Baby Reflux Shotgun

[BigSwede]

A bit of background: I'm making a modular still with separate sections that can be connected with 2" tri-clamp fittings. The plan is to be able to swap out components and execute LM, VM, and pot still runs as needed.

I built a small LM head here: http://homedistiller.org/forum/viewtopi ... 50&t=48224 and for the pics I topped it with my massive 14" shotgun condenser. This thing has 7 ea. 1/2" tubes 14" long, so it's somewhat like a 98" long liebig! That's why I like the shotgun design, big cooling in a small package. With parts left over from the big shotgun build, I decided to execute a small one just for reflux duties. Also, made it a little different.

I redesigned the tooling to rim/bead 1/2" tubes, and the new tools make a perfect bead with a rim exactly 0.625" in a drill press, so no lathe needed.

Rather than do another multi-holed internal plate, I simply drilled and countersunk, for the tube rims, a regular 2" end cap:

The tubes drop right in flush with the cap:

The other end is a normal internal copper sheet drilled in the shotgun pattern, 0.025" thick. The holes in that plate were a bit sloppy, so I made a little tube expander similar to what boiler makers use to spin-in copper tubes in heat exchangers. You insert this thing into the end of the tube, turn the hex screw, and it expands the annealed tube ends a good 0.010" so they grip the plate; everything gets locked nicely into place.

Since I could lock the tubes in before soldering, I gave them a bevel at the ends so that it helps guide reflux towards the middle. Looks like a rocket or something.

I added a riveted doubler plate to the lower end, and since the top end had the cap, I drilled both the doubler and the cap for a small copper ferrule with a female pipe thread. Wired it together for soldering, and all that was needed to wire were the two ferrules... everything else was held in place mechanically. The white thing is a stub of virgin PTFE plastic, which can handle soldering heat, but just barely. Overheated PTFE emits toxic fumes, so if anyone else does this, be very careful not to overheat the assembly. I've used stainless and brass in the past for this, but if solder creeps, it can fuse it in place.

[BigSwede]

I cleaned up the soldering bench, laid out a variety of solder pieces, and went at it. It was a relatively easy job until I reached a certain part... the riveted doubler plate on the 2" tube that supports the water feed had warped the tube slightly, creating a gap between the tube and the copper 2" tri-clamp ferrule. Every time I plopped some 4% silver solder in there, the solder simply vanished. I grabbed some antimony plumber's solder, and it flows much less aggressively than silver; made a nice fillet. So I learned something today - If you have a bit of a gap, antimony fills better than silver.

As usual, looks like crap after soldering...

It took only 5 minutes in a 20% phosphoric acid/hot water mix to bring the shiny copper back:

[Bob Loblaw]

Looks great, top notch work as usual. But how are you going to attach the end with the cap to the rest of the still?

[BigSwede]

Looks much better than the monstrous 14" shotgun that topped my little LM head previously. I can save the big one for other duties.

Got to end with the glamour shot...

Looks great, top notch work as usual. But how are you going to attach the end with the cap to the rest of the still?

TY - I had spent the last few workshop days doing my power controller box, and I find electrical work a bit boring... metal is much more interesting. Anyway, I had some pieces lying around, and was thinking about some sort of dephlegmator, but decided instead to just make a dedicated reflux condenser, so nothing is going to be connected to the top end... it's only job is reflux.

All that is left for now is to finish my power box, pack my column, and try a few LM runs to get a feel for how everything works. Somewhere in the future is a VM head, a pot still - should be simple enough - and I want to do a 3" flute after I save a few pennies for that expensive, big copper.

[Bob Loblaw]

Ah, got it. I see what the plan is now.

I admit I am probably a bit confused about VM/LM nomenclature. I was thinking that design was a VM - where you're refluxing everything and managing the takeoff with a valve - versus an LM where you manage the takeoff by coolant flow through the condensor. But maybe I have those backwards.

[BigSwede]

Bob, this reflux condenser can be used with either VM or LM still heads... It's only mission in life is to knock down 100% of the vapor that reaches it. In the last pictures, it's attached to my LM head. It works like a Bok slant plate, except different inside. A small pool of condensate is captured, and everything else goes back to the packing below. The captured distillate is then slowly drawn off. Should be close to 94% ABV.

Replace the LM head with a simple 2" tee and a valve on the tee, and you've got a VM rig, except I need another condenser to capture the vapors from the tee.

All the varieties and methods of distillation are fascinating, and it's why I made a modular still - so I can try them all without having to build separate columns and such.

Everything I've read so far says that VM is the easiest to run, LM is better for cuts, and for separating foreshots and the like. Some guys combine them, a LM portion above the VM tee. LM is used to get the nasties out before opening the VM valve. I'd like to try that too!

[googe]

Nice work mate, should do the job well . You've certainly got the build bug! .

[still_stirrin]

Man, that's some sweet looking copper work. Your tooling gives me goose bumps. Slick.

I'm building a combo LM/VM for use on the column. I have a 7-tube (3/8" ID) 14" long shotgun for the product. The reflux is a concentric following Rad's design. It has the concentric tube for liquid takeoff. Then, when the foreshots are off, the VM valve is opened. But my minimum reflux ratio is 4 (2" column & tee with reduction to 1" thru the VM valve).

But I have a pot head for stripping that also runs into the shotgun.

Modular designs give you maximum flexibility.

Great threads Swede. Impressive artwork.

[BigSwede]

Appreciate the comments, thanks. Googe, I've had the build bug for 25 years now.

So long as I build, I can put off the hard part, the confusing part, making decent beverages with it all. Tested my power box yesterday and was thrilled that all the magic smoke remained inside, and it worked perfectly. It's one of those potentiometer SSR rigs, so easy to wire. Got a PT100 temp meter in there, and a nice watt meter too.

Still Stirrin - it's hard IMO NOT to go modular. Yes it costs more, a bit more work, but lets you re-use components in all sorts of fun and imaginative ways. Why use up four feet of copper and be limited to exactly one methodology, when by adding a couple of ferrules, you can do them all?

[Da Yooper]

BS, very nice I like your work. Thanks for some more building ideas. Not that I need any more modular parts but I do see a new shotgun in the future. Keep the pics coming

[bellybuster]

what exceptional work BigSwede.

[Halfbaked]

Big Swede, once again you hit it out of the park. Your Dephleg or deflegmator is one of the prettiest I have ever seen. By the way your name is spelled wrong. Your name is spelled Mr.Copper Smith.

[1965 wite]

just when you think you made something cool and fancy some guy comes along and builds one way slicker. nice work. im jealous. looks like i need to tool up some more.

[Swag]

I redesigned the tooling to rim/bead 1/2" tubes, and the new tools make a perfect bead with a rim exactly 0.625" in a drill press, so no lathe needed.

Very nice work Swede. I'm interested to know more about how you make those nice beads. Perhaps you could explain the general process to us.

Thanks,