Help needed

[Stanna]

Hi everybody, I could really do with some advice, i made this nixon reflux column yesterday to fit my 100lt boiler, the boiler has a 3kw and 4kw element fitted, just tried it with 9 liters of 80% heads I had mixed in with about 60 liters of water this should be about 10%, the thing is I cannot get over 82% output I have tried running at 4kw, 3kw and also connected my controller and gone down to under a 1kw with no luck, the column is packed with 24" of tightly rapped copper mesh the stuff they use for pest control, there is a plate soldered in at the top of the column just below the first 90 degree elbow to send the reflux back down the center, I have tried running it at just a few drops a second right through to full blast but not getting over the 82% mark, the nixon condenser is able to condense all the vapour from 4kw element with the output tap closed and nothing escaping from the atmosphere vent on top so I must be getting lots of reflux inside, any ideas as to how to up the output to 95% would be greatly appreciated.

[T-Pee]

Are you allowing the column to equalize for a bit before you start the takeoff?

tp

[Stanna]

Hi, yes i left it for 5 minutes at first till the nixon condenser was red hot just over half way up before opening the output tap, then I only ran it at a few drops a second, the weird thing is as I upped the output to a thin stream the output went to 82%. Should I be running this at 3kw or a lot lower ?

[Stanna]

Are you allowing the column to equalize for a bit before you start the takeoff?

tp

Thanks for the heads up on the equilibrium T-Pee, just had a read up and I ain't giving it anywhere near enough time to equalize, I did used to own a t500, only used the packed column a couple of times on that and I was thinking the nixon was the same, ready to run as soon as the vapour hit the condenser, we'll you live and learn, it needed a good cleaning run anyway, may even do stripping runs first with my pot still head if I can't get satisfactory results after equalizing,even with the pot still column attached the spirit run was putting out 82% so my nixon should piss 95%, cheers

[T-Pee]

Are you allowing the column to equalize for a bit before you start the takeoff?

tp

...just had a read up and I ain't giving it anywhere near enough time to equalize...

Bingo! Good on ya for doing the research on the question!

Let us know how the next one goes, k?

tp

[rad14701]

I'm curious about how well your reflux return path is currently... Could you redirect it horizontal into the center of the column...??? Your reflux might be managing to run down the column wall, depending on how the internals are constructed... Having the column a bit off plumb can make a big difference...

Also, is the entire column packed, or just partway...???

[InglisHill]

Nice boiler

[Stanna]

I'm curious about how well your reflux return path is currently... Could you redirect it horizontal into the center of the column...??? Your reflux might be managing to run down the column wall, depending on how the internals are constructed... Having the column a bit off plumb can make a big difference...

Also, is the entire column packed, or just partway...???

Hi, there is a plate at the top of the column just under the first 90 degree elbow, I knocked a groove into the centre with a hammer and screw driver before soldering it all up, I tested under a tap and all water flowed straight down the center of the column, I setup column using spirit level, the entire column is packed tightly the full 24", tight enough that they hold there self in easily, I can blow through them still fairly easily, one thing that is nagging at me is that the packing is straight up to that top plate, is this ok or should there be a gap.

[Stanna]

Nice boiler

Thanks, it's a Fusti there Italian for storing olive oil, quite cheep really, just cut a hole in the threaded screw lid and welded on a bread bin, made a washer from cardboard and rapped ptfe tape round it works a treat.

[rad14701]

Is there also a dam between the reflux return and the product take off port...???

[Stanna]

Is there also a dam between the reflux return and the product take off port...???

No there is no dam the reflux just runs straight back down the column.

[rad14701]

Is there also a dam between the reflux return and the product take off port...???

No there is no dam the reflux just runs straight back down the column.

Or does it roll right back down the product take-off port...??? Not that it should matter but if it does then why even bother having both ports instead of just letting the take off port overflow do the job...??? Just thinking out loud here... I'd put a shallow dam between the two ports...

[Prairiepiss]

I would also like to point out. 24" of packing isn't much. And it will probably slow your runs down. By this I mean if you are trying to get 95% ABV out of it. It's gona be really slow. To achieve that. If you can achieve that?

I strayed out with just a little over 24" of packing. Trust me it can be hard to pull a high ABV with so little packing. Yes it can be done. And may take a stripping run and diluting it to 30% or 40% to achieve the higher numbers above 90% ABV.

A 2" column will work best somewhere around 2000 to 2400 watts. But the wattage really depends on the still itself and how its packed. If you ran it on the 3000 watts or the 4000 watts. It would have more then likely flooded.

While flooding a column isn't a safe practice. It is however a good way to figure out the needed heat input. If you know how much power it takes to flood it. Then turn it down some. Say it floods at 2400 watts. Turn it down to 2000 watts. And it should be about a good place to run it. Keep in mind the ABV of the boiler charge will also have an influence on this.

These are just some more things to think about. Along with what has already been posted. It could end up being a little bit of all if them.