Coolant setup

[googe]

Hey all, did a little vid to try help newbies ect.

[googe]

Nice video Googe! Is that a New Zealand accent I detect?

Don't make me hurt you! Where's that bird smiley!

[ranger_ric]

Hey Googe,

Thanks for the video.. I have been having thoughts in my head and dreams at night about how I was going to do things differently this winter..
This is real close to what I was thinking. I envisioned connecting 2 drums together but I was going to do it at the bottom.
But alas I see how by putting it at the top now equals total circulation..
(Well that made sense to me anyway)
Nice job..

[googe]

No worries rager, I'm glad you understood, total circulation is a good terminology i was going to do at the bottom to, then bad a second thought, think this should work well, I'll test it soon with a run.

[emptyglass]

I thunk you culd be rite rock, they call them a "stulli bun" (stilly bin) over there.

https://www.youtube.com/watch?v=ZdVHZwI8pcA" onclick="window.open(this.href);return false;" rel="nofollow


Good stuff Googe, very inventive.

[googe]

Cheers empty.

[googe]

Bump for newbies doing reusable water for coolant.

[Saltbush Bill]

Did the hand model career ever go far Gooman?
Jokes aside good idea, and you could add as many drum as needed.

[googe]

sbb I could be a hand model for, (what not to so to your hands) never considered adding extra drums, guesw the sky is this ths limit.

[NormandieStill]

never considered adding extra drums, guesw the sky is this ths limit.

More drums would increase stratification and so keep the feed water cooler for longer. I'm guessing there's quite a bit of mixing in the left hand tank.

I have 1 single 1000L IBC full of rainwater. I did a reflux run a while back when it was less than half full and I did notice it warm up towards the end of the run. I get quite a bit of mixing despite my best attempts to return the hot water to the top.

[NormandieStill]

To add to what I said, ideally your feed from each drum should draw from the bottom and return to the top of the next in line. That way it'll behave like one giant cylinder with the coldest water staying at the bottom (in the drum with the pump).

[kennstminet]

I have never tried such setup and write just my theoretical guess.
Cold water will sink down and warm water will move to the top automatically due to the difference in density.
I think the goal is to avoid the stratification and have a good mixture with equal temperatures at any height. Similar temperatures at any height of the barrels provides the longest time to heat up the total water quantity.
This can be achieved by returning warm water from the condenser to the bottom and by returning the overflow from the top of the left barrel down to the bottom of the righthand barrel. The warm water will automatically raise up in the barrel and mix with cold water.
In addition, I think it would cause a better temperature equalization if the pump would take the water from the top of the righthand barrel.
Just my 5 ct

[NormandieStill]

I have never tried such setup and write just my theoretical guess.
Cold water will sink down and warm water will move to the top automatically due to the difference in density.
I think the goal is to avoid the stratification and have a good mixture with equal temperatures at any height. Similar temperatures at any height of the barrels provides the longest time to heat up the total water quantity.
This can be achieved by returning warm water from the condenser to the bottom and by returning the overflow from the top of the left barrel down to the bottom of the righthand barrel. The warm water will automatically raise up in the barrel and mix with cold water.
In addition, I think it would cause a better temperature equalization if the pump would take the water from the top of the righthand barrel.
Just my 5 ct

So you're right that convection currents will form within the barrel. These will introducing mixing and a homogenisation of the temperature. But here's why you don't want that. As your temperature changes, you need to adjust things on the still. Even running a simple pot still with a liebig, you should be adjusting water flow to get a nice temperature gradient across your condenser. This will prevent huffing, ensure that the distillate is correctly cooled at the exit, and maximise the efficiency of your condenser. If you do so, the water out will be probably uncomfortably hot. By preventing mixing of your cooling water (in an extreme example we could imagine that you take water from one barrel and return it to a different, unconnected one), the coolant flow rate can remain the same across the run (more or less, you might need to adjust up a little as the abv drops).

If you maximise mixing so the coolant temperature rises as the run progresses, you'll need to adjust the flow rate to compensate as the distillate will be getting hotter and condensing further down the condenser. Also, maintaining a concentration of hot water means that it will cool faster through environmental losses so you'll get a greater usable volume of coolant.

Your observations on how to maximise mixing and equalization are 100% correct... you just don't want to that if you can possibly avoid it.

[kennstminet]

I understand what you are saying. However this will require a much larger reservoir volume compared to the case described by me.
You would store the hot water at the barrel top und use only the cold water from the lower part.
I fully trust your experience. If you say that a slowly increasing coolant temperature is causing the need for readjustment, my suggestion is not helpful.

I appreciate the discussion and have learned a lot.

[NormandieStill]

I understand what you are saying. However this will require a much larger reservoir volume compared to the case described by me.
You would store the hot water at the barrel top und use only the cold water from the lower part.
I fully trust your experience. If you say that a slowly increasing coolant temperature is causing the need for readjustment, my suggestion is not helpful.

I appreciate the discussion and have learned a lot.

Actually it doesn't require more volume. (OK. If you go to the extreme of completely separating the input and output then you need double the storage capacity for the same useful volume of water but I wasn't actually suggesting anyone do that). Stratification allows you to maximise the useful volume while keeping the coolant temperature constant... until you reach the end point where the hot water makes it all the way to the pump, but that just means that your total volume wasn't adequate.

I use the inverse situation as well. Our house is heated by a woodburning stove, attached to 1.3m³ (1300L) water tank. When heating the water in the tank, it is drawn from the bottom and once heated, returned to the top. Temperature sensors running down the tank let me see how well it is maintaining stratification. While heating I see a "wave" of hot water descending the tank until it reaches the bottom (at which point a second hotter wave starts working downwards). When the host water is being used to heat the house a cold "wave" rises up the tank as hot water is drawn from the top, and the cooled water is returned to the bottom. If nothing water is used for a few days, that stratification remains pretty much intact. Which means that when needed I can still draw hot water from the top of the tank even if the average temperature of the water is barely luke-warm. Should I want to, I can set the "cold "point to half-way up the tank and maintain a smaller volume of very hot water which floats on top of the cold water at the bottom. As long as you take care to return cold water to the bottom of the heated volume the tank will remain stratified.

I do exactly the same thing with my 1000L tank which provides cooling for my still (although I need to work on the return which introduces too much mixing). Several people on the forum have said that you need approximately three times the volume of your wash available as cooling water in order to run a pot still. The moment you introduce reflux, that requirement goes up dramatically. I already had the 1000L rainwater tank, so opted to use that as a cooling reservoir. At one point in the summer the tank was at best half full and a full reflux run, noticeably heated up the water.

[drmiller100]

I don't know all the details but it seems to me putting a car radiator in line before the first barrel and a fan would help more than adding another barrel.