Concentric Pot/Reflux Still

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rad14701
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

Here is the new concentric (mini dephlegmator) condenser that I constructed, cleaned, and used, yesterday... The parts list is as follows...

8" x 1.25" outer water jacket
10" x 1" inner water jacket condenser tube
1.25" x .25" coolant stubs
12 gauge copper wire (~36")

The 1" inner tube has about 1/2 of a stainless steel scrubber inserted into the upper half of the tube to increase efficiency...
Parts Layout
Parts Layout
Parts Partially Assembled
Parts Partially Assembled
Soldered Assembly End View
Soldered Assembly End View
Soldered Assembly Top View
Soldered Assembly Top View
Soldered Assembly Side View
Soldered Assembly Side View
Soldered Assembly Compared To Single Helix Condenser
Soldered Assembly Compared To Single Helix Condenser
Pyewacket
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Re: Concentric Pot/Reflux Still

Post by Pyewacket »

Well, my 2 cents...I hope this thread continues. And, more and more folks learn about the concentric design concept. It makes for a nice clean little set-up. This is why I decided to build one as my first reflux. I have made countless runs on the little fella...with great success. Just looking at the above pictures pushes me that much closer to a 2inch build. I agree, Rad, it is a great idea for folks that are intimidated by the idea of a coil.

BTW, my little boiler is complete, and that little 1inch concentric looks nice and pretty sitting...waiting to make some gin essence!
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Re: Concentric Pot/Reflux Still

Post by Pyewacket »

Damn, this is such a cool still!
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Re: Concentric Pot/Reflux Still

Post by bluenose »

Pyewacket wrote:Well, my 2 cents...I hope this thread continues. And, more and more folks learn about the concentric design concept. It makes for a nice clean little set-up. This is why I decided to build one as my first reflux. I have made countless runs on the little fella...with great success. Just looking at the above pictures pushes me that much closer to a 2inch build. I agree, Rad, it is a great idea for folks that are intimidated by the idea of a coil.

BTW, my little boiler is complete, and that little 1inch concentric looks nice and pretty sitting...waiting to make some gin essence!
did you use 1", 3/4" and 1/2"?
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Re: Concentric Pot/Reflux Still

Post by Pyewacket »

Yes. Very inexpensive to build. In fact, I had several pieces already and only had to purchase maybe $30 worth of copper from Home Depot.
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Re: Concentric Pot/Reflux Still

Post by beelah »

I really like that design very much there Rad...I have originally built your smaller apartment sized hybrid still and it worked great for me, then moved on over to a bigger more basic pot still...but I like the simplicity and compactness of this new build...I am going to giver a try myself and see how it turns out.
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Re: Concentric Pot/Reflux Still

Post by bluenose »

How well with this work as a pot still? As a reflux still? Does it lean more one way than the other?
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rad14701
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

bluenose wrote:How well with this work as a pot still? As a reflux still? Does it lean more one way than the other?
The condenser doesn't lean at all, it stands straight up as depicted... It works just as well as a pot still as it does as a reflux condenser... The original head, on page one of this topic, can knock down everything my gas range can throw at it... I have not tested this new condenser insert in pot still mode as yet but can handle power all the way up until the reflux head was on the verge of flooding due to still having the original slanted deflector plate in place, as explained in the link in my signature... In true pot still mode you could also slip an end cap onto the top just as long as you aren't using a needle valve on the output...
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Re: Concentric Pot/Reflux Still

Post by bluenose »

rad14701 wrote:The condenser doesn't lean at all, it stands straight up as depicted...
I know it doesn't physically lean :)

I meant does it work better as a pot or reflux, but you answered that too :thumbup:
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baron4406
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Re: Concentric Pot/Reflux Still

Post by baron4406 »

For this stilling season i was gonna build a 3" boka, however after reading up on concentric stills I'm in love!! So with parts I have laying around I'm gonna build a 2" x 1 1/2" x 1" version about 24" long. I'm gonna extend the 1 1/2" out the top so its not sealed, and I'm gonna slot and bend inward a tab at the top of the 1" vapor pipe to make a boka style return to the boiler. Nice because i can run a short column for a pot style, and a long packed column for a reflux style. I may also build a 3" x 2" X 1 1/2" version too but I don't have 3 X 2 reducers laying around and its about $70 for two of them.
My boiler? Hmm how about a 7 gallon turkey fryer, with a 5 gallon pot turned upside down on top welded to it. Cut out the bottom of the 5 gallon pot and stick a large domed salad bowl on top upside down with the still mount welded to it.

