I developed the potstill - thumper calculator that is in our HD Calculators section and have just finished extending it to run with two thumpers in series.
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I have both an Excel spreadsheet model and a Web-Based Javascript version like HD uses. Their results are very similar even though different calculation methods and VLE models are used. Hugelwilli in hobbybrennen.ch has also added a two thumper calculator. I compared my calculations with his and they agree closely when his model uses no insulation. I will show these results later.
There are not many posts in HD on two thumper runs and operation.
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So What?
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In this thread, I will try to point out several uses for two thumpers and what results can be expected from several different runs. You can get an idea of what to expect if you want to add a second thumper. There are some safety concerns - like a small vapor pressure increase with the second thumper and venting the thumpers after a run to prevent decompression of the pot. I will discuss the increased pressure issue later. Others can weigh in on these concerns also.
Possible uses of the two thumpers in series are:
1. Making Rum using previous heads and tails in the thumpers - like Jamaican Style Rum distillers
2. One and Done runs - using only 10% wash - with low and high thumper starting amounts
3. Steam stripping with the first thumper on the grain - then using wash + low wines in the second thumper to up the ABV
4. Spirit runs using heads and tails after some strip runs - to get a high ABV ( maybe close to neutral?)
5. Many other combinations of the above
A common ( main? ) use for two thumpers is in making Jamaican Style Rum. There are several posts in HD on this subject and later I will show how this Rum is made. Several members have done many Rum runs with two thumpers. They are wtfdskin, nuntius01, distiller_dresden and Hillbilly Popstar. I tried some Jamaican Rum run data from wtfdskin and Hillbilly Popstar and will show the calculation results later.
So, first, here are some results of a Spirit whiskey run with tails+wash in Thumper 1 and heads+wash in Thumper 2.
The Input Data as in the HD version:
Input your Pot still charge
Name Your Run - Spirit Run
Initial Volume of Wash 13 US gal
Alcohol Content 10 % by volume
Initial Temperature 30 °C
Power during Pot and Thumper Heat-up 4000 W
Power during Distillation 4000 W
Input your Thumper 1 charge
Total Thumper Volume 10 US gal
Initial Thumper Charge 6 US gal
Alcohol Content 14 % by volume
Initial Temperature 68°C
Input your Thumper 2 charge
Total Thumper Volume 10 US gal
Initial Thumper Charge 3 US gal
Alcohol Content 32.8 % by volume
Initial Temperature 68 °C
Ambient Temperature 30 °C
RESULTS
Time to Heat up Pot contents 52 min
Time to Heat up Thumper 1 contents 14 min
Time to Heat up Thumper 2 contents 7 min
Pot volume after last step 6.54 gal or 24.74 L
Thumper 1 Heat Loss 22.7 %
Calculated Time_Step 9.1 min
Approx Heads Volume 0.51 gal or 1.94 L at ABV about 82 %
Approx Hearts Volume 3.34 gal or 12.63 L at ABV about 71 %
Approx Tails Volume 0.29 gal or 1.11 L at ABV about 38 %
The results in graphs from the Excel file are:
More stuff to come. Anyone interested?
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