10 replies to this topic

[funkysticks]

Hello everyone! Hope all are doing fine!

 

I recently had the task of scaling up of a packed distillation column. Initilal capacity was 100 litres and when I calculated the height and diameter of the tower, it turned out to be 4 feet and 15cm roughly with a total of 40 theoretical stages. However, when I scale it up to 500 litres, the diameter would change but the height of the column remained same, considering the packing material is the same. What is it that I am missing?

 

I would like to learn and know more about this and would like to hear from you.

Thank you!

[latexman]

I recently had the task of scaling up of a packed distillation column. Initilal capacity was 100 litres and when I calculated the height and diameter of the tower, it turned out to be 4 feet and 15cm roughly with a total of 40 theoretical stages. However, when I scale it up to 500 litres, the diameter would change but the height of the column remained same, considering the packing material is the same. What is it that I am missing?

 

Nothing, I think.  Capacity ∝ diameter.  Separation ∝ height.  You changed the capacity; not the separation, right?

[shvet1]

Packing and distributors efficiency depends on diameter. Consult packing vendor if packing/distributors height is equal for both cases.

[funkysticks]

 

I recently had the task of scaling up of a packed distillation column. Initilal capacity was 100 litres and when I calculated the height and diameter of the tower, it turned out to be 4 feet and 15cm roughly with a total of 40 theoretical stages. However, when I scale it up to 500 litres, the diameter would change but the height of the column remained same, considering the packing material is the same. What is it that I am missing?

 

Nothing, I think.  Capacity ∝ diameter.  Separation ∝ height.  You changed the capacity; not the separation, right?

 

That is good to know

And yes sir, separation and the packing material used is the same

Edited by funkysticks, 01 November 2023 - 07:44 AM.

[funkysticks]

Packing and distributors efficiency depends on diameter. Consult packing vendor if packing/distributors height is equal for both cases.

So as the capacity increases, the diameter will only increase if the same packing material is used, am I correct?

[Bobby Strain]

Nothing looks right about your original calculation. Neither the height or diameter.

 

Bobby

[funkysticks]

That is maybe because of the different packing that I used for my seperation process. The mixture I used here was the methanol water system

[breizh]

Hi,

Probably good to review this document:

https://cdn.intechop...tion_column.pdf

edit:

Wetting rate is the key parameter to calculate the diameter of the column.

From my old notes (yellowish), this should be below 0.05 m3/h/m for distillation column.

Good also to review the head loss of the column after scale up. Correlation lobo/Eckert.

Note: As other said, your initial design is weird;  4 feet /40 stages?

 

Good luck

Breizh 

[shvet1]

 

Packing and distributors efficiency depends on diameter. Consult packing vendor if packing/distributors height is equal for both cases.

So as the capacity increases, the diameter will only increase if the same packing material is used, am I correct?

 

 

In theory - correct

In practice - case specific as efficiency depends on diameter, aspecially applicable to bench scale equipment

If this is engineering - consult vendor

If this is training - ignore

Edited by shvet1, 02 November 2023 - 12:55 AM.

[funkysticks]

That's great! Thank you!

 

funkysticks

[deepak.vibhandik@gmail.com]

Hi, with flowrate Diameter will change. But Efficiency also depends on diameter. Didn't know operating conditions. Vapor flowrate needs a certain velocity to operate column efficiently. If distance between plates increases, then efficiency decreases. In your case height of column is same so definitely no problem. Take care of hydraulic. Good day