A Nifty Piece 'O Glass

something at work wasn't working... so i changed what i was using. now i am using what is called a soxhlet extraction and so there is this nifty piece of glassware that i get to use (called a soxhlet extractor, of course). typically, this setup is used to extract something (well call it stuff 1) from something (plastic, a mix of compounds, whatever) when stuff 1 is only very slightly soluble in a solvent. when something is only slightly soluble you pretty well have three options (1) use a ton (almost literally) of solvent to get miniscule quantities of stuff 1 (2) give up or (3) use a soxhlet extractor.
here's the set-up and the run down.

1. knob to turn up stirring. this is a magnetic stirrer so you just turn on one magnet to spin and if you put a magnet in your solution that magnet will stir too. way easier then trying to stir by hand (esp. if overnight or in my case it looks like i'll be doing this several days).
2. knob to turn up heat. gotta love the combo of a stirrer and hot plate. this baby is expensive ($420 if i need a new one), but worth every penny. there are some super spiffy digital ones that monitor and maintain temperatures for you, but i haven't had a problem with just setting the knob on mine and monitoring it for an hour or two to adjust the temp at first.
3. some sort of liquid bath to keep the temperature even and distributed on my flask. in my case i am using water since my solvent boils at a measely 31.7 °C (89.1 °F, in other words a nice summer day). but i do have oil baths to use if i want a warmer temperature. the little bubble looking thing is a teflon coated magnetic stir bar.
4. a round bottom flask (round so there are no corners for things to get trapped in and to promote even stirring) filled with the solvent i am using and contains a teflon coated magnetic stirring bar also. teflon is good since it is very un-reactive and stuff doesn't stick to it and it does well in high and low temperatures. stirring is needed to promote even boiling (otherwise large bubbles form and that can get problematic). the round bottom flask has what is called a ground glass joint at the top with a standard tapper. basically this means that various bits of glassware can be combined in multiple ways and still make a good seal.
5. here's the beautiful piece of glass. vapor (from the boiling solvent) enters the bottom portion, through the tapered ground glass joint, and then goes into two tubes. one of the tubes ends up not really collecting vapor, so we'll ignore it for now. the tube on the far right is where most of the vapor goes. it travels up the tube and then into the main chamber of the soxhlet extractor. (we'll come back to 5 in a moment.)
6. a water jacketed condenser; this is also a nifty piece of glassware. there is a tube in the middle where our solvent vapor enter (again via a ground glass joint) it then condenses in this tube because there is an outer 'jacket' with cold water running through it. so the cold water absorbs heat from the vapor, the vapor the falls to a temperature below the boiling point and condenses into a liquid. (note that the water comes in via a hose at the bottom and exits via the top. the water also never comes in contact with the solvent, there is a layer of glass between the two chambers.)
back to 5. once the vapor condenses it drips back down into the main part of the soxhlet extractor. this chamber will contain a thimble (usually made of cotton and cellulose) which contains the poweder or sample of whatever you are trying to extract stuff 1 from. stuff 1 and its surrounding material can't go through the 'paper' unless it dissolves in the solvent. once the thimble and the volume outside the timble fills up with solvent to a point that is at the top of the second tube (smaller and makes a u-turn) liquid starts dripping down the second tube back into the round bottom flask. this liquid contains some of stuff 1 dissolved in it.

once the liquid with stuff 1 in it returns to the round bottom flask it starts to boil again. but stuff 1 doesn't boil, instead it stays in the round bottom flask. so 'clean' solvent vapor travels up the outside tube again, condenses, picks up more stuff 1 from the timble, and drips back to the flask. repeat for a while; ta-da you have extracted stuff 1 even though it is only slightly soluble. and you did so without using a ton of solvent since the solvent self recycles through the process.