Just curisous if anyone has used that calculator and how it works. I get the general principal, but I don't understand why the time interval for calculation changes the amount, purity etc of the distillate collected.
I would have thought that after an hour the total collected + purity would be the same whether the time step was 10 min or an hour, of course using 10 min I'm talking total collected in the 60 min colum. Anyways if anyone knows let me know.
Thanks
Pot Still Purity Calculator
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Bastardo
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Husker
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The % ABV changes, due to there being a finite amount of ethanol in the mixture to start with. As you distill, you are boiling off a mixture which is higher in percentage of ethanol than the original mix. Thus, as you take out this "stonger" mix, the "strength" of the mix left in your boiler is less (higher concentration of water than before). Thus as this lower % ABV mash boils, it will gradually produce weaker and weaker amounts of ethanol, and at some point, there simply will be no ethanol left in the boiler, so if you continue from that point, you will simply distill water (and some higher volatiles).
The pot still calc seems to be pretty accurate, but its resolution leaves it "lacking".
H.
The pot still calc seems to be pretty accurate, but its resolution leaves it "lacking".
H.
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Bastardo
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THanks for the reply. The part I'm having trouble comprehending is the time interval. If I use a 20 min interval, after 180 min, shouldn't I get
the same quantity and purity as using a 180 min interval in the calculator. All other inputs are the same for each. Here is what I mean:
http://i127.photobucket.com/albums/p135 ... /20min.jpg
http://i127.photobucket.com/albums/p135 ... 180min.jpg
Not sure if these picture links work so I did both. Anyways, maybe it's just me. I would have thought the calculator would provide the same result. Given that it doesn't if I want an accurate estimate, what time interval would I use.
THanks
the same quantity and purity as using a 180 min interval in the calculator. All other inputs are the same for each. Here is what I mean:
http://i127.photobucket.com/albums/p135 ... /20min.jpg
http://i127.photobucket.com/albums/p135 ... 180min.jpg
Not sure if these picture links work so I did both. Anyways, maybe it's just me. I would have thought the calculator would provide the same result. Given that it doesn't if I want an accurate estimate, what time interval would I use.
THanks
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Husker
- retired
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- Joined: Thu Aug 17, 2006 1:04 pm
The problem (one of them at least), with the html calc tony did, is that it does a "hit the middle" of a time interval, and only computes one "shot". That is not horribly accurate. If I remember correctly, tony computes the rates at the start of the interval, and at the end, and averages them together to get what should have been output, then adjust out the H2O and the ethanol removed for that time frame, and then computes the next interval.
I redid what Tony has done (his html code), and wrote it as a Win32 program. Mine has quite a bit more added, but I kept his logic similar (for the most part). The biggest logic change I made, was I made ALL internal interval computations be a 1 minute interval (so it does the average of the begining / ending for each minute). Then if you ask for a 60 minute interval, it is simply 60 successive 1 minute intervals, all summed together. Using this type of method, allows for a much closer approximation.
What you see in the 20 minute interval is much closer to reality (for the data you provided). If you want to check tony's calc in this manner, try doing a 20 minute interval, and a 180 minute interval, but make the mash volume be 5000L. You will see that it is "pretty" close, because there is still enough ethanol left in the mix so that the middle point of 180 minutes was still accurate enough. What has happened in your data, is that you simply exausted the ethanol within the first interval (or took too much out to get an accurate computation.
H.
I redid what Tony has done (his html code), and wrote it as a Win32 program. Mine has quite a bit more added, but I kept his logic similar (for the most part). The biggest logic change I made, was I made ALL internal interval computations be a 1 minute interval (so it does the average of the begining / ending for each minute). Then if you ask for a 60 minute interval, it is simply 60 successive 1 minute intervals, all summed together. Using this type of method, allows for a much closer approximation.
What you see in the 20 minute interval is much closer to reality (for the data you provided). If you want to check tony's calc in this manner, try doing a 20 minute interval, and a 180 minute interval, but make the mash volume be 5000L. You will see that it is "pretty" close, because there is still enough ethanol left in the mix so that the middle point of 180 minutes was still accurate enough. What has happened in your data, is that you simply exausted the ethanol within the first interval (or took too much out to get an accurate computation.
H.