How long does a run take?

[chill]

OK, I realize this is a lot like asking how long a piece of string is but... I have an AirStill now, and am looking for my next step. Given the four litre size, it may seem odd to be asking about how long a run takes in a bigger still, but so far four hour chunks of time are something that I can manage. I have read reports of reflux runs taking 12-15 hours. To me, that seems like a lot of time at one stretch.

I know that run times depends on a lot of thing: still design, column diameter, power applied, purity out etc. Can anyone give me some ideas of how long a run of say 25L of 40% low wines at no more than 1500W with a 2" column would take? From switch on to switch off? I don't require azeotrope purity, mostly I am interested in whiskey, rum, and such - pot stilling territory. But I want to be able to make something suitably neutral-ish as a base for gin, and limoncello etc. So I am thinking of maybe a CM still like a MileHi that can be used for both modes. Or maybe an LM like the PDA-1. VM does not seem suitable to my needs.

Thanks for any education.

Chuck

[Frank]

Hi Chuck
its a fair question mate, and you have answered some of it yourself, I reckon.
Up front, I apologise for not knowing answers for elec heating but i can offer this regarding time taken for a run (as an experienced aristiller whom now uses a gasfired potstill)......
The heatup period is significant on any reasonable sized boiler (esp with ambient wash/low wines temps through cooler months) and the runtime does indeed depend on the type of run (eg strips run flowrates are usually quicker than spirit runs) and type of still you are using.
There are also setup and cleanup times to be considered (possibly)....
To quicken things up, consider insulation, still type and column size and amount in boiler (they are all big ticket items IMHO).
BTW, (only as a guide mate, there's LOTS of options out there) I use a 2 1/2" potstill and can easily strip at 7l/hour with 30 minute startup on LPG. I deliberately slow the spiritl run flowrate to anywhere from 2-4 lph. I make whisky and a (passable) TPW-based 'neutral' for using in macerations etc. I could (of course) triple distill and get a good neutral, etc.

[Spud1700]

A 50 ltr keg with 2200 w takes 1 hr 40 mins to get to temp, if you were running a pot still at 3 ltr an hour then 3 hr 20 mins to do a wash plushest up.

If you stripped at 10 ltr an hour then 1 hour plus heat up time.

1500 w is going to be slow, 2200w takes awhile.

[billmcc]

For me 1500 watt 25ltr wash takes 1hour 20 min warm up from 22deg c then run fast @1200 watt and collect at 1.2 litre per hour @91 abv
4 hour 10 min from start to finish.
Do this twice dilute to 30 abv = 18ltr for spirit run
Warm up 40min@1500@35deg c drop power to 900 watts and collect at 800ml per hour@93 abv
7hr 30 min from start to finish

[scarecrow]

I have read reports of reflux runs taking 12-15 hours.

If any run took this long, I would seriously look at an upgrade.

I have a 50 litre keg over a 3 ring banjo. I run 40 litres of wash in a single pass. Heatup till fore's start dripping is about 45 mins. Startup to packed up and having a beer is usually 4 - 5 hours, tops.

scarecrow

[Swede]

Depends on the size and capacity of your equipment, main two pieces that matter are element size, and condenser size.

In reality though, the smaller the column, the slower you HAVE to run it. Potstills can run fast to strip, but need to run slow on a spirit run to minimize smearing. There is one major thing that you can do to cut down your distillation time when you use a still, and that's to boost heat power during heat up and tails run out. I currently run a 2 x 4.5kW system that gives me 9000w of power to boil up a keg in 25-35 min. I can distill a 50L keg of ujsm wash at 8-10% from heat up to shut down in 3.5-4hrs. I see huge gains from the additional wattage at heatup and tails run out, but can only distill (hearts) as fast as my column can handle.

I use a 4" bubble tray column (4 plate) and this will process hearts at 3.5-5lph depending on how hard I drive it. This happens around 3800-4000w during distillation. I regulate distillation rate by balancing reflux and heat input (an art that you must learn as each still can be different).

I cringe when I think back to my days of running a little 1.5" vm and taking 14hrs to do a vodka run. Thank goodness I can run twice through my bubble column and have the same results.

[Al Q]

I have read reports of reflux runs taking 12-15 hours.

If any run took this long, I would seriously look at an upgrade.

I have a 50 litre keg over a 3 ring banjo. I run 40 litres of wash in a single pass. Heatup till fore's start dripping is about 45 mins. Startup to packed up and having a beer is usually 4 - 5 hours, tops.

scarecrow

Not always that simple SC. neither my garage or kitchen has the head room to run a 3" VM in the standard layout. So I'm stuck with a 2". So with 35L of 40% in the boiler on a neutral run.

Warm up (3kw), 1h+
Equalisation, 1h
low power heads removal for the first 2L (800w), 2h+
10L @ 1.2L/h (1500w), 8h
Shut down before I run into tails leaving 10%+ of the total potential alcohol in the boiler.

Right there is a good 12h work, I sometimes do the heads and the first few jar of the hearts the evening before, so I'm not at it all the next day and get impatient.

On the same keg, I can strip 45L of wash in less than 4 hours with the full 3kw.

[Al Q]

It's a lot of booze and will last the average family a long time. So one saturday every 4-6 months doesn't seem so bad.

Exactly right. It is really dull and I normally do a bit of web surfing, or sit with a book, but its a means to an end for me. Gives me a load of stock neutral, to then do small batches of gin, which I can then do in an evening after work if I like.

4 Saturdays or Sundays a year isn't that bad, or doing a Friday evening then an early start on the saturday, and you can still make it out on the Saturday night

[Spud1700]

If you were to charge a boiler with 40 litres of 40% strip and do a 12-14 hour run being careful to pull off at 95+ and clean you will end up with somewhere around 32-35 litres of 40% vodka.

It's a lot of booze and will last the average family a long time. So one saturday every 4-6 months doesn't seem so bad.

This is exactly what I do, 35 ltr of vodka lasts a long time, well for me it does anyway, 12 hrs on a Sat for me is fine. Watch TV do some welding etc.

[chill]

Hi Everyone,

Thank you all of the very helpful and useful information. This is exactly what I was after!

Some follow-on thoughts and questions:

One calculator that I have seen is at Reflux Still Calculations but it stops after a few hours.

Not being inclined to build, I have been looking at boilers for sale. I also think I would like more access for cleaning than a keg (but what do I know?). So I was looking at this boiler plus immersion element from MileHi: electric 8 gallon boiler. And hoping this is not the element that has had so many trouble reports on Aussie Distiller. I was also thinking to supplement this with a 1500-2000W hot plate. That would allow for quicker heat ups and running tails. It would also allow me to run smaller spirit runs without having the element exposed (one of my concerns about using a keg). Does that make sense?

I am also considering a 3" column, which I have read should be twice as fast as a 2". Is 1500-3500W sufficient for a 3" column, or will that be underpowered? I don't quite understand how input and column size are related yet.

I live in the city on a corner lot, so distilling outside is not an option. Hence I am limited to electricity.

Also thanks for the reminder that I don't need to spirit run a full boiler. At this point, I am more interested in trying a wide range of things than in making a large amount of one product so that is a good thing to keep in mind.

Thanks for the education as I feel my way through this.

Chuck