Build new column need advice

Vapor, Liquid or Cooling Management. Flutes, plates, etc.

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davesims
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Build new column need advice

Post by davesims »

Hi all, I have been playing around with making my own reflux column and looking at different designs of stills and come down to either a Boka (LM) or VM design but then i read more and a lot have said a combo would be a great idea.

I like the design of the concentric boka with a VM branch of, can you please have a look at the drawing i did and tell me if it will work and if anything needs to be changed

The LM vcollection area will only hold around 1 ounce

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Mikey-moo
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Re: Build new column need advice

Post by Mikey-moo »

That might just work... you'd have a bit of a time lag on the LM output, but if you account for that, could be ok.
What I'm not 100% sure about, is the VM take off in the narrower pipe. Narrower means faster vapour travel, does that have a bearing on the output of the 'T'?
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still_stirrin
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Re: Build new column need advice

Post by still_stirrin »

It will work.

My LM/VM head has the VM takeoff below the throat for the concentric. That way the vapor velocity is slower when I “crack” open the VM valve. I use a DWV tee for the branch and neck down for the concentric on the top of the tee.

The combo works very good for making high proof spirits. The LM/VM head is best on a meter tall stuffed column (I use glass marbles, but copper scrubbies are a favorite too).

I suggest making a potstill heat with a short riser for your flavored spirits. It also is a great stripping tool.
ss

edit to add: I don’t have a “rain hat” on the throat of mine. And the collection cup doesn’t have hole drilled in it. The cup, when full, simply spills back over the top of the throat pipe and flows back to the packing. This way, I can run it faster because the opening is much bigger than the series of holes drilled in the pipe. I sized the annular cup to hold about 1 ounce of liquid, so there is always a little liquid there when running the reflux head. It runs like a champ.
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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still_stirrin
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Re: Build new column need advice

Post by still_stirrin »

Looking at your sketch again, I wonder about the small liquid line running through you VM product condenser.

The LM line should be separate from the VM flow path as the vapor will be much hotter than the liquid coming out of the LM outlet. If you want a small Liebig for cooling the liquid even more, then add that separately.

The VM product condenser needs a larger vapor tube (preferably the same bore as the VM valve) to keep the velocity slow (increasing the dwell time) through the condenser.
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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bluefish_dist
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Re: Build new column need advice

Post by bluefish_dist »

I ran one like that for a while. I used a T as the rain hat under the reflux condenser. Look up boka two cup design. Mine was 2" to 1" vm, back to 2". IMHO that is the best way to do a VM. By necking down you can use smaller valves which are cheaper. The higher speed at the VM takeoff is supposed to help as well.
The one thing I did was to run another tube from the Rc to below the VM output so the condensed liquid could no go out the VM.
Now I use a T at the top of the column and do VM on one side and Nixon stone offset on the other. Easier to make from purchased parts. Look for some of my posts and you can see my still head. Honestly I am not using the lm side right now on my big still and just running the VM. The lm is nice as it keeps the heads out of the VM side.
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davesims
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Re: Build new column need advice

Post by davesims »

still_stirrin wrote:Looking at your sketch again, I wonder about the small liquid line running through you VM product condenser.

The LM line should be separate from the VM flow path as the vapor will be much hotter than the liquid coming out of the LM outlet. If you want a small Liebig for cooling the liquid even more, then add that separately.

The VM product condenser needs a larger vapor tube (preferably the same bore as the VM valve) to keep the velocity slow (increasing the dwell time) through the condenser.
ss
Hi Still Stirrin, thank you for you comments they really help.

Are you referring to the output on the LM running into the VM's condenser? if so i have read time and time again that the output from a Boka style can still be very warm and should be cooled down, so i thought rather than have another condenser for the LM section i could use the VM's condenser.

So when running the LM section is running the VM section is closed totally and the LM's output runs through the VM's condenser cooling it down and visa versa
davesims
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Re: Build new column need advice

Post by davesims »

Mikey-moo wrote:That might just work... you'd have a bit of a time lag on the LM output, but if you account for that, could be ok.
What I'm not 100% sure about, is the VM take off in the narrower pipe. Narrower means faster vapour travel, does that have a bearing on the output of the 'T'?
Hi Mickey moo

I hear you on the narrower pipe but with all the combo stills i have seen this seems to the be the norm, the gate valve should slow down the vapor?
zapata
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Re: Build new column need advice

Post by zapata »

The VM in the T is fine. Yes vapor is faster from the reduction but that means it is also turbulent and will evenly split in the T. Mine is 2" stepped to 1".
I also return liquid reflux externally to below the T to keep the VM head dry and not entrain any fluid.
I would (and do) use a 2nd small liebing on the LM rather than sharing with the VM. It can be small, like 8" long. But it keeps all fores and heads out of the entire path of the hearts.

But basically, if you like your design, it will definitely work.
davesims
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Re: Build new column need advice

Post by davesims »

zapata wrote:The VM in the T is fine. Yes vapor is faster from the reduction but that means it is also turbulent and will evenly split in the T. Mine is 2" stepped to 1".
I also return liquid reflux externally to below the T to keep the VM head dry and not entrain any fluid.
I would (and do) use a 2nd small liebing on the LM rather than sharing with the VM. It can be small, like 8" long. But it keeps all fores and heads out of the entire path of the hearts.

But basically, if you like your design, it will definitely work.
Hi Zapta

Yeah i get you about the second Liebig, when you say you return liquid reflux externally , do you have a pic or diagram showing what you mean? sound interesting
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Yummyrum
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Re: Build new column need advice

Post by Yummyrum »

Dave. Check out my lm/vm with external reflux viewtopic.php?f=17&t=67194#p7481508
davesims
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Re: Build new column need advice

Post by davesims »

Yummyrum wrote:Dave. Check out my lm/vm with external reflux viewtopic.php?f=17&t=67194#p7481508" onclick="window.open(this.href);return false;" rel="nofollow
Thank you Yummyrum, seeing it in the flesh sense, rather than hoping it returns down the centre, you are making sure it does
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