What Two Thumpers Can Do

[haggy]

Hi, this is haggy.

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. The HD Calculator results have been verified many times, and I expect the results with this two thumper model will be accurate enough for your planning and expectations.

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. I have found about seven of them and will detail these runs in future posts. The posts did not give many details of results of the runs, only the initial ABV made. My calculator has agreed with what results were given.

So What?
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?

[Hillbilly Popstar]

My personal experience with two thumpers is I can make the same quality product as I did doing 2 strips and a spirit run with my single boiler.

The double thumper is power hungry and will drink propane like it's Gatorade at a sports even, but I can run 20 gallons of mash and make excellent product in about 10-12 hours whereas my former 2 strips and a spirit run was about 18-20 hours driving the still.


For what its worth...
I can charge each thumper with around 2.5 gallons of fresh mash and when the run is done, each one is holding around 3.5-4gal of hot backset. I'm sure this figure is subject to change with a charge of low wines or feints.

[haggy]

HbP.
Thanks for sharing your experience with propane firing. I have seen some posts with electrical heating and will publish those results. They seem to be close to or just above conventional power usage with thumpers. But it might take longer to reach a desired product amount since the distillate rate from Thumper 2 is lower due the added heat loss.

And I will post a One and Done run with only 10% fresh mash in the pot and in each thumper. We will see the thumper fillage going up with run time like your experience. With low wines + mash added to the thumpers, the rate of thumper fillup is less, like the above run in my first post.

[haggy]

Let's look at a One n Done Run here.

But first, something I forgot to mention before.

Re: Thumper?
Post by OtisT » Tue May 11, 2021 10:25 pm
Yes. A thumper half the size of you boiler will work just dandy. Insulate the thumper if you can to save time/energy.
Otis

As Otis said, it is wise to insulate your thumpers and transfer lines. Also, transfer lines should be short and insulated to minimize exposure to external cooling. These factors might be why Hillbilly Popstar used so much propane and had a long run time.

One n Done - Hillbilly Popstar Run

Re: What's your preferred distillation technique?
Post by Hillbilly Popstar » Sun Feb 26, 2023 10:31 am
My distillation techniques are largely dictated by the size of my equipment.

I have a 30 gallon fermenter. I ferment on grain and do about 29 gallon ferments.
By the time I squeeze grains and let the yeast settle I end up with about 19-20 gallons of clean boiler charge and about 4-5 gallons of yeast sludge.

Now I have a 15.5gal keg and two 5gal thumpers, so I can load up about 14gal in the main boiler, then put about 2.5gal of mash in each thumper and run it all once.
As far as I can tell the product quality is almost exactly the same if not a little better. The double thumper is power hungry. I use about just as much propane doing a run as I would doing 2 strips and a spirit, but it takes about half the time.

I ran the Excel and HD programs using the above charges from HbP. Let's look at two effective power levels and a 10% ABV mash. First run is at 1500 watts. The run will stop at about 25% ABV Thumper 2 distillate out the spout. No additional passive reflux in the transfer lines is included in this run. I will discuss this later.

Input your Pot still charge
Initial Volume of Mash 14 US gal
Alcohol Content 10 % by volume
Initial Temperature 30°C
Power during Pot and Thumper Heat-up 3000 W
Power during Distillation 1500 W

Input your Thumper 1 charge
Total Thumper Volume 5 US gal
Initial Thumper Charge 2.5 US gal mash
Alcohol Content 10 % by volume
Initial Temperature 30°C

Input your Thumper 2 charge
Total Thumper Volume 5 US gal
Initial Thumper Charge 2.5 US gal mash
Alcohol Content 10 % by volume
Initial Temperature 30°C
Ambient Temperature 30 °C

RESULTS

Time to Heat up Pot contents 74 min
Time to Heat up Thumper 1 contents 16 min
Time to Heat up Thumper 2 contents 21 min
Pot volume after last step 8.50 gal
Thumper Heat Loss 27.1 %

Approx Heads Volume 0.60 gal at ABV about 69 %
Approx Hearts Volume 2.00 gal at ABV about 60 %
Approx Tails Volume 0.90 gal at ABV about 31 %

The run time ( including the pot heatup time ) to 25 % ABV is about 480 minutes for this 1500 watt effective power level.

Then, if we run at 3000 watts effective pot power, the main change is the time it takes to get to the final 25% ABV out the spout. It would take about 280 minutes to get to the 25% ABV out the spout. The corresponding ABV and gallons out the spout are about the same throughout the run. If during the faster 3000 watt run, the injected vapor does not all mix well in and equilibrate, the product ABV would be slightly lower than the 1500 watt run.

These are not excessive power levels for running the two thumper system. But, additional heat losses in the system will lengthen the time to reach 25% out the spout. If there is much passive reflux in the transfer lines, the ABV of the product would be higher and the run time longer than calculated here.

So, One n Done runs can produce a good whiskey product using two thumpers. This is what Hillbilly Popstar is doing.

What if we changed the amount of 10% mash in each thumper. Try a run with only 0.5 gal in the thumpers or a run with 10 gal in larger keg thumpers. The product ABV will change. I will look at this next.

