JJay
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Hempel Column
I feel like a real idiot asking this, but I can't seem to find a reasonably-priced Hempel column anywhere... cheap Vigreux columns abound, but I'd
like to try using a packed column for a few things... where can I get an inexpensive Hempel column?
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Magpie
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What length and ID do you require? Do you require a ground glass fitting? If so, what size? What do you consider "inexpensive"?
[Edited on 25-3-2016 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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JJay
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Quote: Originally posted by Magpie  | What length and ID do you require? Do you require a ground glass fitting? If so, what size? What do you consider "inexpensive"?
[Edited on 25-3-2016 by Magpie] |
24/29 or 24/40, definitely with a ground glass fitting... it's hard to say what size is best, but 30 cm is likely a good one... inner diameter maybe 1
cm or so (bigger would work well).
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Magpie
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Here's a supplier I can recommend: Eagle.
The single most important condition for a successful synthesis is good mixing - Nicodem
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JJay
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Cool. I think Hempel columns should cost less (why on earth can I find a Liebig with free shipping for half the price of a same-size Hempel column),
but those are the best prices I have seen so far.
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Dr.Bob
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If you want to really go out, then I have one vacuum jacketed Hempel column left, but it is S35 joints at both top and bottom, about 16" tall.
Fortunately, I have s35 jointed 1 and 2L rbfs, and I think I even have a distillation head for it somewhere, or at least can find one. But it might
cost a little more. But it is a beauty. I think I had some simple ones before, but don't have any simple 24/40 ones now.
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JJay
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Right now I have nothing but 24/40 jointware, and I kind of like it that way.
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macckone
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Try roccowareglassworks.com, they have relatively low cost hemples. But they aren't vaccuum jacketed.
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JJay
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I think I'll be ok without a vacuum jacket.
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Sulaiman
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An air condenser can easily be converted to a Hempel column,
and a Leibig condenser into a jacketed Hempel column.
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Dr.Bob
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| Quote: Originally posted by Sulaiman | An air condenser can easily be converted to a Hempel column,
and a Leibig condenser into a jacketed Hempel column. |
This is true, but the inside diameter will be very narrow, which limits the vapor flow a lot. You would want to find a Liebig with a larger inside
pathway in order to make that work well. But a hempel should be very easy to make, effectively just a long tube with 24/40 joints as each end and
few indents at the bottom to hold the packing material. But I would guess $40 is about the cheapest you will find a decent new one.
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JJay
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I'm not sure my Liebig would work well as a Hempel column because it doesn't have any indentations. Also, I only have one Liebig (I should probably
get another one).
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chemrox
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Keep an eye out on the used equipment market. Bob's would be an awesome column. You could use a 1L s30 flask- either he or I would sell you one for
$20. I bought a 16" 24/40 Hempel for $40 used. It's not nearly as nice as Bob's. Vacuum jacketed Hempel's cost big bucks.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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JJay
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I'm probably just going to buy an air condenser from one of my usual suppliers and plug the bottom with glass wool, hoping that it won't fall out.
What can you do with a vacuum jacketed Hempel?
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gdflp
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| Quote: Originally posted by JJay | I'm probably just going to buy an air condenser from one of my usual suppliers and plug the bottom with glass wool, hoping that it won't fall out.
What can you do with a vacuum jacketed Hempel? |
It's a much cleaner and better solution to insulating the column than wrapping it with fiberglass or aluminum. Insulated columns allow for faster
distillations, by preventing heat loss through the great surface area which a normal column possesses.
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chemrox
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http://www.ebay.com/itm/HEMPEL-COLUMN-300-x-25-mm-24-40-DIST...
hell of a deal
also consider a Snyder column
[Edited on 29-3-2016 by chemrox]
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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macckone
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The other suppliers listed are cheaper than the avogadro price.
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JJay
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Yeah, I mean, it's a nice column and all, but I could buy an entire Chinese kit for that if you include shipping.
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