New thumper for pot still

[Bigchambo84]

Sooo... I have been reading a lot on here and there is a lot of information on pot stills and thumpers. So my original set up that I made utilizes two 15 gallon beer kegs, one as the boiler and the other as the thumper. The one picture shows my copper pipe assembly going into my keg thumper. I actually made my first run without the thumper, my thoughts were that the system after the boiler was large and long, I was not confident it was going to hold temperature until it got to the condenser. Oh, and I am only doing 5 gallons at a time for now since my fermenter capacity is only about 7 gallons. I have been reading on here the various opinions on thumper size, some say there is no set size and I read on here that it needs to be about 1/2 to 1/3 capacity of boiler. My question, is there a such thing as too big or two small. In reading, it seems that a lot agree it is a good idea on a pot still to have a thumper. I ask about size because I was designing one from 2” cooper pipe I had left over from building the still. My new design is attached, the drawing on white paper. Is it worth making a thumper like that? Will it be effective? Thanks for all of your wisdom and guidance.

With thumper

Without thumper

Design of new idea

Copper pipe in the thumper

[Bigchambo84]

Or I need to get a pony keg, a 5 gallon one but those seem hard to source around here.

[Corsaire]

Equal sized thumpers aren't a problem. Quite a few people here use a keg boiler feeding a keg thumper.
You don't want too small a thumper because it will overfill during the run.

Regarding your drawing, that 2" tube doesn't need to go down into the thumper.

[Yummyrum]

If you are suggesting using the 2” as a thumper instead of a second keg , forget it . Its just too small and will fill way too soon at which point it’s contents will be forced out the spout .

That is why absolute minimum thumper size should be 1/3 boiler size

[Bigchambo84]

Thanks gentlemen!

[OtisT]

Hi.

I’m looking at your rig and noticed the holes in the side of your thumper spear that go up the pipe a fair distance. The top set of holes is going to determine your minimum volume for the thumper, and for me that min volume level would be a bit much. There are times I want a minimal volume In the thumper that I expect to grow somewhat during the run. With you only creating 5 gallons of ferment at a time, lowering the first set of holes could reduce your total run volume needs and Potentially reduce your time between runs by A full ferment cycle. The impact of this all depends on what you do with your thumper, of course.

As for holding temp, insulating your boiler, the arms between boilers and insulating the thumper will reduce the time to start producing and increase your production rate a noticeable amount.

I run a 1/2 bbl boiler and several different sized thumpers, depending on what I am doing. I run the 1/2 bbl mainly for stripping, and I like my 1/6 bbl or 1/4 bbl keg thumpers when I am doing a spirit run or messing with adding flavors. Because my kegs are all the same height, just different diameters, I can use the same thumper head for all of my different sized thumpers.

Otis

[Bigchambo84]

So should I shorten the pipe that goes into the thumper? I was thinking that I should but was still thinking in that. Right now the end of that pipe is only a couple of inches off the bottom and I worry that eventually when the thumper gets fluid I will choke off the vapor from continuing into the thumper and into the condenser. And yes ideally I would love a 1/6 keg for a thumper. If I had two 1/6 kegs I could essentially down the road run two stills at the same time. I know that is a little crazy, but I am always thinking about things. My mind does not stop.

Or actually if I am hearing you right, have the holes lower on the stem going in. Don’t have them so high?

[Bigchambo84]

I will also buy some insulation for the copper pipe as it goes to the thumper.

[Bigchambo84]

Otis, your still is amazing.

[OtisT]

So should I shorten the pipe that goes into the thumper? I was thinking that I should but was still thinking in that. Right now the end of that pipe is only a couple of inches off the bottom and I worry that eventually when the thumper gets fluid I will choke off the vapor from continuing into the thumper and into the condenser. And yes ideally I would love a 1/6 keg for a thumper. If I had two 1/6 kegs I could essentially down the road run two stills at the same time. I know that is a little crazy, but I am always thinking about things. My mind does not stop.

Or actually if I am hearing you right, have the holes lower on the stem going in. Don’t have them so high?

So my thought was to leave the pipe the same length (ending 2” from the bottom of the thumper) but plug all of the holes on the side of that pipe, except for possibly the very bottom set or two. If you make the pipe shorter, your minimum volume will increase. Wherever that top opening In the vapor path is placed, that will be your minimum volume level for operation.

Having the vapor pipe opening so close to the bottom without a diffuser will make you thumper pretty darn loud, especially at the beginning of the run. You’ll hear all sorts of pops and bangs as vapor collapses next to the bottom of the keg, causing it to ring like a bell. Insulation will also help with the noise.

The best of both worlds would be having a low diffuser. I have seen where a few folks put an elbow at the bottom of their down pipe, with a short Horizontal pipe off of that elbow, capped at the end. (You need to be able to get that into your thumper.). They drilled holes in that short pipe section and cap to diffuse vapor, which should help reduce noise and increase efficiency of the heat transfer.

Otis

[Bigchambo84]

Okay, so same length but only have one maybe two holes at the bottom. I can do that. As it is now, the end of it is like 3” From the bottom.

[Bigchambo84]

Actually, I like the diffuser idea. I could snake that in maybe.

