Sniffity - 30-11-2019 at 16:08
Hey,
Just noticed a slight peculiarity when browsing for condensers..
When looking at 24/40 ones, I find this design constantly:
https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcSE2N...
However, when looking at 14/20 models I find this design:
https://i.ebayimg.com/images/g/xqgAAOSw~4tab2N7/s-l300.jpg
Notice the difference near the top; there seems to be a wide open space at the top in the 14/20 designs, most I’ve found have this same feature.
I’m guessing it’s got something to do with the way the glassware is made, but I’m not sure. I’m curious as to why this is so.
If anyone’s got any input or ideas, they’d be highly appreciated!
-S
[Edited on 1-12-2019 by Sniffity]
[Edited on 1-12-2019 by Sniffity]
G-Coupled - 30-11-2019 at 16:16
Oh yeah - I'd like to know what's up with that, too. 
Are they Chinese glass?
Sniffity - 1-12-2019 at 10:22
That’s the odd thing; not all of them are:
https://www.sigmaaldrich.com/catalog/product/aldrich/sync351...
Dr.Bob - 1-12-2019 at 15:20
All of those are fine, there are dozens of variations of reflux condensers, I like the 14/20 one shown below. The open space should never be used if
you are not overloading the condenser, but it may be there as a head space in case some solvent gets past the coils, so contain the vapors and allow
them time to condense. That 14/20 design works well, I have used them for years. I think I have some of them in 14/20 for $20 plus postage. The
24/40 one shown is not a common design, likely Chinese or other source. Most 24/40 reflux condensers are straight designs, without a bumpout.
https://i.ebayimg.com/images/g/xqgAAOSw~4tab2N7/s-l300.jpg
Sniffity - 1-12-2019 at 22:22
Hmm... I agree that it’s unlikely anything will get past the condensing coil, but assuming it does: how would the headspace contain the vapours? If
they get to that point, there’s nothing further to cool them, they’d diffuse out, I think.
I agree once again that it’s unlikely this will ever happen.
Yet I’m still curious as to why that space is left “empty”, as opposed to taking advantage of it by getting more coil into it. From my search,
this is only common in 14/20 designs, which leads me to believe that it’s related to the way the glass is made.
Could anyone confirm this?
From a practical standpoint I know it works just fine. I’m just curious as to why it’s designed that way! 