Sciencemadness Discussion Board

stupid still or probably the user

shadow - 25-1-2008 at 08:55

My setup has 24/40 fittings, and my heat source have varied from a camp stove, coleman stove, heater stirrer, to glas-col mantle.
The distillate goes up the adapter, collects, and rains back down into the flask, with very little going out into the condenser.
How can I improve the efficiency of this simple setup?

DrP - 25-1-2008 at 09:06

Try lagging the column.

Some other threads talk about speeding up distillation - I think this one might :

MagicJigPipe - 27-1-2008 at 15:28

What are you distilling?

chemrox - 27-1-2008 at 21:59

There's not close to enough information here. A description of the setup would include the type and length of the column, the type of distillation head and the material being distilled. Without these specifics no one can address the problem except in total speculation. It sounds like a column flooding problem caused by excessive cooling but I really need the details.

Mumbles - 27-1-2008 at 23:26

One simple fix would be to wrap the distillation adapter in aluminum foil or something similar. It will help to keep the vapor hor to get it into the condensor. It may also reduce the purity of your compound if two distillables are present, as mixtures will be able to pass together easier. Then again, if you were actually concerned about purity, you'd probably be using a fractionating column.

chemrox - 28-1-2008 at 16:00

I assumed he had a column of some kind and wrapping and/or heating it would solve the problem but he doesn't say that does he? He says the distillate falls back down from inside the head. So the v.p. is so low that distillation isn't starting at the operating temperature. More heat is indicated. I also wonder if the setup is leaky?

shadow - 2-2-2008 at 23:12

Thank you all for the responses.
The distillate is tap water.
The "lab" temperature has been around 50 F lately, I'm sure that had something to do with it.
The foil seemed to help.
A large coffee can on top of an electric 1500 watt stove heater(air bath) with the foil seemed to work but the output was only 1 drop every second or less.
I was expecting more.
Something cracked my 500ml RB flask in all this effort.
I sealed the system and was able to increase pressure in the system.(everything is clamped and sealed)
I also changed the condenser to one with less volume.
I was hoping to get a steady stream from the setup, I'm sure I can rig up a tea kettle to blow steam into the condenser at a far greater rate than the flask.
In Vogel's the simple distillation setup shows distillation flask with a side arm.
The side arms are usually around 7mm to 11mm. There is no mention of how the side arm is sealed to the condenser.
My condenser inlets are 24/40.
How are these pieces sealed?
thanks ahead,

evil_lurker - 3-2-2008 at 02:17

Water is hard enough to boil as it is... that said, you can't just heat a flask on top of a stove heater using an air bath and expect it to work woth a damn... basically your simply not transferring enough heat to get the job done... hell my 1L heating mantle only puts out 380 watts of power, yet it will easily heat and distill something over 200ÂșC... and thats with the power below 70%!

And I'm not sure anyone has told you this, but NEVER EVER SEAL A DISTILLATION SETUP UNLESS YOU WANT to risk AN EXPLOSION!!!!! That is probably the cardinal rul of stills.

If you want to know how a glass still looks when all the pieces are all connected, it looks like something below: