GAS LIQUID VERTICAL SEPARATOR WITH BAFFLES 3

[roker]

Hello,
we are designing a vertical separator for an air stream with water, the inlet will be through a tangential nozzle, at the outlet a demister will be installed.
we consider to install also two baffles below the demister, what are the guidelines for the baffle cut (percent of diameter or area)?
for the distance between the baffles we intend to use the Souder-Brown equation to calculate the vapor horizontal
velocity.
may be there is also a criteria for the vertical vapor velocity for calculating the baffles cut, see attached sketch,

thanks and regards,
roker

 

[TD2K]

What's the purpose of the baffles above the feed nozzle? I have not seen vertical separators with this in addition to a demister pad. Is there something out of the usual with the pressures, temperature or materials?

 

[zdas04]

Souders Brown is a drag model. The baffles (as well as the mist pad) are described in an impingement model. These two models result in very different target velocities. At Souder Brown velocity, those baffles will do nothing at all since you need at least approx 10 ft/s for the impingement model to work. If the bulk velocity target in the vessel is around 4 ft/s then the baffles will just take up space without adding any value at all.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist

 

[25362]

You may find interesting reading in Sulzer's article:

http://www.sulzer.com/en/-/media/Do...rochures/Gas_Liquid_Separation_Technology.pdf

 

[LittleInch]

25362, Great article / document. I was wondering why the OP is trying to design something others have much more experience in...

The baffles for me are worse than useless as they interrupt the liquid flow and don't do anything for the separation

I would have thought vertical baffles would be better / needed to reduce any swirl or circular flow and allow an even flow into the de-mister pads and not interrupt the flow of liquid dropping

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[25362]

LittleInch, thanks for the undeserved star. Baffles, as you say, may probably induce moisture re-entrainment.

 

[roker]

Thank you all for your contribution to the subject.

sometimes you need "external" opinion for convincing your colleague.

regards,
roker