05-15-04 05:43
No 507271
Okay, assuming someone wanted to distill somethings at the 3-20gram level in a 14/20 short path and 25-150grams on a normal 14/20 still setup with rotating cow and 100mm liebig. What would be the best size vigreux to have for each? Vacuum brings 250c eugenol to 65c and others around 50-55c(2.5torr?). Assuming separations will have 10c or better between boiling points. I was figuring about 25-50mm for the short path and a 75-100mm for the full size 14/20 still.
What are some of teh experts opinions too big too short? Other things to consider?
(Hive Adickt)
05-15-04 13:46
No 507305
collums are alvays to short !
But with the standard vigreux at 30cm you get's desent result's. A packet one only have to bee 10-15cm long. But as long you destilate at 1dr./sek it should bee ok
(Stoni's sexual toy)
05-15-04 23:13
No 507363
> with the standard vigreux at 30cm you get's desent result's.
A 30cm vigreux is way too long for a 14/20 distillation!!! That's a great way to reflux your chemicals without actually distilling it.
> A packet one only have to bee 10-15cm long.
When you want to distill only a few grams then a packed column is out of the question, unless you don't care for the yield. In case you do, get a spinning band column or something similar.
BUSH/CHENEY 2004! After all, it ain't my country!
www.american-buddha.com/addict.war.1.htm
(Hive Addict)
05-16-04 08:36
No 507442
So what else would you consider to be similar to spinning band? From what I can gather from the link and this brief discription, these are quite efficient being able to separate things with a 2degree difference(well, the larger ones anyway).
Would you care to pm me with a hint as it seems none of teh major glass makers carries what I'm looking for? I'm assuming a 2-4" column would be sufficient for a 50-150gram full size 14/20 app? It looks as though this column on this apparatus would suffice for all my needs if it were only 14/20.
http://www.chem.orst.edu/ch361-464/ch361
http://www.equilabcanada.com/distillatio
High performance, low cost, Microscale Spinning Band Distillation Column effective in separating low-boiling liquid mixtures with volumes in the 0.5 to 5 mL range. Designed by Drs. Dana Mayo, Ronald M. Pike, and Samuel S. Butcher, authors of Microscale Organic Laboratory, John Wiley and Sons, New York, this 2.5 inch microdistillation column separates close-boiling (5-10°C) mixtures without stopcocks, utilizing a PTFE band uniquely driven by a bottom magnet. Coupled to a conventional magnet stirrer, experimental data indicate satisfactory performance at 1000 rpm. Column has been shown to achieve height equivalent/ theoretical plate values approaching 0.2 inches/plate within 90 minutes of boil-up.
(Stoni's sexual toy)
05-16-04 17:14
No 507501
> I'm assuming a 2-4" column would be sufficient for a 50-150gram
> full size 14/20 app?
For 50-150g batches you can use an even longer vigreux column than 2-4 inches.
I've personally used 4-6 inch long vigreux columns with good results for such batch sizes.
BUSH/CHENEY 2004! After all, it ain't my country!
www.american-buddha.com/addict.war.1.htm