While looking over craigslist, I found this Mad Scientist thingy.
Can anyone identify it?
The guy giving it away doesn’t know what it is, and well, I’m just curious.
Definitely a cold trap, most likely for producing dry air. You put dry ice or liquid nitrogen in the Dewar flask, drop the the glass elbow down into it, and the moisture and other volatiles are chilled out of the air passing through the tube. The bluish crystals are probably Drierite or similar with a color indicator of the moisture absorbed so that you can tell when to change them.
Brian
So, what is its practical use?
Freeze drying, or lyophilization.
You put a cold trap between whatever it is you want to freeze dry and your vacuum pump. It traps water vapor, or other nasty liquids, before they can get into your pump.
Of course, the idiot graduate student who used the lyophilizer before you needed it forgot to put dry ice in the trap, and now the pump oil is a syrupy emulsion of water, benzene, and hydrobromic acid. With luck, the pistons aren’t pitted, and you can strip the whole thing down and get it running again in less than four hours.