Page 1 of 1

Concentric Pot Still/LM Hybrid

Posted: Tue Aug 28, 2012 7:22 am
by Pyewacket
I would like to start out by saying that I am a novice. I have been running a very basic pot still and was in desperate need of an upgrade. I found Johnh89's post (http://homedistiller.org/forum/viewtopi ... =16&t=8046) where he details a concentric designed pot still that he had been running for years. There were some questions about the safety of the still due to the possibilities of pressure build up; running mash with solids would cause a puking leading to a blockage--because of the narrow spaces. Johnh89 and Master-Peter worked on the plan, and the later incantation of the still was safe--including the still is now in two parts making it easy to clean.

The other safety concern is that the take-off is above the heat source creating a possible fire hazard. I am aware, and I plan to place the parrot and collection below and far away from the stove.

As you will see, the top of the still is left open making the still safe. I made some modifications that include the addition of a cold finger (that is removable). The cold finger adds to the concentric nature of the still and may significantly increase the vapor cooling potential of the still. It may also have been a complete waste of time -- it is removable. To accommodate the cold finger I made a loose fitting couple that the cold finger could be settled into -- keeping it in a central position. At the top of the still, I dog eared the tube...again keeping the cold finger in a central position. To accommodate the cold finger I had to drill some venting ports into the steam riser. These ports will also provide the refluxing back down the column while operating in reflux mode.

A needle valve was added so the still could run in LM...

PLEASE NOTE: I have no real experience with copper soldering (outside of stained glass I did years ago). I chose this project because I had access to some of the copper cheap(relative term I know). I also figured the smaller tubes would be a good place to start -- perhaps easier to solder as a beginner. As it turns out...I learned a lot as I progressed through. I know there are better plans that have been proven time and time again. I am also aware that because of my: ignorance (new to the craft and specifically reflux designs), lack of copper working skills, and stubbornness -that- there is a good chance it will be a complete dud! Even if this does not work, it was worth it for experience sake.

The still head as shown will be placed directly on top of the boiler for pot still mode and stripping runs. I have cut an 18" section of 1" tube for the column. I plan to pack it with copper mesh while operating in reflux. I have added a thermometer port, and plan to put packing above it as well.

I am open to criticism and thoughts.

Re: Concentric Pot Still/LM Hybrid

Posted: Tue Aug 28, 2012 4:56 pm
by rad14701
Very nice, Pyewacket... :thumbup: I have copper here to make one when I get the time... I was planning on the LM modification but hadn't considered the possibility of the cold finger... Might have to try that as well... :ewink:

Re: Concentric Pot Still/LM Hybrid

Posted: Tue Aug 28, 2012 5:06 pm
by WalkingWolf
Nice work man -- looking forward to hear how it performs.

Re: Concentric Pot Still/LM Hybrid

Posted: Tue Aug 28, 2012 6:29 pm
by Pyewacket
Thanks guys, it means a lot coming from you. I am a little concerned that cool distillate might drip on the thermometer port; I am not sure if putting packing above it will be enough -- I may have to devise some sort of shield. Here is a picture of how the cold finger snaps into the the steam riser. I also added a picture of the main components disassembled before soldering.

Re: Concentric Pot Still/LM Hybrid

Posted: Tue Aug 28, 2012 9:43 pm
by Prairiepiss
PLEASE NOTE: I have no real experience with copper soldering (outside of stained glass I did years ago). I chose this project because I had access to some of the copper cheap(relative term I know). I also figured the smaller tubes would be a good place to start -- perhaps easier to solder as a beginner. As it turns out...I learned a lot as I progressed through. I know there are better plans that have been proven time and time again. I am also aware that because of my: ignorance (new to the craft and specifically reflux designs), lack of copper working skills, and stubbornness -that- there is a good chance it will be a complete dud! Even if this does not work, it was worth it for experience sake.
I think your full of shite. Because thats some mighty fine copper workin. :clap:

Interesting first build. :thumbup:

Re: Concentric Pot Still/LM Hybrid

Posted: Wed Aug 29, 2012 5:52 am
by hardballer
Can't wait to hear some results as well. I've been eyeing this design since the op and been contemplating a 2" version.

Re: Concentric Pot Still/LM Hybrid

Posted: Wed Aug 29, 2012 12:47 pm
by Pyewacket
Thanks Prairiepiss. If the soldering turned out half-way decent, it's because of Huskers/others posting on the subject. I had a lot of fun doing it though.

I plan on running the still in a couple/few weeks. I have a few things yet to line up...including waiting for the SS flux that I ordered to arrive.

Re: Concentric Pot Still/LM Hybrid

Posted: Fri Aug 31, 2012 3:45 pm
by Pyewacket
The SS flux arrived today. I spent the day finishing my boiler. Basically it is two inverted pots. The pots are from Big Lots...I payed 10bucks on sale( normally 17bucks) they are medium quality (thick enough but not too thick). It creates a boiler of about 5 gallons(could be bigger if wanted). Everything is bolted together (with SS bolts),including the 1.5 copper reducer at the top. The solder is only for sealing, not for structure. I removed the handles from both pots. Once I had the pots inverted, I redrilled 1/4inch holes and reattached with 1/4 inch SS bolts; this also acted as a way to bolt the two pots together. The only downside is that there is only a 1inch hole in which to clean, but there are plenty of tricks to do that. The upside, no need to gasket the thing.

