aga
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Simple Rotavap using standard glassware
Rotavaps seem ridiculously over-complicated.
Why are they rotating the RBF, requiring the use of expensive rotating joints ?
Oh. So the liquid gets coated around the RBF, increasing surface area, therefore evaporating faster.
So if the RBF is stationary, then you shift the Liquid all over the RBF, you get the same effect right ?
Why not have a rotating Ring around the Static RBF and shift two or more magnetic stirbars using Nd magnets fixed to the rotating ring ?
The stirbars will spread the liquid all over the RBF same as if the RBF were rotating.
Does anyone see anything fundamentally wrong with this notion ?
Edit:
If it works, it's called an agaVap<sup>tm</sup>
[Edited on 5-5-2016 by aga]
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Daffodile
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Its a pretty cool idea actually, and with an aluminum frame and some specially designed stir bars, it would probably work. But in either case, most
experimenters who need rotovaps generally have access to them anyway.
Just to express what it sounds like to me; a receiving flask attached to a reflux condenser by a three way adapter, and the perpendicular joint
attached to the evap flask. The evap flask would have a circular aluminum 'track' with a neodymium magnet running around the track, rotated by a
rubber belt attached to a motor or something. Trying to explain, sorry if this is botched.
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Texium
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Sadly I'm
afraid that isn't the case 
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Dr.Bob
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It should work, still need to heat the sides of the rbf, create the vacuum, and have a efficient condenser. But all of those are possible. Sounds
like an idea worth testing.
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CharlieA
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Why not just "normal" magnetic mixing with a hot plate/stirrer combination? Am I missing something here? (It wouldn't be the first {or last} time!)
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aga
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'Normal' stirring would help a little, just that spreading the liquid out as much as possible would be better.
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careysub
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I suppose a cross-paddle type stirrer would work a bit better than a simple bar.
How about this - an Archimedes screw that is inserted in one neck of a two neck flask:
https://en.wikipedia.org/wiki/Archimedes%27_screw
The added evaporation surface area does not have to be the side of the flask.
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Orenousername
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I would think a flexible stir bar would work well, like those wooden toy snakes if anyone knows what I'm talking about
Lol nerds
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aga
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Standard stirbars should work fine.
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CharlieA
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Quote: Originally posted by aga  | | 'Normal' stirring would help a little, just that spreading the liquid out as much as possible would be better. |
But to spread the liquid out as much as possible is when you get into the fancy rotavap glassware with rotating joints.
We used to freeze aqueous solutions of an enzyme (I don't remember what enzyme) on the walls of bottles, then attach them to a manifold, and pulled a
vacuum to pull off the water; I believe the gadget was called a "lyophilizer".
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Corrosive Joeseph
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Maybe a magnetic stirrer sitting atop an old turntable might work...................
Whilst magnetically spinning away it would also be in another wider circular motion......................
This would spread the liquid well out but l see have no way of heating the liquid in the RBF....................
Yet......................... =)
CJ
Being well adjusted to a sick society is no measure of one's mental health
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