New Bubble Cap Design...

[Bob Loblaw]

Personally, I think it's an interesting concept. I've started a 4" flute build and would be interested in trying it out. Lets talk about a DIY version of this design for testing. I'm thinking:

top section:
- 1 1/4 cap drilled out to accept 1/2 tubing, notched for liquid access
- 1/2 tube flared at the top, capped at the bottom with cross drilled holes
- bottom cap center-drilled for the hex bolt

Solder the 1/2" tube into the 1 1/4" cap, and the 1/2 cap onto the bottom. Cross drill and center drill.

Bottom section
- 3/4" tubing through the plate
- half of a 3/4" coupling as a collar, cross-drilled for drainage
- 3/4 cap at the bottom, center-drilled for the hex bolt.

Questions I have are what are the ratios for hole sizes to the top opening, and what's the right height for the riser that projects through the plate. I'd love to see that conversation vs. the fact-free sh!t slinging.

[Bob Loblaw]

Here is a diagram... Still trying to find the picture of the actual plate...



It's from the Plated Potstill topic...

That post was from Artisan Copper Works. AFAIK, that's the predecessor company to Still Dragon (or at least their URL resolves to Still Dragon). Still Dragon is behind this new design. So if you're saying there is "prior art" on this design, the argument doesn't really make sense when the example comes from the same source. Just sayin'

[InglisHill]

Good call Bob!

I have looked at a few different sites and all that I can make out is that one camp says they are great one camp has errrr, reservations.

No real data on how they perform, Bobs idea is on the money. I was having a problem visualising what you were saying though Bob, can you draw us up a little sketch?

I would be keen to give it a try as well.

[Jacksonbrown]

Like this?
It looks like three cups with some holes in them.

bubble.png (9.42 KiB) Viewed 5761 times

I don't think the concept is all that amazing as with all the Still Dragon gear.
Arranging things concentrically is a pretty common engineering trick to get multiple uses out of one whole.
Unless there's something I'm missing this is just natural progression. I lot of people including myself would have come up with this already.

Sure they spent there time and money refining it too but the thing that still dragon does very well, the thing they should be commended and rewarded for is they can produce it to a price.

The concept is nothing special, mass producing it and making it affordable is where the trick is.

[olddog]

Its easy to work out once someone else has done it, you dont have to think too hard then

[olddog]

Like this?
It looks like three cups with some holes in them.

bubble.png

I don't think the concept is all that amazing as with all the Still Dragon gear.
Arranging things concentrically is a pretty common engineering trick to get multiple uses out of one whole.
Unless there's something I'm missing this is just natural progression. I lot of people including myself would have come up with this already.

Sure they spent there time and money refining it too but the thing that still dragon does very well, the thing they should be commended and rewarded for is they can produce it to a price.

The concept is nothing special, mass producing it and making it affordable is where the trick is.

If you think you would have come up with this already, then why haven't you. It's always the same when someone comes out with something new, the knockers come out, and I am speaking from personal experience.

[Edwin Croissant]

The only difference I see with the Combination bubble cap and downflow patent from 1927 is that the downflow does not extent to the underlying plate but has a vapor lock.

US 1744543 A

[Jacksonbrown]

Pissa

I like Still Dragon. I'm just able look past the hype to the great prices on standard dairy fittings.
Their level on service is rare these days too

[heartcut]

I'd question whether this concept scales up to 12" and beyond, but it looks just about right for the 4" I run. More active area and better (IMO) distribution for small diameter columns is a win-win. The plates should be aligned so the phlegm dripping from the middle of the downcomer drips in between the lower plates, of course. The benefits of alternating phlegm distribution are minimal on hobby size plates, you need to get around 12" or bigger to get much from that strategy, at least that's my experience from petroleum distillation.
I intend to order some, try them out (send 'em back for a refund if they don't work) and have a drink or two. Should be fun.

[harley03]

Now should it ring in the alarm bells even so they deaf hear ... because as you all can see that this with the return pipe inside the bubble caps is nothing new ... and then you all shall wonders why none of them established old big PRO manufacturers NOTE use this .....


Cheers from Sweden

[Edwin Croissant]

In the above mentioned patent there is a forward reference to Bubble cap for washing gases and vapors dated 1947.

US2600710

Bubble cap for washing gases and vapors.png (23.33 KiB) Viewed 5700 times

This is an enhancement of the previous mentioned patent by putting a shield [18] around the bubble cap to force the reflux through the vapor into the downcomer. The shield is open at the top [20]. I can see this construction sitting in a bubble ball underneath a packed column. The shield must then be a cap with some holes in the side for the vapor to escape.

I think that in the 200 years of fractional distillation almost everything is invented or reinvented Going through these patents is inspiring.

[InglisHill]

I was thinking you could do this with one cap and a few bits of tube.

Cut a hole in the plate that is of the same diameter, or less, than the diameter of the cap.

Drill a hole in the top of the cap, put a bit of tube in it, extend that down to the next plate and make a little wier out of another bit of tube.

Or something along those lines. It seems that it does not have to be teriffically complicated to work?

