expansion chambers?

[Scribbler]

Hi there. I read somewhere a while back that brandy stills often have expansion chambers in the column to improve the flavour a bit. any ideas on what sort of minimal setup would be needed to make a noticeable difference?

right now my still has a column that goes up about 10 inches, and then turns 90 degrees for about a foot and a half before going into my "super-gattling-shotgun-of-doom" condenser. I have a whole whack of copper sitting around as well as about 6 feet of 2 inch copper pipe. what kind of volume would I need to introduce to get a decent effect? could I just cut a 3 inch length of pipe and mount it halfway up the column? another idea I had was to hammer out some copper sheeting using a discer blade (flying saucer shaped farm implement) as a mould. if I took two pieces of this and soldered them together I could get something that looked like a flying saucer.... does the shape matter? do I want something like a sphere, or more like I football? I think I have seen all sorts of photos, but very little information on what is actually going on with this...


any ideas or thoughts would be stimulating!!!


skoop

[plonker]

I dont know much about brandy stills, but I am impressed by the sound of your "super-gattling-shotgun-of-doom" condenser!!

You got any pics of the doom-bringer-of-death-and-destruction-device??

[IceStiller]

Did you convert the GE M61 Vulcan. that would be the coolest thing ever to be seen by man kind.
also it would fit the name super-gatling-cannon-of-doom

[Scribbler]

here is a photo of my condenser. thus far I have been unable to overpower it. although I have to have the water flow turned way way up to deal with intense heat... I doubt that a recirculating pump could handle the flow needed.... so far I have been attaching it to my kitchen sink tap, and when I do striping runs the tap needs to be turned on somewhere between a quarter and a half of full pressure... at a quarter open, the coolant water leaving the condenser is very very hot. anything less than a quarter-of-full and the water is too hot to even touch.

the above is a photo of the first one I was working on. you can see the spiral fluting inside the coolant flow area. the idea here was to make the coolant flow around and accross the vapor tubes instead of along them. I eventually abandoned this one as the whole thing was a little messier than I would have liked (it was my first attempt at soldering anything other than small home plumbing jobs). also, I held the fluting in place with lead/tin solder. this solder would never have been in contact with the vapors, but after sleeping on it for a few days I decided I just didn't want something with a 'weak spot' in it... even if it would have been safe, as an 'art project' I would have always known it was there. I also abandoned it because doing some drawings I figured I could makes something even smaller and more efficient... I moved away from a cylindrical unit to a square unit. the one I ended up actually going with has 30 1/4" copper tubes at ten inches long in a 6X5 array. I used a similar fluting arrangement inside, but instead of a spiral, it is done more like the steps/climbing ladders that you see at McDonald's play forts for kids: flat plates with an opening on each opposing edge, making the movement go back and forth... here is a pic... I'll see if I can find better ones later...

skoop

[Scribbler]

here are some other photos... I have since hammered out some of the dents and dings as well as cleaned it up a little ncer...

[plonker]

Great stuff martenskoop, thanks for sharing... it's everything a shotgun should be.... its truly an instrument of doom and destruction!!

I wouldn't underestimate the recirculating pump though, I just bought one from ebay for $100 AU that pumps as much power as the mains water.. it is a little large though.

[HookLine]

here is a photo of my condenser. thus far I have been unable to overpower it.

And are very unlikely to be able to, I would think.

It might be a little rough, but I like it. Genuine original handwork.

Did it seal up tight first time?

[Scribbler]

hey... thanks for the cheers. yeah, a little rough. when I dry assembled it, it was perfection in its finest form... but then I had to solder it...


in fact, it did seal up tight on the first go around, but the secret was LOTS of solder... each end of of the shotgun has about 1/4 inch of solder holding the pipes to the end plates. the reason for this is that when putting the end cap on I noticed that the heat needed was melting out my vapor pipes, so extra solder meant it would be able to take more heat before breaking loose.

having done it once, I plan to do it again over christmas but this time make some refinements. the way I had to manipulate all the copper put lots of dings and dents into it. I've got some ideas for a newer model.

I think if I can find a seven inch piece of 3 inch pipe and get a plumber to thread each end on the outside then I could do a really nice canister method that would screw on to the lyne arm/column and have a screw on base-funnel at the bottom... right now my base funnel just clips on with a a few copper pins I soldered to it. my connector to the lyne arm is a bit too messy for my liking because of the way I had to work so quickly with my soldering.


I think that with these shotgun condensers, a really tight spacing between the vapor pipes is key. this way you get lots of turbulence, and a lot of surface area. it was a lot of fun to build, even if it is a bit on the overkill side.

I guess regarding recirc pumps, I had just been assuming some sort of modified fish tank filter/pump which to my eye wouldn't quite cut it for my setup..... but yeah, a real pump that actually puts out some pressure would definitely work!!!

[Hawke]

A trick I used while building my Blockhead was to wrap a wet rag(heat sink) around joints and seams that I didn't want to de-solder, when working close up.

I don't think there is much difference in shape for expansion chambers.
Your sauser would be very simillar to a lentle for an alembic still.

[Scribbler]

and am i correct in thinking that the expansion chamber basically adds just a little touch of reflux to the potstill? is there anything else going on with these things?

jmk

[HookLine]

That is my understanding, they just add a bit of reflux.

[olddog]

A scrubber or two in your column might achieve the same result.

[Hawke]

Unfortunately, just adding scrubbers is not the same.
The expansion chamber or onion has more surface area exposed to passive cooling.
So far, With my Blockhead, stripping runs are putting out foreshots at 80%+. My better 2" to liebeg potstill started at 65%.

[Scribbler]

hawke... im not sure i follow your previous points about theforeshots coming out at 80% verses 65% with a two in to the liebig...

can you elaborate?

[Hawke]

With my Blockhead, I basicly have an expansion chamber, made from .027 copper.
The passive reflux from this design causes the first drops to come at 85% ABV, compared to 65% from the most common design potstill. (2" riser into a liebeg condenser) It also holds a higher ABV throughout the run, simillar to having a thumper. (Heads and tails are more compressed)
Here are the two stills I am refering to.
Here is my Blockhead.


And this is my old potstill head.

[HookLine]

Hawke

How much difference you reckon that reducing lyne arm makes?

[Scribbler]

oooohhhh.... very nice!!! I think I am going to try to make mine looks something like yours!!! tasty photo!!!!


do you find you lose any flavor by running with this expansion chamber?

[Hawke]

So far, I've only done stripping runs with it, so can't comment on taste.

The tapered arm, if nothing else, makes the still run smoother. Liebegs tend to have a pulse to them, the tapered arm smooths out the flow.

[adama_bill]

With my Blockhead, I basicly have an expansion chamber, made from .027 copper. The passive reflux from this design causes the first drops to come at 85% ABV, compared to 65% from the most common design potstill. (2" riser into a liebeg condenser).

Hi Hawke
Would you say that your Blockhead performs the same as, or better than, RumBull's strip head with the big onion?
http://homedistiller.org/forum/download/file.php?id=551

My current stripper is pretty much the same as you've shown:
http://i87.photobucket.com/albums/k150/ ... RigNo4.jpg" onclick="window.open(this.href);return false;" rel="nofollow

I'm mulling over ideas to make something a bit better and faster; possibly with a shotgun condensor (no thumper).

Regards

[Hawke]

All I know is that this design works quicker than the last two liebeg based pots that I built. I can do a stripping run in 2.5 hours, from lighting the burner, to finish. The first drops come out at around 85% on a stripping run. This means I'm getting a lot of passive reflux. Of course, ambient temp will make a difference here.