Other HD posts by Hillblly Popstar, nuntius01, wtfdskin, Pugi, Drunken Unicorn and distiller_dresden show they successfully made very good tasting Jamaican rum using enhanced molasses washes on this 15 gal pot scale using two thumpers. I will get into this way of making Jamaican Rum making in later posts.

[Hillbilly Popstar]

As Otis said, it is wise to insulate your thumpers and transfer lines. Also, transfer lines should be short and insulated to minimize exposure to external cooling. These factors might be why Hillbilly Popstar used so much propane and had a long run time.

One n Done - Hillbilly Popstar Run

Re: What's your preferred distillation technique?
Post by Hillbilly Popstar » Sun Feb 26, 2023 10:31 am
My distillation techniques are largely dictated by the size of my equipment.

I have a 30 gallon fermenter. I ferment on grain and do about 29 gallon ferments.
By the time I squeeze grains and let the yeast settle I end up with about 19-20 gallons of clean boiler charge and about 4-5 gallons of yeast sludge.

Now I have a 15.5gal keg and two 5gal thumpers, so I can load up about 14gal in the main boiler, then put about 2.5gal of mash in each thumper and run it all once.
As far as I can tell the product quality is almost exactly the same if not a little better. The double thumper is power hungry. I use about just as much propane doing a run as I would doing 2 strips and a spirit, but it takes about half the time.

For what it's worth I do insulate my thumpers.
But not my lyne arms

I also typically yield about 7-7.5% on my mashes.

[haggy]

Continuing with the Whiskey One n Done runs with a 10% mash.

Let's see what a very low fill amount ( 0.5 gal of mash) in the 5 gal thumpers will make, and also what half barrel keg thumpers with 10 gal of mash in them will do.

Low Thumper Fill Case

Input Data:
Input your Pot still charge
Initial Volume of Mash 14 US gal
Alcohol Content 10 % by volume
Initial Temperature 30°C
Power during Pot and Thumper Heat-up 3000 W
Power during Distillation 1500 W

Input your Thumper 1 charge
Total Thumper Volume 5 US gal
Initial Thumper Charge 0.5 US gal
Alcohol Content 10 % by volume
Initial Temperature 30 °C

Input your Thumper 2 charge
Total Thumper Volume 5 US gal
Initial Thumper Charge 0.5 US gal
Alcohol Content 10 % by volume
Initial Temperature 30 °C
Ambient Temperature 30 °C

Results
Time to Heat up Pot contents 74 min
Pot volume after last step 7.63 gal
Thumper 1 Heat Loss 47 %
Thumper 2 Heat Loss 43 %

Approx Heads Volume 0.33 gal at ABV about 76 %
Approx Hearts Volume 1.55 gal at ABV about 67 %
Approx Tails Volume 0.73 gal at ABV about 30 %

So, we can get about a 7 % higher Hearts ABV product vs a 2.5 gal thumper charge, but a lower amount is made with this low thumper fill.
Heat losses are high here due to more thumper wall exposed ( by the low fill amount ) and vapor condensing on those walls which removes some heat. That is a premise of the calculations that has been proved by comparing the calculation results with many real data sets. So the thumpers fill up more and the distillate rates are reduced. Thumper liquid ABV after being heated up by the pot/thumper 1 vapor starts high because of the low starting fill, so vapor ABVs are high.


High Fill Keg Thumper Case
Now, we switch to 15.5 gal thumper kegs and fill them with 10 gal of 10% mash and run at a higher 3000 W power level. We use the same 14 gal mash in the pot and preheat the thumpers to get about 25 minute each heatup time from the pot vapor - and we get this:

Results
Time to Heat up Pot contents 74 min
Time to Heat up Thumper 1 contents 22 min
Time to Heat up Thumper 2 contents 28 min
Pot volume after last step 3.81 gal
Thumper 1 Heat Loss 28 %
Thumper 2 Heat Loss 32 %

Approx Heads Volume 1.0 gal at ABV about 62 %
Approx Hearts Volume 4.8 gal at ABV about 55 %
Approx Tails Volume 1.1 gal at ABV about 30 %

So, we can get about a 5 % lower Hearts ABV product vs a 2.5 gal thumper charge, but a much higher amount made with this high thumper fill.
Less thumper wall is exposed and heat losses are lower here. So the thumpers do not fill up as much and the distillate rate is increased. Thumper liquid ABV after being heated up by the pot/thumper 1 vapor starts low because of the high starting fill, so vapor ABVs are lower.


But this high fill case may cause a high back pressure in the pot. A 1 ft column of water would have a back pressure of about 0.433 psi. Each keg could have about 12 pounds of water and tails ( 18 inch height ) at the end of the run, so total of 36 inches or 3 ft of water would give a backpressure of 1.3 psi. You need to decide if this is safe enough before running this case. Another problem might be blockage of solids in the lines or the inlet thumper spear. A pressure relief valve ( PRV ) on the pot is best for a two thumper build. Also, after a run is stopped, an exit valve in the lyne arm from the pot should be opened to the atmosphere to prevent a vacuum in the pot as it cools down.

