Double barrel air cooled boka

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Stew8
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Double barrel air cooled boka

Post by Stew8 »

Necessity is the mother of invention is true in my case. My unheated garage, a frozen hosepipe from the rainwater tank meant I could not use a water condenser. I found this post viewtopic.php?f=87&t=54596 and could not find a reasonably priced radiator so decided to make one. The ambient temperature here is cool, some from hotter climes may even say cold. Anything above 25C/77F is “taps aff” loosely translated to: walking around with your tee shirt off, often seen in the Spanish holiday towns, where reflective white or lobster red men walk around the towns, horrifying the locals. It’s a British thing, replacing the rather attractive knotted handkerchief of the 50’s and 60’s. Google for images “knotted hankie” and “taps aff” for a laugh. :D

Back to the serious stuff.
The condenser consists of a pair of copper pipes, each about 5 foot long, the coils of copper springs were made with scrap/left over earth wiring made up of 6 or 7 copper strands. With a 15mm copper pipe fitted over a 12mm drill bit I was able to form springs of copper from the strands and they simply interlock the spring over the pipe, there is no glue or solder. The cordless drill made the spring manufacture quick, particularly with long strands of wire. The springs were cut to size later. My advice is to wear welding gloves when feeding the wire by hand.

My initial design was a 42mm-1 1/2” slanted plate boka. It then morphed into a “pot” with this air cooled condenser sitting at an angle. As a pot, the results were pretty good. Wanted to try it as a boka; with the air cooled condenser orientation set vertically, it acts as a very long water condenser. I was genuinely surprised that it worked. It uses less real estate than the lyne arm and fortunately I’ve the height available in this shed.

The addition benefit is that the weight of the column and air condenser is heavy enough to seal the stainless salad bowl to the top of the milk churn. It’s so cold you can see leaks by a stream of condensation. It means I’m not making a bread mix and then cutting it off at the end of each run. It also lets you add experimental botanicals at various stages in a gin run. (Fire off and let it cool slightly then add botanicals)

The technical details
I have a camping gas stove that takes about an hour to heat about a 5 gallon from just above freezing to turning down the heat and running
I used various sizes of copper to make springs, it’s all about surface area so you could make the spring diameter bigger.
The condenser is vented at the top, was the spout for the lyne arm when in the “horizontal” pot position.
I’ll post photos in the next post
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Stew8
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Re: Double barrel air cooled boka

Post by Stew8 »

B79E4ABE-AD87-4EF9-8985-04973D63C183.jpeg
B79E4ABE-AD87-4EF9-8985-04973D63C183.jpeg
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Stew8
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Re: Double barrel air cooled boka

Post by Stew8 »

To explain
This is in pot mode, where the 2" column goes into an air cooled arm, then into a liebig (for stripping)

Interesting to see thermal images, I can "feel this photo" but I've a new toy at work.

Top photo is fire up
Next image is slow spirit run - a closeup of the air cooled arm at the bottom of the image
Next image is a fast strip - you can see it's all hot and then cold when it goes into the liebig.
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thermal images
just sayin
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Re: Double barrel air cooled boka

Post by just sayin »

I like your fin design, thinking outside of the box! I am amazed that your springs are able to transfer enough heat with the tiny contact area between two circles, I love it, thanks for your post.
I am wondering if a stack of pennies separated with little pieces of aluminum foil as solder proof spacers to keep from soldering the pennies to each other could be soldered to a thin strip (1/4-5/16" wide) of copper then wrapped around a piece of tube like you did with your springs. It would be tedious set up a jig to solder it, not as slick as your design, but I don't have loads of copper wire around but I do have buckets of pennies and a near life time supply of solder.
Again, very very clean and ingenious design!
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Stew8
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Re: Double barrel air cooled boka

Post by Stew8 »

Thanks for the comments.
The reason it works is that the water supply (tank and hose) freezes. The temperature difference is huge, with the ambient temps around zero freezing. I tried one Emma copper pipe but it was not enough hence the two pipes. The semi scientific view on using wire coils was a large surface area vs mass.
I used scrap wire, cut off the plastic outside insulation revealing 6 or so this copper cores.
Using a 10mm drill bit, inserted into a 15mm copper pipe, and using welding gauntlets I was able to make long springs from the wire fairly quickly on the hand held electric drill. I then cut them size and stretched them around the pipe.
I’ve also used a small fan to blow air across the coils that has some effect.

With regards pennies, it could work and you could also use lead solder, as it is not in contact with the vapour, in my view much easier to work with. From a production line point of view, If you heated a pot of lead up (usual safety caevats) and dipped a small section of each penny into the lead, to presolder it, would make assembly quite quick with a torch and a 1” 22mm copper pipe.

Thanks again and post photos
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