My 22mm continuous “Koffie” still with a twist.

We don’t condone the use of Continuous Stripping stills as a method of running 24/7 as this is a commercial setup only .
Home distillers should never leave any still run unattended and Continuous strippers should not be operated for longer periods than a Batch stripping session would typically be run to minimise operator fatigue..

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Lafras-H
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My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

A few months ago I posted in the Welcome Center about the intrinsic safety features of my 22mm continuous “Koffie” still. As I was preparing a draft post on how it worked and how much I thought it was such an ideal hobby size, liking it to the “Airstill of continuous distillers” when a hell of an idea struck me.

The Airstill is appealing to beginners because it looks safe, it looks and feels like something that is familiar in your kitchen. It does not look like a hill-billy contraption waiting to fall over or explode if you make a mistake. Unfortunately, most beginners that try the Airstill lose interest in the hobby after a few weeks partly because of all the effort it takes to make a little product in such a small still. I believe if there are familiar and convenient kitchen appliances that anyone can use, it will help to normalize home distilling in the eyes of the general public.

So I set my new mission - that home distilling should be just as safe and feel just as familiar and convenient as making bread in a bread maker (since both use yeast).
Regarding a comment on a Pico distiller thread by CatCrap: “It kind of makes a joke out of this craft. It grossly oversimplifies the art and craft of Distillation, and everything that goes along with it“. I do get that some may feel this way but I don’t see why an easy induction to the hobby would detract from the craft, after all, master bakers did not become redundant when bread maker appliances became popular, it just made making your own bread more popular, and likely inspired a new generation to get back into home baking and off shop bought confectioneries.

So next time some wise-ass criticizes our hobby with "Don't blow your house up" or "Don't poison yourself" you could say modern distilling is just safe as making bread. We should want everyone to know someone who distills. Hopefully, that will change the general public's perception and advance the legal status of the hobby.

Well, since that epiphany I have been working frantically to make it into a product and the result is amazing - I still cannot believe what I have made in such a short time.

I do not intend to it sell here on HD… experienced distillers are not my market. There is no way a convenience like this will be a substitution for the art and craft of an experienced distiller, like a master baker won’t use a bread maker I doubt an experienced distiller would use my appliance.

So, I am not going to give a brand or website or any sort of sales pitch – it is not live yet anyway – this if the first public information on this project. Rather my intent is to share with the community a little about what it does and how I dealt with various issues so that if some newbie later sees it in the market and asks a question about it here on HD, the members will know about it.
SidebySideOnBarrel.png
The design is a compromise between form and performance, it processes only about 10 litre of wash a day, and produces just under 1 litre at 90% which is more than a novice distiller for their own use should ever need, so it does not really matter that it runs very slowly...it will slowly work its way through any volume wash.

DiagramText.png
[a simplified diagram]
Internal.png
[Without covers and thermal insulation]

Without the powder-coated aluminum covers and thermal insulation, we can see most of what is going on.

The copper spiral I have dubbed a “trumpet”. Compared to “flutes”, this sort of looks like a trumpet. Only cold low ABV wash gets pumped via a silicone tube into the trumpet, the rest of the path is all copper with stainless steel 316L SPP. There are no plastics anywhere near the path.

It has to be periodically cleaned in place(CIP) using citric acid which is why I chose the packing to be SPP 1mm 316L Stainless steel wire(which is quite big for such a small still). I found the thin strands of copper mesh start to decompose and “turn into mooch” after a just few run/clean cycles but the 1mm thick SS lasts, showing no signs of wear even after dozens of cycles.

The boiler is 50cc, there is a fitting at the bottom to get a brush into the boiler just in case it got scorched. The boiler PTC heaters can deliver 160W, but Vodka is run at about 60W.

I cast molten aluminum in a rectangular block around the 22mm boiler tube to evenly distribute the heat around the tube and have some thermal mass to smooth out the PWM signal that drives the two 80 Watt PTC heaters.

It is a completely open system from the boiler to the vent, there are no valves that could block up the trumpet, and even if the vapor path was blocked the waste path would still be open. (during development and testing when I used higher power heaters and put too much energy into the boiler for all the pressure to leave via the column I got quite violent spurts out of the waste but at least it did not create a pressure hazard and in production units power is limited by the smaller PTC heaters and further by software). Worst case if the boiler control fails it will result in a software shutdown of the pump, a dry boiler, and PTC heaters that just sit there at 160’C.