Here are some pics.

Re: Concentric Pot Still/LM Hybrid

Posted: Mon Sep 03, 2012 7:14 pm
by Pyewacket
Here are a few more pictures. I finished the parrot, and I am running my vinegar cleaning. I am a few hours in, my wife just turned on the laundry machine which messed with my water pressure...steam is rushing out of the top of the still.

Re: Concentric Pot Still/LM Hybrid

Posted: Mon Sep 03, 2012 10:05 pm
by bentstick
Nice set-up pyewacket! :thumbup:

Combined liebig/parrot configuration

Posted: Tue Sep 04, 2012 12:48 pm
by lampshade
I like the idea of moving the liebig down to the parrot for cooling the hot distillate from a LM. (Considered that myself before. But instead of connecting a separate liebig to a separate parrot, I thought about inserting the parrot inside the liebig, as one assembly.)

Has anyone else ever done that? What were the results/pros/cons?

Re: Concentric Pot Still/LM Hybrid

Posted: Tue Sep 04, 2012 3:49 pm
by Pyewacket
That sounds like a good idea to me. I can't really think of a disadvantage (I am a newbie though), just have to have to right copper/fittings. It sounds like a slick way to do it.

Re: Concentric Pot Still/LM Hybrid

Posted: Fri Sep 14, 2012 3:30 pm
by Pyewacket
Here is an update.
I am running a low wines cleaning run (from a sweet feed batch made months ago). Things are going great, considering this is the first time the still has made alcohol. It balances nicely and stays stable at 171.6 degrees. It is producing 190 proof of cooled alcohol. It takes a very slow flow of water to keep it cool, and I have my gas burner at just above medium. I packed the column tight with copper scrubbers and went to the top of the thermometer port. It will be a slow still, but I do have it running a couple drops a second and it is still well balanced at 171.6. I will update again after I run my sugar wash and reflux the stripped low wines.

Re: Concentric Pot Still/LM Hybrid

Posted: Sun Sep 16, 2012 10:01 am
by Pyewacket
Ok, stripping runs have been made. I used the tomato paste sugar wash recipe on the boards. This produced roughly 9.5 gallons of just over 12% abv wash. I did the stripping runs in two still charges. The distillate came off surprisingly clear. I collected all the way down to 5pct abv. on both runs. This produced just over 3 gallons of 40% abv low wines. I am running this spirit run now, and I have collected 675mils of foreshots and heads and plan to use this as bbq starter fluid.

***as a side note***On my cleaning run I was using low wines that had been distilled several times. I believe this is why my ABV was running around 95%.

This sugar wash batch is right at 94%abv. I am running the still at 4-5 drops per second... I was able to accomplish this by inching up the temp in the boiler a bit allowing me to maintain a good reflux ratio. The temperature at the top of the tower is just under 171...and is very stable.

This still has a tendency to cough a bit if you push in too much heat. With 4-5 drops per second I am running my gas stove at about 75% open (medium high). I figure it is the still way telling to back the hell off...and I oblige.

Since I increased the heat a bit, my ABV increased a touch... I would call it 94.5% abv. This does amaze me considering my lack practical experience...and that I haven't done any tweaking of any kind. At this rate it looks like it will produce 1/2 gallon every 90minutes. Seams slow to me, but I really don't want to push things...all things considered.

I think scaling this up to 1.5inch would my next reasonable step. I will update again when the run is complete.

Re: Concentric Pot Still/LM Hybrid

Posted: Sun Sep 16, 2012 10:36 am
by bentstick
Sounds like you are on a roll, you are in it now, no hope,another soul for the stillin arts! :thumbup:

Re: Concentric Pot Still/LM Hybrid

Posted: Sun Sep 16, 2012 11:08 am
by Pyewacket
Haha, you aren't kidding. The other day some plumbers were wheeling around a cart full of 2inch copper pipe/fittings to fix the water tank at our local YMCA. It stopped me in my tracks...I damn near complemented them on it!

Re: Concentric Pot Still/LM Hybrid

Posted: Sun Sep 16, 2012 3:37 pm
by Pyewacket
I finished up my run a little bit ago. I ended up with just under a gallon of 94%-95%ABV. After the still became hard to balance, I opened the valve, turned up the heat and collected down to approx 5%ABV tails...about half gallon that is going in the feints jar.

In conclusion,
1)the still was very easy to run
2)only needed to take it to 100% reflux a few times toward the end of the run.
3)Stable, with very little fidgeting.
4)She gets a little cranky when you push too much heat in her.
5)She required very little water flow to keep the vapors down.
6)Heads were easy to clear...The spirit is nice and clear...will not require filtering.
7)As soon as I opened the valve up (when I finished reflux) ABV dropped rather fast...getting some stinky stuff quickly...faster than I thought. I feel like it did a good job compressing the tails.

These are just some of my thoughts as I try to understand things a little better.

I really do want to scale this thing up to 1.5 at some point.

I am looking for any pointers,ideas and criticisms that you folks might have...to fine tune or otherwise make it or me perform better.


Thanks...