I don’t quite understand what this means.
Well what do you want to know.
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If I understand you mean that if I run the setup described (picture diagram below sorry for the poor quality sketch) I’ll have a difficult time keeping the part between the last collecting flask and the cold trap clean? Why is that?
And “get the trapping power back right up against your spd”, I’m not quite sure what you mean by that.
Ok, I guess the best way to explain it is a linear form.
Start with head → discharge device(laminar) → cold traps.
You don’t want bellows or extensive devices between the discharge section and the cold traps etc.
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Is that because it has a negative effect on vacuum depth?
The reason I like the set up as diagrammed which is basically the new Lab Society G3/G3X set up, is because 1) I wouldn’t have to break vac to swap to mains. And 2) The cold finger or any kind of secondary condenser with a collection flask seems like it would be very useful when running the condenser hot. I know @Rowan recommends this and uses an Allihn condenser for this (or used to?)
If you only have one collection flask, and you’re doing hot condenser method, wouldn’t you end up with all of your heads and volatiles in the cold trap? Is it not better to try and minimize the amount going into the cold trap in the first place?
It’s just going to reside anywhere really. Cold trap or cold finger device. The reason why you want that trap right up at the spd is becusee the larger space around a cold condensing surface creates molecular vacuum - this piles molecules along a surface like a magnet. The spd behaves cleaner and your vacuum system stays healthy. There’s even a laminar setup with swing arm that we have that you can drain into a separate flask. Not the cold trap.
None the less molecular drag onto the cold surfaces makes the cusp of the distillation perform at a higher efficiency and lower temps and speeds. The farther you move your trapping systems away from the spd the less efficient it gets basically.
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