corniluis kegs and vacuum safety?

[rubber duck]

Does anyone know how much vacuum I can put to a corniluis keg before I get into trouble?

[skow69]

27 inHg. 26 inHg with any margin of safety. This happened at 28.

I thought somebody fired a cannon.


Here is the new, improved model. No worries now.

The black band is a strip of 1/4" plate, sheet soldered all the way around.
The band below it is a heater.
I've had it up (down) to 29 inHg (~25 torr).

[rubber duck]

So a corniluis keg really isn't going to get down far enough to do much with out some modification. Is that about right?

[pfshine]

27 in hg will bring the bp of water down to 110f. Or there abouts.

[skow69]

Oh I wouldn't say that, duck. A 10% wash boils at 200f at atmosphere. At 26 inHg it boils at 117f. A reduction of 83 degrees can be useful. At 27 inHg it boils at 105f. At 28 it boils at 93f, but your distillate, at 55% ABV, boils in the collection vessel at room temp and disappears up the vacuum line. So that is a natural limit also.

We should remember that we can't change the latent heat of vaporization, so time and energy savings only happen in the heat up, but lower temps have other advantages, too, like less chance of scorching. If I lost my Corny boiler tonight, I would make a new one tomorrow.

Here is the curve for boiling point by vacuum for a 10% wash.

You can see the knee of the curve lands about 28 inHg so anything beyond that, shit starts changing fast. Perfect vacuum is 29.92, at which point everything would boil at any temperature. Har.

[rubber duck]

Ahhh now I see, I was thinking water not alcohol durrrr. So a corniluis keg will get the job done.

[skow69]

It does for me. But a lot of people think I'm crazy, too.

I ran the pot dry one time when I was experimenting with absinthe recipes. A soccer ball size blob of herbs just rinsed out. They didn't even smell bad.