[Tōtōchtin]

Why should the system be vented from the lyne arm? What are the advantages rather then at the boiler?
Tōtō

[haggy]

Tōtō,
It should be vented at the boiler or in the boiler exit piping. I meant that you can add a Tee and valve in the boiler exit piping rather than on the boiler. Maybe lyne arm was not the right choice of word. But if you think that the piping could plug up before the valve, then it should be vented at the boiler.
Thanks for the question.

[haggy]

The double thumper/retort still has been used mostly for making Jamaican Rum. This is a two-part post on my view of how to make this Jamaican Rum on an HD scale.

Here is a picture of a Jamaican Rum still taken from the following post:

Re: Double thumper
Post by HookLine » Wed Sep 02, 2009 1:01 am
Some rum makers in the Caribbean use a double thumper set up, so it obviously works. Somebody else posted this pic, can't remember who:

Here is a diagram of the Jamaican Rum process done by Harry and is from the same post. There is recycle of high wines and low wines back to the two thumpers for the next batch.

For a long time, there was a question of what the recycled high wines and low wines were, but that has been determined by grim in this post from the Stilldragon forum. Also see the attached definitions.

Heavy Rum - High and Low Wines
grim
5 July 2018 10:43PM edited July 2018 in Usage
Digging through old rum literature, I finally found a clear definition of high and low wines as would be used for charging a double retort still.
Tagged: rumtailslow winesheavy rumhigh wines
This indicates that High Wines are not heads, as some have stated, but that high wines are "early tails" - collected immediately after rum, and low wines are "late tails", collected after high wines.
grim
5 July 2018 11:15PM edited July 2018
Just for clarity - Over Proof and Under Proof refer to the delta above and below 100 proof.
So 20 over proof is 120 proof, and 60 under proof is 40 proof.
Plugging some of the old math into alcodens, it looks like this is based on US, not UK proof.

So, "Rum" is collected from 85+% ABV down to about 75% , then the "High Wines" are collected from 75% ABV down to 50% (100 proof ) , then the "Low Wines" are collected from 50% ABV down to 20% ABV.

We will make a calculator run using the above process diagram, and say that the low and high wines recycle are mixed with fresh 10% Wash. The "Low Wines" are mixed with Wash ( 50:50 ) and recycled back to Thumper/Retort 1 for the next batch. The "High Wines" are mixed with Wash and recycled back to Thumper/Retort 2 for the next batch. I think in order to get the high 85% ABV Rum product, the recycle back to Thumper should be 75% "High Wines" and 25% Wash.

The following table shows the expected amounts of low wines and high wines recycle ( 0.45 gal/34%ABV and 0.6 gal/64% ABV ) and the thumper charges for a run with a pot charge of 12 gal of 10% wash:

image.png (11.91 KiB) Viewed 7543 times

Let's calculate this Jamaican Rum batch distillation process on an HD scale with a 15 gal keg pot and two 5 gal thumpers (retorts ). The pot would be charged with 12 gal of 10% wash and run at 2200 watts power. Thumper 1 would have 0.9 gal at 22% ABV and Thumper 2 would have 0.8 gal at 50% ABV. Whoops, 40% ABV is the maximum charge for safety, but let's see what this exact scaledown will do.

But, I cannot get all the results graphs into this post, the filesize maximum would be exceeded. So, go to the next Jamaican Rum post to see the results of this calculator run and what the distillate ABV, amount collected and other values are vs batch time.

[haggy]

Continuing with the post on following the Harry Chart to make Jamaican Rum.

Here is the Input Data:

Input your Pot still charge
Name Your Run - Jamaican Rum from Harry Chart
Initial Volume of Wash 12 US gal
Alcohol Content 10 % by volume
Initial Temperature 30 °C
Power during Pot and Thumper Heat-up 4000 W
Power during Distillation 2200 W
Riser Added Reflux 6 %

Input your Thumper 1 charge
Total Thumper Volume 5 US gal
Initial Thumper Charge 0.9 US gal
Alcohol Content 22 % by volume
Initial Temperature 0 °C

Input your Thumper 2 charge
Total Thumper Volume 5 US gal
Initial Thumper Charge 0.8 US gal
Alcohol Content 50 % by volume
Initial Temperature 0 °C
Ambient Temperature 30 °C

Results
Time to Heat up Pot contents 48 min
Time to Heat up Thumper 1 contents 5 min
Time to Heat up Thumper 2 contents 6 min
Pot volume after last step 6.39 gal
Thumper 1 Heat Loss 36.3 %
Thumper 2 Heat Loss 28.9 %

From the distillate/vapor ABV graph below:
The "Rum" first cut at 160 minutes is about 1.8 gal at 84% average ABV.
The "High Wines" cut at 220 minutes is about 0.6 gal at 64% average ABV.
The "Low Wines" cut at 330 minutes is about 0.45 gal at 34% average ABV.

The thumpers do fill up somewhat, Thumper 1 to 3.5 gal and Thumper 2 to 1.8 gal but they end up with no alcohol so can be pitched (or saved?). The pot has about 6.4 gal of dunder in it at the finish and can be used in later batches if desired. Refer to other Rum posts to see where/when dunder is recycled.

So, I think this is a good representation of the Jamaican Rum process. If you have other ideas on how this is done, please comment.

I did not add dunder to the pot or thumpers here but it can ( should ? ) be added. Where would you add it? Give me some suggestions and I can try a run using dunder. But the ABV would come out lower because of the dilution of the charge ABV. Also, I did not discuss that high ester compounds can be made ( using dunder ). Someone could weigh in on that.

A good read on using dunder and high ester compounds is in the following post:

Pot still with retorts for high ester Jamaican-style rum?
Post by lamowery » Sat Nov 28, 2015 4:07 pm
Hi,
I posted an intro a few weeks ago as a journo looking for folks to comment via their forum ID only (no real names), on producing pot still, high ester Jamaican-style rum with dunder.

Specifically, I want to hear from anyone who is focused on this style predominantly. Why did you choose it? Did you have an experience with high ester rum either in Jamaica or elsewhere that imprinted on you? Do you try to emulate the style because of the unavailability of the product in the market or your curiosity and propensity to experiment? Has anyone actually built a system with retorts and used with dunder? How well does it work?

Thank you in advance.
Lauren

In this post, wtfdskin makes several good comments and describes his process and the run he made on the hobby HD scale. It is fairly close in ABV to what I ran here. He put dunder in both thumpers. His "Rum" ( heads and hearts ) came out at 81% ABV with a lot of flavor. I will discuss his run in my next post.

[haggy]

I have found two posts describing Jamaican Rum runs made similar to the Harry diagram, a run by wtfdsin and another by Hillbilly Popstar. They both recycled heads and tails from previous runs to the thumpers, not the early tails and late tails like grim discovered. And wthdskin mixed them with dunder, HbP mixed them with wash. Here are the posts.

Re: Pot still with retorts for high ester Jamaican-style rum
Post by wtfdskin » Thu Apr 14, 2016 2:29 pm
Well here we go. Finished up the build and cleaning / sac runs. First run of rum with double thumper is under way.
Charged boiler with 12 gal 10% wash, 1 gal 50/50 rum tails and dunder in 1st thump, 1.75 gal 50:75 rum heads and dunder in second thump.

Here is my calculator Excel simulation for the wtfdskin run.
First the thumper charge estimate:

image.png (11.9 KiB) Viewed 7488 times

Input your Pot still charge
Name Your Run wtfdsin rum run w dunder
Initial Volume of Wash 12 US gal
Alcohol Content 10 % by volume
Initial Temperature 30 °C
Power during Pot and Thumper Heat-up 3000 W
Power during Distillation 2000 W

Input your Thumper 1 charge
Total Thumper Volume 7.5 US gal
Initial Thumper Charge 1 US gal
Alcohol Content 16 % by volume
Initial Temperature 30 °C

Input your Thumper 2 charge
Total Thumper Volume 7.5 US gal
Initial Thumper Charge 1.75 US gal
Alcohol Content 32.6 % by volume
Initial Temperature 30 °C
Ambient Temperature 30 °C

Results
Time to Heat up Pot contents 60 min
Time to Heat up Thumper 1 contents 6 min
Time to Heat up Thumper 2 contents 14 min
Pot volume after last step 6.24 gal
Thumper 1 Heat Loss 38.1 %
Thumper 2 Heat Loss 35.3 %

Here are the charts of key variables vs time of the run.

And wtfdskin made these remarks:

Re: Pot still with retorts for high ester Jamaican-style rum
Post by wtfdskin » Thu Apr 14, 2016 7:42 pm

One hour heat up time then ran a super thin stream. 5.5 hours since I lit the flame, just switched to quarts from pints and turned up the heat to run out tails for next time. Could have done that just a little sooner. Heads and hearts came through at 160-162 proof and by far the most flavorful I have made yet. Sweet but not molassey.

Here is the post by Hillbill Popstar:

Re: HbPs' double retort potstill build.
Post by Hillbilly Popstar » Sun Apr 10, 2022 7:19 pm
This run was an all Panela rum. 2 days into fermentation I infected the ferment with about 2 gallons of live dunder.
The still was loaded as such:
Main boiler:
14 gallons of 8% panela wash
1st Retort:
2 quarts of rum tails plus 2 gallons of fresh panela wash
2nd Retort:
A gallon of rum heads plus a gallon of fresh oanela wash

He used wash to mix the heads and tails with for the thumper charges. The Thumper 1 charge was 2.5 gal at about 13.4% ABV. The Thumper 2 charge was 2 gal at about 40% ABV. His results were similar to the wtfdskin post and to my simulation of the Harry chart. He remarked:

The first pint from this run smelled so good from 6ft away it made my mouth water and the proof weighed in at 178 proof.

So, Jamaican Rum can be made on the HD scale. You can use dunder in the ferment and early tails and late tails in the thumpers and mix them with wash. The heads can mostly get esterified and be a flavorful part of the product.

Next, a very good use for two thumpers: Steam stripping of an all grain mash in Thumper 1 and using Thumper 2 to raise the ABV and make the cuts.

[BlueSasquatch]

Not specifically a dual thumper question, but it is thumper related. If I have two 15 gallon kegs, one for creating steam, to feed a 2nd thumper keg that I would like to fill with 10 gallons mash (distilling on-grain) how much water do you think I'd need to have in the steam keg? One doesn't want to run out, but why have way more than you need?

[haggy]

Thanks for the question. I can answer that using the Haggy Pot Thumper calculator in the HD calculator section.

So, I plugged this data into the calculator:

This run starts with 10 gal water in the first keg. The second keg has 10 gal of on grain mash at 10% ABV. The pot keg is run at 2000 W.

Here is the top and bottom pages of the results:

Lot of information there to see what the run will make. And you can see in the second box that the pot volume after the last step was about 7 gal of water remaining if we stripped the 2nd keg down to about 24% ABV in the exit distillate ( end of the tails ). Using a different power level will just change the time it takes to get to the 24% ABV

I did this with same run with 7 gal water starting in the pot and with 4 gal to start with. Results were:

Pot charge Water Remain in pot
10 gal-------------7 gal
7 gal -------------4 gal
4 gal -------------1 gal

So, 3 gal water will be vaporized to steam to do the job. Other results were the same in each case. And water usage is about the same for a mash that is in the range of 8 -12% ABV. Adding a second thumper will raise the product ABV higher.

You can decide how much you safely want to charge the pot from this data.

The graphs from my Excel spreadsheet program.

[BlueSasquatch]

GOLD

Wow that's awesome! I appreciate you taking the time to plug it in and share, I'll go track down that calculator down, I'd be interested in messing with the numbers some and then recording my field numbers to see how they line up. I use quite a few calculators for mashing, and then some for proofing, but haven't found many good ones for the distilling part.

I'd be using a 5500watt element the entire run, stripping.
Is "power during initial heads run" for the thumper, if you have a heat source for the thumper?
Having a "total distillate" collected under the head/heart/tail portion, could be nice. I'm using my thumper as a on-grain stripper.
There is a time to heat up pot, time to heat up thumper, could there be a end-time?

I understand alot of these numbers are guides more than exact, but could be nice to know.

[haggy]

Blue,

Ok, you are using a higher power level to strip.

All power is into the pot, not into the thumper. You can specify a lower pot power for the heads portion and the end time of that power level. Sometimes that is good for spirit runs. See the example below.

The following screenshots are the inputs and estimated results close to your run.

Look at the last row of the Table. That is the end time of the run. And that row also gives the end total volume collected in one of the columns. I did not put that info up above. In a future update to the program, I could put the total amounts and end time with the other info above. Look for this in my next posts.

Also, notice that in this post, the HD program has been updated to allow inputs of gal or liters and C or F temperatures. Maybe I will submit the updated HD version soon.

The Table says:
The end time is 100 minutes and the low wines collected are about 3.1 gal at 33% ABV with the ABV out the spout about 10% ABV.
Likewise, if you want to stop the run at 20% out the spout, the table says to stop the run at 76 minutes and you will get about 2.28 gal at 39% ABV low wines.

[haggy]

Let's talk abut steam stripping on the grain mash some more.

And let's compare one thumper vs using two thumpers.
We will make two strip runs with one thumper and collect the low wines to charge to a final spirit run. The spirit run will be comparing the hearts made with one thumper vs that with two thumpers. The amount of hearts made is calculated from the heads gal made down to gal made at 40% ABV out the spout


Here is the strip run with a 10% ABV grain mash in the one 15.5 gal keg thumper. The pot is also a 15.5 gal keg with 10 gal of water.

So, the two strip runs went down to 20% ABV at the spout in about 2 hours and collected about 4.6 gal at 39% ABV.


One Thumper Spirit Run

We will put the low wines in the pot and add water to get to a 9 gal charge at about 20% ABV in the pot. We will charge 10 gal more of on the grain mash in the thumper and do the run. Here are the inputs and results.

So, the spirit run made 2.56 gal of hearts at 55% ABV. That would be 2.8 gal at 50% ABV.


Two Thumper Spirit Run

Here we take the low wines and charge half of them to the pot and the other half to the Thumper 2. The pot will have 9 gal of 10% ABV, the Thumper 1 will have 10 gal of the on the grain mash and Thumper 2 will have half the low wines, 2.3 gal at 39% ABV. The Thumper 2 will be a 7.8 gal keg. Here are the inputs and results.

Sorry, could not get the files loaded, not enough file space. Will show them in the next post.

But, this spirit run made 2.8 gal of hearts at 70% ABV. That would be 3.9 gal at 50% ABV.


Comparison

So, running the spirit run with two thumpers will get you about 1.1 gal more hearts at 50% ABV.

Why so much more?
More gal are made at a higher ABV going down to the 40 % ABV out the spout might be the main reason.
Better separation of the hearts? - Less alcohol left in the kegs? -
The higher ABV at the start helps - is more efficient?

Is this what we should expect? Any other ideas why or why not?

