Small concentric build

[Neuspeed61]

Hello,

I stumbled onto several posts depicting concentric reflux columns and decided I want to build one. I have only dealt with potstilling up to this point as I didnt want the hassle of winding a coil. After seeing the simplicity of the concentric though I'm wanting to try one.

I figure I'll go small with the first to see how I like it.
I'm thinking of 1 inch packed with copper mesh down to .5 inch throat. Condenser will consist of .75 inch sleeved by 1 inch, I'm thinking one foot of 1 inch sleeve.

After reading and seeing others calculations I will need roughly 7.5 inches of the half inch pipe inside the 3/4 to achieve a 1 ounce cup. Does the top of the half inch inlet need to be below (or at the base) of the 1" outer jacket?

Thanks for any thoughts/advise.

[ben stiller]

[align=][/align]Great choice building the concentric in my opinion LOL. I run a 1.5 inch concentric packed with marbles and am pleased with it. If at all possible go with a bigger still. It will produce a little faster. Not exactly sure what you are asking about the top half of the half inch inlet? It should be flush inside the bottom reducer and extend into the condenser enough to give the cup volume that you are looking
for. Most use 1 to 2 ounces. The link below should answer most if not all of your questions. I highly recommend wrapping a wire around the inside of the condenser as shown in the thread. Don't skimp on condenser height if you have the room and also make your packed
column 20:1 ratio diameter of column to height. Really easy design to build and pretty easy to learn to run. How do you plan to heat the boiler and what size are you shooting for?

http://homedistiller.org/forum/viewtopi ... 50&t=36382

[Neuspeed61]

Yes that is the thread that turned me on to become interested in reflux again. My first attempt was with my Brewhaus PSII...and I was not a fan, lol. I guess I over complicated the question by adding too much information. What I am asking is:
the inner piece that is extending into the condenser, should the tip be at height (or lower) than the height of the bottom of the liebig sleeve? I figure I dont want to be shooting in hot vapor half way into my condenser...but being my first venture into LM builds I'm not sure if this matters or not.

[StillerBoy]

Having used the concentric for over the past five yrs in 1.5", 2", and 3" column configuration.. I would recommend that you consider 1.5" build instead of what you are considering, at best it will work quite well on a 12 - 16 liter pot/boiler..

It 's not that it will not work, but you will not get the performance from it unless you have the intend to use it on a 10 liter pot, and even at that, the performance will be very slow..

For spirit runs. the 2" works at it best on a 30 liter boiler, and the 3" on a 54 liter boiler..

Mars

[ben stiller]

. I guess I over complicated the question by adding too much information.
the inner piece that is extending into the condenser, should the tip be at height (or lower) than the height of the bottom of the liebig sleeve? I figure I dont want to be shooting in hot vapor half way into my condenser...but being my first venture into LM builds I'm not sure if this matters or not.

Confused again. What are you calling the liebig sleeve? The tube needs to extend into the condenser to equal at least one ounce of collection. An advantage of the 1.5 inch column is that you will only need to extend the tube roughly 4 inches to get 1 ounce of collection. The condenser on top of the column is referred to as a concentric condenser. I also run a liebig product condenser like
Rad did in his apartment still. Not trying to correct you just want to make sure we are on the same page. This will be fun to watch
you build this and learn to run it. Also look at Pyewacket's build to help get some ideas.

[Neuspeed61]

I realize it sounds small...when I build I first build small, trial size if you will. It allows me to test drive it and see if I like the results on a small scale. My first build was a simple pot, 4 gallon SS Stockport with lid. Then came the 2 inch stripper on 15 gal keg, that I built obnoxiously large, but hey, copper porn.
Then came my 5 gal brioler to 2 gal thumper...found out I love thumpers so then it was a 15 gal keg to 7.5 gal keg thumper.

That's just the way I like to do my hobby, test it small scale and if I like it then put money into a larger one.

[Neuspeed61]

Sorry, trying to convey what I'm a little unsure of is difficult...I will try to more properly describe.
The condenser head is comprised of an outer sleeve with a smaller diameter inner pipe with water flowing between the two. Inside the inner pipe there is a smaller vapor pipe comming in from the column. The cup is comprised from the space between the vapor tube and inner pipe of condenser. The length of the vapor tube dictates the volume of the cup. Basically what I'm trying to figure out is does it impact performance in any way if the inner vapor tube stands at a higher point than where the water is flowing outside of it.

