Knockout Drum Design - Mass Velocity vs Height

[sys1]

What is the relation of the mass velocity with the height of the knockout drum? Or does it affect only the diameter determination?

[tuan]

Nothing actually. Mass velocity would contribute towards diameter only.
Height is governed by separation zones, operability, and practically there is no single equation like Souders-Brown to address that. Need to be established zone by zone.

[jeem]

Height is controlled by different physics entirely:
1. Liquid holdup time
Required residence time for liquid disengagement
2. Surge volume
Handling slugs / flow fluctuations
3. Mist elimination zone
Space for mesh pad or vane pack
4. Vapor disengagement space
Calm zone above liquid
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Mass velocity can indirectly influence height because:
Higher velocity ➡ more turbulence
More turbulence ➡ droplets need more time/space to settle
That can increase disengagement height requirement
But this is secondary, not the main design driver.

[sys1]

Alright, no direct equation to have height calculations done then.

Nothing actually. Mass velocity would contribute towards diameter only.
Height is governed by separation zones, operability, and practically there is no single equation like Souders-Brown to address that. Need to be established zone by zone.