5 replies to this topic

[Natural FAL]

Today lecturer teach us about the vapor liquid separtation.
He mentioned about impringment plate install at the inlet nozzle for better distribution.

I asked around found that the impringment plant orientation can be in different way.
Refer to my sketch. Can some one tell me what is the advantage or setback of using this orientation?
Why it is so important to have impringment plant when we already have pall ring (randow packing) install inside the vessel with demister?

Just curious.
I asked my lecturer, he do not want to reveal more and want us to find out ourself.
I hope i can impress him on the answer.
Thanks!

Uni Student

Attached Files

•  Nozzle_distribution.xls   16.5KB   55 downloads

[Andree]

Inlet nozzles or as in your case impingement plate assure even distribution of flow prior to separation element (mat, packing etc.). Moreover, impingement plate can provide some initial removal of coarse droplets, which can deposit and coalesce on the surface and then be drained out and removed (or entrained by gas stream hopefully as bigger droplets). However, first afore-mentioned role is much more important

[Natural FAL]

Thanks! Assume that the feed stock is clean. How the orientation of the plate make a different?
1. Flow in & splash to TOP & DOWN
2. Flow in & splash to RIGHT & LEFT

Any different?

[Andree]

1. Flow in & splash to TOP & DOWN
2. Flow in & splash to RIGHT & LEFT

if flow is perpendicular to the plate then liquid splash is evenly distributed in radial direction for all angular position - therefore optimum seems to be design of inlet distribution device to enable 360 degree axisymmetric flow distribution
please refer to: http://www.nt.ntnu.n...kument/22-3.pdf - there are some design options of feed stream distribution

[JoeWong]

Apart even distribution of flow in a large surface i.e schoepentoeter for proper gas -liquid separation, impingement plate probably to break the momemtum of inlet fluid especially liquid to minimize the disturbance to liquid liquid level. Apart it try to minimize the liquid re-entrainment into gas.

Impingement plate may have lesser degree in coalescene and deposition effect. In turn may have breakage and promote entrainment effect. Very much subject to fluid properties e.g surface tension, density, droplet size, inlet piping arrangment, etc.

As for the orientation, subject to the flow pattern of fluid, orientation of separator, etc. Hard to decide.

Why it is so important to have impringment plant when we already have pall ring (randow packing) install inside the vessel with demister?

Inlet device, packing, tray, demister, cyclone, vane pack, etc are mean to promote separation, increase efficiency of separation, to handle turndown, to handle separation of different droplet size, etc. So no straight forward answer to question.

[Natural FAL]

Thanks for the information.
I need some time to study the information you guys generously provided to me here.
Appreciated that very much.

If i have any doubt will continue ask around.

I believe "continuous learning" is very important for engineer to become competent enough to provide solution.

Hope you guys do not mind.