Refinery
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Sep funnels and vacuum?
Do separatory funnels generally withstand vacuum? I need to do some vacuum filtrations with larger volume liquid and I thought I could use sep funnel
as receiver and drain the liquid as needed. Based on their shape they should withstand reduced pressure. Obviously the vacuum needs to be settled
before operating the sep valve, unless unwanted things will happen.
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monolithic
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I've seen them used under vacuum like in this video https://www.youtube.com/watch?v=lBNhu4kJ4Mc
That said it's probably a good idea to use a smaller separatory funnel without any visible voids in the glassware.
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SWIM
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They should be able to take it.
Sep funnels with a ground standard taper bottom joint are made to function as an addition funnel too, so they have to be made to take vacuum as this
happens a lot with addition funnels.
The other ones (drip tip bottom, no joint) seem pretty much the same, but I agree that you should check the glass for voids and defects.
If we're talking about a 250 ml or a 125 or less then I wouldn't worry at all.
Bigger is riskier, but as you pointed out they do have a good shape for vacuum, so they ought to be okay.
I'd be reluctant to evacuate a 2 liter or bigger though.
That might be okay for all I know, but I wouldn't be eager to test it out for myself without lots of duct tape.
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wg48temp9
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The usual separation funnel with no flat areas or defects should be fine but check it first empty just in case.
Old cathode ray tube with almost flat 6in front faces and made with glass no thicker than the average separation funnel contain very good vacuums.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Refinery
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I presume that safety margin requires that sintered glass filtering funnels can generate up to about 1kg/cm2 vacuum pressure with sufficient pump.
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wg48temp9
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Quote: Originally posted by Refinery  | | I presume that safety margin requires that sintered glass filtering funnels can generate up to about 1kg/cm2 vacuum pressure with sufficient pump.
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Not on the joint to the seperation funnel if its like this one:
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Refinery
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It's like this. With ground joint and vacuum connector.
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Sulaiman
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When filtering there is a lower limit to pressure usually determined by the boiling point of the liquid
(and ambient temperature)
CAUTION : Hobby Chemist, not Professional or even Amateur
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