Concentric Pot/Reflux Still

[rad14701]

Thanks Rad for that info, which leads me into a couple more questions. I am working on my first still build and I am really fascinated with your concentric pot/reflux design. I am mostly a pot still kind of imbiber, bourbon and rum; but I want to be able to make a decent neutral for making liqueurs for the wife. I am starting with a 13 quart boiler. I can strip a 5 gal wash in 2 runs, save up the low wines for a spirit run, but still use it on the stove top. Thanks for your patience, now the questions. Will the tube dimensions of your column work with this size boiler? And now the technical one. I noticed in your pics that you coiled the 12 ga wire used in place of a reducer all the way through the cooling jacket. SInce that wire is to take up the space between the two tubes, the water must follow the coil pattern around the vapor tube. I assume this increases the cooling effects of the water flow, but is there a set dimension for the spacing between the coils, as I am sure that spacing would alter that cooling effect?

I run 8L/Q & 16L/Q boilers with the heads in this topic...

[Doogie]

Thinking out loud here ... and sorry if it has been brought up

OK, I was running in reflux mode for a BW neutral, and was collecting heads. Realizing that the heads are very compressed (20G wash of BW, low wines to 16L at 30% gives me about 500ml fores/heads), I am thinking of something.

Normally I run in potstill mode for rum (no packing) - but I think I may try this for my upcoming rum run - run in full reflux mode to compress the heads and once clear of the heads, pull the packing and go into full potstill mode. Reason is I would improve my yield of hearts because there would be less loss as the heads bleed into the hearts even in a slow pot still mode run. I will give it a try in a week or so ... but ... thoughts?

[coyojosh1]

Won't those paper clips pop off when the still get s good and hot?

[Doogie]

Nope, use a lot of them - I use them all the time.

To test their gripping power, put one on a sensitive part of yer body, say a nipple, and all doubt will be removed ..

[bluenose]

...I said it once and I'll say it again, these stills are so efficient they don't need to be very long. Even when running mine hard in tails its ice cold about 3 inches above the output in a tiny trickle of water, its why my 3" rig is gonna be shorter. My column is too short to get above 90%, another 12 inches and it would be perfect.

Baron, if you were going to make another 2" x 1.5" x 1" what would you use for lengths for the different components? How big would you make a 1.5" column?

[Doogie]

RE:2x1.5x1" - I have one of those at 24" - and I figure it is about 6" too long ...

[bluenose]

RE:2x1.5x1" - I have one of those at 24" - and I figure it is about 6" too long ...

Your column or the whole shebang?

[Doogie]

the concentric part - there is more (uprise, thermo port, collection/reflux area)

[bluenose]

is there any benefit to having a thermometer in this design? If so, where's the best place for it?

[Doogie]

my two cents is yes, as it is needed in the reflux action of this design

[rad14701]

I run mine with a thermometer because I primarily run in hybrid mode... Other times I run with a tall packed column... I've only done one run in pure pot still mode with no thermometer...

[bluenose]

do you have one mounted in it, or do you just run a probe in it?

Am I right in thinking it should go right at the top of the opening?

[rad14701]

do you have one mounted in it, or do you just run a probe in it?

Am I right in thinking it should go right at the top of the opening?

See the first picture in the first post in this topic... That's my primary configuration for hybrid mode...

[bluenose]

Doh!

there it is

[elektrosport]

Hi all,

I moved. From house to apartment and across country borders.

I'm in need to build myself a new still and I'm very intrigued by this design and it's beauty. I originally wanted to build a boka for it's simplicity but reports on this design are - to say the least - very enthusiastic!

However, parts wise and construction wise the CH design is a lot more complex and expensive. Is the design so much better than a boka, isn't it essentially a Boka, only concentric?
Would I not get more performance from sticking a 2" Boka head on my boiler, than building a 2"-1.5"-1" design? I need to run both for flavour and neutral.

Benefits are of course the lack of a wound condenser, but I foresee great challenge building this design with my soldering skills. Any tips on keeping the column/steam pipe parallel to the condenser if not using reducers (costly) - and how do I solder in the take-off tube without everything falling apart?

Anyway, great thread, great invention and innovations.


Cheers,
Elektrosport

[lampshade]

Check this out http://homedistiller.org/forum/viewtopi ... 50&t=34160

[elektrosport]

Thanks Lampshade,

That is pretty good looking - like a small steam punk gem, however it doesn't seem to fit the bill regarding simplicity. I'm sure I would have solder soup for dinner if I tried to do this one, it seems out of my league.

cheers,
ES

[Pyewacket]

My guess, you would love this still. I just want to give you some encouragement to give the soldering a try

By the time you are done, you would have learned some good skills--not really as hard as you think... Good luck to ya!

[bluenose]

I'm thinking of having a removable liebeg condenser and was thinking I'd run the coolant in the top of the concentric condenser and out the bottom on the opposite side. Then it would come from there and into the bottom of the liebeg and out the top of the liebeg on the opposite side and back to the a cooling bucket.

Does this sound about right?

[Doogie]

yup - that is what mine does - uses a 1/2" union connector for the water line, and a 3/8" connector for a slip on fit for the connection to the needle valve

[rad14701]

My coolant comes in through the bottom of the liebig, out the top, into the top of the concentric, and exits out the bottom with the line looped up over the concentric inlet...

