SPP Packing

Fittings, parrots, packing, tooling and so on.

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SPP Packing

Post by skow69 »

Odin, thank you for this thread. I have read the whole thing several times. [Actually, I skip the pages where you got hijacked for the terminology debate.] It inspired me to read Ian Smiley's book [several times] and to try the method with my VM/LM combo. I bleed off the fores and heads on the LM side, switch to VM for the hearts, and back to LM for the tails. To my complete amazement, it works like a dream. In fact, the flavor is so intense that I ended up mixing it down with neutral like Ian suggests. On the second round I thought I must have lost my mind, so I had a friend try a blind test, and he preferred the "diluted" version as well. It still has more than enough taste, even blended 1 to 1 with neutral. I think it's important to note that the neutral must be absolutely tasteless to preserve the integrity of the whiskey. I suppose you might get something interesting by blending with a flavorful vodka, but I'm not going to try it.

I don't want to divert the discussion, but I have to ask about comment you made about SPP. I'll be happy to start a new thread for it if you like.
Odin wrote: It seems that those darn Russians not only invented SPP, but also found the perfect way to run it. "Close to column flooding" they call it. As close to column flooding as you can get! By doing that, they can actually lower HETP even further. How they do that (I just found out) is by upping the power. And by adding a glass section as the top part of the column with packing. "Get as close to column flooding as you can all the way from where reflux starts to where the glass stops. Usually 20 or 30 centimeters. That's where you can really see the boiling (or so it looks, because it cannot be boiling but is gasses travelling up in an aquatiq environment) take place. Now, I looked at my rig, and it does exactly that: boiling action at the top. But just for 5 to 6 centimeters. You know what those Russians do? They up the power to like ... 2.7 kw on a 2 inch column. Now I do not even want to get close to that. 2 kw suits me fine.
A while back I swapped out most of my standard scrubbies for some material that is similar to SPP, made from a different kind of pot scrubber. This picture shows two short scrubbies above a section of the faux SPP.
faux SPP.jpg
This stuff is not as efficient as the real thing, for sure, but it did improve separation, and it forced me to reduce the power to avoid flooding. I am intrigued by your comment about the aquatic environment. With the borosilicate column and power control I can dial in flooding at any level I like, but I have always kept it down in the boiler because, frankly, it's pretty scary, and I thought it would decrease the effective height of the packing. I may need to reconsider that now. Could you point me toward a discussion of the Russian work, please?

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SPP

Post by Odin »

Great to see you being able to replicate my results!

And I think you should ask a MOD if he can make a new thread from this, because it is about SPP and not about pure whiskey. And I feel SPP deserves a stage of its own.

What I can do is share my experience with my SPP columns. I fitted my iStill with a power management system. Just took a 48 mm internal diameter glass version from the standard 2 kw to 2.8 kw and she ran like a dream. More redistillations, more stability, an even bigger hearts cut. I will test the power on my SS 2 incher (with 54 mm internal diameter) and am sure she can take well over 3 kw.

The more power you throw at your column, the more reflux you create. The more reflux you create, the wetter the conditions are in which the SPP has to do its job, making it ever more efficient. Until you push it too much and create actual column flooding.

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Re: SPP Packing

Post by skow69 »

Thanks, Odin.

[This discussion was ported over from Odin's Making Pure Whiskey thread.]

I think the evidence is clear about the efficiency of SPP, but I am still curious about this aquatic environment. I've done some more reading and found some wildly conflicting recommendations for how to run it.

If I don't find anything definitive I might run some trials myself.

If anyone has knowledge or experience regarding running the SPP in a flooded or semi-flooded column, please post.

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Re: SPP Packing

Post by DAD300 »

SPP is/was a huge step forward for the hobby distiller.

I think the only issue Odin and I disagree on is the inventor. I have found lab papers describing it's use in the 1930's and 1940's, by labs in the U.S. for the separation of radioactive materials.

