4 replies to this topic

[wait_what]

Let's say we have a distillation column which has valve trays.

 

What does it do to the overall hydraulic performance if we lose one or more valves?

 

 

[breizh]

Hi,

Globally you will lose one tray, no residence time for the liquid on this particular tray. Will it affect the overall performance of the column? Only you can answer, a simulation can assist.

 

Breizh

Attached Files

•  separation tower design.pdf   1.41MB   10 downloads

[latexman]

The liquid will drain from that tray through the hole of the missing valve(s).  That tray will not have intimate vapor/liquid contact.  Vapor from below will flow more. as there is less restriction.  As Breizh said, this tray will be useless.  The tray below will not get liquid as per it's design.    It will not be good,  Will it be a mighty issue?  Up to you to find out.  We have no data.

[Bobby Strain]

It is rare for such to happen in most services. In those fractionators where it happens, the effect is hardly noticeable.

 

Bobby

[Pilesar]

Losing movable valves is very common in some services. Usually missing valves mean corrosion or other problems. Wear and corrosion can make the holes larger so that the valve feet no longer get a purchase on the tray. I have seen columns that have lost a third of their valves as well as whole tray panels without operations noticing any problem great enough for them to shut down and inspect. Compare the performance of movable valve trays to sieve trays. If all the valves were removed, you would be left with a sieve tray.