Bubble plate in boka

[NZBoka701]

Hi Everyone,

Been a little while since I have been chatting but I ended up being away with work for almost a year and the still took a back bench for the duration With the current world situation I have a new found freedom and the undying will to get back to it so here I am!

I know this topic has been discussed before but I couldn't find anything related to my exact issue. I wondered if anyone had any advice on the location of bubble plates in a Boka. My column is 3" and I have a 24" packed section followed by an 18" section where the plates, valves, cooling head etc are mounted. Would I be able to put the bubble plates between the 24" and 18" section or do they have to go at the bottom of the still?

So far I have been running it in reflux for neutrals but I am just brewing a single grain scotch using Jimbos recipe. I am currently waiting for it to cool before pitching so fingers crossed! Obviously doing a single grain scotch means I will be running in pot still mode with no packing so I thought a bubble plate may just help refine things or should I pull it out completely when running in pot mode?

Any advice for running in pot mode is also welcome as it's my first time running in pot mode!

Thanks!

[Saltbush Bill]

I've never head of anyone try to put plates in a boka....are you sure there isn't a better way to get the results your after?

[NZBoka701]

There very well may be a better way. I have another 24" column that I could pack but I am restricted on ceiling height hence why I was wondering about installing a bubble plate as a way to increase purity without increasing height?

[LWTCS]

There very well may be a better way. I have another 24" column that I could pack but I am restricted on ceiling height hence why I was wondering about installing a bubble plate as a way to increase purity without increasing height?

Actual plates will require more height. Especially if you want good hydraulic behavior.
You'll be able to "pack" more theoretical plates into less height with random packing materials.

[NZBoka701]

So I wouldn't get an improvement from running a 3" bubble plate followed by a 24" packed column or a 24" packed column topped with a 3" bubble plate? My thought it that I already have the joints there to put a bubble plate (or two) in and I have the bubble plates so I thought it's better than not having them?

[LWTCS]

So I wouldn't get an improvement from running a 3" bubble plate followed by a 24" packed column or a 24" packed column topped with a 3" bubble plate? My thought it that I already have the joints there to put a bubble plate (or two) in and I have the bubble plates so I thought it's better than not having them?

Ah I see what your asking.
There are some folks that do run actual plates below their packed section. This all started with the "bubble ball" experiments. Minime over at AD was able to demonstrate (and illustrate) some really good still behavior.
Basically, actual plates are able to create more dense liquid hold up by virtue of deeper liquid beds. Thereby giving the actual plates more capacity to absorb what will become unneeded heat at the top of the apparatus. And since the alcoholic liquid bed initially acts acts as a condenser to incoming vapor, the abv on the plate will then determine the optimal flash point of the alcohol at each plate level. This behavior keeps the packing material cooler at the base of the packed section and allows more of the packing material to do it's job.

Another benefit is that the deeper liquid beds on the plates allow for more alcohol shifting into the distillation apparatus. This also amounts to better behavior. Ultimately this allows the operator to run harder with with more stability with out compromising abv.

However, at some point plate count (actual or theoretical) will determine final purity.

Does that make sense?

[NZBoka701]

That makes complete sense! The reason I asked originally was to find out if the returning distillate from the column would hit the bubble plate and build up leading to poor flavours further up the still head but that's been dismissed so thankyou! Out of interest is there a reason to run it at the bottom and not above the packed section?

Also would I gain anything by running it in the column when I am running in pot still mode (packing removed) do you think?

[LWTCS]

That makes complete sense! The reason I asked originally was to find out if the returning distillate from the column would hit the bubble plate and build up leading to poor flavours further up the still head but that's been dismissed so thankyou!Well the liquid hold up on the plates do have more ability to trap congeners on the plate that can re-infuse with forthcoming vapor. This is why packed columns do a relatively better job at making neutral at the hobby scale Out of interest is there a reason to run it at the bottom and not above the packed section? I believe you will get better behavior for the reasons I have explained above. But you could set up both example configurations and prove it to your self which configuration provides your best outcome

Also would I gain anything by running it in the column when I am running in pot still mode (packing removed) do you think?Sorry I don't quite understand the question?

[NZBoka701]

I may give it a go and see what happens! I am running a few 24 hour turbo brew washes at the moment for testing cleaning and to make hand sanitizer with as supply is 0 at the moment. I've made a recipe with natural oils etc that I have been giving to people and the reviews are positive.

Part of the reason I am looking at the plates is to up the output volume whist retaining the abv so, for turbo brew, the flavour doesn't matter at all for those washes. Plate at the bottom seems logical but the plate at the top will be interesting for the sake of experimentation. I feel like maybe having at the top might reduce the congener trapping and act like an extra layer of refinement which it currently doesn't have. I have a 3 way with sight glass so it will be interesting to see what happens during the washes.

