tomholm - 16-6-2017 at 07:56
Elemental Scientific has acquired a significant amount of used and new unique glassware. These items are being listed on our website in our Used Glassware category. Some of it, I'm having trouble identifying. Anyone know what this is? There's a reservoir inside, so it can be used
for condensing or controlling the temperature of a liquid.
elementcollector1 - 16-6-2017 at 07:59
Maybe it's used for reflux? Hard to explain why the top and bottom are joints and not hose barbs, though.
kavu - 16-6-2017 at 08:25
It's an Abderhalden's drying pistol. Nowadays a fairly obsolete piece of equipment.
The male joint in the end is connected to a vacuum source, the male joint on the side is connected to a flask with solvent of suitable boiling point,
and finally the female joint is connected to a reflux condenser. Boiling solvent will heat up the material placed inside the inner tube and drive off
residual solvents and/or moisture.
[Edited on 16-6-2017 by kavu]
alking - 16-6-2017 at 08:28
Yeah, I can't really imagine what that could be used for. Since the top larger joint is a male it's likely pictured upside down, or simply designed
very poorly, both seem likely.
Regardless the two side joints would be horizontal and that's just a bad design if you're supposed to pass anything through there but air, maybe it's
a leak and/or frustration condenser, you know, an adapter designed to slowly leak and frustrate the chemist.
edit: Ah, a drying pistol makes sense now that I see one in action. So it looks like it's missing the vacuum/desiccant adapter.
edit2: Doesn't sound too useful unfortunately. Unless I am misunderstanding the sole purpose is to utilize a solvent's BP to regulate the temperature
of what you're drying. These days now that we have electrically regulated heat sources the whole thing could be replaces by a flask and vacuum adapter
immersed in a water bath. It seems pretty wasteful since it's not even designed to reflux the solvent. You could rig up something to condense it
'upstream' and feed the condensate back into the pot though.
[Edited on 16-6-2017 by alking]
Geocachmaster - 16-6-2017 at 08:35
Kavu is right, it's a drying pistol. It is intended to be used like this:
A liquid is placed in a flask and connected to the side male joint. It is then refluxed, the hot vapors passing by the sample placed in the inner
tube. A condenser connects to the other joint on the side. The large male joint allows the sample to be inserted and it also connects to a chamber
filled with dessicant. P2O5 is usually used for water and paraffin wax for organic solvents.
alking - 16-6-2017 at 08:39
Looking at that picture it does seem they attached the condenser directly on top. That just seems very inefficient to me though, am I wrong? The tube
will be heated, but you're also dripping your condensate right back on it. It would be much more efficient to condense it in a loop and feed it into
the bottom of the pot, you still have to reheat the solvent, but your tube never gets cooled and will be held at or near the BP.
Geocachmaster - 16-6-2017 at 08:47
Other have thought that before, alking. Here's one selling on eBay with exactly the design you mentioned:
Dr.Bob - 19-6-2017 at 07:05
Drying pistol it is, if you need more, I have a few also to get rid of. As stated, the idea was to use the BP of a liquid to create a very specific
temperature inside the chamber, so you could heat samples under vacuum to dry them before sending off for analysis. (Typically elemental analysis,
which requires dry samples.) Given the drop in people running elemental analyses, the ability to buy heating ovens cheap, and the issues with
refluxing solvents, these are nearly obsolete now.