Sciencemadness Discussion Board

Vigreux and reflux column combo. Custom piece

organicchemist25 - 3-11-2017 at 16:16

I bought this off of someone. It looked like something I wanted to add to the collection. He couldn't tell me what it is used for.

One side has a vigreux column and on the other side a coiled reflux condenser, but they are connected to were one could bypass over to the other side?

Please explain where this could be used.

IMG_5904.JPG - 1.3MB

[Edited on 4-11-2017 by organicchemist25]

DJF90 - 4-11-2017 at 09:30

I can't think of any possible use for this. From my perspective, it is nonsensical and certainly can't be used for fractionation.

Sulaiman - 5-11-2017 at 00:24

Quote: Originally posted by organicchemist25  
Please explain where this could be used.


I think that it is a molecular discombobulator, that could be used on a movie set

unionised - 5-11-2017 at 02:40

Have you ever looked up the origin of the word "fiasco"?

organicchemist25 - 5-11-2017 at 06:55

Yeah, I don't know either, but it came from a university's previous collection. The craftsmanship in the joints, coil, vigreux, thickness of the glass and fusion of the two parts is of professional quality. I'm sure it could be used for some odd application. I just have no idea what. I can't foresee someone making it for no reason.

organicchemist25 - 5-11-2017 at 06:56

Quote: Originally posted by unionised  
Have you ever looked up the origin of the word "fiasco"?


I did after you mentioned it. ;)

markx - 5-11-2017 at 07:27

Could be used as a stillhead with regulated reflux ratio (on top of another packed column. If one attaches a needle valve (or any other valve that allows for a fine regulation) at the bottom of the reflux condenser outlet to force the major part of the condensate to overflow and return to the main column via the lower connection arm, then you have a glass stillhead with regulated reflux ratio. A peculiar design nevertheless....

Dr.Bob - 5-11-2017 at 16:48

Might have allowed mixtures of solvents to be distilled, the higher boiling fractions went the lower short path, the lower ones take the high road. That idea makes as much sense as any other I can come up with.


BromicAcid - 5-11-2017 at 17:55

Quote: Originally posted by Dr.Bob  
Might have allowed mixtures of solvents to be distilled, the higher boiling fractions went the lower short path, the lower ones take the high road. That idea makes as much sense as any other I can come up with.



Yes, I have seen something similar. The condenser is set cooler than the condenser on the top of the Vigreux column so that it can collect the 'lights' fraction while the heavy can collect on the top finger.

j_sum1 - 5-11-2017 at 18:22

So, BromicAcid, it is basically a fractionating column with the ability to add a reflux condenser to the top. And the condenser to the side is designed to remove some of the light material from the reaction mixture. Presumably it also removes a good portion of the heavy as well.

I was trying to visualise what the pressure gradient might be like in the unit and figured that if the side condenser was cooler then more condensation would happen there which would then lower the pressure and cause more of the vapour to be sucked in that direction.

It strikes me as the sort of equipment that, if it was doing exactly what you wanted and was separating the desired fraction, it would be great. But it could be a fickle bastard to work with. I would have guessed better progress might have been made with a Dean Stark -- assuming of course that there was some kind of phase separation of the condensate.

BromicAcid - 5-11-2017 at 20:31

That would be my best guess based on a similar setup I saw before.