The question about pot still mode- When running a boka in "pot still" I should run it with no packing correct? Valve fully open and just let it run? I was wondering if running the bubbler plate at the bottom of the column in pot mode when running a single grain whisky wash would produce a more refined product or just strip away valuable flavours?

[LWTCS]

I've never head of anyone try to put plates in a boka....are you sure there isn't a better way to get the results your after?

Hi Bill,
Maybe not the slant plate or cup style "Boka" take off. However an LM type take off is what can be used for product collection to allow heads to bleed off further up the column on a continuous apparatus.

Sorry if this drifts too far off topic?

Though you can't be as precise with respect to cuts on a continuous system, if you pull product off in liquid form rather than vapor, the more volatile heads compounds can make their way up the column as vapor and condensed once they make their way past the dephlegmator at the very top of the apparatus.

Here is an example of LM take of on a plate section.

[LWTCS]

The center of the take off aligns with the very top of the bubble cap. This insures the plate doesn't run dry while collecting product.

The bubble cap has a fully integrated downcomer btw.

[LWTCS]

I may give it a go and see what happens! I am running a few 24 hour turbo brew washes at the moment for testing cleaning and to make hand sanitizer with as supply is 0 at the moment. I've made a recipe with natural oils etc that I have been giving to people and the reviews are positive.

Part of the reason I am looking at the plates is to up the output volume whist retaining the abv so, for turbo brew, the flavour doesn't matter at all for those washes. Plate at the bottom seems logical but the plate at the top will be interesting for the sake of experimentation. I feel like maybe having at the top might reduce the congener trapping and act like an extra layer of refinement which it currently doesn't have.I really don't think so. But you should experiment and see for yourself. I have a 3 way with sight glass so it will be interesting to see what happens during the washes.

The question about pot still mode- When running a boka in "pot still" I should run it with no packing correct? Valve fully open and just let it run? I was wondering if running the bubbler plate at the bottom of the column in pot mode when running a single grain whisky wash would produce a more refined product or just strip away valuable flavours?Imo no it won't

[acfixer69]

I don't know anyone that has done the mix in a 3" column so take this as such. I did try my 4" with the plates on the top, 3 plate bubble cap and 24" packed section was able to control the still but was a wobbly run. If I was to do the same with sieve plates I don't think it would work. Packed section would flood then turn down would collapse the plates. I did run with the bubble cap plates on the bottom and 24" packed on top and was able to run steady at 93 to 88 ABV. This may be some help for comparison.

[LWTCS]

IMO, what acfixer69 said.

[NZBoka701]

Thanks everyone, acfixer69 I have bubble caps at the moment so I was going to use those.

I think I will give it a go just to see what happens as it seems to be relatively unexplored territory... Ill run it once at the bottom and once at the top and see how it goes. My main plan is to get more output at a higher abv. I'm surprised you have had such negative results, I would have thought that it would add to the relfux as apposed to making it unstable. Maybe I am taking a bit of a "Better than nothing" attitude! I can sit at about 93% but it's a pretty slow trickle and it would be nice to get the volume up a little more.

[LWTCS]

Thanks everyone, acfixer69 I have bubble caps at the moment so I was going to use those.

I think I will give it a go just to see what happensAs you should as it seems to be relatively unexplored territory...Actually the concept was explored pretty well. Most of the info is just not on this forum Ill run it once at the bottom and once at the top and see how it goes. My main plan is to get more output at a higher abv. I'm surprised you have had such negative results, I would have thought that it would add to the relfux as apposed to making it unstable Unstable because the larger liquid mass in the plate(s) draining down as reflux likely overwhelmed and collapsed the gradient in the packing. Maybe I am taking a bit of a "Better than nothing" attitude! I can sit at about 93% but it's a pretty slow trickle and it would be nice to get the volume up a little more. I'm sure you'll see that plates on the bottom will behave a lot better. Though I do recommend that you see for your self to help build your own point of view

[NZBoka701]

In regards to more fluid flow collapsing the gradient in the column, wouldn't this mean that I am able to retain the same reflux rate with a lower heat?

If I have the same amount going up the column as coming down (100% reflux) then surely I can't have more reflux than I did before by installing a bubble plate? If the gradient was collapsing due to the flow of returning spirit then I should be able to reduce the heat input and run a more efficient balanced set up in theory? Or maybe I'm just chatting rubbish?

[LWTCS]

Reflux "rate" (ratio) is not necessarily going to improve abv or collection speed.

