Calculators

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Uncle Jesse
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Calculators

Post by Uncle Jesse » Thu Aug 06, 2020 9:29 pm

A while back Husker emailed me a new php file for the calculators. He said it should fix them.

https://homedistiller.org/wiki/calcs.php

I put it there. Could folks please check and see how things are working? If it works, we should link it from the wiki home page, agreed?
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NZChris
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Re: Calculators

Post by NZChris » Thu Aug 06, 2020 11:55 pm

The dilution calculator has always been flawed. E.g. at 80%, 1l has 800ml of alcohol. To dilute that to 40% you need to finish with the 800ml in 2l. While the calculation might seem logical, in practice, by adding 1l, you would get close to 1.960l at a bit over 40.8%.

I'm sure it's a lot easier to design a calculator that can tell you the final volume to aim for than it is to come up with an algorithm for water to add. I can do both calculations without help from an online calculator, but I don't think I'm capable of writing an algorithm for water to add.

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GCB3
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Re: Calculators

Post by GCB3 » Sat Aug 08, 2020 4:32 am

Hey Jesse,
The ethanol temperature conversion calculator is still kicking you back to the parent site homepage when you hit calculate.
Thanks for working on this.

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Bushman
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Re: Calculators

Post by Bushman » Sat Aug 08, 2020 6:28 am

GCB3 wrote:
Sat Aug 08, 2020 4:32 am
Hey Jesse,
The ethanol temperature conversion calculator is still kicking you back to the parent site homepage when you hit calculate.
Thanks for working on this.
Good catch, with very little programming experience I thought I could look at the code but I do not have access (probably a good safety net). Also if you click on the HD table link within that formula it sends you to a Not Found page.

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NineInchNails
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Re: Calculators

Post by NineInchNails » Wed Sep 23, 2020 7:50 am

Yeah it's still doing that today. I just checked.

Question ... is there a vapor temp to ABV calculator on the Parent Site? I looked a couple times and couldn't find one.

Also is there a boiler temp to ABV calculator or would that be the same as vapor?

Mr Sippy
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Re: Calculators

Post by Mr Sippy » Thu Oct 08, 2020 4:29 pm

VLE_Calc.zip
(11.78 KiB) Downloaded 11 times
Here is a boiler temp to ABV calculator for a pot still that I wrote but have not yet tested. The equations involved for these type of thermodynamic problems are based on experimentation/observation under lab conditions. So without additional end-user coefficients/parameters, they all are only approximations, albeit close ones. I compared results from my own calculator to Perry and from other sources (see the screenshots). At lower concentrations of ethanol, my calculations differ from Perry by 0.2 - 0.4 degrees C.
Shot1.png
Shot2.png
This calculator uses an atmospheric pressure correction so you're not constrained to 'sea level' results. Enter known pressure in mmHg or have pressure calculated from elevation (meters) and air temperature (degrees C). The data must be entered in integers- NO decimal points. There's not much in error handling, so if the program hangs up, just close and start again. The program then generates a VLE_Calc.dat text file containing all the data fields. Copy to Excel to plot boil curve or use as a lookup table.

The application is in C and uses standard thermodynamic algorithm: Antoines Eq. to find temperature and saturated vapor pressures, and modified Raoults Law to find vapor concentration. Raoults is modified with van Laar activity coefficients to model for non-ideal behavoir. Molar to ABV conversion uses Edwin Croissant's data.

As a note: Perry's data is heavy at the lower concentrations of ethanol where the slope seems to change the most. The data also seems to index on key inflection points. I have a suspicion that a linear interpolation between Perry's data points would yield a reasonably approximate result also.

For those who like to keep an eye on data I hope you find this calculator useful.
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zapata
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Re: Calculators

Post by zapata » Mon Oct 12, 2020 8:37 pm

This german distiller site that was linked a few days ago has awesome calculators. (Including the simple vapor temp / ABV requested above, and a dilution calculator that factors shrinkage) Somebody official wanna put on a clean shirt, knock on the door and ask if we can copy (and translate) them?

https://hobbybrennen.ch/Rechner/

Destillationssimulator2 in particular is simple and polished (though I'd love to see a thumper version of it). Destillationssimulator1 makes a nice graph with cuts based on various parameters. Begleitstoffesimulator is just a stupid good simulator with relative volatilities of 50 or so congeners. Really though, if we can't copy and translate or at least emulate, I'm just going to use theirs for everything going forward, it's a very useful site even with the language barrier.

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Corsaire
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Re: Calculators

Post by Corsaire » Mon Oct 12, 2020 11:36 pm

Just send Hügelwilli a pm? He's on here every now and then.

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