That's what i love about this forum, you read and read and the mind juices start flowing. My goal is to make a setup I can run off propane for the summer, and electric in the winter.
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

Lots of ways to make it fittingless, baron4406... Heavy copper wire, 1/4" tubing bent into rings, work the copper to reduce it, slot the copper and bend it, etc... Think sweat equity rather than buying fittings... You can putter a lot for $70... At least I can...

What I'll be interested in seeing is how well larger bores will work and how much packing they might require... And larger bores could also employ a cap with a vent tube for reflux or just a cap for pot still...
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Re: Concentric Pot/Reflux Still

Post by baron4406 »

Threw together the 2" setup last night with a bunch of spare parts. The 2" section i think it 16", total length is longer. For the 1 1/2" tube I coiled 1/4" tube tightly around it, it fits with a little wiggling inside the 2". I slotted the vapor tube at the top and made a point like a Boka, then bent it inward and down to encourage the distillate to drop down the center packing. The center vapor tube is 1" and it extends about 2" above the takeoff point to make a well. With it setup like this I can run any column I like, empty for pot still mode or packed for reflux.
I looked around and I actually have enough parts to make a 3" x 2" x 1 1/2 " setup. I'll make that one shorter maybe a foot. I made this one kinda long thinking it would be more efficient and you could drive it harder for stripping runs. Now I'm in the mood to try it out!!
BTW not shown in the pics I have a cap with a compression fitting in it and two vent holes. The compression fitting with be a guide for a 1/4" tube that will run down the center and thru it I will thread a thermocouple so its right in the vapor stream
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rad14701
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

Looking good, baron4406... :thumbup:

Can't wait to hear a performance review... I like how you used 1/4" as your turbulator within the water jacket... I'd have gone so far as to use it in place of the reducers as well...

One other thing that I do these days is to trim down my reducers to help keep things light, short, and cleaner looking... Because there isn't any support issues like with full lengths of copper running across ceilings/floors and up/down walls we only need enough copper for the solder to make a tightly sealed join... I then have those small pieces that I can use elsewhere in my many projects... Just tossing that out there...
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

I just completed another hybrid run with the concentric condenser in my dual reducer LM head... It performed far better with the slant plate removed as it was impeding its full performance potential... I ran 3.5 gallons/14 liters of Gerber Barley sugar wash... It takes all the heat I throw at it although I wasn't running quite enough coolant at one point and that caused unexpected variations in %ABV of a couple jars in the tails... Still dialing things in with it... I ended up blending 1.25 liters of 146 proof and am enjoying some in a drink with Diet 7-Up as I type...
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Re: Concentric Pot/Reflux Still

Post by Doogie »

Good Day Mr. Rad Genius Sir,

OK, went to the scrap yard and scored some nice stuff ... unfortunately they cut up about 5 feet of 4", but I scored the following:

32" x 1" (which will be cut down for the inside of this thing)
29" x 1.5"
26" x 2"

I have some smaller pieces of each as well, and some 1/4 flexible tubing which I will use to go reducer-less between the components. I have a heavy gauge wire (12?) I will wind around the 1.5"

the question(s) I have are

1) Will this length work? Optimally? If it were you? I am running a 30L boiler.
2A) Since I lack free packing, I am thinking of modifying Pyewacket's coldfinger design with a 1/2" coldfinger with some 1/4" flex tubing running down the middle. Length on this can be all the way down the whole condenser as I was to too dumb to pick up some 1/2" while I was there and will go buy some. Would this work? Should I extend the CF into the 1" tube (maybe to the bowl?)
2B) If I was to score some packing, do I pack the condenser (1.5" in my case) or the feed/throat (1")?
3) How do I determine the height of the 1" tube inside?

Sorry for the dumb questions ... still trying to figure it out ... :crazy:
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

Doogie wrote:the question(s) I have are

1) Will this length work? Optimally? If it were you? I am running a 30L boiler.
2A) Since I lack free packing, I am thinking of modifying Pyewacket's coldfinger design with a 1/2" coldfinger with some 1/4" flex tubing running down the middle. Length on this can be all the way down the whole condenser as I was to too dumb to pick up some 1/2" while I was there and will go buy some. Would this work? Should I extend the CF into the 1" tube (maybe to the bowl?)
2B) If I was to score some packing, do I pack the condenser (1.5" in my case) or the feed/throat (1")?
3) How do I determine the height of the 1" tube inside?
Sorry for the delay in replying... It was a hectic weekend...

1.) My thinking is that the sizing is more than adequate just as long as there is some type of structured packing in at least the top portion of the inner condenser tube to help slow the vapor speed during the vapor collapse process...

