ConocoPhillips) in the plant where I have been working. My experience with these internals confirms the same: before I joined the crew in EG, they were experiencing intensive carryover of liquid phase from the KO drum onto Mol Sieve beds, and eventually it has been decided to replace the mistpad with "high-efficiency internals" comprised of Schoepentoeter, agglomerator, and the vane pack. What happened, is that carryover has become even more intensive (the plant operates at 75barg upstream of Liquefaction Unit). So they accepted the advice from internals vendor and replaced the mistmat with the new assembly. From the day I joined, I was listening stories that the plant can operate without problems but dP buildup across Mol Sieve beds was telling different story. Finally, water balance across the KO drum has shown >2% liquid carryover which was more than with the previous set of internals! From that moment we are looking to confirm whether the DP buildup and the consequence of plant shutdown due to more frequent Mol Sieve changeout will pay for the vessel replacement (bigger KO drum!), or not.

Hope this answers your query.
Best regards,

[djack77494]

Thank you, Zauberberg. Every once in a while you can teach old dogs new tricks.