Pressure drop through bubble cap column 1

[v8landy]

I am looking to buy a used column, 1m x 14m bubble cap 42 caps, 52 trays.

I have no history of this column etc, is it possible to calculate pressure drop through this column or can it be only done from actual data.

All I am after is a ball park figure.

 

[v8landy]

Like I said I am after a rough figure.

Our current column is 1m x 12m 34 actual plates 20 theoretical. i.e 60% effeicent.

Taking this 60% effency as a ballpark figure, can I assume that my new one of 52 plates has 31 theoretical?

Rough figure needed!

 

[dcasto]

You can get a rough estimate for pressure drop knowing the tray weir height. Typically 2 or 3 inches. 52 tray times 2 inches is 104 inches of whatever the liquid on the trays density. If its water, then .43 psi/foot of water or 104 inches dived by 12 is 9. 9 times .43 is 4 psi. Plus about 2 psi for the gas flow. 6 psi would be a minimum drop.

Tray effiency is a design variable for the trays and is quite complex. Typical ranges are 40% to 80%, so 60% isn't an unreasonable value.

 

[unclesyd]

If my recaller is working we used 2 mm pressure drop per tray as a standard on our vacuum bubble cap columns. We were separating Diamines and Diamines/water. I know that all the weir heights were set a 2". We kept the 2 mm/tray to keep the base temperature down to prevent product degradation.

 

[v8landy]

Thanks to you both for the above information, very good.