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Author: Subject: How large amounts are separated?
Fyndium
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[*] posted on 28-2-2021 at 11:03
How large amounts are separated?


How labs do bigger batches of separation and extraction? Bigger than 5L separatory funnels begin to get too heavy to handle, so I suppose they use stationary, stirred separatory funnels like in brewing?

Years ago, I did an improvised separatory funnel from transparent bucket and a valve. It did work great, and cost about 5€ with all the parts.
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itsallgoodjames
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[*] posted on 28-2-2021 at 17:59


If you're trying to separate large amounts of liquids, decant as much of the liquid as possible then use a sep funnel on the rest of it



Nuclear physics is neat. It's a shame it's so regulated...

Now that I think about it, that's probably a good thing. Still annoying though.
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Fyndium
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[*] posted on 28-2-2021 at 18:28


During benzaldehyde synthesis I used glass tube and tubing to suction out the BzH settled to the bottom. So yeah, there are other methods too.
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zed
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[*] posted on 28-2-2021 at 18:49


Use vacuum to siphon.
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draculic acid69
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[*] posted on 1-3-2021 at 04:12


I think once U go past the 5L point U go with buckets/tubs/the/drums with taps on them or go with the vacuum siphon method
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Praxichys
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[*] posted on 1-3-2021 at 08:14


Here is a 50L example. Coarse extraction is achieved using a bottom tap (in progress, see image). Once the boundary gets close to the drain, the flow is slowed to prevent a vortex which would cause waste.

When the level is as close to the layer as one can best manage, the valve is closed. Rapid stirring commences to dislodge adhering liquid from the reactor walls, followed by more settling time to let it fall to the bottom.

The bucket is meanwhile swapped for a pitcher-like transfer container eventually used to fill a 2L sep funnel. The tap is pulsed open and shut a few times until the amount drawn reaches about 3/4 the volume of the sep funnel. This purges remnants of the heavy layer from the reactor and purges the valve body with product. The sep funnel is used as normal for fine separation and any product is returned to the reactor for the next step.


50L_Sep.png - 598kB


Siphoning with a long glass tube is also an option. This method would be preferable if the next step could not tolerate any waste from the previous step, as there are invariably adhering droplets. In my case they are taken care of during the drying step and are of little consequence.
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njl
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[*] posted on 1-3-2021 at 08:27


What solvents are you using here?



Reflux condenser?? I barely know her!
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Praxichys
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[*] posted on 1-3-2021 at 11:33


Just water. The bottom layer is mostly aqueous sodium sulfate with some sulfuric acid; the top is product. This is just a big acid-catalyzed esterification.
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