Jor
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Advice for distillation setups needed
First of all, I know there have been numerous topics about : 'where to buy a setup'' ,etc. But this is not about where to buy, but what to buy.
I mostly concentrate on inorganics, but sometimes I just need a distillation setup, when I dont have it. I would never have to distill large amounts.
I was considering buying the following (all in EUR):
-Roundbottom flask 250mL, NS29 : 4,00
-The piece of glass between a cooler/condenser and round bottom flask, where the thermometer can be attached (dont know english translation for it
 ) , NS29, with NS14 for thermometer : 5,00
-Liebiegcooler NS29, 20 or 40 cm (???, wich one is preferred?): no cost yet available, needs to request from supplier.
-Vaccuum Allonge, NS29, 5,50
-'Round'bottom flask, wich can be put on the ground without falling (I dont know English again!), NS29: 4,00
-Thermometer NS14: 5,80
But Im wondering , would this be sufficient for a good destillation setup? Is NS29 good size (have no clue what it means)? And do I need something to
close the opening where vaccuum should be attached (im not buying vaccuum)?
What size should my cooler be?
I would greatly appreciate help, this is my first destillation setup im gonna buy, so I have no clue what if I'm forgetting things.
Edit by Chemoleo: More descriptive title
[Edited on 28-2-2008 by chemoleo]
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chemrox
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You have described a basic distillation setup. I would use a West condenser instead. To the list you might add a short vigeraux column or a liebeg
condenser with nubs at the bottom to retain packing material. I think we just went through all this with another new guy. Anyway, buy this stuff on
ebay and be a little patient. I just got the condenser you would want for $9.99 plus shipping. At that kind of pricing you can get everything for
around $30 versus $150-$200 for complete setups. The flat bottom rb is a good idea if you want to use a hot plate/stirrer. But its not essential to
have that. Get standard taper .. 19/22 or 24/40. The latter will offer more choices. If you elect the former I have a vigeraux column you can have
cheap.
"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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209
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How should you attach a vacuum? I have a still with a vacuum but how do you attach a vacuum without causing the glass to implode if there is nowhere
for air to be pulled into the still?
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not_important
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One bar is not much pressure for smaller glassware to withstand. Chips and cracks, including the star cracks from banging a flask into something
hard, weaken things enough that such glass should not have vacuum pulled on it.
If you let air in, you'd not have a vacuum, and the whole effort would be pointless.
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Jor
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''Get standard taper .. 19/22 or 24/40. The latter will offer more choices. If you elect the former I have a vigeraux column you can have cheap.''
Sorry, i dont understand, what is 'taper' ?
And secondly, why do I need a vigeraux collumn?
I can get a full setup (NS14) with liebig condenser and vigeraux column (only excluding a thermometer and a flask where to collect the destillate, but
those are cheap).
, but I did not yet take it because of the vigeraux collumn, wich I thought I dont need..
Thirdly, what does the NSxx indicate? Does it matter what xx is, as far as they 'fit'?
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not_important
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why a Vigreux column? Fractional distillation:
http://en.wikipedia.org/wiki/Fractional_distillation
http://www.chemhelper.com/distillation.html
Vigreux columns are a bit less fussy than many other fractionating columns, and decent separations provided you know how to do fractional
distillation. They're one of the better choices when distilling smaller amounts of materials, as they have less holdup.
NS == ST more or less
http://en.wikipedia.org/wiki/Ground_glass_joint
the joints will not fit proper if they're not of the same taper. The bigger the number, the larger the joint, the wider it is. If you're likely to
be working on a small scale, you don't want ST29 because it's big, your product will get lost coating the walls of the glassware. If you're working
with a liter or more, ST19 or ST14 would be silly, the apparatus would be too small.
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Jor
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Ok, I understand now. I will just order all my pieces NS14 size. The cooler will probably be 20cm long.
As a last question. How do I get rid of overpressure in the distilling apparatus? Say Im working in a system (without vaccuum) and a gas is evolved.
Where does it go? Just out of the vaccuum allonge? If yes , that would be troublesome, because I might gass myself when for example distilling
bromine, as Iit would just escape. I could try a safety tube ofcourse (in NaOH)... But still , is it possible to 'block' the glass entry where
normally vaccuum is attached? Or shouldnt I do this (under-/overpressure) ?
EDIT: Im gonna order the following now (I think):
-round bottom flask, 250mL , NS14: 3,00
-flat bottom flask, 100mL , NS14: 2,50
-Still Head NS14: 5,00 (Im not gonna buy a vigeraux column, maybe later)
-Liebig Condenser, NS14, 20cm: 17,50
-Vaccuum allonge: 4,50
-thermometer NS14: 5,80
-Hotplate: still need to buy one...
I would be glad if anyone (in Europe) can sell me a hotplate for a decent price. This also goes for a liebig condenser.
I would greatly appreciate answers to the questions stated above. After all, this is one of the most important investments in a home-lab.
