zombie616 - 14-7-2008 at 14:07
I am trying to get a glass distilling setup and I was wondering if I really have to use a sand bath or or oil while distilling with a hot plate. I was
also wondering exactly how I have to set up the oil or sand bath to eliminate hot spots.
Thank you in advance for your time.
chemkid - 14-7-2008 at 16:43
Well, if you are using expensive glassware it is totally worth it to protect your glassware. I have only performed distillations of solid dissolved in
liquid to obtain the solid and never used an sand or oil bath, though it might make things go a bit smoother, i don't find it worth the effort (i have
very little time to experiment usually ).
The concept is that the oil or sand is more thermally conductive than having air around the flask (or vessel). Therefore the heat is distributed
through the sand/oil and also around your flask. In addition sand and oil won't carry the heat away from your vessel.
Chemkid
Klute - 14-7-2008 at 17:04
Using directly the hotplate as is will be very unpractical, and very wastefull heat-wise. Even a so-called air bath is crap IMHO, too much
fluctuantion, heat dissipation, etc. The bets option is a water bath when the bp's are no higher than 80°C. Otherwise just use a pan with some oil
adequatly chosen according to the desired pot temperature, and if you are using a stirrer hotplate, throw in a piece of steel wire to provide some
stirring of the oil (like one of those things you use to hold several pieces of paper together).
Phosphor-ing - 15-7-2008 at 03:40
Paper clip in the oil bath. Genius
Klute - 15-7-2008 at 03:44
That's the word I wa looking for, thank you
vulture - 15-7-2008 at 08:50
Be wary that most oils are flammable, this a serious hazard when distilling high boiling or oxidizing compounds.