1 reply to this topic

[chessboss]

I'm designing a plant which has a 10.1 bar liquid stream to be throttled to 1.5 bar before it enters a distillation column with condenser pressure 1.1 bar and reboiler pressure 1.2 bar. The vapor fraction after the valve is 17.2%. I'm worried that this would damage the pipeline. Is such an operation acceptable if the valve is placed directly before the distillation column, just like a flash column?

[Padmakar Katre]

I'm designing a plant which has a 10.1 bar liquid stream to be throttled to 1.5 bar before it enters a distillation column with condenser pressure 1.1 bar and reboiler pressure 1.2 bar. The vapor fraction after the valve is 17.2%. I'm worried that this would damage the pipeline. Is such an operation acceptable if the valve is placed directly before the distillation column, just like a flash column?

 

Vapor quality of 0.2 is quite normal in case of feed to distillation column. The precaution you have to take is to keep minimum 2-phase flow length i.e. put the feed control valve close to column inlet. Also pay attention to the feed inlet device or spacing inside column for proper vapor liquid separation.