loading and flooding points

[sally111]

hi everybody
i am designing a packed column for distillation and i want to knwow how does the loading and flooding points for a sytem changes with viscosity?
thanks

 

[katmar]

Sally,

As the liquid viscosity increases the capacity of the tower decreases. The way to picture it is that as the liquid gets more viscous it flows down the packing less freely, thus increasing the liquid hold-up and the resistance to the gas trying to flow upwards.

You can plug the numbers into the Eckert (or other) correlation to see the actual effect for your conditions. If you want to avoid doing it by hand and rather use a program to it for you, you can download various packages.

A free spreadsheet is available from ESCO Engineering at

http://www.mnsi.net/~pas/brochure.htm

Koch-Glitsch offer their tower software (KG-Tower) for free at

http://www.kochind.com

My own program is not free, but the free trial version which can be used 30 times can be downloaded from

http://www.katmarsoftware.com