Simple pot still head design question

Simple pot still distillation and construction with or without a thumper.

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brick
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Simple pot still head design question

Post by brick »

copper still head.jpg
Has anyone tried to make a pot still using a few fittings like this? It would require a 90 degree elbow, a 45 degree elbow, and a reducer. Then you could hook it up to an in-line Liebig condenser. The cost for a 3 inch setup would run about $150 or less, minus any adapter needed to fit it to the boiler. This seems reasonable to me given the prices I've seen for ready-built pot stills.
Am I missing something?
Mud Mechanik
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Re: Simple pot still head design question

Post by Mud Mechanik »

It will work for ya, just try and step the reducer down in a few fittings instead of all at one time, i remember someone on here saying that reducing too quick would hinder vapor traffic.
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sambedded
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Re: Simple pot still head design question

Post by sambedded »

Brick, what I'd your boiler heat source?
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Re: Simple pot still head design question

Post by brick »

Heat source is Banjo-type propane burner
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Re: Simple pot still head design question

Post by sambedded »

Do you know its BTU rating? .
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Re: Simple pot still head design question

Post by brick »

210,000 BTU
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Re: Simple pot still head design question

Post by sambedded »

wow! It's equivalent to 60 000 Watt. You will need a not a liebig but big shotgun condenser. Though you still don't need a 3" column. 2" will do the work with no problem.
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Re: Simple pot still head design question

Post by HookLine »

A 2" diameter riser (pot 'column') will work fine for a basic pot still, but if I had a choice I would pick 3" over 2".

A 3" riser (about 12-24" tall) roughly doubles the speed you can do the spirit run. 3" is probably the sweet spot for a basic hobby pot still, IMHO.

You can reduce down to 2" at the top of the riser, doesn't matter there.
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Re: Simple pot still head design question

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HookLine wrote: A 3" riser (about 12-24" tall) roughly doubles the speed you can do the spirit run.
It's absolutely not true for pot still.
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Re: Simple pot still head design question

Post by HookLine »

sambedded wrote:
HookLine wrote: A 3" riser (about 12-24" tall) roughly doubles the speed you can do the spirit run.
It's absolutely not true for pot still.
Vapour speed affects the flavour profile from a pot still with an uninsulated riser above a few inches tall. The taller the riser is, the more effect it has (due to passive reflux from heat loss through the riser wall).

Increase the diameter of the riser by 1.5 times (2" to 3"), and the amount of vapour that can be passed roughly doubles, without increasing vapour speed - that is, without altering the flavour profile.

Can be tested. Try doing the same run on the same pot still, comparing the riser being fully insulated, to completely uninsulated. My prediction is there will be different results (for %ABV/vapour temp patterns, and flavour profile of final spirit).
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Re: Simple pot still head design question

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HookLine wrote:
sambedded wrote:
HookLine wrote: A 3" riser (about 12-24" tall) roughly doubles the speed you can do the spirit run.
It's absolutely not true for pot still.
Vapour speed affects the flavour profile from a pot still with an uninsulated riser above a few inches tall. The taller the riser is, the more effect it has (due to passive reflux from heat loss through the riser wall).
.
It is true. However following your logic - bigger riser - more surface, less vapor speed -> more passive reflux -> lesser output (if everything else are same).

And Passive reflux plays any significant role only at very low heat input (ie low production rate)
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Re: Simple pot still head design question

Post by brick »

The 210000 BTU burner is adjustable and need not be run at max output.
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Re: Simple pot still head design question

Post by sambedded »

brick wrote:The 210000 BTU burner is adjustable and need not be run at max output.
Sure. But anyway your will have no real advantages if you build 3" pot still column. It will work, of cause, but just waste of money.
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Re: Simple pot still head design question

Post by HookLine »

sambedded wrote:However following your logic - bigger riser - more surface
True, but not by the same proportion (ratio).

Doubling the diameter (of a cylinder) increases the perimeter (surface area), by a factor of 2. But it increases the cross-sectional-area (volume) by a factor of 4.
But anyway your will have no real advantages if you build 3" pot still column. It will work, of cause, but just waste of money.
That is bad advice.

What you are saying, in effect, is that vapour speed does not matter for a spirit run in a pot still, that it can be run at any speed (as long as the product condenser can handle it), and that you will get the same basic result, which is clearly wrong.

The only control over a pot still is the amount of power (heat) going into it. Finding the right power setting for each still (for the spirit run) is the main task of the still operator.

