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what is min reccomended size?

Posted: Tue Jan 19, 2016 1:19 pm
by Massassi
i was thinking about making a pot head for my electric keggle so that i dont get my boka full of essential oils. i also have a bunch of scrap 1" copper laying around.

does anyone here have experience running a 1" head/column off of a 15.5gal boiler or is it too small? my suspicion is that 1.5" was the minimum reccomended for that size boiler - but i dont recall where i'd seen that info

thanks

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 1:27 pm
by Euphoria
Personally, I would think you will be soon disappointed attempting to running a 15.5 gallon boiler with such a small head on it. It'll take a long time to run a batch with a 1" top. I would recommend at least a 2" head, and bigger wouldn't hurt if you could swing it. Not to say that it wouldn't work, but with such a small head on it, it will take you much longer than necessary to run a batch through it. Just my 2 cents.

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 1:29 pm
by shadylane
If your running it as a pot still Then 1/2" is the minimum.

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 1:33 pm
by bearriver
Massassi wrote:i was thinking about making a pot head for my electric keggle so that i dont get my boka full of essential oils. i also have a bunch of scrap 1" copper laying around.

does anyone here have experience running a 1" head/column off of a 15.5gal boiler or is it too small? my suspicion is that 1.5" was the minimum reccomended for that size boiler - but i dont recall where i'd seen that info

thanks
If it's a pot still then yeah, that sounds functional. 1/2" is the minimum size for the vapor path.

If you are talking about reflux column diameter then I don't think a beer keg is well suited under 3 inches in diameter. Many owners of 2 inch reflux columns on kegs have complained about the speed...

Edit: posted same time as Shadylane

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 1:35 pm
by pfshine
It's fine. What size is your condenser? My guess would be 1/2". Bigger don't always mean better just more expensive. A decent sized cap could calm the vapor and give a steady drip but its not needed. Most go with 2" because it clamps right to the keg. Again the 1" is fine.
Posted with others

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 1:41 pm
by shadylane
Here's a simple way to connect 3/4" to a keg.
The copper disk is made out of a 3" long piece of 1" tubing that was split and pounded flat.

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 2:16 pm
by pfshine
I do it the same way shady. Made a couple of em in different sizes. I am thinking its one of the easier ways to do it

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 3:24 pm
by jb-texshine
Pf-shady, does that work with a tri clamp to the sanke fitting? Would it work with one inch also? I'm going to be building a thumper an am still planning it out plus trying to work my existing two inch pot head in to it.

Re: what is min reccomended size?

Posted: Tue Jan 19, 2016 5:07 pm
by pfshine
Yep it does.

Re: what is min reccomended size?

Posted: Wed Jan 20, 2016 12:21 am
by Massassi
Awesome thanks guys!

And Shady, I think that's going to be what I try.

Condenser will probably be a leipeg made of ½ inside a 1"

Re: what is min reccomended size?

Posted: Wed Jan 20, 2016 5:37 am
by shadylane
JMHO
I'd use a 3/4" inside the 1" for the liebig.
There's not any advantage to having a jacket more than 1 size bigger than the inside tube.

Re: what is min reccomended size?

Posted: Wed Jan 20, 2016 8:47 am
by Massassi
alright. i guess i just presumed that a smaller vapour path would ensure a greater amount of cooling. ie prevent the center from staying hot while the edges condense?

Re: what is min reccomended size?

Posted: Wed Jan 20, 2016 12:18 pm
by Euphoria
Basic rules of physics. Heating a liquid to the point of vaporization releases a lot of latent heat in going from liquid to gas, and the heat causes those gasses to expand. Since the still is open to atmosphere, those expanding gasses are looking to equalize their vapor pressure with the lower ambient atmospheric pressure by escaping. The smaller (more restrictive) the ID of the vapor path pipe, the faster the velocity will be of those expanding heated vapors. More speed = less time to transfer heat by cooling while travelling down the pipe. The larger the ID of the pipe, the slower the velocity of the vapors, thus allowing more time to cool.

Re: what is min reccomended size?

Posted: Thu Jan 21, 2016 12:32 pm
by rad14701
Euphoria wrote:Basic rules of physics. Heating a liquid to the point of vaporization releases a lot of latent heat in going from liquid to gas, and the heat causes those gasses to expand. Since the still is open to atmosphere, those expanding gasses are looking to equalize their vapor pressure with the lower ambient atmospheric pressure by escaping. The smaller (more restrictive) the ID of the vapor path pipe, the faster the velocity will be of those expanding heated vapors. More speed = less time to transfer heat by cooling while travelling down the pipe. The larger the ID of the pipe, the slower the velocity of the vapors, thus allowing more time to cool.
Yes, but with a pot still the smallest diameter component is what determines the performance of the entire circuit... It doesn't matter what size comes before the condenser as that is usually the choke point of the vapor path... Therefore, if you had a 1/2" inside 3/4" liebig product condenser you will see very little difference in performance regardless of the sizing before the liebig, even if it was 1/2" all the way from the boiler... We had a member do some comparisons a while back to prove that concept as folks thought otherwise...

Re: what is min reccomended size?

Posted: Thu Jan 21, 2016 12:53 pm
by Euphoria
Well rad, I don't disagree that the most restrictive portion of any closed system will become the "choke point" to impede the flow. And thus, it will become the determining factor to establish the ratio between flow rate and velocity. But as a rule, given a fixed vapor or liquid pressure, the smaller the cross-section of the orifice, the faster the velocity will be. But by using a conduit with a larger cross-sectional area, you would decrease the velocity accordingly.

Re: what is min reccomended size?

Posted: Fri Jan 22, 2016 12:01 pm
by rad14701
Euphoria wrote:Well rad, I don't disagree that the most restrictive portion of any closed system will become the "choke point" to impede the flow. And thus, it will become the determining factor to establish the ratio between flow rate and velocity. But as a rule, given a fixed vapor or liquid pressure, the smaller the cross-section of the orifice, the faster the velocity will be. But by using a conduit with a larger cross-sectional area, you would decrease the velocity accordingly.
Umm... :wtf: Kinda talking in circles there, eh...??? :think:

Atmosphere is the after the choke point and any larger cross-sectional area before the choke point becomes moot... All you can end up with is some parasitic reflux at best... We've beat this critter to death many times here...

Re: what is min reccomended size?

Posted: Fri Jan 22, 2016 2:21 pm
by Massassi
ok, so i guess i will do a 3/4" internal. i might twist in some copper plumbers strap too though in order to add to heat transfer