On my last run I accidentally had the water running the opposite and it acted quirky so I quickly switched it around the right way... Running about 2 gallons of 35% low wines in hybrid mode with an ounce every 90 seconds I ended up with over 3.5 liters/quarts of 100 proof after blending and diluting... Hearts came off from 188 - 168 proof... I'll be enjoying some shortly...

[Lester]

As a follow up here, I recently ran my old single helix LM head and was shocked at how inefficient it is compared to this concentric LM head... I could barely get beyond medium heat before the wound 1/4" copper condenser couldn't keep up and vapor was escaping out the top whereas the concentric head can take full heat... Now I'm considering a concentric insert for the dual reducer LM section... I'm thinking 1" inside 1.25" with the 1" dropping slightly below the top of the vapor/reflux throat... Damn...!!! Now I have the itch to put solder to copper again...

Hello Rad,

I have a theory as to why this condenser has superior performance. Please correct me if I am mistaken. I did not see any explanation in this thread.

On a reflux condenser, if we remove the cooling water for a moment...........
This concentric design affords the vapors some room to expand into and as such the temperature of the vapor is lowered BY THE SHEER CONFIGURATION OF THE TUBING ALONE: A small tube goes into a larger tube, the vapors EXPAND. Now compare this configuration with a double-wound helix coil + coldfinger condenser inside the reflux column and you can see that with the latter the volume of the vapor in the tube is significantly reduced by the condenser, and because of that the temperature of the vapor will increase.

Now when we add the cooling water we see that we needed much less flow for the same drop in vapor temperature. Therefore, within the bounds of what can be reasonably fabricated, we should increase the volume of the vapor in the condenser to cool it so less water will be required. I think this concept was beautifully demonstrated here with this condenser configuration.

So I think condensers should be fatter than the column to make up for the space taken up by the coil. A shorter length will be needed.Just my 2c............

[rad14701]

Lester, what you are referring to would actually be vapor speed... Yes, compressing and expanding the vapor does have some impact as well but not as much as decreasing vapor speed so that there is more time for the vapor to cool and condense within a volumetric area... It has been discussed in the theories and fundamentals that for a reflux column a vapor speed of 15 - 27 inches per second is the ideal range, if my memory serves me correctly... I'm still on my first morning cup of coffee...

[Lester]

Lester, what you are referring to would actually be vapor speed... Yes, compressing and expanding the vapor does have some impact as well but not as much as decreasing vapor speed so that there is more time for the vapor to cool and condense within a volumetric area... It has been discussed in the theories and fundamentals that for a reflux column a vapor speed of 15 - 27 inches per second is the ideal range, if my memory serves me correctly... I'm still on my first morning cup of coffee...

I see what you're saying, going from a smaller pipe to a bigger pipe will slow the vapors down. I just see it in a different way. Which is the cause and which is the effect doesn't really matter.

BTW, I don't think this ideal vapor speed applies to the condenser portion of the column...... Shouldn't we have zero inch/sec right after the condenser? Otherwise there will be vapors coming out the vent. (I'm not trying to be a smart-a**, it's just that English is not my primary language)

[Tomb]

Rad:

I am trying to understand the differences between this and the reducer design.....

I understand the reducer design can easily hold 1 oz of condensate. However, a 3/4" inside the 1" condenser leaves only about 1/10 oz space per inch of overlap.
Thus a couple of inches would only make a reservoir of 1/5 oz. (is this enough to mix properly?)

How much overlap did you have in your design? (can't see from the pictures)

Tom

[RNaka]

Hi Rad,

I apologize in advance if this has already been asked but does your concentric still have a diversion plate similar to your LM reducer still? If not why not?

Thanks

Reed

[rad14701]

@Lester

No problem... The numbers I posted were for vapor speed in a packed column and that same speed is what reaches any reduced section and accelerates... You are correct that the vapor speed should be virtually zero, or negative, at the product outlet...


@Tomb
My one head has about a 4" vapor tube extending up into the condenser area... I don't recall how much it holds but I think it was close to one ounce... That is part of the reason I moved my needle valve to the bottom end of my product liebig, along with further reducing product temperature...


@RNaka

I have two different configurations... One uses the same slant deflector plate that my small scale LM rig uses... The other doesn't have any deflector but it doesn't seem to be an issue because all there is in the upper portion of the condenser is SS scrubber... Most of the condensate is running down the walls and I get very little unintended reflux from droplets coming off the scrubber...


Hope that addresses everything... If not, I can elaborate further...

[RNaka]

@RNaka

I have two different configurations... One uses the same slant deflector plate that my small scale LM rig uses... The other doesn't have any deflector but it doesn't seem to be an issue because all there is in the upper portion of the condenser is SS scrubber... Most of the condensate is running down the walls and I get very little unintended reflux from droplets coming off the scrubber...


Hope that addresses everything... If not, I can elaborate further...

Makes sense. I assume a slant deflected plate could be used on a concentric as well, just not considered necessary.

I love the simplicity of the concentric design! Gonna be my next project.

Thanks

[Doogie]

I have been using it all summer. While I made mine a bit large (2x1.5x1 @ 24"), I am very happy with this design. Simple, easy to operate, produces good results.

[bluenose]

so would anyone who's built this dare to say that this design could outperform the Boka given the right dimensions?