by Professor Green » Sat Jul 29, 2017 11:41 am
Hi mate,
that means setting the reflux condenser so that ALL the vapour is converted back to liquid and falls back down the column where it reboils and rises again as vapour and is subsequently re-condensed when it reaches the top. Doing this for a period of time will "stack the plates" where your lighter alcohol fractions will remain at the top and the heavier ones at the bottom. Once that occurs you can open up the reflux condenser a little to allow the vapour out at an appropriate rate to keep the fractions separate.
There are some excellent posts on running reflux stills in the newbies section.
Cheers,
Prof. Green.