2A.) Either a 1/2" or 3/4" cold finger would work... It would only need to extend part way down into the condenser chamber... Less than halfway down from the top should suffice, and perhaps only 25% - 33%... This figure could be played around with...

2B.) Answered in #1, but you pack the 1.5" condenser tube...

3.) The height of the 1" inside the 1.5" is what determines the collection well and you'd want 1 - 2 ounces of liquid spirits to collect in the well before refluxing, if you are planning on running in reflux mode as well as pot still mode... Therefore the 1" should extend between 2" - 4" up into the 1.5"...

Hope this helps...

Heck, the overall condenser might be able to be scaled down in height by half but we won't know without experimentation... I know that even this last condenser insert I made could be shorter than it is, but I don't know how much shorter... The structured packing really helps improve performance... I'd really like to build another one with downward facing slant plate baffles extending into the vapor flow to see how well that would work...
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Re: Concentric Pot/Reflux Still

Post by Doogie »

cool - thanks for the input - miscalculated the well height, nothing a sawn down coupler wont patch.

One other thing - packing - is steel wool acceptable? Only thing I can find - not S.O.S. pads, just plain steel wool for furniture finishing.

As for the height, I may saw it down in the future. I tried avoiding the couplers, but man after 3 attempts and way too much solder, I caved and bought the couplers ... lol
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

Doogie wrote:One other thing - packing - is steel wool acceptable? Only thing I can find - not S.O.S. pads, just plain steel wool for furniture finishing.
No, those are mild steel and will rust apart on the first use and contaminate the spirits... I can usually find 100% SS scrubbers just about anywhere... Wal-Mart... Dollar General... Family Dollar... K-Mart... Grocery stores...
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Re: Concentric Pot/Reflux Still

Post by baron4406 »

Will probably make a cleaning run with some bad wine on my 2" setup this thursday, I was looking at my setup and I may unsolder it and try to improve on some things. For my 1" vapor tube I'm thinking of making a deflector for it. I took a 1" cap and cut out the sides leaving two small "legs". I then wanna install it on top of the vapor tube. In theory it will do two things. One as the vapor goes up the tube it will hit the deflector and shoot out to the walls of the 1.5" condenser pipe instead of going straight up into the packing helping efficiency, second it will keep distillate from dripping off the packing back down the vapor tube. I got the idea from looking at Hookline's PDF of his still drawings. Since no one has really run a 2" version of this I'm wondering if this will improve things? I really want to keep scaling this up hopefully ending up with a 3" x 2.5" x 2" setup. I just need to find some 2.5" pipe.
I kinda realize here I'm actually downsizing when I wanted to upsize this year, even if I get the 3 X 2.5 X 2 version running I'm basically looking at the same speed/function as your typical 2" Boka. So I'm really looking at this as sort of a pot still that can provide a little reflux like an inline thumper. For a big wash like I typically run it would be way too slow, especially since I have a 2" Nixon-Stone setup already. Even so its a neat design for a very small scale and I just want to report how well the 2" version works.
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Re: Concentric Pot/Reflux Still

Post by Doogie »

Did a water vinegar test run on mine - worked fine - a few little leaks, etc, etc. Distillate coming off way too hot so today's task is to build a mini liebig ... then onto a feints/garbage spirits run ... found the "packing" - did not put pot scrubbers into the equation :oops:
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Re: Concentric Pot/Reflux Still

Post by bluenose »

Quick question on this design... since the outermost pipe is the outside jacket of the condenser, does it have to be copper? I've seen some people using PVC or similare as the outer jacket of condensing coils. I suppose there might be problems with getting a watertight seal between it and the middle pipe, but other than that...?
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baron4406
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Re: Concentric Pot/Reflux Still

Post by baron4406 »

If you can get it to seal there shouldn't be a problem.
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

bluenose wrote:Quick question on this design... since the outermost pipe is the outside jacket of the condenser, does it have to be copper? I've seen some people using PVC or similare as the outer jacket of condensing coils. I suppose there might be problems with getting a watertight seal between it and the middle pipe, but other than that...?
The issue at hand with this design is that the outer jacket is in contact with the alcohol so it should be either copper or stainless steel... If you look at the concentrics I have constructed you will see that the outer tube is what seals the unit to the condenser head section and the inner tube is actually suspended within the vapor chamber... Don't confuse concentrics with the jacketed reflux CM designs depicted elsewhere in these forums...
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Re: Concentric Pot/Reflux Still

Post by bluenose »

rad14701 wrote:
bluenose wrote:Quick question on this design... since the outermost pipe is the outside jacket of the condenser, does it have to be copper? I've seen some people using PVC or similare as the outer jacket of condensing coils. I suppose there might be problems with getting a watertight seal between it and the middle pipe, but other than that...?
The issue at hand with this design is that the outer jacket is in contact with the alcohol so it should be either copper or stainless steel... If you look at the concentrics I have constructed you will see that the outer tube is what seals the unit to the condenser head section and the inner tube is actually suspended within the vapor chamber... Don't confuse concentrics with the jacketed reflux CM designs depicted elsewhere in these forums...
I just looked at your up close pictures and I don't see how the outermost pipe is in the vapour path. It looks like the middle pipe extends beyond the outer jacket at both ends. However, it's your column so you know more about it than me.

