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Re: Not sure what to do...

PostPosted: Wed Jan 17, 2018 6:03 am
by Myles
Maker wrote:I tried running the still differently today and it certainly saved time, I used full gas power until half way heated, water on full, keep going until vapours appear, back off gas to slow burn and tinker until you get a steady trickle of liquid, stabalise the gas so the temp stays the same, after some time the output gets slower so back off the water to increase the flow of distillate, from now on as the distillate gets slower add more gas very slowly and as long as no vapours are seen keep doing it, had a pencil lead sized trickle pretty much constant for the whole run, well the tails were a bit stoppy spurrty but not a problem.

Thanks ever so much for the advice.


I am going to have to jump in here. The still in the photo is a short packed column with what looks like through tube cooling for a reflux condenser. What you described above is really NOT the recommended method for running this type of still. Your posted collection results support this.

There is an intrinsic feature of this design that means during the hearts phase of the run you need to INCREASE the cooling flow several times in order to maintain the product quality. Each time you do this the product rate will get slower.

On this type of still you really should put it into full reflux at the start of the run - find the correct power level and then leave the power alone. Control the run with the reflux ratio via the coolant flow rate.
During the main part of the run the temperature on that dial thermometer (I hope it is in the vapour path) should be rock solid and not moving. If it changes you are taking product too fast and should put the coolant flow to max and start slowly reducing it again.

Here is a pretty good set of operating instructions for this type of still. I hope it helps. The link will download the document.
Kiwis Guide to CM

You have to work out your methods for your still, but a lot of folks have tried this before, so it is worth at least reading the collective info and experience that has been compiled over time.

Re: Not sure what to do...

PostPosted: Thu Jan 18, 2018 12:54 am
by Maker
What you described above is really NOT the recommended method for running this type of still. Your posted collection results support this.


If I added 8L @ 50% watered down that must be a potential of 4L @ 100% in the perfect world.
I got 3L of heads and hearts @ 91% and a litre of tails at 60%, surely thats a good haul, I can't work out the maths but that must be most of the alcohol collected and I stopped when it got smelly so the left over alcohol was not wanted? Last time I tried running quite similar to the way described in the download and it was a lot slower, BUT tasted better, although this lot came off much quicker and was high alcohol it certainly has a twang to it (Vodka star)
I think the guide is excellent and I can see many things in there that ring bells and some new to try!
I think my plan of action is to run the 2 lots of turbo I have brewing in the same way just to clear the slate, then I'll brew 2 fresh batches of birdwatcher as I have not tried this yet and run the still exactly as per the guide and see how that turns out!

Re: Not sure what to do...

PostPosted: Thu Jan 18, 2018 4:28 am
by Myles
It is just a matter of personal taste.
You are only producing at 91% which throws off the numbers, so you might be doing just fine. It was the proof of your tails that seems a bit high to me.

The targets for a packed column (of what is collected) are 10% heads and 20% tails with the rest hearts. To be honest I think you will find the still performs better if you save up your strip and run a bigger boiler charge.

8 liters in a 25 liter boiler leaves a lot of empty space in the boiler, and does not give the column a lot alcohol to work with.

Packed columns - especially in 2" are never going to be fast. Typical performance for a 2" column with 48" of packing is 0.75 liters per hour. Shorter columns need to run slower to get the same purity as a longer column.

Some folks run a 5 foot 4" column at only 1 liter per hour, to get absolutely pristine neutral.

Re: Not sure what to do...

PostPosted: Thu Jan 18, 2018 11:31 pm
by Maker
Myles, great advice, it is starting to make more and more sense, I have read so much information on different setups it is confusing.

Tomorrow I will cut the column just under the reflux tubes and weld on another length of tube, this should make the column about 4 feet, maybe a bit more, see what I can find.
I am tempted to ditch the reflux tubes idea and make a copper coil to insert from the top, maybe even go boka style, I'll see whats available in the workshop.

I had not realised that 91% was enough under spec that the flavour would be effected, I hope the taller column with packing achieve the higher target.

As for tails, I decided to cut when the alcohol level started to slide so I diddn't spoil the hearts, I have a litre of what I collected after but I guess it's not going to waste, I'll get the good stuff out next time.

I am on the lookout for a larger width column, something will turn up, ideally 4", I have a few scrap yards to try and some reclamation companies, I'll get lucky, I usually do. ;D

Re: Not sure what to do...

PostPosted: Fri Jan 19, 2018 6:07 am
by Myles
If you want my advice - and if it is not too late - don`t do anything to your existing column.

Honestly if it was me, I would disconnect the cooling to the through tubes, take out the packing, seal the vent in the top and use it as a pot still.

Although it is a poor design reflux column - what you have will make a fine pot still.

On a 25 litre boiler probably 3" or 76 mm tube is enough. I would just order a 1.5 m length of 76 mm copper tube from JTM Plumbing and build yourself a proper column.