The boiler waste is a P trap with a vent that runs all the way to the top and then joins with the open top of the column – this is mostly for aesthetic reasons. It could have been two separate vents. When you are done, shut it down, let it cool, then empty it by turning it upside down over a drain so all the liquid will run out of that one vent. Same for cleaning – you block the nozzles with little caps and fill via the vent with citric acid.

The top of the stripping section(22mm tube) has a kind of dephlegmator thermally connected to the back of the case and the case forms an effective radiator. Then the top of the rectifier section (15mm tube) also has a kind of dephlegmator thermally connected to the front of the case, which also acts as the condenser for the hearts weir. Then the heads have a condenser connected to the back of the case and a weir to collect the heads. Both the hearts and heads drain attach to a Nozzle Heatsink that also attaches to the front of the case. And a fan keeps the whole enclosure cool.

A strange feature is that both the dephlegmators have a heater at the interface to the case/heatsink, this means I can independently control the amount of effective reflux on the hearts and the heads independent of the temperature of the case. I control the amount of cooling by slightly heating the thin interface between the dephlegmator and the heat sink. This greatly simplifies the mechanical design. Originally I really really wanted it to be all passive cooling and during our winter the prototypes worked well, but as the days got warmer is was clear I had to add a fan. Having the heaters also means I can completely flatten the reflux gradient effectively running down to just about any ABV.

The tails all leave via the waste and the amount of tails are determined by how close to the pure water boiling point we let the boiler run. Even when I run as close as I can to 0% I do not get the wet dog / wet cardboard flavors of tails, maybe this is due to the short residency of the wash in the boiler, or maybe due to good tails compression.

On a continuous still, some Fusil oils will slowly accumulate below the hearts until there is so much that it will all come out with the hearts(some comes out anyway). I have a simple solution. The software will periodically flush the column and boiler, wasting a little bit of wash.. but it is a really simple solution.

The user interface is a web interface, you connect to it’s Wi-Fi (an ESP32), and you can set it up to connect to your Wi-Fi network –all sorts of remote monitoring/notifications can be done although not implemented yet.

The user selects a “recipe” like Water, Vodka, Rum, Whiskey, Brandy, etc that sets the main process parameters, then there are “heads”, ”Tails” and “Fusil” slider adjustments which will slightly tweak the parameters within range so you can adjust the hearts according to taste, or judge the proportion of hearts/heads that you produce. From making the adjustment it takes about 10 minutes for the new taste to come through. The center setting should work well enough for a novice not to have to worry about adjusting them initially. You can also set it so it will continue with the same recipe after a power outage.

Safety features from my original koffie still post mostly still applies (amended):
Complies with the new safety standards (IEC 62368-1)
All-electric - No open flames.
All copper still, the cold wash is all that comes in contact with the siphon-feed tube.
Totally open with no valves.

The boiler is lined with fireproof thermal insulation
The boiler over temperature is limited by 160'C PTC Heaters.
The boiler over temperature is limited by Software to not exceed 105'C.
The boiler power is limited to 160W, even if the boiler reaches 160’C the appliance enclosure will not rise above 55'C in a 25'C environment.
The boiler is small, and with less than 50ml (2 shot glasses) of liquid at boiling point, so scorching hazards are limited.
The boiler mass is small, limiting the available energy for an unexpected event.
The boiler waste outlet is small to limit sudden spurts but has a large and tall overflow section to contain any sudden spurts.

Software limits a run to 12 hours.
12 Hours gives under 500mL product at 90%+ ABV, so I have to check and clear the container twice daily to carry on. Even if I used a smaller container and it did overflow, it would be limited to a small volume.
The software will shut down the still if the vent temperature indicates the fan has failed.
Possible vapor leaks due to solder joint leaks would be so small that they would never reach LEL.
Possible vapor leaks can be easily checked.

The peristaltic pump tube is expected to last about 25 x 200 liter drums.

That is about it.


All in all, I love the vodka it makes and so do my family and friends, and that's Marvellous... Well, That's What I think.

I will be happy to answer any questions…?

Thanks
Lafras
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EricTheRed
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Re: My 22mm continuous “Koffie” still with a twist.

