3” CCVM with SPP - how fast before smearing?

[wow400]

Hi guys, how fast would a 3” CCVM with 30” of SPP go before you start to get smearing?
I’ve finally gotten around to doing a spirit run of my 40l of 40% low wines (accumulated over quite a few months from kale sugar washes).
Although I’ve done quite a few stripping runs, this was my first spirit run so was feeling my way.
Seeing as I didn’t take any cuts on my stripping runs, I took a fore’s cut of 600ml, then collected in 300ml jars for the next 3.5l. Then, hoping I was going to be near hearts, started collecting in 750ml containers for the next 8l then back down to 300ml for the next 6l. I stopped when I thought I could detect tails.

It’s all been airing for a few days so I thought I’d have a watered down (40%) try of some of the cuts - just a quick try as I’ve not had time to properly go through them all!
TBH, I couldn’t taste that much difference between any of them which makes me think I’ve smeared it all the way through.
Either that or my taste buds are shot (which is a definite possibility!).

I did a slow heat up - about 70 mins to first drips, fore’s took off at 2 drips per second rate then back into reflux for 30 mins (perhaps I need more?) then start taking the main load. Around 2.5Kw power used throughout and PC/RC cooled with mains water at about 13°c. Because I’m doing it outside and my PC is CSST, I don’t get to use the twisted pencil lead stream analogy.

Any thoughts?

[kimbodious]

I reckon your cuts are ultra conservative! I think a lot of the first 3.5 litres will actually be hearts.

I also do spirits runs using 40 litres of kale wash low wines. I collect and discard about 200 mls of foreshots and then the next 1.5-1.8 litres is heads.

Your procedure looks fine. Slow heat up then 30 minutes of total reflux will have done a great job of compressing the fores and heads. But hey if you aren’t convinced, you can always dilute your product and run it again!

[wow400]

Thanks Kimbodious,
I was being ultra conservative as I had taken no cuts when stripping
Yep - it's hard to start learning cuts as I have no reference when tasting! I can make out the acetone type smell of the fore's, didn't get any wet dog or cardboard smell of the tails so whether I've got tails or not who knows!

I guess there's a sweet spot with a CCVM where you're going slow enough so you know you're NOT smearing (and therefore not having a set reference to work with) but also fast enough that you're using the setup to the best of it's ability. Probably not much point running the CCVM at 2 drips per second (for example) for the entire run!

Does anyone know the answer to how fast you can run it before smearing takes over?
I might PM DAD but I'll hold off annoying him in case I get any more great info.

Thanks again Kim

[Sulaiman]

as far as I know;

If the reflux ratio is maintained,
and no gas/vapour escapes the (product) condenser
and the column does not flood,
you can go as fast as you like.

A lower boiling rate would allow a larger reflux ratio,
which would make fractionation finer / give less smearing,
but I have no experience with your column size and packing,
So I can't guess at 'optimum' conditions.

[wow400]

A reply from DAD which I'm sharing here as it adds some great info!

Math says you collected approx 18l total. But at what ABV? What's your packing? I'll assume you are using a 50l keg.

Approx guess is you would have had 1l of fores and totally trash heads @ say 90%+, 2-3l of evil heads, 2-3l of tails and 11-13l of drink depending how clean you are trying for.

Light fires, clean things with heads, save tails and add to next run.

Well at 3" by 30" all of your fores and most heads are in the column as you finish heatup. The column probably hold 2-3l of vapor/liquid. Probably why you couldn't detect much dif after another total reflux/restacking column. The fores and heads were mostly gone.

A 3" CCVM over a keg should be 3-4 hours maximum. 1 hour heatup, 2-2.5 collecting and a half hour to collect tails/feints.

Your takeoff sounds excessively slow...slow takeoff can cause smearing. Think about this...when your heavily refluxing you can actually drop fores back down thru the packing as liquid...smearing everything over and over...you end up just running heads up and down.

Let the fores and heads escape when first opening takeoff, then slowdown and start your small jars. As it seems purer larger jars when abv starts to drop go back to smaller jars, when takeoff rate gets so slow you can's stand it open the takeoff into a large container and save it as feints to add to next run.

So your fores and heads should be about a liter every 20 minutes and hearts a liter every 12 minutes, as abv drops and you question tails coming on drop takeoff to a liter every 20 minutes...and eventually turn up the heat, open the takeoff and blow out the last few liters as feints.

I air out for at least 24 hours, open jars with a dish rag or paper towel on top.

Your column is making 94%, your doing great! Don't be afraid to speed up a little at a time till you find the point you loose your desired abv.

I vary both power and RC to some extent. You'll find that you will play with it less and less as you know what to expect.

Kind of like your flying learning curve...sometimes less fooling with controls is good thing.

I have some nice controls on my big still now so I work in percentages.

I have 170 gal still with 33,000watts with 5 plates and have set a schedule of 6.5 hours for heat on to heat off, and usually make it. Summer slows me if my recycled cooling water is too warm.

Heatup is between 90-95% as I want some maliardization to happen, not asap, usually 1.5 hours.
then to 50% for fores heads and hearts...aiming for 80%abv.

As abv starts to drop I'll Increase the reflux and try to keep abv, but not to the point of a takeoff so slow I won't make my time schedule... if going for flavor (whiskey & brandy) there is a lot in late hearts and early tails.

50gal still with 16,500watts for vodka and gin about the same... 25 gallons 80% strip neutral watered to 40% with 4" x 40" spp column... heatup time not a factor but ~1 hour at 90% power, reduce to 40% and catch a few small containers and then collect into a keg until I can't hold abv, remainder into gallon buckets for airing and decide what to use or rerun. Usually less than 4.5 hours, no cooling water concerns here.

Look for the abv and flavor you want, and find the takeoff speed it takes to get that.

[DAD300]

Sulaiman,

Knowing he has SSP, "flooding" is not necessarily a bad thing. There are posts here about flooded column, fluidized bed and such.

If the packing is holding liquid, but not to the point of overflowing the takeoff, you are staking or separating better than you would with vapor and reflux constantly mixing up and down.

One of the things I used to do was listen for the SPP to start jiggling around, you can actually hear it! If you have SPP moving around, your probably on the edge of to much power/vapor speed. You would effectively be wasting power and reflux water!

Go back to the science here. With slow heatup, First thing off the boiler is fores...first thing to top of column is fores, so why do you want to reflux them back down the packed column?

Example: This happens in a pot still. The first amount taken off is higher abv because it has the fores and heads in it and then abv slowly declines through hearts and tails.

I know about what amount of fores I'm going to throw away every batch distillation. I also know most of our packed columns store that amount of vapor in the column. I let that amount out before I think about increasing reflux.

It's a little dif in a plated column, but not much...my plates will start to stack at the bottom before the fores are out, just because the top of the column is colder than the bottom.

With SPP, in a 3" x 30" or a 4" x 40" at proper power, you're probably making Azeo before it gets to the top and minimum 1:1 reflux.

[kimbodious]

Here’s my example of a fluidised bed, 2” column CCVM. This is about as high as I let the level get, any higher and I seriously run the risk of condensate splashing out the offtake.

[DAD300]

kimbodious,

Nice video, a pic is worth 1,000 but that video explains it.