Column operation
Column operation
(OP)
Hi,
For purification column operation, if the feed rate to the column is increased in order to increase top side draw of high purity product, what should be the change to reflux rate, reboiler steam input etc to ensure that there's no flooding in the column? WHat do I expect to see in the temperature profile along the column?
Thanks.
For purification column operation, if the feed rate to the column is increased in order to increase top side draw of high purity product, what should be the change to reflux rate, reboiler steam input etc to ensure that there's no flooding in the column? WHat do I expect to see in the temperature profile along the column?
Thanks.





RE: Column operation
If the change in feed rate is very strong and abrupt, I guess the temperature profile all over the column will drop. If you do not change the steam (heat) input to the reboilers accordingly, there is quite a good chance to disturb column operation in a magnitude that material flow will interupt completely, as rising vapors will be condensed by the feed stream.
To ensure there is no flooding, change gradually and keep constant watch on the overhead product flowrates and overhead temperatures. If you notice a substantial drop in either one of those, you are flooding the column. Keep in mind to increase reboiler steam flowrate (heat input) proportionally to feed increase. And wait for some more experienced guy from this forum to verify my suggestions ;)
hth,
chris
RE: Column operation
http://eweb.chemeng.ed.ac.uk/courses/control/restr...
http://www.svce.ac.in/~sundar/Distillation%20Colum...
may be of help.
Otherwise, get hold of Distillation Control For Productivity and Energy Conservation by F.G. Shinskey (McGraw-Hill) to better understand the parameters and constraints that affect the operation of the column, including flooding conditions.