Air Cooled Reflux column, - AKA The Very Silly Still.

[Easydrinker]

18 months ago I first mentioned this.
It is finally done.
For anyone interested, some info on my air cooled reflux column, Scroll down to look at the pics and then pour yourself a drink and come back for a read.
My Silly Still (a large version of the Smart Still) is just a 1m x 54mm copper column on an urn, run through a power controller, with a very LARGE air cooled copper condenser.
The new Very Silly Still swaps out that column for a SS scrubbie packed 700mm length of 54mm pipe sitting on a 4" bubble plate, above the packing is a thermowell and then almost 5 metres of coiled 10mm pipe followed by a doo-hickey Swan Neck and Lynn arm.
A piece of timber (I used whisky barrel stave for the fun of it) helps keep it rigid.
The hd.org HETP calculator gives it a HETP value of 8.3 + 1 for the pot , a theoretical vapour purity better than 93.9%. + 1 for the bubble plate, even higher?
The bottom of the 10mm coil has a short length of 8mm soldered inside and protruding down into the 22mm, to ensure that cooled distillate drips/runs into the centre of the packed section. With hindsight this is obiously the busiest part of the column, with all vapour rising and liquid falling through this restriction,virtually a mini bubble plate,this may have been a mistake, or a piece of accidental genious (luck!).
When running, the top section of the column is enclosed in a wooden box, which takes a couple of minutes to assemble with an electric screwdriver.
The bottom of this box has a 6" duct to outside air, near the top is a 6" 25 Watt domestic extractor fan with a short length of duct to the room.
This changes the air in the box twice a second. This was hard to photogragh in place, so one from the side and one from beneath.
The cheap Chinese thermometer in the thermowell is not there to be believed for actual absolute temps, but for relative temps at different stages of a run, something that it is capable of. I have much better thermometers,but they have longer probes, and I did not want to interfere with falling refluxed product..
Touching, (or not! ) the pipes either side of the 'box' and looking at the power controller, gives as much different useful information.
Outside air on the runs so far was 7-8°C, TBH the 10°C temp diff either side of that I can expect year round, with night time air where I am, I believe will not make a great difference, as a temp. diff. of 55°C, is all I believe needed for the reflux condenser to work
I would expect bigger changes from a larger reflux condenser, and re-jigging that short length of 8mm pipe.

So does it work? Yes! well sort of...
I seem to have a similar problem to T500 owners in balancing the cooling power, for them it is someone turning on a tap, for me it is a fridge or freezer kicking in or out, or some such.
It seems to happily knock down everything @ around 570 watts supplied to the boiler, (which is twice the power that I really expected from that length of reflux condenser pipe) but it does not take much more power to have distillate flow from the product condenser.
After equalising,it outputs at a steady 92% from stripped wash at 650 -700W, at just under a litre/ hour.
I struggle to slow it below this rate without it falling back into total reflux due to voltage fluctuations, but have managed 94% @ 620 W and 600ml/h.
Towards the end of the run the take off rate slows,and ABV drops a couple of percent, Kind of weird as I thought that was LM column behaviour,and that this was basically a CM column,using constant cooling of the reflux,and run as a power management still by the ability to regulate the boiler heater. But what do I know?
Whatever, discovering the points at which to increase boiler power are still to be learned.
I have had a few plays with the new toy, I may continue.
The silly still neutral was easy and quick, averaging 67-71% and around 7 litres when the cuts were combined from a couple of stripped neutral washes,and after running through the Essencia was acceptable.
The product from the Very Silly Still does taste a little better, and is at a higher ABV, but seems harder work.
The latest run produced 4.4 litres of very neutral 92% hearts from two of my usual stripped neutral washes.

I am still undecided about it being an improvement, but have proved to myself that it works.

Robert.

[Myles]

Nice, the only real issue with air cooled is the low power applicability, but with forced air cooling this is improved. Are you using an air cooled PC also.

I tried this with 1" dia coil but it was intended for a strip boiler application. Using a 1" dia coil (hot water cylinder coil) with winter ambient air temperatures I estimated it was good for about 1 kW, so only for low power.

You can use bigger 10" or 12" dia coils with a bigger fan to make a 3 kW or more air cooled Product condenser. However it is more efficient with recirculated coolant, and even better with an evapourative cooling tower configuration combining water and forced air flow.

[Icefever]

Like I said this morning I've not been on fully due to a bad session at the dentist on Tue which knocked me about a bit.

Any way back to normal now...well as normal can be for me... ...

I really enjoyed your write up ED...this could help folks who due to water metering or such like now know they can run a still.

This should start another listing within the airstill section....well done sir.

[Easydrinker]

It is good to finally see some responses to my post, I was starting to think that it was invisible to the rest of the interwebs.
Anyone that hangs out here knows that I don't seek the easy route, I do like to push boundaries.
I don't try for clever or pretty.
I am also a little bonkers.
Did I say a little?
I also do not care too much what people think of me, and I desire to impress no-one, but I will share what I know or learn with anyone.

This one was all about air-cooled; re-circ. water may be the next project.

Tomorrow is another day.

Robert.

[RumJohn]

@ EasyD: Nice job. May I ask why your condenser is such that condensate will flow back in the direction of the boiler rather than to your collection point. A really efficient cooling system would cause all condensate to return to the boiler, or at least pool in that direction until it puked.

Try angling it down and away.

[Mash]

How odd. I was convinced I had posted on this topic. No matter.

Very good. Very interesting.

I like this idea always have. I do wonder if there is a swamp cooler begging to come out to play. Lightly cover the coil with fabric then install a fresh water dripper.

