What is Percent Flood?

[pipeENGR]

We are being given a design of an amine plant that describes Percent Flood. Can someone please explain what this term means? If it helps at all, the designers say they prefer it to run at 70% flood, but some people will run as high as 80%. This is on an amine contactor with structured packing.

 

[mbeychok]

pipeENGR:

The term "percent of flood" applies to absorption or distillation columns using either packed beds or trays. Such a column operating at "80 percent of flood" means that the column is operating at a ratio of vapor flow-to-liquid flow such that the column is within 20 percent of being "flooded" (i.e., in essence, within 20 percent of being ineffective).



Milton Beychok
(Visit me at www.air-dispersion.com)
.

 

[25362]

Don't forget that amine contactor effectiveness is also affected by a variety of other factors beside hydraulics.

 

[dcasto]

There are generalized tables for the different types of trays and random packing. Get you McCabe or Smith books out. I believe there some packaged programs on the net to get you a rough idea of the diameter required to meet the requirements.

For structured packing you can get a good idea from the generalized calculations, but I'd get a vendor to do his propritory calculations and a performance gaurentee from a vendor if the vessel is smaller than the generalized equations by say 15%.