Extension to the ultra pure reflux column

[stilly_bugger]

Good news. That's what you want: better separation.

On:

Here's the strange thing the last jar took 3 times as long or more than any other and yet most of it came out at above 60%.

Here's why [Physics nerds, if I'm wrong on this please correct me. :violence-stickwhack: ]. The %ABV (percentage alcohol) of the wash in your boiler is dropping off towards the end of your run, so the boiling point of your charge is getting closer and closer to 100 degrees. As you get to the end it takes more and more energy to keep the wash boiling. However, the power applied to the boiler through your heating element remains fixed thoughout the whole run. As a result, as you approach the end of the run your wash produces less and less vapour and your flow rate drops off.

If you were to do a run of pure water you'd find that the flow rate is much slower than a water/alcohol mix.

There's an up side. When you're applying constant heat throughout a run, the more energy it takes to boil the mix, the less energy it takes to condense the vapour coming off that mix because there's simply less of it. Think of it this way: alcohol's lower boiling point is a vapourising dream but a condensing curse. Its lower boiling point means that it loves to get out of a hot boiler as vapour but because there's so much vapour it's difficult to turn it all turn back into liquid.

You notice this a lot more on a pot still stripping run, where (if you keep the heat constant throughout the run) as you approach wash and vapour temps of 100 degrees the output flow rate drops off with the alcohol percentage.

[crow]

yes but strangely it use to maintain a similar out put throughout the run but the ABV would rapidly drop and now its producing a high ABV right through most of the tails but the out put rapidly drops > I can't work out why the change in performance , I'm on gas but I couldn't increase the temp for the tails as I had a bugger of a time preventing the wash from puking . Just a shitty looking wash thats all , wouldn't clear and I new I was going to have fun with it from start to finish

[stilly_bugger]

NOW
The reflux in the packed column's giving you the high ABV.
The constant boiler temp is giving you the drop off in output flow towards the end.

BEFORE
Not sure. Maybe the short column didn't have enough packing to properly reflux and separate tails towards the end of a run, so you got lower ABV tails?

[grumpthehermit]

Question for Croweater or Stilly.

What is the thread / connection size on the bottom of the Pure Distilling column ???

What thread / piece do I need to buy to connect an extension piece like you have both done???

Cheers
GTH

[stilly_bugger]

Hmm. I don't know my fitting threads, but here is a pic:

adaptor2.jpg

It's just called something like the female half of a 2" brass union. Someone can correct me: :text-imwithstupid:

These are handy joins, but they're ugly. I cut mine off and replaced it with a regular 2" copper coupler soft-soldered on. The male part of the join on the Ultra Pure is easy enough to pull off with a cheap propane torch. It's only soft soldered on there. Clean it up, soft solder on the coupler, clean it and away you go. It's permanent, but then I never saw the need to ever disconnect the extension.

[grumpthehermit]

Thanks Stilly,

:D

Cheers
GTH

[crow]

Mine is a bit different and if you wanted to have a threaded junction I' d go with Stillies as I used a Crox and nut join . They are uncommon and difficult to make

[grumpthehermit]

Thanks Crow.

I was hoping I might find out what the thread was on the base of the Pure DIstilling column, do you know what the thread is ???

Metric 50mm, BSP ??? etc ... I have no clue about such things ... :?

Cheers
GTH

[MacStill]

Mine is a bit different and if you wanted to have a threaded junction I' d go with Stillies as I used a Crox and nut join . They are uncommon and difficult to make

The brass fittings in that pic would make an excellent sight glass too :handgestures-thumbupleft:

[MacStill]

Thanks Crow.

I was hoping I might find out what the thread was on the base of the Pure DIstilling column, do you know what the thread is ???

Metric 50mm, BSP ??? etc ... I have no clue about such things ... :?

Cheers
GTH

I'm pretty sure they're BSP :handgestures-thumbupleft: I was playing around with some brass fittings at the plumbing store yesterday ;-)

[grumpthehermit]

SWEET !!!