[haggy]

Continuing with on the grain mash steam stripping and comparing one thumper vs two thumper spirit runs.

Two Thumper Spirit Run

Here we take the low wines and charge half of them to the pot and the other half to the Thumper 2. The pot will have 9 gal of 10% ABV, the Thumper 1 will have 10 gal of the on the grain mash and Thumper 2 will have half the low wines, 2.3 gal at 39% ABV. The Thumper 2 will be a 7.8 gal keg. Here are the inputs and results.

The screenshots of the inputs and results are:

So, we started with 30 gal of 10% ABV on the grain mash and made 3.9 gal at 50% ABV hearts with this two thumper still. The one thumper still made 2.8 gal at 50% ABV. Steam stripping was used for 20 gal of mash and the other 10 gal of mash was stripped with alcohol/water vapor.

Barrel strength is 125 proof / 62.5% ABV. So, we made 3.1 gal hearts at 62.5% ABV. That is about 1/10 of the 30 gal 10% ABV mash and just about agrees with the following post.

Re: Standardized Hearts Yield
Post by DeepSouth » Sun Dec 04, 2016 12:53 pm

I average about 65% yield of hearts in my bourbon. That's 65% of all the potential alcohol created in the ferment. For example, if I made a 100 gallon batch and fermented to 8% ABV, using 2 lbs per gallon of grain, my fermenter would have 8 gallons of 200 proof alcohol in it. 65% of this is 5.2 gallons of pure alcohol. If all of my heart's were collected and diluted to barrel strength of 125 proof, I'd have about 8.3 gallons to put into a barrel. In reality, I recycle some heads and tails into spirit runs, so my yield is a little higher than that. It works out to roughly a rule if thumb to 1/10 of the mash volume will be my heart cut at 125 proof to go in a barrel. So 100 gallons of mash ends up making 10 gallons of 125 proof whiskey to go in a barrel, if I'm recycling heads and tails and redistilling them.

Anyone have experience with doing something like this? Any comments?

[haggy]

One Thumper or Two Thumpers - any advantage of one over the other in a standard strip and spirit run operation?
Let's compare them.

We will start with 46 gal of 10% mash or wash to be charged to each still and compare how many gal of hearts can be made in the spirit run, and also compare the total run times for each setup. Grains are to be separated in a mash to prevent scorching.

The strip run in each case will go down to 32% ABV out the spout and collect all distillate as low wines ( except fores ). The low wines will all be charged to the pot or thumpers for the spirit run. The spirit run will go down to 33% out the spout and make cuts to get the amount of hearts made. Hearts are calculated by the amount and purity made down to 40% ABV out the spout minus the heads which contain 20% of the total alcohol charge.

One Thumper Strip - Two Runs
The one thumper setup will have a 15.5 gal boiler pot and a 15.5 gal thumper keg. The strip run starts with 13 gal mash/wash in the pot at 30 C and 10 gal wash in the thumper at 60 C. Power is 4000 W for heatup and also for the run. Two strip runs are needed to use up the 46 gal of mash/wash. Here are results of one strip run for the one thumper. The Total Distillate Volume are the low wines.

About 3.5 gal of low wines at 51% ABV are made in 175 minutes (123 + 52 ), about 3 hours. Must do two strips here plus setup time to use up the 46 gal wash and make 7 gal low wines at 51% ABV in about 6.5 hours. So, that is 8.9 gal at 40% ABV.

One Thumper Spirit Run
In the thumper, we charge 2 gal of the 40% ABV at 60 C and the rest ( 6.9 gal ) is put into the pot along with water for a total of 10 gal. That would give 27.6% ABV in the pot to start. The run is at 3000 W power. Results of this spirit run are:

About 3.5 gal of Hearts at 75% ABV are made, or 4.2 gal at 62.5% ABV barrel strength. The run time is about 206 min ( 174+32 ), call it 3.5 hours. So that is about a total of 10 hours for the three one thumper still runs.


Next
Two Thumper Strip Run
We use three 15.5 gal kegs now and can do a strip run with the 10% mash/wash in each. The pot has 13 gal and the two thumpers 10 gal each. The remaining 13 gal mash/wash will go to the pot in the spirit run. So, we only need one strip run here. The thumpers are preheated to 60 C and the pot is heated up at 4000 W and the run is made at 4000 W, just like the one thumper run.
Results of the strip run follow. The Total Distillate Volume are the low wines.

This run takes 302 min ( 250 + 52 ), so 5 hours. It is longer than the one thumper run, but we only need one strip run here. About 5.3 gal at 53% ABV low wines are made, and we dilute that to 7 gal low wines at 40% ABV.


Two Thumper Spirit Run
We put the 13 gal 10% ABV mash/wash in the pot and will run it at 3000 W. And 2 gal of 40% ABV goes into the second thumper at 60 C. The remaining 5 gal 40% low wines is put into first thumper with 5 gal water to give 10 gal at 20% ABV in the first thumper.
Results of the spirit run are:

About 4 gal at 73% ABV are made, which gives 4.7 gal at barrel strength 62.5% ABV. The run time is 344 min ( 292 + 52 ) , almost 6 hours. So, a total of 11 hours to make these two runs using the two thumpers.


