Blowdown with liquids

[Renoyd]

Hello,
For gas plant blowdown calculation, if the vessel has liquid in it, how would the calculation be done?

Thanks

 

[PaoloPemi]

as for gases but take care to
liquids have higher densities than gases which means higher forces in velocity changes (by momentum conservation)
liquids can vaporize, the cool down process can produce temperatures which are below the limits admitted for the plant's materials

 

[chemjock]

Hopefully, your liquid will remain in the blowdown vessel. If you don't have a dynamic simulator then run successive flashes at about 1-2 minutes interval. You should be trying to reduce pressure by half in 15 minutes. Calculate the mass removed during the interval, recalculate the liquid composition, then reflash. With LPG you should see the temp drop.