I do agree that the Russian hobbyist may have been first to use it for home distillation of ethanol. I found on a Russian distilling forum, "Old fishing wire, make good vodka!"

Where it came from is not that important to us. It works as described.

It will reduce any column height by 60%. Think you need a 90" column to reach azeo? SPP can do it in 30".

It has more mass making it energy efficient. While it takes a little more time to heat it, it is far more stable after it reaches the correct temp.

This is the first chart (1982) I would throw at anybody. It shows a sub 3 cm HETP for several designs of SPP. While tight packed SS Scrubbies come in at almost 12 cm HETP.
Pages from [Krell, Erich.]_Handbook of Laboratory Distillation With an Introductio...(BookFi.org)-2 r.jpg
While practical experience showed me it work well in a flooded state, I thank Odin for describing the flooded states and giving me understanding of it.

I'm trying to scale SPP for larger columns and balance the mass vs throuhput (vapor speed) vs liquid retention.

Skow69...look for Russian home distillation forums and get ready to translate...or just look at the pictures and videos (what most of us do on the interweb).

If you want lab type material, there is a lot of it and hard to sift through. But remember, most of the lab data is done in small dia (20-30mm) columns and without induced reflux.
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Re: SPP Packing

Post by skow69 »

Thanks, Dad. I will look up the Russian boards and look for pictures. I found some Russian research on water purification and deuterium isolation. Fortunately, I don't have any heavy water to deal with.:wtf:

This is the topic that I would like to explore here:
DAD300 wrote:While practical experience showed me it work well in a flooded state, I thank Odin for describing the flooded states and giving me understanding of it.
Could you elaborate on that, please? I haven't had the benefit of Odin's description.
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Re: SPP Packing

Post by DAD300 »

There are lots of videos of SPP filled glass columns. They look to be flooded (full of liquid) with bubbles going up through them like soda water.

http://www.homedistiller.ru/" onclick="window.open(this.href);return false;" rel="nofollow

All basic still experience would say, the column is about to puke. Not so...with proper power SPP can ride this saturated stage and actually benefit from it. In fact it is possible to flood the bottom or the top or the entire column by balancing power, reflux and insulation of the column.

The HETP of SPP decreases (benefits) from being in this liquid filled/saturated stage.

A while ago, Odin and his glass column, wrote a description of the stages of vapor and liquid in an SPP column. I hope they will be adapted as proper definitions. Maybe he will paste it here...

SPP has a great mass compared to Ss Scrubbies. 18 SS Scrubbies weight less than 1.5 pounds. The same volume of SS SPP weighs ~13 pounds. It takes a little longer to heat but retains the heat offering greater stability.

Once heated the temp gradient from bottom to top is much more even than Scrubbies. The temp from bottom to top is so stable, I don't insulate the top of my column so as to create a temp gradient so that the reflux will penetrate deeper.

I used to do long equilibration at 100% reflux. I had a column with thermometers bottom, middle and top. I could stabilize this column top to bottom at 1 deg F dif between the bottom and top.

Flooding at the top can be induced by supercooled reflux. Reflux that is over cooled and vaporizes when it hits the top of the hot packing, instead of penetrating the column/SPP. Another way to stop the top flooding is to have a SS Scrubbie on top to spread the reflux.

When I first started with SPP I had other "first" experiences. My column was too loosely packed and it made noises. A sizzling vibration sound...it sounded like the SPP was vibrating. I now believe it was the liquid and vapor bubbles surging between the SPP bits.

I don't do more than 10 minutes of 100% reflux any more...by the time first vapor reaches the top of my column, it is at 95%. That's with 30" of SPP...in a 3" x 36" column. With 1:1 reflux/takeoff, I'm making ~18 Theoretical Plates. I could make 24+ if I were willing to reflux more and slow takeoff to say 2:1.