[LWTCS]

If I have the same amount going up the column as coming down (100% reflux) then surely I can't have more reflux than I did before by installing a bubble plate? If the gradient was collapsing due to the flow of returning spirit then I should be able to reduce the heat input and run a more efficient balanced set up in theory? Or maybe I'm just chatting rubbish?

Yes your logic does make a bit of sense on the surface. And no doubt with enough fiddling you could get that configuration to behave.
The problem as acfixer69 points out,,,its really hard to get the thing to find that steady state of operation. And the reason for that is that random packing has a different turn down ratio (operating range) than a bubble plate does.
Of the two plate (actual or theoretical) systems, the bubble cap plate has by far the widest operating range. Random packing not so much. So the operator spends an inordinate amount of time trying to find out where those two operational ranges optimally intersect just to get the still to behave. Never even mind getting to the point where that configuration could potentially render the best outcome with respect to spirit quality.

Thus far, anecdotal evidence suggests that if you want to mix plate (actual or theoretical) systems, the system with the widest operating range works best at the bottom of the apparatus.

[bluefish_dist]

I have done a lot of neutrals using a bubble ball. Larger plate under a packed column. Seemed to work well, better than just adding that extra 6” of packing. Odin has mentioned that bubble plates trap tails, so with that in mind I ran a bubble plate when doing neutrals. Sieve plates also worked, never did a back to back comparison to see if tails were less with the bubble plates.

[LWTCS]

I have done a lot of neutrals using a bubble ball. Larger plate under a packed column. Seemed to work well, better than just adding that extra 6” of packing. Odin has mentioned that bubble plates trap tails, so with that in mind I ran a bubble plate when doing neutrals. Sieve plates also worked, never did a back to back comparison to see if tails were less with the bubble plates.

Yeah that's the thing with plates. Definitely do trap flavors (both good and bad). And high reflux ratios can compound that behavior.

[LWTCS]

Odin has mentioned that bubble plates trap tails

An additional dephlegmator/reflux condenser at the top of the kettle (under the bubble ball) and some pretty precision cooling adjustment capability can mitigate quite a bit of that.
Spendy? Maybe?

Most hobby guys struggle with ceiling height limitations too.

[googe]

I had similar results to AC when I did 3 single plates over packed section. It ran strange, the run was ok and taste was fine, mine surged and coughed and farted, just didnt seem happy. If you want faster returns its always been better when I can hear the lava rattling in the column which to me would mean just below the point of flooding.

[NZBoka701]

I had to google what a bubble ball is, ended up with a load of people running into each other wearing some sort of inflated jobby! Based off of what everyone has said I will run one at the bottom and see what happens then. I kind of wanted to run it at the top (I may try it at some point) mainly just based on the aesthetic results! I am surprised that the reflux ratios etc make it worse. I would have thought with the bubble caps at the top the lowest BP spirit would be the only thing to get there reducing the issue and then only be refined by the bubble cap. I have a lot to learn!

[LWTCS]

The BubbleBall is a pre modular iteration of what is now widely known as a modular tee section. Ya know,,,the kind you see all over the internet these days.
After the BubbleBall came the Torpedo. Same concept,,just cheaper to manufacture. No difference in performance. Then came the modular tee section. So BubbleBall, Torpedo, then modular Tee. Ask me how I know...

The BubbleBall's origin is predicated upon a mini thumper. In those days not many at the hobby level really knew what or how a plate or tray really worked ( including myself) with the exception of just a few.

Look mate,,,been trying to nicely tell you (because the work has indeed already been done) that your better off with plates under packing.
I'm not really speculating....

[bluefish_dist]

My still was built with a 6” tri clamp on the boiler. That made it easy to place a 6” plate right at the boiler. A 6 to 4 window reducer from Stilldragon, then a 4” packed spool on top. Made it easy to watch to keep an eye on flooding and I could use the cheaper bubble caps instead of the pro caps to be able to handle 6000w. Pro caps handle significantly (25%) more power, but when you get to 6” it’s an expensive proposition. So not really a bubble ball, but it worked the same.

[jedneck]

My understanding is plates under packed. Plate helps feed packed section a little higher abv therefore packed runnin smoother.

[LWTCS]

[quote=bluefish_dist post_id=7599094 time=1585869337 not really a bubble ball, but it worked the same.
[/quote]

+1

[NZBoka701]

Fine, Ill put it at the bottom In all honestly though, thanks for the advice. My next issue is my single grain whisky brew didn't ferment Awaiting a delivery of more iodine and a PH tester to work out where I screwed up

**Edit**: Started to ferment, just taken 2 days to start