Comparing the Above Results - One Thumper vs Two Thumpers

The main difference above is that only two runs, not three, are needed for 2 thumpers. But the total run time is slightly longer when both cases are run at the same pot power levels. Not a big difference in run time, a difference would be seen if the power levels used in each case were different. The final amount of hearts made is close, about 0.5 gal more for 2 thumpers. Nice, but not that much.


Conclusions of This Thread
There is a slight advantage for using 2 thumpers in the amount of hearts made and a good advantage in doing one less run in a strip and spirit type operation. But, maybe this is not so much an advantage for most stillers to switch to two thumpers for making a whiskey.

However, as we have seen, two thumpers do have an advantage for making a High ABV Rum product and for steam stripping mash on the grain. And, two thumpers can do a One and Done Run with a 10% ABV mash/wash and make close to barrel strength ABV. That is a good advantage.

So,
I hope this thread has informed you more on the pot with two thumpers operation.
That is all I have for now.
haggy

[rubberduck71]

Clandestine timing on this topic. I was doing some runs on a buddy's rig with a thumper & though to myself, "would there be any time savings and better product/yield if I could hook up a 2nd thumper?"

Thanks for the detailed info!

I'm ordering a thumper for my 8 gal rig, but excited to see it hooked up to the larger 15 gal rig borrowed from my bud.

[Bolverk]

Hey Haggy, these are fantastic, please keep them coming!

I'm am curious if the calculator takes into account the additional pressure ie higher boiling temps in the main boiler by having deeper or multiple thumper/retorts?

[haggy]

Bolverk,

Thanks for the comment. No plans right now for more stuff, but, I will try to come up with another application or find a post with some run data to simulate and compare.

I think I once estimated the pressure rise in the pot running with two thumpers to be about 1 psi and 1.5 psi at the most. The two thumpers were each about 9 - 12 inches liquid depth. Transfer lines were not long.

I do not include the effect of a pressure rise or a different atmospheric pressure on the normal pot boiling temperature or the amount boiled over. Providing an estimate of the possible pressure rise through the thumpers might be a good idea.

haggy

[Bolverk]

I think I once estimated the pressure rise in the pot running with two thumpers to be about 1 psi and 1.5 psi at the most. The two thumpers were each about 9 - 12 inches liquid depth. Transfer lines were not long.

I do not include the effect of a pressure rise or a different atmospheric pressure on the normal pot boiling temperature or the amount boiled over. Providing an estimate of the possible pressure rise through the thumpers might be a good idea.

The reason I ask is I'm going to be making two tall skinny retorts first out of 4" spool with 3g capacity, second out of 3" with 1.5g (i have a 7.75g keg for a boiler). They will be 54" tall and create about 2psi back pressure each when full. They whole point is to emulate some of the pressures generated in the 3 chamber still at Leopold. At 2psi my boiling temp should be around 219f and at 4psi I should be right around 225f.

I'd be very interested in seeing the numbers run through your calculators with these pressures with the Caribbean rum process (high/low wines as described in that drawing that's posted).

[haggy]

Wow, tall, skinny thumpers. Not sure that is the way to go. I hope others can give you some advice and support. Safety first. I think you know enough and will have the proper pressure relief valve and setting.

Also, I passed on reading about the 3 chamber Leopold still. I will go read up on that.

And, the Hobbybrennen web site calcs do have an absolute air pressure setting ( in hPa ) built into them. I worked with Hugelwilli when we ( at the same time ) were each developing our two thumper models. I compared the results of our two thumper calculators and found where they agree in the critical heat losses estimate.

So, maybe by using both two thumper calculators I can see the pressure effect and get the proper results.

I will scale down the initial charge numbers in my March 3 post to fit your equipment sizes. Those charges gave the very high hearts %ABV.

Stay tuned.

[Bolverk]

Safety first, and yes absolutely will have a PRV.

The conversation surrounding the 3 chamber is really fascinating, especially in regards to the higher pressures they operate under and esters and oils that can be generated.

Here's a few other threads on SD

https://www.stilldragon.org/discussion/ ... r-still/p1
https://www.stilldragon.org/discussion/ ... ort#latest
https://www.stilldragon.org/discussion/ ... l-build/p1

My personal specs, 1650w element 6g boiler charge, 8% wash, the rest follows the Caribbean rum formula

Awesome man! Looking forward to it!

[dukethebeagle120]

Nice write up.
But through experience there isn't much us in running two thumpers..
Take alot of power to run.
Strips then spirit run will get you there faster.
Imho

[haggy]

Bolverk,

OK, I will look at two run conditions - the same pot charge with two different thumper charges but at the same % ABV.

Run 1
First is a close scale-down ( by 50% ) of the above Jamaican Rum conditions and charges. The problem here is that the thumpers have low starting charge ( fill ). Low thumper fill gives a higher % ABV distillate. Thumper 1 will have 0.45 gal, Thumper 2 has 0.4 gal charge. So, the depth of liquid is 8.5 and 15 inches and total pressure drop in thumpers is only about 1 psi.