:D

[crow]

Yeah I would be amazed if they were metric , for one that nut that screws on it would be at least forty yrs old as its from Dads old plumbing fittings and pre PVC . I did think about the possibilities of using the thread and nuts for sight glasses , dead certain they'ed work but the new portal style ones look so much better IMO

[crow]

Ok if anyone would like to make a croxed connection like mine I found this on ebay . Croxed connections are about the best detachable connections going for copper I think as there is nothing in the vapor path but copper , they seal really well and are easy to attach and detach . I have fittings just like this and intend to cut it as long as possible and solder a furrel on the end but you could put an easy flange on it or join a length of 2" to make a column extension . The thread on this nut is identical to the one on an ultra pure still and the other fittings on this may come in handy for a variety of other uses to
http://www.ebay.com.au/itm/2-Copper-S-B ... 35bda2c725

[grumpthehermit]

Got my extension in now ( Thanks McStill !!! :D )

Gave it a cleaning run and then ran a TPW on Friday night.

I packed it with 7 scrubbers and insulated it with a foil windscreen shield that I bought and then hacked up / cable tied on nice and snug.

I experienced a much better run using this, I had a much more stable temp through the run. Once the fores were done and I refluxed for a second time I got very little variation right through into the tails ... I was reading 78.9 - 79 for almost all the run and only saw 79.1 right at the end.

Using this still without the extension gave me temps of 79.1 at the start, slowly creeping up to 79.5 / 79.6 into the tails.

And for me the finished product is better, The hearts I taste tested yesterday were the best I have have yet.

I definitely recommend doing this modification if you have this rig.

:D

And here it is ...



Note the tissue box is temporary thing lol ... :laughing-rolling:

Cheers
GTH

[stilly_bugger]

Got my extension in now...

Looks good. Nice work. :handgestures-thumbupleft:

What's the modification you've made to the take-off valve? Is that a new valve?

[grumpthehermit]

Mrs McStill hooked me up with the needle valve.

:-D

Much better flow control than the little ball valve it comes with, which reminds me the offtake is speed limited by one of the fittings that connect to the valve, I tried to open it right up at the end of the run and 10 mins per 200ml was as fast is it went, one of the fittings that connect to the needle valve is a plug with only a very small hole through it, I'm thinking I will drill that out larger now so I can experiment with run speeds.

Cheers
GTH

[crow]

I take it the triclover union near the base is to allow you to put it on a keg if you want :handgestures-thumbupleft:

[grumpthehermit]

Exactly !!! :D

Wanted to future proof it so I can upgrade later with no fuss.

:-D

Thanks
GTH

[stilly_bugger]

...which reminds me the offtake is speed limited by one of the fittings that connect to the valve...

The Ultra Pure ball valve is calibrated to 1.5L/hr fully open. And they only tell you to run it shut or fully open. It's part of their 'a monkey could run this thing' approach. Fair enough if you're only collecting hearts as they instruct, but not much help when you want to open her up towards the end of a run.

I noticed Mrs McStill hooked up the 2" boka auction with a needle valve too. What, does she make them or something?

[grumpthehermit]

I always tried to bleed off the foreshots at 20 - 25mins for the first 200ml and the rest of the run I tried for 15mins per 200ml to make the best tasting product.

The ball valve made that almost impossible ...

I understand why they have made it a generic design, the ball valve is cheaper and the restrictive flow like you said "any monkey could run this thing" approach.

The instructions only tell you to take the heads and throw them away and to keep the rest, by heads they mean foreshots and by hearts they mean heads,hearts and a bit of tails all mixed together ... :puke-huge:

The needle valve is awesome, I have no clue about about Mrs McStill's distilling supplies but it's a great piece of kit and it works well, I highly recommend upgrading to one over a ball valve if you want a precise flow control.

:)

Cheers
GTH