Pot still column concers

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Midwest
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Joined: Mon Jul 10, 2017 4:33 pm
Location: Missouri

Pot still column concers

Post by Midwest »

I do have a couple of questions that I would appreciate your help with.

The still I inherited is approximately 20 gallon SS pot still that I am in
the process of reworking. The
attached picture Was at the beginning stages of the still, I don't have one
of the current progress as it is at the welding shop right now. If you will
observe the original design had acopper reflux coil built into the short SS
column. Ive addded to the pot a 2" ferrule for a 4500 watt element as well
as a 5" ferrule for a top access port and a 4" ferrule added at the bottom
for easy cleaning. The Liebig in the picture is one I have built, Here are
my Questions

1. Is the reduction in the pipe at the top of the short column to
aggressive for clean pot stilling. should I find a way to add more gradual
tapering?
2. As I am going to run the still as a pot still, should I remove the
copper coil to add packing material? Will the copper coil work as well as
packing and should I leave it.
3. Would there be any benefit to running cool water through the reflux coil
during the distillation on that short of a column, as I'm going to be
running for flavored spirits.
4. The welder is also going to make me a plate that has a SS ferrule on it
that I can bolt on to the pot and take off the short column. I can then
build a taller reflux column in the future. As the opening is quite large
approx 5" should the plate have a 3" or 4" ferrule and use a step down
reducer for better vapor flow? could I go straight to a 2" ferrule? Would
it even matter that much?

Thanks in advance
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still_stirrin
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Re: Pot still column concers

Post by still_stirrin »

Midwest wrote:I do have a couple of questions...
1. Is the reduction in the pipe at the top of the short column too aggressive for clean pot stilling. should I find a way to add more gradual tapering?
What it does is limit the mass flow of vapor by causing the vapor to speed up. When it does this, it will try to push vapor out of the end of your Liebig. So, you turn down the heat. When the heat is lower, you'll likely reduce the aggressiveness of the smearing. So, it should help you. But with that 5" column, you should be capable of running faster. But the throughput will be limited by the ID of your Liebig ultimately.
Midwest wrote:2. As I am going to run the still as a pot still, should I remove the copper coil to add packing material? Will the copper coil work as well as packing and should I leave it.
As a potstill, neither the packing or the deflag (reflux condenser) do you any good, except slow the vapor throughput.
Midwest wrote:3. Would there be any benefit to running cool water through the reflux coil during the distillation on that short of a column, as I'm going to be
running for flavored spirits.
Well, it would stimulate a little reflux, which would help to separate the fractions a bit for you. It may also raise your product proof a little too...if that's what you'd like.
Midwest wrote:4. The welder is also going to make me a plate that has a SS ferrule on it that I can bolt on to the pot and take off the short column. I can then build a taller reflux column in the future. As the opening is quite large approx 5" should the plate have a 3" or 4" ferrule and use a step down reducer for better vapor flow? could I go straight to a 2" ferrule? Would it even matter that much?
No need to reduce unless the cost of the fittings and pipe get prohibitive. A larger diameter riser simply means that the vapor velocity will be slower. It will allow heavier vapors to rise less and lighter vapors to rise higher, again aiding in separation of the fractions. But, because the costs of larger fittings and pipe are higher, most opt to reduce to 2", or 3" depending on the boiler size and the heat source. 4" is good if you're building a flute as well.
ss
My LM/VM & Potstill: My build thread
My Cadco hotplate modification thread: Hotplate Build
My stock pot gin still: stock pot potstill
My 5-grain Bourbon recipe: Special K
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Midwest
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Posts: 77
Joined: Mon Jul 10, 2017 4:33 pm
Location: Missouri

Re: Pot still column concers

Post by Midwest »

Thanks SS I was hoping it would be ok, didn't want to go back and redesign the column at this point. I will have the 2" ferrule plate made so I can build a reflux column in the future.
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