[FullySilenced]

you could put the bottom cup on with a screw.... and you would need something to hold the downcomer cap tight to the plate.......

[InglisHill]

Personally I would weld it all. The only problem I have seen is the liquid could just fall through this arrangement. I will post another idea later

[LWTCS]

In the above mentioned patent there is a forward reference to Bubble cap for washing gases and vapors dated 1947.

Bubble cap for washing gases and vapors.png

This is an enhancement of the previous mentioned patent by putting a shield [18] around the bubble cap to force the reflux through the vapor into the downcomer. The shield is open at the top [20]. I can see this construction sitting in a bubble ball underneath a packed column. The shield must then be a cap with some holes in the side for the vapor to escape.

I think that in the 200 years of fractional distillation almost everything is invented or reinvented Going through these patents is inspiring.

This from the patent holder of this particular assembly:
"I have discovered that, particularly in the large dephlegmators now in use, the condensate tends to fiow more rapidly across the center line of the tray than at its edges, and

40 that there is a highly material difference in quality of condensate between the back edge, or portion farthest from the runback, and the portion immediately around the runback. The eifectiveness of the condensate as a scrubbing medium is thus materially reduced, as

td obtain the best results it must be of uniform quality over the entire surface of the tray so that each portion of the condensate may be subjected to the same amount ofreevaporation by contact with up-flowmg vapors, and each stream of vapor may be contacted with condensate having the same power of absorbing and withdrawing its heaviest and least volatile constituents.

To overcome the disadvantages of the type of construction heretofore used I prefer to use the new and improved bubble cap illustrated in the attached drawings, in which provision is made for taking the excess condensate downward through each cap to the tray below, thus draining all parts of each tray uniformly and insuring the maintenance on each tray of a layer of condensate of uniform quality over its entire area. By this means uneven scrubbing is avoided and the highest dephlegmating efliciency is secured. In these drawings Fig. l is a detail of my improved bubble cap in vertical section and inside elevation".


Really not sure what gives one of the posters of this thread the credentials to dispute the findings of the patent holder? The issue with wide spread use is that this type of system is simply more historically expensive than a simple perf plate.

The poster that is especially critical also appears to be especially non factual.

[InglisHill]

Yup, the more I think about it the more I think I am inventing a perf plate with caps. Or reinventing the wheel. Perhaps someone can see it different, but at any rate, I shall continue on with the improvements and post them later

[Bob Loblaw]

Good call Bob!

I have looked at a few different sites and all that I can make out is that one camp says they are great one camp has errrr, reservations.

No real data on how they perform, Bobs idea is on the money. I was having a problem visualising what you were saying though Bob, can you draw us up a little sketch?

I would be keen to give it a try as well.

Here is crude drawing. I think it can be made all from copper/solder. No welding required. Just need to figure out the ratios for opening sizes, height of bubble cap, and length of downcomer

EDIT: I printed out the picture and did some measuring/comparison against known values (36mm diameter cap, 23.6mm diameter plate opening). From that I infer that the height of the bubble cap is about 15mm, the length of the downcomer about 36mm, the opening in the downcomer about 6mm and the opening in the bubbler tee about 5mm. They're asking $30AUD for these on SD Australia - probably a well-deserved premium for the development costs. But I think they can be built for a few dollars each. Big plus is that I only need 3 for each plate on a 4 inch column.

Top section (bubble cap) is 1.25" copper cap, a bit of 1/2" tube, and a 1/2" cap
Bottom section (downcomer) is a short bit of 3/4" tube, a shorted up 3/4 coupler, and a 3/4" cap
Join together with an allen-head bolt/nut.

I priced out parts at supplyhouse and it's less than $3 per unit before tubing - which I have laying around. I'm looking for somewhere local that has the 1.25 caps so I can build a test unit.

[LWTCS]

Ah, pardon me I referenced the wrong assembly.

This assembly here is what I intended to reference:

Combination bubble cap and downflow patent

BTW Edwin, really nice find.

[waxernz]

For a small scale still would it matter having multiple small downcomers within the cap but more towards outside and vapor coming up center as usual. Would they disrupt the vapor path enough to matter on this scale. Makes for more effort to build. Wouldnt need to be a cone. Although cone caps would look amazingly sweet. If in a 3" sightglass with one big cap per plate and say 3 smaller diameter down comers that would offer a nice spread on plate below? and no dripping from above directly into drain below. It would be making extra work for yourself but look cool.

[googe]

Nice stuff Edwin, there's some amazing old.designs out there, was looking at some from the early days last night, things were discovering now already have been, but were just making them.more.efficent!. have been scouring old.pics, and found the one I was referring to early, I thought of the idea many moons.back and gas on had a go and made it work, im trying to find my old original pics of center downcomer cap plates. Many people.have done them but not shared on open forums, doesn't mean they don't exist .

[InglisHill]

I like that Waxer, I could see how that would work.

Just a thought, if you are using one big cap, could you make the internal portion a perf plate, still have the usuall cap configuration, and still do what you are thinking. Would there be any benifits to doing this?