Like I said, this can be tested.
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Re: Simple pot still head design question

Post by sambedded »

Bad advise is to use pot still in reflux mode. Yes pot still can be used on very low speed as a poorly controlled reflux column/ But if you need a reflux to get your "flavor profile" it's much more efficient to build normal reflux column.
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Re: Simple pot still head design question

Post by brick »

I'm sorry. I think we got away from my question, which was meant to be about the geometry of those fittings rather than their diameter.
So what if I were to use 2 inch diameter fittings?
Would this not be an inexpensive and functional still?
How long should the riser be between the boiler and the first elbow?

maybe I should just make one and try it out.

thanks for all your thought-provoking comments.
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Re: Simple pot still head design question

Post by Thebigthumpa »

All mist if the designs I have seen have said around the 500mm mark. But they also say that column height is governed by the size of ur condenser and ease of output (pure ergonomics)
I dont know alot, but u will be playing with ur still alot, so u want it to be practical and not having to lift up and maneuver boiler and condenser arm all the time just coz u made ur tower to tall or short! If u get what I mean?
And i have made my column head and arm exactly as ur design, (I have a 1m 7/8 5/8 Liebig but. which is samohons easy pot still design! :)
Good luck, Aaron
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Re: Simple pot still head design question

Post by BentJar »

brick, if you dont get up some you will be collecting on the floor. Say 2 foot or 3 foot to get some clearance.
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Re: Simple pot still head design question

Post by sambedded »

brick wrote:I'm sorry. I think we got away from my question, which was meant to be about the geometry of those fittings rather than their diameter.
So what if I were to use 2 inch diameter fittings?
Would this not be an inexpensive and functional still?
Yes, 2" raiser is more than enough for potstill.
How long should the riser be between the boiler and the first elbow?
The main part of potstill is condenser. It should be able to knock down all planned heating power. Raiser can be any reasonable length
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Re: Simple pot still head design question

Post by CuWhistle »

I have a 2" unit made exactly out of the fittings you show here ( 3 reducers to step down from 2" to 1/2"), and I've been using it for 12 months with pleasing results in both strip and spirit runs. What I will say is that I have included 2 short lengths of pipe in between the elbows and put the 45 degree one in first, then the 90 degree. This does 2 things. Provides smaller bend for vapours to get a bit higher and provides horizontal offset. The 90 degree elbow can then be swivelled or rotated to the desired level of incline. It makes a nicely balanced still this way but it probably doesn't change the performance much, if at all. I did not have M&F elbows as you have shown there, hence the need for short lengths of pipe in between.

Pictured here is a smaller one I have also just made for my father out of 1 1/2 " pipe to use on a smaller stockpot boiler. It has 2 reducers up top and the third one is at the bottom to step up to the 2" flange size. I have tested it during cleaning and sacrificial runs as well as a pure water followed by a strip on my boiler (50 L keg) and it works just fine. My opinion is 3" is overkill plus my boiler has a 2" flange.

I'm using an 18" 3/4 over 1/2 diameter pipe liebig condenser and a good sized 3 ring propane burner for heat. I cannot run the burner flat out. Once it comes to temperature I turn off the inner and outer rings and there is enough adjustment in the middle ring to go fast or slow.
1 1/2" unit during testing.
1 1/2" unit during testing.
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Re: Simple pot still head design question

Post by S-Cackalacky »

CuWhistle wrote:I have a 2" unit made exactly out of the fittings you show here ( 3 reducers to step down from 2" to 1/2"), and I've been using it for 12 months with pleasing results in both strip and spirit runs. What I will say is that I have included 2 short lengths of pipe in between the elbows and put the 45 degree one in first, then the 90 degree. This does 2 things. Provides smaller bend for vapours to get a bit higher and provides horizontal offset. The 90 degree elbow can then be swivelled or rotated to the desired level of incline. It makes a nicely balanced still this way but it probably doesn't change the performance much, if at all. I did not have M&F elbows as you have shown there, hence the need for short lengths of pipe in between.

Pictured here is a smaller one I have also just made for my father out of 1 1/2 " pipe to use on a smaller stockpot boiler. It has 2 reducers up top and the third one is at the bottom to step up to the 2" flange size. I have tested it during cleaning and sacrificial runs as well as a pure water followed by a strip on my boiler (50 L keg) and it works just fine. My opinion is 3" is overkill plus my boiler has a 2" flange.

I'm using an 18" 3/4 over 1/2 diameter pipe liebig condenser and a good sized 3 ring propane burner for heat. I cannot run the burner flat out. Once it comes to temperature I turn off the inner and outer rings and there is enough adjustment in the middle ring to go fast or slow.
Photo0129.jpg
Brick, sorry to jump into your thread, but I have a question for CuWhistle about his build.

CuWhistle, up in your first paragraph you say, "The 90 degree elbow can then be swivelled or rotated to the desired level of incline.". Does this mean that you don't solder the connection that's closest to the riser on the 90 degree elbow? If this is the case, how do you seal the connection and how do you prevent the weight of the liebig from causing some inadvertant rotation while you're running?

I was thinking of doing something similar, but with a union fitting just before the 90 degree fitting. Do you see any reason why this wouldn't also work?
Thanks,
S-C
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