Sciencemadness Discussion Board

The perfect washbottle - which one should I get?

Gargamel - 8-7-2021 at 04:56

I already have two of that kind and an improvised one.

I found that a mere pipe does not create a very good contact, the bubbles are big and get through in no time. No problem with ammonia, but there are more challenging things.

I want better diffusiuon, and I I also want the flask to be vacuum proof.
Some bottles have a pipe with many small holes, some have a piece of white ceramic. I guess the ceramic is better, but how much better? And how does it react to concentrated acids ect?

PS:
my opld one looks like this:
https://www.corning.com/catalog/cls/products/p/pyrexBottleGa...

Do you think it's vakuum proof?

And while seeing the picture, I've got another question:
that little ball in the feedpipe - what's it's function?

unionised - 8-7-2021 at 08:52

A frit on the end of the pipe to break up the gas into many small bubbles helps.
You can get them made from borosilicate glass so that's OK with most acids.
The bulb in the outlet is to try to burst bubbles that get there.

I'm not sure if they still make the ones which i found to be the best.
They feed the upward gas into a spiral channel so they rise slowly.
You get a long contact time, but not much back pressure.

If something does not say in big letters that it is safe for vacuum use, you should assume that it isn't.

Dr.Bob - 8-7-2021 at 16:51

The Corning design should hold a vacuum if you grease the tapered joint. Those are excellent ones.

I have a few of those left if you are in the US and looking for some. I have a few other designs as well, but like the Corning ones best.

unionised - 8-7-2021 at 23:52

Fundamentally, if you want to remove a gas that is dissolved in liquid, you apply a vacuum.
What's the point of a low pressure bubbler?

Vacuum traps are designed differently. notably you wouldn't include a frit.
Nor can you have a bubbler- there's not enough pressure to blow bubbles.

Gargamel - 9-7-2021 at 13:24

Well in fact I had the thought in my head to double use the bottle.

First to wash gases, and secondly to protect a vacuum pump (that I do not have yet;)) from stuff like acid vapours and from sucking in liquids that find the way into the sucking train.

I think thats what people usually use a woulff type bottle for...


SWIM - 9-7-2021 at 15:23

Quote: Originally posted by Gargamel  
Well in fact I had the thought in my head to double use the bottle.

First to wash gases, and secondly to protect a vacuum pump (that I do not have yet;)) from stuff like acid vapours and from sucking in liquids that find the way into the sucking train.

I think thats what people usually use a woulff type bottle for...




That old bottle you showed us should work okay for most of those things.

Back when I had a limited set of glassware I used to just use a filter flask with a single hole stopper and glass tube in the top.
Kind of a cheap way to do it, but it does give you lots of volume for suckback problems.

Mateo_swe - 12-7-2021 at 13:11

If you want really small bubbles there is these all stainless steel diffusion stones used for homebrewing.
Look at ebay.
I have one 0.5 micron and one 2.0 micron variant that i will use for some ozone experiments.
I add a pic.


0.5 and 2 micron Diffusion stone.jpg - 43kB

draculic acid69 - 13-7-2021 at 01:39

SS isn't really an Ideal material for what most amateurs/home chemistry ppl
use bubblers for. Acid gases / chlorine will mess with SS

Gargamel - 15-7-2021 at 12:09

No SS indeed.
Quote:

Back when I had a limited set of glassware I used to just use a filter flask with a single hole stopper and glass tube in the top. Kind of a cheap way to do it, but it does give you lots of volume for suckback problems.


You mean a sucking flask for buchners! Why did this not occur to me in the first place :P
I'm well equipped in that regard, and they are definitely vakuum proof.

Thanks for the tip :)