Post by EricTheRed »

interesting read!
Hope it does well for you as it sounds like an interesting system.
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Steve Broady
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Steve Broady »

Just a thought. Are you familiar with any of the trials and tribulations that people have had when attempting to commercialize espresso machines? This seems to me at least somewhat similar in terms of complexity, cost, and market size. I know there have been several that were great ideas and great products in theory, but which just couldn’t get the finding to turn into a reliable product.

With that said, I hope this does well, and I agree that normalization and sanitization of the equipment could go a long way toward making the hobby more acceptable to the general public.
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

Only what I learned from James Hoffmann about the ZPM :
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squigglefunk
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Re: My 22mm continuous “Koffie” still with a twist.

Post by squigglefunk »

is it possible to get drinkable booze from a continuous still? I thought they mainly produced "low wines"
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

a stripping still will produce low wines because it can't separate out the heads.
This is a fractional still, the heads come out of a separate spout and you can set it according to taste or judge the hearts/heads ratio.
You can smell the heads are quite different from the hearts... sometimes you set it too low and produce way too much out the heads nozzle, then I just throw it back in the wash and turn down the heads setting a bit.
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Re: My 22mm continuous “Koffie” still with a twist.

Post by squigglefunk »

is someone with no experience supposed to know how to set this based on Smell and taste? how does someone with no experience know what heads/hearts/tails are supposed to smell/taste like? you didn't mention the tails so where do they come out? a third tube or do they come out with the "hearts"?
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Steve Broady »

Lafras-H wrote: Wed Sep 21, 2022 5:48 am Only what I learned from James Hoffmann about the ZPM
Funny, that’s exactly what I thought of first when I saw your post. Hopefully you can take whatever they learned along the way, apply those lessons, and make a successful product. Do you have any idea what the price point will be?
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

no experience supposed to know how to set this based on Smell
- squigglefunk

You can smell the difference. Even with my attenuated senses, I smell it.

The point of the default, it is that midway, it takes experience to know the difference and that is what is intended...it is not some all magical Absolut maker that can predict your wash...it is a tool that a novice can use to get fairly close to an acceptable result without much effort but as they learn the will tweak it....and as they do they will learn how to "chase the craft" (to steal a great slogan). Some will just drink anything.

The tails all leave via the waste, with the waste (backset), you don't get to taste the tails like you would in a batch process... more like you have to taste the hearts to see if you get a sense of wet dog/cardboard, generally continuous distillation is known to "compress" the tails (i.e.) you don't get to taste the flavor of tails even when you run the waste to near 0%. But you can control how close to that point you want to run.
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

. Do you have any idea what the price point will be?
- Steve Broady

It is a rather expensive machine to build compared to an Airstill so I will never reach those sub $100 prices.

I intend to build the assembly line from scratch, contacting out only things like PCB assembly and laser cutting/bending.
I have plenty of space and labor (and contractors) to do the manual assembly. I already have a full assembly manual, QC, Safty, training plan and growth plan.

So as opposed to the ZPM story of a lot of customers with a low price trying to figure out how to deliver, I plan to start with a high price and a few customers figuring out how to reduce the cost for future customers

So I plan a soft launch, with limited marketing, and building up. So unfortunately the launch price will be about $500 (including $100 shipping -from ZA it is expensive)...but I think I can reach $400 after a year and reduce shipping. Maybe landing at around $350. Eventually fully industrialized it may reach about $200.
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Re: My 22mm continuous “Koffie” still with a twist.

Post by squigglefunk »

Lafras-H wrote: Wed Sep 21, 2022 9:39 am Some will just drink anything.
indeed, I hear attenuated senses help ;) lol

good luck!
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

Yea, I donno if it is a good thing getting older or bad :?
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Steve Broady »

Let me know if you need a beta tester! It’s definitely an interesting concept. Personally, I think that part of the appeal of this hobby is in making my own equipment, but I’m also the kind of person who would rather make bread from scratch than use a bread maker. I get that a lot of folks want convenience and are willing to pay for it.
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Yummyrum »

I'm curious about the heads and hearts draw. You show tubes that look like they would drain all the liquid that is falling back down the slope .
Does each tube collect all the liquid at that point or only a percentage of it so that the remainder continues downward so there is some reflux still happening in the packing below .

Do you have a more detailed drawing of that area?
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Re: My 22mm continuous “Koffie” still with a twist.

