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From pot still to reflux still -temperature problem

PostPosted: Tue Jun 21, 2022 12:30 pm
by St Plugger
Background:
For years I've been using an electric [controlled] twin element beer keg/copper pot still and using crap wine as the mash. [Live in a wine area and collect the "failures"!] The pot still has a water filled pocket at the top of the column and a food grade thermometer is placed in the water. Once the wine/mash heats, the controller is turned down and the second element urned off. The temp rapidly passes 78 [production of ethanol temp] and settles at around 84 and creeps up to 94 as the volume decrease, taking out 6 litres of spirit, starting at about 75% and finishing about 60%. Then a couple of litres are taken off as "feints" for the next distillation. All up about 5/6 hrs.

Now to the problem:
Recently I've moved into using a reflux still, still using the crap wine as the mash. The reflux seems to take much longer to reach 78 degrees. After discarding the first 200mm, about 1 litre is taken before it reaches 78. It has a thermometer in the top of the column, Then once I turn on the water for the reflux to occur, it is impossible to maintain 78 degrees and the temperature drops down to the early 60's. I can turn on the second element, but the mash then quickly boils. So in the need to maintain 78 degrees or better, I've just left the reflux off, and used the still in "pot still" mode, not getting the benefit of the reflux at all and only producing 4 litres of spirit. I've seemed to have gone backwards in getting the new still!

So any advice will be greatly appreciated.

Re: From pot still to reflux still -temperature problem

PostPosted: Tue Jun 21, 2022 12:42 pm
by BigRig
The common response will be stop relying on temperature for running a still.

Can you put a pic of your still so we know what type of reflux still you are using ?

Re: From pot still to reflux still -temperature problem

PostPosted: Tue Jun 21, 2022 3:03 pm
by howard
agree with bigrig, you can control the rate of boil and the rate of output, but not the temp.
pics of shiny new still would be helpful :smile:

Re: From pot still to reflux still -temperature problem

PostPosted: Tue Jul 05, 2022 9:44 pm
by St Plugger
howard wrote:agree with bigrig, you can control the rate of boil and the rate of output, but not the temp.
pics of shiny new still would be helpful :smile:


Thanks for the reply [s], I've just got back to my posting! I'll take a picture of the still asap and post it for your consideration!

Re: From pot still to reflux still -temperature problem

PostPosted: Sun Jul 10, 2022 2:54 pm
by St Plugger
Hey guys, I took the said picture today but It won't upload! [as an attachment] What's the trick here?

Re: From pot still to reflux still -temperature problem

PostPosted: Sun Jul 10, 2022 4:39 pm
by The Stig
Must be smaller than 2mb in size

Re: From pot still to reflux still -temperature problem

PostPosted: Sun Jul 10, 2022 6:31 pm
by St Plugger
Thanks Stig. Learnt how to do that now!

Here is the photo. Hope this helps with my dilemma!
still copy.jpg

Re: From pot still to reflux still -temperature problem

PostPosted: Sun Jul 10, 2022 8:32 pm
by The Stig
Get rid of that plastic take off tube, not a good idea at all

Re: From pot still to reflux still -temperature problem

PostPosted: Sun Jul 10, 2022 11:09 pm
by RC Al
What packing are you using?
The 12" spool you have there is nowhere near enough to get to a neutral, what are your goals?

Are you doing stripping runs? It helps both the pot and reflux process.

Re: From pot still to reflux still -temperature problem

PostPosted: Sun Jul 10, 2022 11:42 pm
by howard
you will probably need about 1m of column between boiler and reflux condensor, with copper and/or SS scrubbies, to achieve a good output if you are doing neutral.
insulation on columns.
a water supply that is fairly constant pressure and temperature.
if height is then a problem, the bit from the reflux to the reducer(?) could be replaced by a 90 degree bend with a thermowell built in.

Re: From pot still to reflux still -temperature problem

PostPosted: Mon Jul 11, 2022 12:41 pm
by St Plugger
Thanks for the replies. So to get this straight, a good idea would be to have extra height from the sight glass to the reflux condenser? The current piece is 30cm. A further 70cm in height is possible [just] but a further 60cm would be preferable. I'm using copper in that 30cm section, and in the section above the condenser. Hadn't thought of insulating that part of the column, an easy fix. As for water, it's pumped from and returned to a 1000L IBC with a submersible pump.
As for the spirit, I just take that and filter it through a homemade carbon filter!