[seabass]

Having the vapor pipe opening so close to the bottom without a diffuser will make you thumper pretty darn loud, especially at the beginning of the run. You’ll hear all sorts of pops and bangs as vapor collapses next to the bottom of the keg, causing it to ring like a bell. Insulation will also help with the noise.

This is how I have mine set up. Holy shit it's loud when the thumper liquid is cold. I was very concerned the first time I ran it. Sounded like someone hitting the keg with a wrench. It subsided as everything heated up. Now I'm used to it, but the 90deg diffuser is a good idea.

[still_stirrin]

Have you ever heard a “klinker”, a steam heat/radiator system that has condensate in the pipes as it is “coming online”? Sounds like someone hitting the jail bars with a hammer. It’ll wake you up for sure.
ss

[Beerswimmer]

Mine(a 16g keg) doesn't klang, but sounds like someone with no rhythm is trying to do a drumroll on the thumper. Only about 20mins or so. Once it's hot it's silent.

[BlackStrap]

There's a few on here with a similar setup. This is mine... mine sounds like someone snapping their fingers, but like SS said there is no rhythm. LOL

this is a shot with out the thumper, a cleaning run to take care of the flux and other nasties that may be present in the arm that goes into the thumper.
It's modular, so I'm able to steam cook corn with it as well.
Credit goes to MichiganCornHusker (a fellow member on here) He's the one who inspired me to build this.

[Bigchambo84]

Blackstrap, what did you do to get the clean out in the bottom of your boiler? I have seen this on a lot of keg boilers but I am hesitant to cut into mine!


I am going to go get supplies tonight to make the diffuser at the bottom of my stem going into the thumper.

[BlackStrap]

This is a 2 boiler system (1st boiler has wash or water converted to vapor) 2nd boiler some would call a thumper, which it can be. (It's all about terminology) Right fellas?

First boiler has no solids, it is what powers the system with a 5500 ULWD element. It has a 1/2 FNPT at the bottom and a 1/2 ball valve for drainage. The 2nd boiler (thumper) has a 1 1/2 drain on the bottom (sometimes I like fermenting and distilling on the grain, so I needed a bigger valve for the solids)

On a typical run the 1st boiler will add about 2 1/2 gallon to the 2nd boiler, once things are up to temp and you are collecting... The volume in the 2nd boiler level out with a slow rise in fluid level (depends on how well things are insulated)

The top of the first boiler also has a 2" tri clamp with 5lb pressure relief valve (just in case) but it can be removed and more wash or water added to the boiler fairly easy. (gotta keep the element covered) This works out really nice when you have a lot of wash to process on a strip run and need to refill the boiler with out having to reseal everything...also when shutting down, if you "pull" the pin on the top of the relief valve nothing gets sucked back into the first boiler, from the 2nd boiler.

the tops of both kegs are cut out and the lid is held in place with 8 stainless 1/4 x 20 bolts fender washers and wing nuts secure everything in place, a golf ball size flour water paste seal keep the vapors going where they need to.

(on a different version of this setup the first keg does not need to have the top cut off)

When the run is finished, just siphon off what's inside, give it a good rinse, (inspect the element for anything stuck to it) and you are good to go for the next time.

[The Baker]

Blackstrap, I love the wooden 'stands' with the slot for the drain.
So simple but i never thought of that.

Geoff

[Twisted Brick]

It's modular, so I'm able to steam cook corn with it as well.

Blackstrap,

Thanks for sharing your thumper designs. It appears on the second boiler wand that you split the vapor path into two opposing directions. How does this perform? It looks like it would reduce the collapsing vapor bang by 50% and maybe even create a whirlpool if the thumper charge was cleared wash. I like the idea that the larger exit diameter would greatly reduce the chance of a blockage.
.

Blackstrap 2nd boiler wand.jpg (26.97 KiB) Viewed 3328 times

Your symmetrical diffuser looks like it utilizes the outside ss sheath from flexible tubing, correct? Does this diffuse the vapor bubbles fairly uniformly?

Thanks for any details you can provide.

Twisted

[BlackStrap]

It appears on the second boiler wand that you split the vapor path into two opposing directions. How does this perform?

Well Twisted in a clear wash the opposing wirlpool effect was what I was after, and for a clear wash it worked well. However running through wine leas, or through a grain bed, when distilling on the grain, the openings were too large, and it plugged up...
Another reason to never leave a running still unattended
This picture the modified "lower" part of the diffuser

IMO the diffuser works better...The stainless have smaller openings so solids would not enter and "build up" while coming up to a boil, and steam bubbles passing through the diffuser are smaller will have more surface area to heat what ever was in the 2nd boiler, shortening the heat up time.

Your symmetrical diffuser looks like it utilizes the outside ss sheath from flexible tubing, correct?

Yes they are the outer stainless coverings off of pressure hose (Wal-Mart plumbing dept.) believe the one used is 3/4" x 24" gave enough stainless braid for the modification...

[Twisted Brick]

BlackStrap - Thanks so much for the clarification. Much appreciated!

Twisted

[Yummyrum]

Love your work BlackStrap

[Bigchambo84]

Thank you for all the wisdom, guidance, and awesome builds! After some suggestions, here if the simple diffuser for the stem into the thumper. I also have insulated the 3/4” pipe. Now to make another run!