Some of the stats, weights vary from others SPP. Mine is a clone of Heli-Pak, rather than the more prevalent Star shape. And my wire dia is twice that of others. My average run, my HETP is about 3.6cm. There is SPP well under 3cm HETP. So, your mileage will vary.
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Re: SPP Packing

Post by Odin »

I will try to have a go at it. And "create" a sort of setting that can help us understand better. Oops posting, while DAD was ...

SAT

Let's start with the workings of scrubbers and other packing material. The theory explaning their effectiveness is what I call the surface area theory (SAT). The theory goes like this: the more surface area a packing material provides, the easier evaporation of reflux takes place. Huge areas of thin layers of reflux interact easier with rising gasses than packing with less surface area.

The theory did a good thing at explaining how scrubbers work, but not necesairily how other packings work. This was shown for instancy by my own tests with basalt rock packing, by Mash Rookies experiements with lava rock, and - most of all - by SPP. So let's concentrate on that last form of packing and dive in deeper.

Notions on SPP

If we look at SPP, what we see (in relation to scrubbers and Surface Area Theory:
1.- SPP has less surface area than scrubbers;
2.- SPP is heavier than scrubbers;
3.- SPP has a very distinct shape;
4.- SPP has an HETP of 3 centimeters, where scrubbers have an HETP of 12 centimeters;
5.- SPP gives a more stable run, cares less about that door being opened, that breeze of cold air hitting the column.

Notion number one makes clear to anyone understanding SAT that SPP cannot have a lower HETP than scrubbers. Hey, they offer LESS surface area! But results are undenyable: SPP has an HETP of 3 centimeters, while scrubbers are much less efficient. This is why I stated early on that SAT is not applicable, but another thing is going on. More on that later.

Even though notions number 1 and 4 do not seem to be agreeing with each other, notions number 2 and 5 definately do. SPP is heavier. And because it is heavier it takes more time to heat up. And since it is heavier and took more time to heat up, it holds more energy. The extra mass makes for a stable run. No more scrubber stories like "I had to restabilize because my wife came in and didn't close the door right away!"

Now let's take a look at notion number 3, that states SPP has a very distinct shape. And believe me, it does. Even the angles at which the tread is wound are tested and found to work better at specific angles. But in general, without going into too much detail, that shape is suited for one thing and one thing only: to hold a drop of liquid. So ... less surface area, more water retention, so not a thin layer of reflux, but big blobs of it. From the standpoint of SAT that makes even less sense, but it is exactly the key to understanding why SPP is so effective.

So ... if not via SAT, how does SPP work?

In short? Liquid is easy to redistill. We do it every week or month: take a boiler, fill it up with a liquid, add energy at the bottom and - lo and behold! something shoots away from the top of that liquid. And that's what's going on inside an SPP spring (or in bigger stills: inside a rashig ring). It traps some liquid. That liquid is bombarded from the bottom with energy (rising gasses, other drops of water bouncing and weaving and resonating ...). And guess what? Something comes out at the top. The lighter molecules first. Distillation theory one point one. Nothing very new. We have been distilling like that (simple pot distillation) for close to 3000 years.

An SPP spring is no more or no less than a micro redistillation unit.

... given you create the right circumstances for it to do its job. Just as with our normal potstills, if you don't fill them with liquid, they don't do much. And if you overfill them with liquid, well, that's not good either, is it?

Some theoretical starting points and observations

Watching my glass column, which is filled with SPP, I saw different action taking place at different parts of the column. And at different energy inputs and vapour speeds. Here is what I learned from it and how I propose we can look at it or even understand it. Let's take a boka design LM as the rig of choice, just for convenience sake:
1. More energy creates more gass;
2. More gass means more reflux;
3. Reflux is induced from the top of the column on to the packing (nothing new so far!);
4. Since, while it drips down the column, more and more reflux is re-evaporated to a gass state (travelling upwards again) ...
5. The highest amount of reflux can be found in the top part of the column;
6. ... and at the very bottom of the column, because that's where relatively water rich vapours are redistilled creating a lot of water travelling down the column and falling back into the boiler.
7. If we travel upwards a bit, we see less liquids, and then pretty much no liquids;
8. Until we reach the upper part of the column, where liquid levels increase again (see point 5).