[Edited on 27-2-2008 by Jor]
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woelen
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I purchased a hot plate and it did not work well. Transferring the heat to the flask is a real pain in the ass. its OK for distilling Br2, I just
managed to get it working for HNO3, but for distilling water, or even higher boiling things, it simply does not work without a oil bath.
You should not use a hot plate, but a heating mantle (dutch: verwarmingsmantel). Second hand, these are hardly more expensive than a decent hotplate.
Labstuff (in NL) has them for EUR 30 ... 60 in varying amounts and sizes. Don't know the current status of what he has, but I advice you to take a 250
ml one. In such a one, you also can hold a 100 ml flask. I myself have a 500 ml one, which also is suitable for 250 ml, but not really for 100 ml.
I have NS24 equipment, and that is fine for 250 ml distillations. I distilled my bromine and some 90% HNO3 with this setup without any problems. The
only disadvantage of NS24 is that it is somewhat harder to find components with this size. NS29 is more common. NS14 is somewhat small to my taste,
unless you are working with 100 ml or less flasks. If possible try to find NS19, which also is fairly common (but not as common as NS29).
You should not close/block the opening in the vacuum allonge!! If you do that, pressure may build up in the total setup and components, such as the
thermometer may pop out of the setup during distillation. You definitely don't want your thermometer and cooler jumping around while you are
distilling your Br2  . I always connect a long rubber tube to this opening, the
other end being immersed in a bath, which absorbs the compound, which you are distilling (e.g. with my bromine distillation, I used a solution of
NaOH). In this way, you won't stink up the entire room if things are going a little too fast.
The following picture shows my setup (except the hotplate and water bath, now I have a heating mantle):
Here, the setup is used, making bromine.
EDIT: I forgot to mention something. I also strongly advice you to buy a few stoppers of the same size as your flasks. I have NS24 stoppers. Once you
disassemble your setup, you can stopper the collector flask and the heated flask with the glass stoppers and set them aside, while you are cleaning
the other parts.
Another convenient thing is to use a two-necked flask for the heated flask. The second neck is stoppered during normal operation, but when the flask
is almost empty, you can carefully add new reagent or liquid to be purified, without the need of disassembling the entire apparatus. In this way I am
going to distill 250 ml of impure CCl4. Each time I add 50 ml or so in the flask through its second neck, while leaving the distillation equipment
assembled.
EDIT2: Made link to picture working again.
[Edited on 30-7-16 by woelen]
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Jor
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QUOTE
''I purchased a hot plate and it did not work well. Transferring the heat to the flask is a real pain in the ass. its OK for distilling Br2, I just
managed to get it working for HNO3, but for distilling water, or even higher boiling things, it simply does not work without a oil bath''
And does it work then if I use an oil bath? Oil is very cheap.(you mean the yellow supermarket stuff right?)
I would buy a heating mantle, but they are pretty expensive, and I had the idea of buying a hotplate, so I could also heat beakers/erlenmeyers. If I
take a heating mantle I cant. Well, I will look around. Is tehre anyone here who still has a 250 or 500mL heating mantle for a decent price??
Yes I will buy stoppers. 
Problem is , I have a budget of approx 70EUR. The (new, not used) destillation setup will set me back 50-60 euros. I then only need a heating mantle,
but I dont have enough money if it costs 30+. Damn, I shouldnt have bought my 1L glacial acetic! Dont use it much anyways, and I would have had the
money if I didnt buy it!
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woelen
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With a heating mantle you can heat erlenmeyers. Although the bottom is not round, it works very nicely. I can tell you from personal experience . The hot air simply is trapped between the round mantle and the flat bottom of the
beaker or erlenmeyer.
It will work with an oil bath, but the use of an oil bath is not without risk. If a flask cracks, and it contains hot oxidizer like HNO3 or Br2, and
this comes into the oil, then you'll have instant fire, or even explosion. Even without oxidizing stuff things can get very nasty. Imaging getting hot
water in oil of 200+ C. Besides the risk, I also dislike very much the immense mess. Cleaning up after a distillation with an oil bath is not a
pleasant thing to do, hence my choice for a heating mantle. Simple, effective, safe and clean.
I would suggest you to buy the setup for distillation right now. It looks like a bargain. Then, after some time, you could buy the heating mantle.
These heating mantles are available all the time at labstuff's website. My experience with this kind of things is that one needs to collect and only
after some time, everything is complete.
The hot plate, which I purchased, is from Blokker, it cost me EUR 29 + EUR 10 for the teflon coated pan, and if you add a few euros for some oil, then
the money, spent on this, will hardly be less than the money, spent on a heating mantle.
Btw, I just distilled my 250 ml of deep yellow green CCl4. It took me just over an hour with my setup, including the setting up and cleaning up. I now
have 200 ml colorless sweet smelling CCl4, and 50 ml of some dark green liquid, which also still contains quite some CCl4. I stopped distilling,
because I am afraid that this last 50 ml may spoil my now pure 200 ml of CCl4. This was my first distillation with my new 500 ml heating mantle and it
works great! This time, the safety tube simply was lead through the window on the roof, so any excess vapor was expelled outside.
[Edited on 27-2-08 by woelen]
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