## Condenser Calculations

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• Hi everyone, I m making progress on my little still (28mm diam Stone & Nixon style) but I want to use a condenser similar to the STILLMAKER design (i.e.: water
Message 1 of 9 , Jun 6 9:28 AM
Hi everyone,
I'm making progress on my little still (28mm diam Stone & Nixon
style) but I want to use a condenser similar to the STILLMAKER design
(i.e.: water jacketed tube) as I already have the parts lying
around. I was thinking of a 15mm condenser tube with a 28mm jacket.
The question is how long do I make it? Anyone got formulas for
this? I know 15mm is a little bit narrow, but the still will have a
pretty low throughput.
Thanks in advance for any help!

-Tone.
• Hi all, Thanks for your help. I have posted a procedure to calculate the condenser area for an air-cooled condenser. My process is close, but still needs some
Message 2 of 9 , Apr 19, 2006
Hi all,

Thanks for your help. I have posted a procedure to calculate the
condenser area for an air-cooled condenser. My process is close, but
still needs some work. Please take a look at it and see where I can
be corrected.

The procedure can be found in the files section under "Proposed
Calculations.doc"

Here is the URL:
http://f1.grp.yahoofs.com/v1/MPlGRNpC5uktnu32_2McivaUkdPnNd_GxYx5FEGti
olevGJoSeMhVB2EYqJ__NwQj9qMFwGbbJ9I1je-c_XWaP1-aXiVXRU/PROPOSED%
20CALCULATIONS.doc

If I can get the procedure fine tuned I will post a properly
corrected version in the files section.

Any and all help is appreciated.

Thanks

ab
• You can also use the calculator at Tony s site. Just change the heat transfer coefficient to 40 W/m2C and you ll get acceptable guestimates for copper. - Riku
Message 3 of 9 , Apr 19, 2006
You can also use the calculator at Tony's site. Just change the heat
transfer coefficient to 40 W/m2C and you'll get acceptable
guestimates for copper.

- Riku

--- In Distillers@yahoogroups.com, "aborzachtd" <aborza@...> wrote:
>
> Hi all,
>
> Thanks for your help. I have posted a procedure to calculate the
> condenser area for an air-cooled condenser. My process is close,
but
> still needs some work. Please take a look at it and see where I can
> be corrected.
>
> The procedure can be found in the files section under "Proposed
> Calculations.doc"
>
> Here is the URL:
>
http://f1.grp.yahoofs.com/v1/MPlGRNpC5uktnu32_2McivaUkdPnNd_GxYx5FEGti
> olevGJoSeMhVB2EYqJ__NwQj9qMFwGbbJ9I1je-c_XWaP1-aXiVXRU/PROPOSED%
> 20CALCULATIONS.doc
>
> If I can get the procedure fine tuned I will post a properly
> corrected version in the files section.
>
> Any and all help is appreciated.
>
> Thanks
>
> ab
>
• ... but ... can ... http://f1.grp.yahoofs.com/v1/MPlGRNpC5uktnu32_2McivaUkdPnNd_GxYx5FEGt i ... Hi ab, Posted an altered file.
Message 4 of 9 , Apr 20, 2006
--- In Distillers@yahoogroups.com, "aborzachtd" <aborza@...> wrote:
>
> Hi all,
>
> Thanks for your help. I have posted a procedure to calculate the
> condenser area for an air-cooled condenser. My process is close,
but
> still needs some work. Please take a look at it and see where I
can
> be corrected.
>
> The procedure can be found in the files section under "Proposed
> Calculations.doc"
>
> Here is the URL:
>
http://f1.grp.yahoofs.com/v1/MPlGRNpC5uktnu32_2McivaUkdPnNd_GxYx5FEGt
i
> olevGJoSeMhVB2EYqJ__NwQj9qMFwGbbJ9I1je-c_XWaP1-aXiVXRU/PROPOSED%
> 20CALCULATIONS.doc
>
> If I can get the procedure fine tuned I will post a properly
> corrected version in the files section.
>
> Any and all help is appreciated.
>
> Thanks
>
> ab
>

Hi ab,
Posted an altered file. /files/PROPOSED-CALCULATIONS-Harrys-mods.doc

Let me know when you've downloaded it, so I can delete it from
files. You were close, just a couple of minor errors. You'll see
when you read the modded version. As Riku said, you can always use
the calculators at Tony's. Riku has a lot of experience with air-
cooled finned condensers.

Slainte!
regards Harry
• Hi Harry, Thanks loads! I have removed the original and downloaded the modified version. So now you can remove it as well. I will study the corrected version
Message 5 of 9 , Apr 20, 2006
Hi Harry,

now you can remove it as well.

I will study the corrected version to see how it can be drafted for
general purpose use.

One thing you did not correct was the U value I used. I am guessing
that means I used the right one for ethanol condensation and a
convection-only smooth-tube air-cooled condenser at ambient
temperatures. Is that right or is there a more appropriate U value to
use?

Heck, if anyone has a good U values for the above purpose, please let
me know the values and their source.

Thanks

ab

>
> Hi ab,
> Posted an altered file. /files/PROPOSED-CALCULATIONS-Harrys-mods.doc
>
> Let me know when you've downloaded it, so I can delete it from
> files. You were close, just a couple of minor errors. You'll see
> when you read the modded version. As Riku said, you can always use
> the calculators at Tony's. Riku has a lot of experience with air-
> cooled finned condensers.
>
>
> Slainte!
> regards Harry
>
• ... guessing ... The U value should be ok. There is one very large thing not being considered, however (there s that however word again). The calculations
Message 6 of 9 , Apr 20, 2006
--- In Distillers@yahoogroups.com, "aborzachtd" <aborza@...> wrote:
>
> One thing you did not correct was the U value I used. I am
guessing
> that means I used the right one for ethanol condensation and a
> convection-only smooth-tube air-cooled condenser at ambient
> temperatures.