Post by stillness »

Nicely done! I love it! I don't know that it's everybody's jam, but I love the creativity.

On the diagram you have a thing labeled heat exchanger - is that the connection to the case, for passive cooling? Are you using the wash as coolant at all? Is there a liquid heat exchanger, like on traditional continuous stills?
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Re: My 22mm continuous “Koffie” still with a twist.

Post by stillness »

Also, came back to say, the heater idea to regulate the cuts is brilliant. Maybe some loss of efficiency, but no moving parts is a big win. (Running the wash next to it, to pull the temp down could get rid of your fan, and preheat the wash a bit).
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

look like they would drain all the liquid that is falling back down
- Yummyrum

Yes they are just above the dephlegmators so the dephlegmator regulatres what vapour passes onto the next stage, the rest goes back down as reflux. What makes it past the hearts dephlegmator as vapour, will continue to reflux up the next stage up to the heads dephlegmator, what fails to make make it past the heads dephlegmator falls back as reflux down the rectifier section and eventually ends in the hearts drain, what passes the heads dephlegmator is only the lightest molecules with lowest condensation point, which are then condensed by the condenser and runs back to the heads drain..,

The drain ID's are about 2.5mm, before building the first one I thought I would need some complicated trap to prevent all vapour from just pushing down the drain, but that was not necessary because the pressure in the column is low enough that the vapours refluxes up the column (I am sure some small fraction of vapour pushes down the drain).
a thing labeled heat exchanger
- stillness

The heat exchanger is not connected to the case, it pre-heats the incoming wash with the energy in the outgoing waste, it is exactly like in a traditional continuous still, except it is very closely 'integrated' inside the still. In the diagram the bottom waste tube is long but if you imagine the top tubes wrapped in a spiral and the bottom direct then the bottom tube is only about 35mm and the heat exchanger is only a short section, but since the flow is so slow it is still quite effective.

The wash then is fed through the hearts dephlegmator where it acts as reflux coolant, and again rises the wash temperature, then it runs further along the reflux section of the stripper, and by the time it enters the column, it is at the same temperature as the column injection point.
Running the wash next to it, to pull the temp down could get rid of your fan, and preheat the wash a bit
- stillness

Yes, that is exactly what I did. And it works, it can run without a fan, but the days get quite hot here then it needs the fan.
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Re: My 22mm continuous “Koffie” still with a twist.

Post by drmiller100 »

That thing is really cool!!!
Another marker would be to up it to 5 gallons per day for fuel.
Now I know how you claim azeo so easy, it's based on a meat thermometer. :lol:
Lafras-H
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Re: My 22mm continuous “Koffie” still with a twist.

Post by Lafras-H »

Thanks,
To make 5 gallons per day, a 'normal' stripping still like you see all over this board would be much better...
The whole concept for my vodka maker is to be safe - producing a small amount of potential vapors, making 5 gallons per day is a different (and dangerous) beast.
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Re: My 22mm continuous “Koffie” still with a twist.

Post by fzbwfk9r »

Lafras-H wrote: Wed Sep 21, 2022 10:02 am
. Do you have any idea what the price point will be?
- Steve Broady

It is a rather expensive machine to build compared to an Airstill so I will never reach those sub $100 prices.

I intend to build the assembly line from scratch, contacting out only things like PCB assembly and laser cutting/bending.
I have plenty of space and labor (and contractors) to do the manual assembly. I already have a full assembly manual, QC, Safty, training plan and growth plan.

So as opposed to the ZPM story of a lot of customers with a low price trying to figure out how to deliver, I plan to start with a high price and a few customers figuring out how to reduce the cost for future customers

So I plan a soft launch, with limited marketing, and building up. So unfortunately the launch price will be about $500 (including $100 shipping -from ZA it is expensive)...but I think I can reach $400 after a year and reduce shipping. Maybe landing at around $350. Eventually fully industrialized it may reach about $200.
what currency is that in?

where I live, cheapass vodka is still around $33CAD/liter. if suppliese cost $2/L, then savings would be $31/L round down to add some power... $30/L savings
even at $1000CAD, it would only take 31 liters to break even, and beyond that, it would be all cheapass vodka!

I LOVE IT!

I just wish I had the skills to make this kind of machine.
I just wish I had the money to buy this kind of machine.
I know folks who'd love this!
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