I figured the problem would be more about sealing it, and maybe about the bottom getting too hot near the takeoff.
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Beavercreek
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Re: Concentric Pot/Reflux Still

Post by Beavercreek »

I have read somewhere that copper is needed in the vapor path. Does anyone know why, I searched but didn't readily find the answer.

bluenose wrote:
rad14701 wrote:
bluenose wrote:Quick question on this design... since he outermost pipe is the outside jacket of the condenser, does it have to be copper? I've seen some people using PVC or similare as the outer jacket of condensing coils. I suppose there might be problems with getting a watertight seal between it and the middle pipe, but other than that...?
The issue at hand with this design is that the outer jacket is in contact with the alcohol so it should be either copper or stainless steel... If you look at the concentrics I have constructed you will see that the outer tube is what seals the unit to the condenser head section and the inner tube is actually suspended within the vapor chamber... Don't confuse concentrics with the jacketed reflux CM designs depicted elsewhere in these forums...
I just looked at your up close pictures and I don't see how the outermost pipe is in the vapour path. It looks like the middle pipe extends beyond the outer jacket at both ends. However, it's your column so you know more about it than me.

I figured the problem would be more about sealing it, and maybe about the bottom getting too hot near the takeoff.
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rad14701
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

bluenose wrote:I just looked at your up close pictures and I don't see how the outermost pipe is in the vapour path. It looks like the middle pipe extends beyond the outer jacket at both ends. However, it's your column so you know more about it than me.

I figured the problem would be more about sealing it, and maybe about the bottom getting too hot near the takeoff.
Ah, I just looked back through the topic and it depends on which pictures you look at... With the complete head at the beginning of the topic the outer tube doesn't every touch vapor... However, you might have a tough time sealing other materials to copper due to differing expansion/contraction rates... For the mini-dephlegmator later in the topic the outer tube definitely contacts the vapor...


@Beavercreek

Copper removes sulfites from the distillate vapor and that is the reason why even stainless steel stills should have some copper in the vapor path... The subject has been discussed countless times...
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Re: Concentric Pot/Reflux Still

Post by bluenose »

rad14701 wrote:...you might have a tough time sealing other materials to copper due to differing expansion/contraction rates...
that makes sense

I was hoping to get away with having the middle pipe be 2"... guess I'll have to go 2" - 1.5" - 1"

what kind off takeoff rates are you getting with yours Rad?
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rad14701
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

bluenose wrote:
rad14701 wrote:...you might have a tough time sealing other materials to copper due to differing expansion/contraction rates...
that makes sense

I was hoping to get away with having the middle pipe be 2"... guess I'll have to go 2" - 1.5" - 1"

what kind off takeoff rates are you getting with yours Rad?
If you want you could try using 1/4" annealed copper instead of reducers... That would save a bunch of money and allow for a more compact size...

As for take off, I haven't run in straight pot still mode as yet because I've been using hybrid mode for speed and consistency... But with a 1.25" column my ideal take off rate is 1oz per minute with minimal reflux diminishing to no reflux throughout the run...
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Re: Concentric Pot/Reflux Still

Post by baron4406 »

Bluenose I just set up my 2" x 1.5" x 1" rig to do a shakedown run, its sitting on a 24" column. This will be my "inside" still for my basement electric setup which isn't done yet. I'll be running about 5 gallons of skanky wine, its about 14% alcohol. One thing I noticed, water jackets always fill from the bottom and out the top, and that's the way my liebig on my pot still runs. Also on a still you want the water entering away from the boiler and going towards the boiler. However on a concentric you would have to go in the top and out the bottom. Rad runs his unit that way but I notice on two other concentrics in this thread they run the water in the bottom and out the top. Is there a proper way? Both ways obviously work.
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Re: Concentric Pot/Reflux Still

Post by rad14701 »

As I mentioned to baron4406 via PM, I do run counter-flow with the water entering the top and exiting the bottom... I usually loop the exit line up over the top line and thought I had mentioned that earlier in this topic because one of the pictures was taken before the line was tied into place...
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