Otis’ Vacuum Still Build

Vapor, Liquid or Cooling Management. Flutes, plates, etc.

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bronctoad
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Re: Otis’ Vacuum Still Build

Post by bronctoad » Fri Mar 08, 2019 12:49 pm

forgive me for being quick,
but I think if you did put the buffer tank from the drawing in your system some where in the red hose
it could possibly fix, or help 2 problems.
1) cooling of your air condenser
2) amount of vacuum held in reserve for the run.
nothing sure just food for thought.

bronctoad

OtisT
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Re: Otis’ Vacuum Still Build

Post by OtisT » Fri Mar 08, 2019 1:33 pm

bronctoad wrote:forgive me for being quick,
but I think if you did put the buffer tank from the drawing in your system some where in the red hose
it could possibly fix, or help 2 problems.
1) cooling of your air condenser
2) amount of vacuum held in reserve for the run.
nothing sure just food for thought.

bronctoad
Thanks bronctoad. I think you are right about adding the buffer tank. With a high pressure needle valve between collection tank and buffer tank, I could vacuum down the buffer tank first then bleed vacuum slowly with the needle valve so the second condenser is not overloaded. An added benefit is that adjusting vacuum mid run does not involve a pump. Much safer. (I’ll need to think about how that second tank may still fill with vapor)

I still need a bigger volumed second condensor or bleeding would be extremely slow. I’m thinking of my 2” dimroth for this, stuffed with copper mesh.

My keg boiler or thumper could be my buffer tank. Would only need to pick up two more FNTP threaded ferrule caps for the I/O. Either keg would have a bigger volume than the collection and boiler system combined.

I have a high pressure regulator gauge and valve set that may work nicely between the tanks. One gauge already measures vacuum down to -30 psi. I would need to replace the existing second gauge with a second vacuum gauge for the input side. It will take two hands to operate this. One on the condenser and one on the bleed valve.

Otis
Otis’ Pot and Thumper, Dimroth Condenser: Pot-n-Thumper/Dimroth
Learning to Toast: Toasting Wood
Polishing Spirits with Fruitwood: Fruitwood
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Oldvine Zin
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Re: Otis’ Vacuum Still Build

Post by Oldvine Zin » Tue Jun 25, 2019 5:31 pm

Hey Otis, hows this project going? With my new interest in rice based alcohol I was told that a vacuum stilled sake makes for a good soju. The lower temp keeps a lot of the nice rice flavors . Thinking that I might have to build one.

OVZ

OtisT
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Re: Otis’ Vacuum Still Build

Post by OtisT » Tue Jun 25, 2019 7:50 pm

I did a few other short runs and kept having that slow leak I could not seem to stop, so the runs were limited to 20 to 25 minutes once I reached a boil before I lost too much vacuum and lost the boil. I did vacuum it down further and with ethanol boils around 130 F. I saw no reason to vacuum more due to the leak.

I decided to put this on hold with other priorities, but intend to build a new dedicated unit, rather than try to make my mini to one more trick.

Changes:
The boiler was fine, but I do need to replace the factory keg ferrule with a real ferrule for a better seal.

The collection tank worked just fine, no changes.

The new copper parts of the system will be a dedicated one piece unit so I no longer need to deal with the unions leaking. I tried to make my mini pot still parts work for this too and it was just too much with all those joints. The manifold will be more complex to support a vacuum buffer tank, with its own valve and a second vacuum gauge for that tank. The pump vapor condenser will need to be beefier than what I made on this first one too.

I can share details at our PNW meet-n-greet if you want. I know what I need to do, but just need to find the time and priority to do it.

Otis
Otis’ Pot and Thumper, Dimroth Condenser: Pot-n-Thumper/Dimroth
Learning to Toast: Toasting Wood
Polishing Spirits with Fruitwood: Fruitwood
Badmotivator’s Barrels: Badmo Barrels

manu de hanoi
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Re: Otis’ Vacuum Still Build

Post by manu de hanoi » Thu Aug 29, 2019 4:32 am

TL;DR
In vacuum it's very hard to get fractionation, you should remove the reflux condenser

OtisT
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Re: Otis’ Vacuum Still Build

Post by OtisT » Mon Sep 02, 2019 2:08 pm

manu de hanoi wrote:
Thu Aug 29, 2019 4:32 am
In vacuum it's very hard to get fractionation, you should remove the reflux condenser
Hi manu de hanio. That is not a reflux condenser, and there is no packing. In summary the system is a pot still with a vertical Liebig product condenser. The extra coil of copper wrapped around the liebig’s outer jacket was an earlier attempt at a second condenser between collection and the vacuum pump. It was not powerful enough for that purpose so I don’t use it, but it’s soldered there so it stays for now. ;-)

Otis
Otis’ Pot and Thumper, Dimroth Condenser: Pot-n-Thumper/Dimroth
Learning to Toast: Toasting Wood
Polishing Spirits with Fruitwood: Fruitwood
Badmotivator’s Barrels: Badmo Barrels

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