To sumarize it: an SPP filled column has different zones, when working optimally. That's based on above explanation as well as of careful observations of both my glass SPP rig and my bigger rashig ring packed rig. From the bottom to the top:
1. Aquatic environment (aka semi-flooded, where I use semi to say you should not actualy flood the column);
2. Semi-aquatic environment (notice that I use the term aquatic to state there is liquid, not stating it is water, it can be high abv reflux as well);
3. Non-aquatic environment (roughly the middle of the column);
4. Another sem-aquatic environment;
5. And the aquatic environment at the top.

Phases

Based on my observations and paragraph above, I distinguish between 3 phases. I have used them before and in various orders, but let's create a common language that goes like this:

Phase 1:
In a situation where there is little reflux (or lower energy in puts), SPP springs get wettened in the same way as scrubbers do. Stability will be better, but HETP (since there is always some liquid building up in some springs) is only marginally better than scrubbers. If I were to make a guess, I would say HETP is around 8 or 9 centimeters. We see this happening in the middle part of the column (zone 3).

Phase 2:
In a situation where there is more reflux (or more energy is put into the column), The spaces between the wire (for open SPP that is!) collect tiny droplets. These small droplets start resonating and start collecting rising gasses. This creates a more effective functioning of the SPP packing. HETP drops. This is what happens in zone 2 and 4 in your column. SPP works in a semi-aquatic environment.

Phase 3:
This is where SPP works in an aquatic environment. Zone 1 and zone 5. Every spring acts as a redistillery on its own and HETP crashes to around 0.5 centimeters.

Power input and HETP

The more power you throw at an SPP packed column, the more reflux you get. And as you up the energy input, you don't just get more reflux at the top, but also more at the bottom, where more relatively water rich vapours now enter the column. Zone 1 and zone 5 get bigger at the costs of especially zone 3. More SPP is in its optimal working range, thus lowering the overall HETP of the total column.

But please notice: HETP is not a given. If we state "SPP has an HETP of 3 centimeters" that holds true for the column as a whole. Some parts have much lower HETP, others have a higher HETP, but in all cases: more power & reflux lowers HETP.

Creating a situation of "close to column flooding" creates a situation where a big part of the column (maybe 50%) works under ideal, sub 1 centimeter HETP conditions.

But if you push it too far, off course the column will flood. That you do NOT want.

Entrainment

Take a 2 inch column packed with scrubbers and she will probably do a good job when you throw 1 kw at her. Not sure, but from what I read, you can throw 1,25 at it as well. If you really pack it very, very dense, maybe a bit more. But if you throw 2 kw at a scrubber packed column, you will get entrainment. I hope that is the correct word. What I mean is that relatively high boiling point alcohols (tails) smear into hearts. Why? Because there is pretty much a free path for gasses to rise up in.

A 2 inch column packed with SPP easily handles 2 kw. How come there is no entrainment? Liquid (again). The liquid at the bottom and top parts of your column make that the gasses that (due to higher power input) rise up to be catched in the liquid bed. From there on they (the heavier, higher boiling point alcohols) are pushed outwards again, downwards instead of upwards.

Did you ever see those movies? Try finding some on Youtube. "What stops a bullit?". Where straw, mellons, or a wall don't do the job, a glass fish tank filled with water will. That's a great metaphor: the bullit can be seen as the high energy, quick traveling higher bp alcohol, the fishtank as the SPP holding a drop and functioning in an aquatic environment.

So how do you make sure you don't get entrainment? Make sure there's enough reflux. Right: push the power.

