Problem reaching Equilibrium

[desahih]

Hello friends,

In my previous post: viewtopic.php?t=79524 i got so demotivated but then i re-upgraded my still to this (find attached).
it's 24 L boiler filled with 19 liters of 35% abv grape alcohol.
the column is 2inch,1 meter long filled with copper scrubbers.
it is taking about 2 hour to heat up with my gaz burner set on low heat and i can't reach equilibrium, the temperature on the still head is at constant 78-80C before starting to collect and i know there is methanol and ethyl acetate in there.
As i read in the compleat distiller and john stone's book, the temperature at the top should be related to the alcohol(methanol , acetone and others head)at equilibrium.
i am getting 92 ABV from that still, but i want to hit that 96 ABV as i think my setup is not bad at all.
at the top you can see a shotgun condenser.
and for the note:i am collecting at 10ml/min max or 2-3 drops per second

one more thing, you might see a condenser at the top of the column,this , i did before doing the offset head. i might use it as CM to compress tails if i wanted.
i tried increasing heat input so i can increase the reflux but no results.

Please help and thank you

[RC Al]

Is that Air conditioner next to it running? cant help but feel it would affect things

Your not going to get to 95 % without changing to Spiral Prismatic Packing in a 1 meter tall column

[desahih]

no the AC is not running. so i understand my packing is the problem, nothing to change with heat input or anything?
and how much spp do you think i need to fill that column?

[RC Al]

The 1m of column is the limiting factor here with regular packing. You can throw as much heat and reflux as you like at it, you will only ever gain a theoretical plate or so at best down that path (without reducing output to a stupidly small number) and smear everything to hell

You will have to do your own research on the SPP, it will vary a bit by manufacturer/size

[greggn]

i think my setup is not bad at all.

AS RC said, you need more height to gain more theoretical plates. Your rig is nice but I'd suggest the following modification:

• turn that 90 bend upside down with the shotgun now a product condenser

• add an 18" spool to the bottom of your column

• add a 6" spool to the top of your column

• add a reflux condenser (copper tube or CSST)

Now you have a CCVM, with sufficient height to get you to azeo.


... and stop collecting in a plastic pitcher.

[desahih]

i'm sorry but what's the spool for?increasing height?

[RC Al]

yes, more packed section

[Demy]

Desahih I don't know if there's a specific reason why you want to get to azeo but in my opinion it's not necessary to get a great product. I have a small VM column (1.5 ") full of scrubber (113 cm fill) and I get 93-95 ABV with a really neutral flavor. It is true that there is some satisfaction in taking the column to the limit but I don't think it is necessary for a great product, from a certain ABV onwards you have to increase the height a lot compared to the gain or change the packaging as suggested.The changes that people much more experienced than me have suggested to you are fine but do not create a fixation with 96 abv Just my opinion.

[desahih]

You're right Demy, i could redistill my batch and get a more neutral flavor.
As to why i want that azeo is for making vodka and neutral to use for gin and liqueur. After all i think it would be a nice achievement getting the 95-96 each degree over 92 will be a step stone.

[NineInchNails]

The first thing I would do is remove that long shotgun and replace it with a 6"-7" double wound copper coil and lightly stuff & wrap it with copper mesh. My 3" VM has a 5.5' packed column and a 9" long 5/16" copper coil in a 3" pipe and it works perfectly. That will give you all the knockdown power you need while drastically reducing the overall height of your still. Next, as mentioned previously, add more height to your packed column. Also check out this Distilling Vapor Speed Calculator. Enter your info and it will tell you the power range you should be running at to keep your vapor speed from being too high during a spirit run. If you switch over to electric 240V with decent controller you will have excellent and verifiable control over your input & vapor temp.

It would be ideal if you cut the dephlegmator off and have Tri-Clamp ferrules welded to the top & bottom. That would allow you to remove it and provide even more length of column for neutral spirit runs. Most fabricators have band saws and can make clean, perpendicular cuts to ensure the job is done right and you won't have a crooked column after modifications. You can buy pre-fabricated Tri-Clamp spools at different lengths with ferrules already welded, but I'd compare the cost of making your own our of copper pipe & ferrules by simply silver soldering them. I found that copper ferrules were easier for me to solder, but they do cost more than stainless ferrules.

With just a couple modifications you can have it running great neutral very easily. Many have reported replacing most of their copper packing with Lava Rock broken into relatively small pieces made a huge improvement on their output purity. Here's one link for instance and notice how darn short his column is. I'd still go taller than that.

I have some of these ceramic rings arriving today and these are said to be an improvement over lava rock so I'm excited to see how they do.

[Demy]

You're right Demy, i could redistill my batch and get a more neutral flavor.
As to why i want that azeo is for making vodka and neutral to use for gin and liqueur. After all i think it would be a nice achievement getting the 95-96 each degree over 92 will be a step stone.

I also often use neutral for spirits, it is true that it is very satisfying to get a high ABV. You can upgrade your gear for as long as possible, so don't worry if you don't reach the higher levels. Neutral ingredients, good fermentation and calm distillation will still give you a good neutral. I highly recommend a stripping before the final run.

[desahih]

Yea the alcohol i use is stripped grape alcohol as it is always available in my country use to make arak, raki or ouzo.I can make it brandy or neutral...nothing to worry about . i think my heat increase wasn't enough as i wasn't getting the 50ml per minute to measure my reflux and collect 5ml per minute as stated by the book. i'll try to get the 50 ml output before i start refluxing for like 2 hours and watch the temperature.

[bluefish_dist]

In theory it takes 15 plates or equivalent to get to azeo. I found 18-20 works better and even there I could not get an output that was true azeo, but simply above 190 for the whole run. That is all that is required by US law for vodka. IMHO it is hard to make a true azeo and I suspect most home distillers do not own the equipment required to determine proof accurately enough to tell the difference between 190.5 and 191, let alone 189 to 191.

The typical home brew hydrometer won’t cut it. You should really have a calibrated high accuracy, high proof Hydrometer and a calibrated thermometer. That will run about $150. Even for uncalibrated hydrometer and thermometer it will be $50-$60.

[greggn]

The typical home brew hydrometer won’t cut it. You should really have a calibrated high accuracy, high proof Hydrometer and a calibrated thermometer.

For me, accuracy is less important than repeatability. The readings can be off as long as they are consistently off by the same amount. I'm just looking for indicators that my process is, or is not, in control.

[bluefish_dist]

The typical home brew hydrometer won’t cut it. You should really have a calibrated high accuracy, high proof Hydrometer and a calibrated thermometer.

For me, accuracy is less important than repeatability. The readings can be off as long as they are consistently off by the same amount. I'm just looking for indicators that my process is, or is not, in control.

The best way to know abv is an accurate thermometer in the still head. Then correct for atmospheric pressure as that gives a 1 deg swing or more. I used temperature to know what my still was doing and made it quite repeatable.