Re: From pot still to reflux still -temperature problem

PostPosted: Mon Jul 11, 2022 10:29 pm
by RC Al
The copper (mesh?) above the reflux condenser is doing you little good, possibly a factor with the surging you got

Happily spending your $$, i would loose the long tee as howard said and get as much packed section under the rc as is possible.

Definitely check out the newbies area and look at stripping and cuts, you will produce much better drink with these

Re: From pot still to reflux still -temperature problem

PostPosted: Mon Jul 11, 2022 11:19 pm
by howard
St Plugger wrote:Thanks for the replies. So to get this straight, a good idea would be to have extra height from the sight glass to the reflux condenser? The current piece is 30cm. A further 70cm in height is possible [just] but a further 60cm would be preferable. I'm using copper in that 30cm section, and in the section above the condenser. Hadn't thought of insulating that part of the column, an easy fix. As for water, it's pumped from and returned to a 1000L IBC with a submersible pump.
As for the spirit, I just take that and filter it through a homemade carbon filter!

yep, add a 600mm column for 900mm + sight glass
insulate the 600mm+300mm section
remove the copper from after the RC and use it before the rc.
use S/S scrubbies (or more copper mesh) to fill the rest of the 900mm section.
play around with the RC water v power controller until you get a good output (1.2-1.5l/hour for a 2")
then you won't need to filter.

Re: From pot still to reflux still -temperature problem

PostPosted: Tue Jul 12, 2022 9:56 am
by St Plugger
OK so I'm slowly getting the picture. Just to be clear here, do I replace the long t with a short t? ie just above the condenser at the top of the 900mm insulted copper mesh filled tower?

Thanks [again]

Re: From pot still to reflux still -temperature problem

PostPosted: Tue Jul 12, 2022 10:13 am
by The Stig
Or you could get rid of the T and replace it with a bend directly on top of the RC, remove the reducer things and connect to your 2” 90 bend. And you can get a bend with thermo port so you keep the thermometer

Re: From pot still to reflux still -temperature problem

PostPosted: Tue Jul 12, 2022 10:17 am
by howard
Free-Shipping-2-51mm-OD64mm-90-degree-Pipe-Bend-With-Thermowell-Nipple-And-Plug-Tri-clamp.jpg
that's up to you, if it gets a bit too high.
90 degree bend with thermowell.
just had a thought - maybe fit the new bend, then buy a triclover cap for the t-piece (block the side opening) and use it below the RC.
how long is that piece?

Re: From pot still to reflux still -temperature problem

PostPosted: Wed Jul 13, 2022 2:18 pm
by St Plugger
Thanks to both of you![Stig and Howard] Your great resources!!!
Stig, I like the 90 degree bend with the thermo port. I'm guessing it's similar to what I have atm with the pot still. IE has a pocket that is filled with water and a thermometer sits in it. Could you recommend where I source one similar?
Howard, Makes sense to reuse something I already have! The t piece is 300mm. Then I would just need a further 300mm piece. Again, where would I source an SS cap suitable to block off the side outlet? I'm also guessing it would need a 2" silicon ring as well as a triclover.
[Country living means I can't just drop down to the local shops to get this sort of equipment!]

Again Thanks

Re: From pot still to reflux still -temperature problem

PostPosted: Wed Jul 13, 2022 2:26 pm
by The Stig
St Plugger wrote:Could you recommend where I source one similar?

https://5stardistilling.com.au for all your needs.
https://5stardistilling.com/product/2-9 ... ermo-port/
https://5stardistilling.com/shop/?s_app ... ;s_keyword
Brisbane based and shipping daily :handgestures-thumbupleft:

Re: From pot still to reflux still -temperature problem

PostPosted: Wed Jul 13, 2022 9:51 pm
by St Plugger
Thanks for those links Stig.

Just what it seems I need to get this sorted!

Cheers

Re: From pot still to reflux still -temperature problem

PostPosted: Fri Jul 15, 2022 2:01 am
by Jedstar
Your next problem after all those fixes may well be stability due to your cooling water warming up. When I moved to a bubbler RC I set up a 1000L IBC like you have and found that I couldn't get the setting to stick until I realized my cooling water was warming up several degrees after only a couple of hours. Once I pulled & returned water from the swimming pool I had no more issues, if you don't have a pool you may want to consider a water cooling system like a car radiator & fan or some other system to keep the cooling water stable.