More on power and SPP performance

Just as a comparison. I used to run my SPP LM rig on 2 kw. automatically. Just to give you some numbers that will stagger anyone using a scrubber packed LM: on a 30% low wines charge, I can collect up to 3.5 liters of pure azeotrope. Fores cut dwindles from 3% (reference: Ian Smiley's - Making Pure Corn Whiskey) to 1%. Heads go from roughly 17% to around 6%. Tails are better compressed and hearts cuts are bigger and better.

3.5 liters per hour, now that's something different from how to run a scrubber packed LM (3 drips per second). 3.5 liters per hour is what a 4 inch diameter, 4 plate Flute produces. Or a potstill. How come? Read the above: it is the SPP doing its magic.

And 2 kw is nothing for a 2 inch SPP packed column. I have done tests, just this weekend, where I threw 2.8 kw at a 1.75 inch diameter column. I learned that the still runs better, faster, more stable, with even better cuts with the upped power input.

If I translate this to my SS 2 incher, I expect it to be no problem to run with 3 kw. That's 50% over the original 2 kw power input. Output will improve to an expected 4,25 liter per hour of pure azeo on a 30% low wines charge.

In short?

In short, SPP is a game changer for the home distiller that wants to make a pure product.

Well, that's my take on it. Long write up. I hope you guys like it.

Regards, Odin.
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Re: SPP Packing

Post by cyborg »

Odin, I have a 54mm boka column with a packing space height of 90cm on top of a 25L 2kw boiler with a power controller.
I have thought to use 6cm of SS scrubbers at the top, 78cm of your SS SPP in the middle and 6cm of copper scrubbers at the bottom, does this sound OK.
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Re: SPP Packing

Post by Odin »

Cyborg. Just a scrubber on top and one at the bottom will do. Or a holding pad. By introducing two times 6 centimeters, you are not gaining but loosing. I mean the SPP will for sure take you to 95%, but why introduce a less efficient packing in those zones where SPP is most effective: top and bottom? Not sure about the copper. I mean, it can clean up sulfur, but you need to put it in in such a way that you can take it out and put it under 40 to 50% alcohol after the run. The copper that is.

Hope this helps.

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Re: SPP Packing

Post by cyborg »

Odin wrote:Cyborg. Just a scrubber on top and one at the bottom will do. Or a holding pad. By introducing two times 6 centimeters, you are not gaining but loosing. I mean the SPP will for sure take you to 95%, but why introduce a less efficient packing in those zones where SPP is most effective: top and bottom? Not sure about the copper. I mean, it can clean up sulfur, but you need to put it in in such a way that you can take it out and put it under 40 to 50% alcohol after the run. The copper that is.

Hope this helps.

Odin.
Thanks for that Odin, I will just put 1 SS scrubber at the top as a stopper and 1 copper at the bottom also as a stopper which can be removed for cleaning.
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Re: SPP Packing

Post by DAD300 »

Thanks Odin...your explanation is far better than my experimentation. And I've never seen mine in a glass column. But once you've heard the explanations of the Phases, it is very easy to imagine it in the SS column.

Cyborg...I used to use a copper scrubbie on the bottom as my SPP retainer, but it was very hard to change it as it requires a breakdown of the still. If I feel the ferment needs it, I put it on the top now. I'm trying to switch to a sieve plate on the bottom.

I had also thought about a "T" between the boiler and column. That way I could add copper scrubbie, drain and reflill boiler from "T".
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Re: SPP Packing

Post by skow69 »

Thanks, Odin, for your time and that excellent writeup. I haven't seen my rig develop an aquatic zone at the top. I have seen it appear at the bottom and grow upward, but then I was trying to avoid it rather than promote it. Your post has given me just the info I needed to do some more experimenting, which I feel certain will improve my process even more.

That's what I love about this hobby. There is always a higher goal to strive for, a better product, more efficiency, another challenge to conquer. And, thankfully, a helpful guru, like Odin and Dad, to point the way. Thanks to you guys it just keeps getting better.