The U value should be ok. There is one very large thing not being
considered, however (there's that 'however' word again).

The calculations are based around the quantity of product drawn per
hour from Alex's ministill, some 600ml. What's not considered is
that represents about 15-20% of the TOTAL liquid produced during
distillation, the 80-85% balance being returned to the column as
reflux. The pipe resulting from the calcs will have the capacity to
cool that 600ml. But what are you going to use to condense the ~5
litres of reflux? If you use the same idea of air-cooled tubing,
then you'll need another 8 times as much.

IOW, whatever the reflux ratio is set to i.e. 50, 60 or 80 percent
of total, that's the amount of tubing you'll need + the initial
tubing for the output product. Thus the amount of air-cooled tubing
becomes quite large (or long). You cannot change the total area of
tubing needed. Figures don't lie (hopefully). To overcome this you
will probably need to investigat larger diameter tubing to keep the
same radiating surface area while reducing the length to something
manageable. It's either that, or resort to a small liquid-cooled
reflux condenser, which kinda defeats the entire project.

The initial idea was to furmulate a 'rule-of-thumb'. These calcs
will do just that, for EACH ~15% of TOTAL vapour produced by the
still.

Sorry to be a wet blanket.

Slainte!
regards Harry
• ... Ultimately, why not just overengineer and be done with it. For all the time spent finding *just* the right amount of cooling with *just* the right length
Message 7 of 9 , Apr 20, 2006
--- Harry <gnikomson2000@...> wrote:

> --- In Distillers@yahoogroups.com, "aborzachtd" <aborza@...> wrote:
> > something < <
>
>
> some reply to something <

Ultimately, why not just overengineer and be done with it.

For all the time spent finding *just* the right amount of cooling with *just*
the right length of whatzitz made out of *just* the right thicknes of
whatevertheheck, you can fudge on a couple inches here, a few gph there,
solder, braze, plug-in, and be running.

Using the cliche'd "Time is money" - the amount of time spent re-hashing the
most minute parameters in the calculations can be offset by an extra inch or
two of copper, a few extra fins on the radiator, and so on.

Besides, larger capacities can be scaled back whereas the smaller capacity will
limit you to its max and no more. So then, suppose you want to go
bigger...you're back to the drawing board spending both time *and* money for
the next size up.

Trid
• AMEN !!! ... From: Trid To: Sent: Thursday, April 20, 2006 5:00 PM Subject: Re: [Distillers] Re:
Message 8 of 9 , Apr 20, 2006
AMEN !!!

----- Original Message -----
From: "Trid" <triddlywinks@...>
To: <Distillers@yahoogroups.com>
Sent: Thursday, April 20, 2006 5:00 PM
Subject: Re: [Distillers] Re: Condenser Calculations

> --- Harry <gnikomson2000@...> wrote:
>
>> --- In Distillers@yahoogroups.com, "aborzachtd" <aborza@...> wrote:
>> > something < <
>>
>>
>> some reply to something <
>
> Ultimately, why not just overengineer and be done with it.
>
> For all the time spent finding *just* the right amount of cooling with
> *just*
> the right length of whatzitz made out of *just* the right thicknes of
> whatevertheheck, you can fudge on a couple inches here, a few gph there,
> solder, braze, plug-in, and be running.
>
> Using the cliche'd "Time is money" - the amount of time spent re-hashing
> the
> most minute parameters in the calculations can be offset by an extra inch
> or
> two of copper, a few extra fins on the radiator, and so on.
>
> Besides, larger capacities can be scaled back whereas the smaller capacity
> will
> limit you to its max and no more. So then, suppose you want to go
> bigger...you're back to the drawing board spending both time *and* money
> for
> the next size up.
>
> Trid
> -is the horse dead yet?
>
>
>
> Distillers list archives : http://archive.nnytech.net/
> FAQ and other information at http://homedistiller.org
>
>
>
>
>
>
>
• ... Probably. :-) These things need to be thrashed out (pardon the pun) so people can see why such-n-such is a better option than so-n-so. The simple answer
Message 9 of 9 , Apr 20, 2006
--- In Distillers@yahoogroups.com, Trid <triddlywinks@...> wrote:
>
> Ultimately, why not just overengineer and be done with it.
>
> Trid
> -is the horse dead yet?
>

Probably. :-)

These things need to be thrashed out (pardon the pun) so people can
see why such-n-such is a better option than so-n-so.

The simple answer to sizing for ALL condenser types is thus: Power
in = Power out.

Once you're up to temperature, it goes like this: If you're putting
1,000w/hr in then you have to remove 1,000w/hr at the business end.
Then you can vary your reflux ratio all you want. Build a condenser
(any type) to handle that, you're done. If you use some other value
of power input (1,200 1,500 2,000 whatever) then your condenser
needs to be capable of handling that input, and probably 10% more,
just as a comfort zone.

ab's calcs are useful as a starting position in determining air-
cooled types. It always help to have an idea of how big the thing
is going to be. But the power in : power out concept is much easier
for people to understand and work with. No engineering degree or
calculus required.

Slainte!
regards Harry
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