9 replies to this topic

[Root]

Hi Als,

In our LPG caustic wash column, we have Koch Glitch sieve trays without wire. I tried to rate the rates in Aspen Hysys and Aspen plus but there is no option to rate the trays without wire. can anyone advice how to size or rate sieve trays without wire in aspen Plus.

Thanks

[Bobby Strain]

Use Google to find methods. It's not a difficult exercise.

 

Bobby

[shvet1]

Please describe a bit sieve trays with wire. Aspen is able to model sieve tray with wire, correct?

[Bobby Strain]

There should be no difference in the results with wire or without wire. The wire only provides additional surface for mass transfer.

 

Bobby

[Root]

Bobby,

practically wire provides mass transfer. in my case trays don't have wire and downcomers clearance is only 25 mm. hence liquid retention time is very low, perhaps less than 5 seconds. the result is low mass transfer or lower trays efficiency as well.

[Bobby Strain]

Can you provide a drawing or sketch? You give the downcomer clearance, but not from what. The downcomers are usually short and have a seal pan. They don't extend to the tray below.

 

Bobby

[Root]

Existing tray Details attached.

Attached Files

•  T-703 Tray.bmp   3.72MB   31 downloads

[Bobby Strain]

Well, does this work as it is supposed to? Whoever designed it didn't know how to design an extractor. Are you having difficulty with the operation?

 

Bobby

[Root]

Yes, what I learned from old guys, they faced problem for level control and caustic solution going with LPG.

[Bobby Strain]

So, what is your interest? Poor level control could be caused by lots of things. Does the LPG usually meet specification?

 

Bobby