[still_stirrin]

...Basically what I'm trying to figure out is does it impact performance in any way if the inner vapor tube stands at a higher point than where the water is flowing outside of it.

Nope.

Your concentric reflux condenser is liquid cooled. As a result, it will conduct heat from the rising vapors quite readily. So, the water jacket will work even if the vapor tube (throat) extends upwards beyond the water jacket. The copper walls will pull the heat out of the vapors and the vapors will condense on the RC's inner wall, dripping down to the collection cup.

I didn't put an "umbrella" on my vapor tube as some have simply because if some condensate were to drip down the center of the throat, it would return to the column as reflux anyway. But, in actuality, the condensate forms on the RC's inner wall, not in the middle of the upper vapor chamber.

One thing to keep in mind, is that the vapor speed will slow as it passes out of the throat (venturi tube) and into the upper chamber. When it does that, it'll cool and start to condense along the walls.

Don't make the liquid cup larger than 1 ounce. In fact, with the scale of concentric column and head you're building, I would not make the liquid cup larger than 1/2 ounce. If it is too large, it will smear the fractions...foreshots -> heads -> early hearts. The smaller cup allows a finer degree of collection and discharge through the liquid modulation control valve (needle valve).

In conclusion, I agree with other commenters here that your 1/2" throated 1" over 3/4" RC condenser is too small. It'll produce distillate for you...but very slowly. And your boiler power will have to be controlled very carefully so you don't overdrive the reflux condenser. Personally, I wouldn't make a reflux column smaller than 1-1/2" with a minimum of 3/4" for the vapor (throat) tube.
ss

[still_stirrin]

If you're using a bell reducer on the top of the column to where the throat tube is, I recommend extending the bottom of the throat tube down into the column below the point where the bell reducer (hub) solders to the throat. Otherwise, the condensate will "wick" back to the column walls instead of falling back into the center of the column where your packing is. Extending the throat tube will give the condensate a "jumping off point" from the lower edge of the throat. That's the way I built mine and it works well.

Incidently, you don't need a "trial size" concentric. Build it to manage the boiler heat input with the proper vapor speed (refer to the calculators on the parent site). Vapor speed is fundamental and critical to proper reflux action as well as production efficiency. Do the math before you begin soldering anything.
ss

[Neuspeed61]

Thank you very much Still Stirrin! That was exactly what I was wondering about. I guess I could forego the trial build and do a full size. I have 5 feet of 2 inch, and 10 feet of 1 inch sitting in the shed. I also have a couple of kegs with element fittings welded in, one with a single and one with two. And yes I will be using bell reducers, so the advice with the lower throat extending into the column is much appreciated!

Seven years running pot stills and I'm starting to feel like I'm starting from scratch again, lol.

The build will start to commence this weekend...assuming I can manage to avoid getting forced to go to the in-laws for new year...

[still_stirrin]

Definitely do the 2” column. And use a 1” throat. You can get some 1-1/2” for the inner shell of the reflux condenser and you’re all set. The collection cup height is about 2”, I think. Maybe just a little bit longer.

I used Rad’s “reducerless” design to transition between the 1-1/2”OD to 2”ID. I flattened some 1/4”OD soft copper tubing and made a donut to slip in between the pipes. Flux it up and solder in place.

And don’t forget to add the spiral of wire (or flattened tubing) between the condenser’s inner and outer wall...in the water jacket. It will significantly improve condenser efficiency.

The LM takeoff is 3/8”ID soft copper with a needle valve to regulate the product flow. Because the liquid will come off hot, I added a secondary product Liebig on the liquid line. It’s a spiral of 3/8” soft copper inside a vinyl hose as the water jacket. It really doesn’t need much water flow at all to cool the product as it flows. It works great.
ss

[still_stirrin]

Combi LM/VM head

This is my concentric head:
-> You'll see the liquid line Liebig spiral on the right.
-> The branch line of the 2" DWV Tee goes to the VM valve, a 1" ball valve, and feeds into a shotgun condenser.
-> The vapor tube (throat) in the concentric is 1"OD and the outer shell of the concentric RC is 2"OD.
-> A Triclover ferrule adapts to the 1 meter (39") tall 2"OD column.
-> The 1/2" copper pipe is water feed and discharge lines, also the SS braided hoses too. I have water flow control (ball) valves on each condenser so I can regulate the coolant flow (to minimize the flow, as possible).

