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Author: Subject: liebig, Allihn, or graham?
friendlyterry
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[*] posted on 29-9-2009 at 17:36
liebig, Allihn, or graham?


guess theyre all the same but which condenser do you fine people prefer?
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crazyboy
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[*] posted on 29-9-2009 at 17:49


I use a liebig because they are cheap and simple. Allihn condesers and graham condensers work well for long refluxes or distillation of volatile compounds such as diethyl ether but when doing standard distillations liquid often becomes trapped in the bulbs or coils.



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mr.crow
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[*] posted on 29-9-2009 at 18:10


West is supposed to be slightly better then Liebig, but both are fine for standard distillation.

Allihn condensers are good for vertical distillation. That is when the condenser is mounted straight up and down.

You can get more efficient (expensive) condensers for reflux. Some have a jacket and coils, or double coils.
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UnintentionalChaos
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[*] posted on 29-9-2009 at 18:22


West is just a narrower jacket, IIRC, meaning that the coolant has little chance to heat up while in contact with the inner glass tube. It should improve cooling if similar flow rates are used for it and a liebig.

Liebig is cheap and it works for most things, though. Allihn is better for reflux or vertical distillation.

The cooling is very efficient in a graham, but some product is lost on the high surface area. They also should be used in a vertical position.

I use a 500mm liebig for most distillations, and a very sexy Friedrich for refluxing. I'd like to add a shorter liebig for higher boilers, however, and perhaps a graham for vertical distillation of very volatile solvents.




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