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Re: SPP Packing

Post by skow69 »

Hey DAD, that Russian forum is fantastic. I actually found homedistiller.ru yesterday after your first post. Google translate does a pretty fair job, once you work out some of the terminology [cube, filter, nozzle.] They have a rather different focus that I find refreshing. Thanks for the tip.
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Re: SPP Packing

Post by DAD300 »

Yes, they use the word nozzle a lot. To them it is that each bit is shooting vapor...

Did you find the Russian Glass column videos? http://www.youtube.com/watch?v=MHSPTCEpITo" onclick="window.open(this.href);return false;" rel="nofollow Look at his library...he tried broken glass, cut srubbers, nut shells, 5 videos of SPP...
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Re: SPP Packing

Post by skow69 »

Shooting vapor it is, then!

That video was just the confirmation I needed. It's hard to accept that as a good idea, but I'm finally catching on. I can run like that. It's between 1100 and 1400 watts. I always back it off. Now I gotta try it and see if it works on my faux SPP. May be too light.

I gotta go round up some low wines. Thanks again, DAD. I'll be back.

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Re: SPP Packing

Post by sambedded »

About nozzle - actually it is column packing . Google translator just is not perfect.
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Re: SPP Packing

Post by Odin »

More on SPP. On some forums we see a move towards putting a bubble capped or perforated plate under a column and filling that column with scrubbers. That hugely improves how a scrubber packed column runs. Better cuts for (especially) tails, easier to hit pure azeotrope, and more product per hour.

But would that work on an SPP packed column as well? Maybe. But maybe not. And if it works, is it a desired way to move forward? Depends. Let's dive in a bit deeper.

Refering to my description of how distillation in an SPP packed column actually goes, we can distinguish between 5 zones in the column. Zone number one, the very bottom of the column, is (with enough power input) aquatic. In general two things happen in this zone:
1. Water, plenty of that in the gasses rizing up from the boiler, is being stripped out of the gasses entering the column and sent back to the boiler;
2. Higher boiling point alcohols (tailsy molecules) are catched in the water bed and shipped back to the boiler as well.

Zone 1 can be seen as a stripping zone.

Now let's take the comparison with a scrubber packed column with a bubble/sieve plate underneath. Here the first plate does most of the stripping, feeding the column with less water rich gasses. Easier for the scrubbies to handle.

Let's put one section of a magic flute under an SPP packed column. What will happen? Two things:
1. By feeding higher abv with less water to the SPP packed column, no aquatic environment will be established in zone 1. This lowers the overall effectiveness of the SPP;
2. Ethanol blockage. We have read DAD's remarks on that the temp grade from bottom to top of an SPP packed column is very little. If you feed an SPP packed column with too high abv, you may encounter a situation where the packing takes the abv to pure azeo too soon.

Zone 1 may work less efficient, but it is still (phase 2) very efficient. A pure azeotropic temperature only 10 centimeters from the bottom, means gasses won't rize up anymore. You get a situation of over and underpressure in your column. Not what you want. This is a "maybe" not a "definately". I have seen it happening with some clients where others do not encounter this problem.

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Re: SPP Packing

Post by bearriver »

Thank you odin, You answered questions I didn't even have yet.

I'll be watching the development of this concept very closely.
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Re: SPP Packing

Post by DAD300 »

Odin, as a previous conversation has gone to my eliminating the long equilibrium of my column, and having no ill effect, I think you just described my situation.

"A pure azeotropic temperature only 10 centimeters from the bottom, means gasses won't rize up anymore."

This accounts for why we no longer see the need for a long 100% reflux with SPP.

So, my bleeding the takeoff slowly for fores and early heads, would disrupt the stagnation? In a positive way?
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Re: SPP Packing

Post by Hound Dog »

OK. Help me understand the "aquatic environment" a little better.

On my latest setup I put a sight glass even with the top of my packing (lava rock not SPP) to monitor for flooding. By watching through the glass and adjusting the heat input, I can control it to a slight flood of just an inch of liquid over the rocks and have it bubbling through like my plate on the bottom or cut the input back a bit to have just vapor rising.