"Food for thought".
ss

[zapata]

You habe a PSII and are building a 1" diameter column?
Why not fix the PSII? Stock it's more than capable of outperforming virtually any 1" column. And with some mods it could easily be made into a beast.
I guess it does sound like you know what you are building is practically a waste, you just want to play with it. Which I guess there is some value to. I just wonder why not play with something a bit more practical?

[Neuspeed61]

Zapata, yes I have a PSII. I realize it is capable of outperforming a basic pot still. I ran it a couple times packed with raschings ( I probably misspelled that) and just had a complete pain with flooding, not to mention it looking like some bastardized R2D2..rubber bung...ECT. They are nice to learn on, and fine for casual. And again, the way I generally do stuff is build small and test. If I like it I then build functional. Funding is not an issue so I dont care about the additional costs, and keeps me busy...always tinkering. I dunno, kinda hard to explain, but it keeps me happy when I'm putting something together, regardless if it is attaching to a 2 gal pot or a 15.5 keg.

[StillerBoy]

2" concentric in storage form

This is the 2" concentric setup I use most with a take off rate of 3.5 p/h liter at 95% abv in the body section.. most versatile of all my column setups..

Adjustable from 24" to 36" column
2" outer over 1.5" inner x 12" condenser
1.25" x 5" vapour throat body
60 ml cup with 3/8" valve

Mars

[Neuspeed61]

Both of those are very nice looking setups!

[ben stiller]

How are you guys sealing between the modular column sections?

[StillerBoy]

How are you guys sealing between the modular column sections?

I have a 1/4" ring solder just at the join on the column.. the ring sit tight to the coupling..

I wrap 2 turns of 1/2" teflon tape, half on the ring, half on the column, then use 3/4" tape with 2 turns tight just under the ring and continue down the column, overlapping 50% to the end or about 3 additional turns.. no issues with sealing if done in the manner describe.. using it just about every weekend, I used about 10 -12 rolls of 3/4" per year..

At the time I needed 4 tri-clamps, and the extra cost vera couplings lose.. recently purchased some 2" tri-clamps with ferrules at a very good price like 5 dollar a piece, so in the future I will put tri-clamp..

Mars

[Neuspeed61]

So I finished the build for the most part. I want with 2 inch column 30 inches tall, 1 inch throat into 1.5 inch with 2 inch outer water jacket. All that's left needed is a takeoff cooler. I'm a little concerned about the weight of a small liebig hanging off a 3/8 tube soldered with home depot solder. Any opinions as to how much weight they hold? Kinda wishing I had brazed the takeoff in now...

[zapata]

The tube could hold 50+ pounds? If vertical. It's what you soldered it into that is the weak spot. Soldered into a sweat fitting, 50 pounds? If just through a hole drilled in pipe a lot less if you didn't do anything to beef up the hole. Flow drilling or dimpling were invented for that scenario.

It's usually not the solder that is the problem, It's the surface area. For many fittings and many solders, brazing actually makes a weaker joint as the heat required aneals the pipe. But for an unreinforced hole through pipe brazen offers a little more ability to build up a bit of a fillet so may ne a bit stronger.

Small liebigs aren't very heavy, but if you are suspicious of your joints mechanical strength the potential motion and leverage may ne the bigger problem. Often you can brace the liebig or takeoff back to the column/head in a way to reinforce it, either with a brace or by surface soldering it.

[ben stiller]

Take a close look at the first picture in Rad's concentric thread (probably in trouble for mentioning his name). I copied his product
condenser because it is simple and super light weight. It is basically a 3/8'' copper tube inserted through a larger ( I think it was
3/4'' tube). this is an extension of the product tube and connected to the output. A short stub of 3/8" tube is put in each end of the 3/4
alongside the product tube and then the ends of the 3/4 tube are crushed and soldered to the inserted 3/8 tubes. Cooling water is hooked up to each of the 3/8" stubs which flows through the 3/4 and surrounds the product tube. Probably did described it in a confusing way, but if you look at the picture it should make sense. Connect this condenser to your product outlet with a union and you are all set. Ugly looking at first but it grows on you and works very well. At some point in one of his threads he elaborates on how he built it.