Personally I don`t like the slant plate version and prefer some of Alex`s other designs - but they all work. It is only personal preference.

You won`t go far wrong with any VM or LM design. CM like you have is a bit more fiddly and needs constant tweaking.

I consider a packed CM a bit more of a tool for someone that really wants to be hands on and constantly tweaking the still, the other versions are a lot more "user friendly" more set and just let them get on with it.

Re: Not sure what to do...

PostPosted: Fri Jan 19, 2018 9:49 pm
by Maker
I read your post this morning and decided to ponder on it for a while, I diddn't chop it in the end. I have a 2" ferrule ordered to weld on the column and I'll fit a 4" on the boiler, buy relevant reducers. I also have a chap picking up a 4 foot length of 3" copper next week so I'll have a play when it all turns up, I have some booze in stock now so I'll sit tight and consider options, ideally I'd like to build something like Anarvin has, I have some still envy but also and engineering background and a tig welder :P

Re: Not sure what to do...

PostPosted: Fri Jan 19, 2018 10:44 pm
by Easydrinker
Nice one mate.
I would consider advice from Myles a personal favour.
And Anavrin's name took me many attempts to get right!

Robert.

Re: Not sure what to do...

PostPosted: Fri Jan 19, 2018 11:41 pm
by Maker
I'm still getting to grips with who is who but Myles certainly knows his onions and has a nice way of explaining things as do you, infact most people here are pretty sound.

I will attempt to in future reference 'Anavrin' more sucessfully, not promising anything but I will try!

Re: Not sure what to do...

PostPosted: Thu Feb 08, 2018 11:34 pm
by Anavrin
Just think of Nirvana backwards and you can’t go wrong :)

For volumes of I have a simple rule, 1kg of sugar per 5 litres of wash will produce an approx 10% wash, yielding 1 litre of strip at 50%

Assuming you stop stripping when you reach 30% on your output, so 25 litres with 5kg of sugar will produce 5 litres of 50% strip.

I would half this again for hearts collected from the spirit run, but I do take a large heads cut of the first 30% including fores, and I don’t collect the last 20%, I leave it in the boiler as tales.

(Deleted video links) sorry I won’t leave video links on for more than a week

Re: Not sure what to do...

PostPosted: Fri Feb 09, 2018 12:02 am
by Easydrinker
Thanks for sharing, and putting the effort in.

Robert.

Re: Not sure what to do...

PostPosted: Fri Feb 09, 2018 9:58 am
by H12rpo
Brian, can I see an in line needle valve in your water exit pipes? (The same type as comes with the T500? ) and is that how your3 controlling the water flow rate in the condenser ie by restricting or opening a valve on the 3xit as opposed to the input?

Re: Not sure what to do...

PostPosted: Fri Feb 09, 2018 10:58 am
by Anavrin
Hi H12rpo

I control it on the output yes, but I’m not called Brian lol

It’s recommeded on the input side if there’s a chance the mains water pressure could cause a cooling pipe to blow off, I don’t have that problem with my setup, and so prefer to control the water file on the output.

The SD deflag holds quite a large volume of water and only a small flow is needed, because of this, any changes in flow rate take a few minutes to take effect on the performance, that’s why I set the flow initially at my desired starting power, then increase the power to speed up the output.

This method also helps maintain the reflux ratio during the run, as more power equals more Vapour to be refluxed, of course more gets past the reflux condenser, that’s the point, but at least I’m not reducing the amount of reflux as much, each time I run a little faster.

I’m going to change it again soon, I want it to be a VM setup for neutral so I’m going to add another 4x4x2 section below the deflag and connect a ball valve on the 2” output.

The ball valve I have is 1” fully open, giving a minimum reflux ratio of 16-1, I’ve got another copper reflux coil that I’ve made myself to fit above the deflag, just to ensure no Vapour escapes the top of the column.

Re: Not sure what to do...

PostPosted: Fri Feb 09, 2018 12:31 pm
by Runningman
Hi Anavrin
Nice wee videos there and very informative on how to run a Flute really enjoyed that. Lovely bit of kit you have there.
Regards
Runningman

Re: Not sure what to do...

PostPosted: Fri Feb 09, 2018 12:50 pm
by Myles
Nice videos.
There are two basic methods of running a CM dependent on the thermal capacity of the reflux condenser.
You can set a power level and control it with coolant flow rate. OR you can set a coolant flow rate and control it with power input.

Sometimes you do both.

No matter which you pick the end result is the same. The still is in effect a low pass filter. Low boiling point vapour is allowed through. Higher boiling point vapour is sent back to the boiler.

It is a simplistic model but it helps to keep you focused on what the still is trying to do. HOW you do it is personal choice and there are no wrong methods. You will settle on one that works for you.