Is it beneficial to have a liquid layer at the top of the column?
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Re: SPP Packing

Post by Odin »

For SPP it is, Hound. And - if I understand it correctly - so it is for bubble caps/perf plates. A larger amount of liquids above the plate seems to lead to a more neutral product. Lava rock ... not sure. I mean, the same principles apply, but lava rock takes up a very large part of the column. I can easily imagine that by the time you get an aquatic environment at the top ... you may encouter full column flooding. Not sure though. Inducing my old basalt rock with lots of reflux seemed to work fine.

Regards, Odin.
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Re: SPP Packing

Post by sergiolis »

You are awesome guys!!!! Your explanations are delightful!!! I really appreciate your help. Odin, Dad, Rad.... and many others a tone of thanks. Due to your great job, I 'm whishing to become a Master Distiller ;-)
Just a short question:
I'm planning to build a 3" boka using SPP I will try to make myself. But I have some doubts about the height of the column. My boiler is just 30 liters and my heating element it's a 3500W.
Could you guide me about the maximum advisable height of the column? Thanks a lot
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Re: SPP Packing

Post by DAD300 »

18" should get azeo with say 4:1 reflux, I started with 30" but a scrubbie top and bottom, 24" of SPP.

Looking for max production rate with 1:1 reflux ratio, I ended with 3" x 36" a scrubbie top ad bottom, 30" of SPP.

I'll keep repeating, making azeo may be a cool a goal, but few want to drink it. I've ended up much happier making whiskey and rum in the 90%'s range.
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Re: SPP Packing

Post by sergiolis »

Thanks a lot Dad, my goal is not relly to get azeo, it's just to speed up a bit...
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Re: SPP Packing

Post by BigSwede »

My 3" column FINALLY came... It is 30" tall, and I am seriously thinking about cutting it down to 24", but for now, I am going to fill her up, and from there, it's necked to 2"

The good news with that at least is that there is no further restrictions on the VM side of it. It is wide bore 2" long sweep down to a jumbo shotgun. It will be an interesting rig to run!
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Re: SPP Packing

Post by humbledore »

Love to see it BigSwede. Post some pics!
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Re: SPP Packing

Post by DAD300 »

The extra 6"'s will allow for a little more speed and neutrality.

You can always try/experiment the 36" column with just 24" of SPP?
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Re: SPP Packing

Post by Hound Dog »

I was thinking the same thing. See what your optimal packing height is first then you can cut the column later to suit it. The empty column above the packing for now does nothing, but if you find you want it, better to have it.
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Re: SPP Packing

Post by BigSwede »

Sounds good fellas. 3" copper isn't cheap, and it's a lot easier to cut rather than extend. And that awesome thread we have with the video showing the "boil" above a stainless scrubbie reflux packing tells me I want some inches of head space between packing and VM takeoff arm, thinking 4" or so, at least. So call it 25" of SPP and 5" of void, for initial testing. And I'm definitely going to first try some stainless scrubbie packing, to get a decent baseline for comparison.

I know I've waffled on this forever, and embarrassed myself along the way, but literally 95% of my spare time these last 4 months has been taken up with an airplane (Citabria) rebuild. You know how the old saying goes - "If it floats, flies, or f's, rent, don't buy." Well, I bought instead, and the cash and time funnel into that thing is just astronomical. But if I can't get back to my aviation roots, I'm going to go nuts. I want to fly upside down and pull some G's again. Passengers generally don't like that stuff. :moresarcasm:

Back OT: This thread is a good example of the quality of input we have here on HD. I've bookmarked it so I can find it again. TY Odin and Dad and others experienced with this material for your efforts and inputs. :clap:
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Re: SPP Packing

Post by DAD300 »

I believe I now have an A&P to help with my Glasair! Life will get easier...
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