wrote on 9/8/2017 8:58 AM:
On Thursday, September 7, 2017 at 8:11:13 PM UTC-4, Danny D. wrote:
Anyone know if saturation by carbon dioxide has a time constant?
http://i.imgur.com/MSm72Tp.jpg

Swirling seems to work with these 2L bottles, where I mix 4 degrees C (or
about) water under 30 psi CO2 pressure (or about) for about 10 minutes per
bottle (give or take) because I assume "diffusion" is slow; but is
diffusion slow, or is it (nearly) instantaneous?
http://i.imgur.com/gUJnLk3.jpg

Anyone have experience with how long it should take for carbon dioxide to
diffuse into the surface layer of water, and then to diffuse deeper if I
don't swirl?

If I just plug it in for a few minutes, the water isn't bubbly enough.

If I leave it for an hour, two things that are bad happen:
1. I lose CO2 because my connections are imperfect, but worse,
2. The water warms up (meaning it will hold less C02).

If you don't know whether the diffusion "should" be instantaneous or if
there is some kind of pragmatic coefficient, that's OK. It works.

I just don't know what I'm doing and why.
Do you?

Diffusion is slow*. You can calculate it. There is probably some
thermally driven currents in water that will mix things faster.
To get an idea of speed put a drop of food coloring into water.

George H.
(*I'm not sure about water, but I mixed up my own tanks
of gas for a CO2 laser and it took weeks to diffuse...
surprised the hell out of me.)

Yes, it can be slow compared to many uses of the word "slow". I've brewed
tea in glass and watched the tea diffuse. Since the water is hot the
diffusion is faster and the cooling causes some current, so you can actually
watch the tea colored water fall out of the tea bag. At 3 °C diffusion will
be much slower. Stirring mixes up the water to bring fresh to the surface.
Better yet is to push the gas through the water as tiny bubbles which is
what they do at a soda fountain. Nearly instantaneous diffusion.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998