[Easydrinker]

@ RJ, the small condenser seen atop the column is my attempt at an air cooled reflux condenser.You have to cause reflux by cooling somehow.
Doing with air what others do with water is a little harder.It isn't high tech. or pretty, (actually I find it cute), but it does work.
When vapour is allowed past this first small condenser, after refluxing, it will meet the product condenser, and all is as expected, although that condenser is also air cooled, so a little funkier than an average set up.
Sorry if I wasn't clear.


@ Mash,I don't doubt the efficacy of a swamp cooler,not in my remit here, but dripping liquid in my domicile? How is Mrs Mash with that in yours?


Robert.

[Mash]

@ Mash,I don't doubt the efficacy of a swamp cooler,not in my remit here, but dripping liquid in my domicile? How is Mrs Mash with that in yours?

Robert.

LMAO. Only just fixed the dripping liquid event we had at Christmas

[Myles]

Robert is your product condenser a coil in some sort of container with an extractor fan mounted at the top? Air in at the bottom and out at the top?
How is that working and what power level is your boiler?

[Easydrinker]

Myles,
Having just written a response to you,I realised that I was answering the wrong question.I am going to leave that as part two. and answer what you actually asked.

Yes and Yes and yes and yes.

The product condenser.
About 22.5 metres of 10mm pipe ,a double coil,in a bin.
I use this to strip at around 1350 Watts.
And spirit run with the Silly Still at 1250 Watts.
This regime works.
And with indoor ambient air,and has, year round for a couple.
Why I chose to experiment further I know not


Part two (the reflux condenser of the Very Silly Still)
It will reflux all at around 570 Watts to the boiler,just a nudge more power and it is hard not to get a litre/hour at 92%.
With some fine tuning of the power input, and the domestic freezer or fridge not needing to kick in for a cool down,I can get 94% at a slower take off rate. Electrickery is tired by the time it gets to me, switch something on and it affects everything else.
The beast is running as I tap this, giving slightly different numbers to the last run,700ml/hour @ 93%, 620 watts going into the boiler.
I have just switched on the George Formby grill to cook tonights dinner and so expect things to change.
TBH, I think that I have built a slightly bigger, more bonkers and out of control version of the last thing that I saw Riku post.
I believe that a MUCH bigger reflux condenser would negate the need for a product condenser and may help with control.
Maybe I will find time to play with that.

Robert.

[Easydrinker]

My creation and I have spent a little more time together, and there may be some good news here.
I have reached a point that I can fiddle about a bit and then go away and leave the unit unattended for 30 minutes to an hour, before checking and changing collection vessels.

That is good, as the standard time for initial warm up, + an hours full reflux, + heads collection and around 4 litres of (now) 95% ish hearts is 10 or 11 hours, I don't collect tails with this one, - the ambient air temps., an uninsulated boiler and everything else leaves them sitting in the boiler, unless I leave it another hour or two, in which case it really is some of the worst stuff you have ever smelled, or foolishly tasted.

This may yet become the choice tool for a quality neutral.

I KNOW THAT THERE ARE EASIER WAYS!

(Repeatable) Stillin' by numbers is what appeals to me here.

I'm still playing, no pun intended, and may report back.

Robert.

Did I mention yet that I am as daft as a box of frogs?

[Mash]

For me unattended has always been a big deal. As long as you get a quality product, a long run doesn't matter (within reason). But a long run holding the sky up is not acceptable.

My strip takes 3 days! 99% unattended in the freezer.

Keep up the good work we only learn stuff by trying bonkers stuff.

[Anavrin]

Not so long ago, I was striping a run, got distracted by the kids and family stuff while the boiler was heating up, only to suddenly remember

"SHIT THE FUCKING STILL IS RUNNING"

I ran to the garage to find the parrot full of liquid and steam (alcohol vapour!) blasting out of my surge breaker just above the parrot!

I turned the water tap on the wall and within a second or two it was panic over, I recon it could have only been boiling a minute before I caught it, but it was a big wake up call!

I've since decided to run my water cooling (not metered) at the same time as I start my boiler, also when stripping I now use a large 15 litre stainless pan to collect everything in, I'm not saying this is ideal, or perfectly safe but we all lead busy life's these days and it's easy to get complacent, a spirit run is a totally different story, I baby sit the hole time, at leat I time a few jars so an alarm always goes off a good few mins before a jar needs changing, works for me :-)

[Easydrinker]

I am a little unsure why you chose to post this on this thread
My logic tells me that a domestic extractor fan, has a long life, and in the event of a power supply failure, my boiler goes off along with my condenser.
I am fortunate in being able to still so close to my normal,chosen home position/seat, and am virtually always present.I would hear if my cooling failed, due to the lack of noise!
I will admit to occasionally falling asleep during a run, but am a few strides away from the action, with a large fire extinguisher just inside the still room, and several others in-between.The one kept by the bed has caused some comments!
For a while now I have collected both strip and run over a larger 3 litre vessel to allow for overflow.
I have on occasion forgotten to tighten something down properly and walked into a room so filled with alcohol vapour that it makes your eyes water...
Good thing that I gave up smoking!
I agree totally that it is easy to become complacent, and within reason, it is our duty to keep ourselves and others safe.
Some of us may have more reasons than others.

Robert.

[Mash]

"SHIT THE FUCKING STILL IS RUNNING"

LOL. Been there. I have a smoke detector above it. An 'OFF' timer. Stainless steel tray to catch anything and a webcam.

But I am not babysitting it. Thats one of the reasons I like the VSS still idea so much.