It seems that all we are really doing at the moment is changing the configuration of existing ideas, are these changes going to make any noticable impact on the hobby level?

I guess there is one way to find out. If we keep throwing ideas out there I am happy to run some tests, I can make something up fairly easy that will test an idea. Just need to get a bit of four inch glass for a triclamp and we are away

[waxernz]

I didnt think having an internal perf would make a difference to the positive?. On the still dragon design their Down comer(top of cap) is higher then the level of the vapor intake below. So I assume the vapor is enough to hold back any liquid from entering the cap and going back down the vapor path. I guess the question is at what level is the liquid bed within the cap or is it so little that you could define it as stopping at the gratings on edge of cap.
The thing I would like to know is how much flow restriction for vapor can you allow. The procaps have small slots rather than a large outer tube. Is restricting the size and increasing the speed important or is the difference in the sizes we are talking negligible and they made that decision purely for assembly design with screw at bottom pulling the two parts together.
As far as hybrids go with perf sections doesnt that kind of defeat the benefits of bubble caps and might as well just go full perf plate?

[rad14701]

Having a deep enough fluid bed for the vapor to bubble through is essential for proper operation... The amount of restriction merely determines how much pressure each plate builds during optimal operation... That can take some experimentation which I'm sure has already been done with the new bubble plate design... There is quite a bit of leeway but there is most likely a sweet spot...

[Bob Loblaw]

I started putting together a test/ DIY version. It's pretty straightforward

Bubble cap
This is WIP, but you can see how it comes together
- Top piece is a 1.25 inch cap, cut down to be 15mm high.
- Tee piece is 1/2 tubing. I haven't cut to length yet because I don't have a flare tool. Need to pick one up tonight. Then the tube will be soldered to the top of the cap.
- Bottom hole is drilled for M4 bolt. Got off center on me, I need to work on my aim!
- I haven't drilled the outlets yet either. The'y will be ~5mm holes

Downcomer
Also WIP, but closer.
- It's a piece of 3/4 tube w/ a 3/4 cap
- There's a ~10mm piece of 3/4 coupling above the cap to bring it to the right length
- Tube should project about 8-10mm above the plate when installed
- bottom hole is drilled for an M4 bolt. Also off-center...
- this one just needs the vents drilled at the top. I'm thinking 6mm holes.

[LWTCS]

Wtg Bob.
After you get the first one worked out, I would be really curious to hear your estimate of how many man hours it takes to fabricate enough to populate a plate diameter of your choosing.

[emptyglass]

I still feel its going to be hard for any bubble cap to compare with perforated plates.

A stack of 5 plates can be drilled in under 2 hrs if you set up carefully. There is more "active" area on a perf plate. Excepting for the downcomer, the entire plate is active. A 4" plate will not flood with a 3/4" diameter downcomer.

4" plates use 3 "super" caps @ $25 each, so $75 per plate by 5 plates is $375. They still don't use the whole plate, there is space lost. Or make them yourself, but as LWTCS pointed out, how long is that going to take, plus you still have to buy/beg/borrow/steal/make the caps to make them from.

On performance perf plates trump bubble caps, same on cost. There is little discernible difference in taste, I have tried both and the others I know that have tried both say the same thing.

Perf plates also have the added charm that they can make the tails cut for you. Bubble caps keep on pushing everything through.

Also, with a single downcomer, bath depth is easily changed. There seems to be more surface area unnecessarily lost to having a 1/2 tube in each bubble cap downcomer.
If you like the idea of dripping the down coming liquid over the plate below, a single short downcomer will do that for you, or you can run it all the way to the next plate. With these bubble cap downcomers, you have no choice. If you find it smears, then your stuck with it.

I'm having a lot of trouble seeing why bubble caps are better than perforated plates.

[googe]

No positives for caps empty? , I like my caps! . I may one day make some sieve plates, then again I probably won't lol. Maybe someone should put a cap on a perf plate, then everyone will be happy

[emptyglass]

Bubble caps don't require as much drilling...

Sorry Googe, thats the best I can do.
Oh, and they are easy to understand (stuff goes up, stuff comes out), some people don't have faith that the vapour will hold the fluid up on a perf plate.

Its just my opinion, everyones got one.

[heartcut]

Sieve plates are more efficient than bubble plates within the (narrow) range they are designed for. They're even more efficient without a downcomer in an even narrower range. I prefer bubble caps because I run in a variety of ways for different spirits. If I always ran at the same power setting or had multiple stills, no contest, it'd be sieve plates optimized for that power. Can't knock either choice, that's just my 2 cents.
Wasn't too long ago that very few thought either one was a good choice for hobby distillation.

[Bushman]

I finally had the opportunity to go back and read through this entire thread, this is what the forum is about, learning takes place through discussions such as this keeping the topic positive and throwing out ideas and examples to discuss and expand upon. We give credit to members and people that design something new but in reality although they did come up with an innovative design it most likely was spurred on by this kind of research and collaboration. I am not trying to take away the accomplishments of the innovative design or the credit one deserves just saying that the old adage "It takes a village" holds true in many aspects.