The volume in both Thumpers will fill up considerably during the run. This is because of more heat losses in both thumpers that will give less vapor off. They both keep filling up during the tails and a cutoff point at 20% ABV out the spout is best to prevent excessive fill up.

There is some pressure drop in the transfer lines, you estimate that. The total pressure in the pot is lower than what you want.

Run 2
Second, I will try to maximize the charge ( fill ) of the thumpers. Here the thumpers fill up some initially while they are being heated up but do not fill up much during the run. Thumper 2 decreases a little. Why? ( later ) We should try 1.5 gal at 22% in Thumper 1 and 1 gal at 40% in Thumper 2. That gives liquid depth of about 28" and 38" for a total of about 66" - 5.5 ft. Pressure drop may be about 2.4 psi plus transfer lines pressure drop.

The product % ABV and recycle early tails and late tails % ABV for this run will be a little lower than the first run but maybe be close enough for a good product. Plus, you make more product here.

Comments?
So, Run 2 would be best for you to try when I confirm the inputs and results. Do you estimate a different ( higher ? ) pressure drop for these liquid depths? What is the transfer lines pressure drop? Is this enough pressure drop to give you the pot pressure that you want?

Let me know:
Do you have a long riser off the pot? It can give some passive reflux and raise the %ABV.
Are you able to set and control the power? I will estimate a wattage to run for both runs.
And for sure, insulate both thumpers well to reduce heat losses and have less fill up during the run.
Check my pressure drop estimates and transfer line pressure drop.

haggy

[haggy]

duke,

Maybe so what you said.
There are not many posts on double thumpers. But I saw a few that were very positive. Here are two of them:

Re: 2 thumpers?
Post by skow69 » Wed Jul 16, 2014 6:34 am
Go for it. I've run double and triple thumpers successfully. It doesn't take as much heat as you'd think because the increasing ABV lowers the boiling point a little in each repetition. I'm back to running a single now, but I'm glad I did the experiment.

Re: FIRST TIME THUMPER HELP Sept 2017
nuntius01 wrote:
remember the first time i ran mine. scared me to death. now, i dont even notice it. wait till you add a second thumper and they both are just purring along.
Building my second thumper was the best mod I did. I never do a run without the twins now.

Maybe there is less power required than you think. Insulation is a must. Burner gas if used can be inefficient.

There are several pluses ( as I mentioned in posts above ) and a few minuses for two thumpers, but mostly pluses for one thumper.

haggy

[Bolverk]

Comments?
So, Run 2 would be best for you to try when I confirm the inputs and results. Do you estimate a different ( higher ? ) pressure drop for these liquid depths? What is the transfer lines pressure drop? Is this enough pressure drop to give you the pot pressure that you want?

Let me know:
Do you have a long riser off the pot? It can give some passive reflux and raise the %ABV.
Are you able to set and control the power? I will estimate a wattage to run for both runs.
And for sure, insulate both thumpers well to reduce heat losses and have less fill up during the run.
Check my pressure drop estimates and transfer line pressure drop.

Run 2 does seem to be the better choice and will more closely emulate what is I'm going for.

Yes, I'm counting on the thumpers filling up to get that needed back pressure on the boiler. Just need to determine the initial fill volumes and abv.

I have a 4" 26" tall single plate column that reduces down to 2" at the lyne arm. I'll remove the plate/packing when running the retorts. Rough estimate is I'll need 18" of 2" at an upward sloping 45° angle to get to the retort.

Yes, I can control the power input.

Sorry I don't know how to check pressure drop, I looked at a few sites and am still not sure how to give you those numbers.

[haggy]

Bolverk,

The thumpers should have about 20% free volume above the liquid level at all times. You do not want to tempt puking. So about a 45 inch liquid depth maximum in each thumper. The hydrostatic pressure of a 1 foot column of water is 0.433 psi. We have a mix of alcohol and water so that is about 0.4 psi per foot. So, two thumpers have 90 inches depth or about 7.5 feet. So, 7.5 X 0.4 is about 3 psi max pressure drop in the two thumpers. That is about a 20% increase in the normal atm pressure that the pot runs at ( maybe it is a little higher than atm ).

The normal pot temperature at 8% ABV is 93.9 C and at 17.7 psi, it is 98.9 C, that is about 210 F.

Continuing at the 17.7 psi pressure, the pot temperature rises during the run up to about 102.5 C ( 216.5 F ) when the pot is down to 4% ABV. At 1% ABV remaining, the pot temp is about 104.6 C ( 220.3 F ). The pot temperatures are gotten from calculations in Hobbybrennen.

Is this enough pressure and operating temperature increase to make a difference in the product?

haggy

[Bolverk]

I'll have about 9" of 2" spool above the thumpers that I'm not counting as part of the thumper volume. If there is any foaming or puking I'm hoping that w8ll contain it

That makes sense.

I guess we'll see, my goal was 4 psi but even at 3 psi I should have a noticeable temp increase I'm hoping that should make for a more interesting rum.

Thanks for putting all that together. I appreciate it!