Finally made a start on a bubble ball packed column hybrid.

[YHB]

Building from the bottom up basically.

If I was to do it again, there is one thing I would do differently and that would be to start from the bottom and build up. I, like a lot of people were fixated with making a coil - a mistake to do it first.

[ant]

Well I had this before I started...




Includes a capillary temp sensor with adjustable narrow band switch to turn the coolant flow on and off. Won't use that at first as I don't think I need it but it came on it so might as well leave it on in case.

[ant]

Big party over the weekend so not a lot of progress this week.

But a little bit.


Pulling a 2" inlet dimple in the base of the bubble ball. MUCH harder than pulling the 1.5"




The dimple ready to have the inlet tube pressed in.




The bit of pipe pressed in from the inside. The threaded end is the keg spear fitting cut down and pressed into the end of the pipe.



View from the inside. The flange is the female part of an IDF fitting, minus the nut, that happened to be on the end of the pipe.



Screwed into the keg.



Proof of principle cutting sight glass from 6mm pyrex lid.




Principle proven. Bit chipped on the lower edge last to be cut but very usable.
Shame it is too small but having made the test with what I have I am happy to buy in the right sized cutter knowing it will work.

Well that's all for this week.

[ant]

Started to braze with silver solder to put it all together now. Bit rusty at first and made some stupid mistakes but the skill is coming back to me a bit faster than the first time I learned to do it.




This is the funnel off the jug I have been recycling into the top of the bubble ball. Cut it in half across and used the bottom bit to make a bottom for the top bit so I would have a reflux redistribution tray to drop the reflux from the column to one side of the bubble plate. The downcomer goes on the other side so the reflux flows across the plate before exiting back to the boiler.











Here is the finished tray ready to be brazed to the underside of the top of the bubble ball.






Here are the stages of adding the outlet pipe for the column to attach to.
First of all butt brazing the RJT fitting to the end of the pipe. A clamp to hold it while I get the first tack brazed on. Then braze around, grind it down, Check for leaks, rebraze, rinse and repeat. Took three runs around before it was leakproof. My first braze in some years. Solid as the parent metal though.



Then slide the nut over and braze it into place on the top of the ball.





Brazing the sight glass fitting into the stainless collar that forms the middle of the ball.





Bubble tray drilled out. Top hole spaced differently to the others is for the downcomer which I have made and fitted ok but not got a pic at the mo.




Totally rubbish first attempt to attach the top of the ball to the collar. Tabs are too large and it was drinking gas and silver to produce an ugly, ineffective, joint. Don't do this at home.





OK, trimmed the tabs down and made much less of a pigs ear of the next attempt.
After getting some tabs brazed on around the rim I debrazed and trimmed those ugly first tabs. Very hard to cut through any solder on the copper. Had to do them hot. Strong stuff. Not done the lot yet but happy it will go ok and be leak proof with minimal use of silver and gas.





The underside showing the reflux tray brazed in. It is only attached at the left hand side. There is space above it for the vapour to pass easily.

I have seen people ask about using gauze instead of slots on bubble caps. They were always blanked with no reply at all that I have found. I take this to mean the answer was unknown to the people being asked. So I tried a little experiment using some 30 mesh stainless gauze scraps I had.









I used a bit of welding wire and some tape to seal a gauze skirt around a 28mm cap. Stuck it in a jar with some white spirit (all I had besides water) Blew air underneath it.

Could see the air displacing the white spirit down the inside of the gauze. Bubbles came out from the gauze but only really at the top just underneath the edge of the bubble cap. Also mostly from the edge that was slanted highest. Seems to work though. 30 mesh might not be the best size to use. Something a little more open perhaps. Is what I have though. Main reason for using it is just to raise the caps a little higher to run with a deeper pool to bubble through.If it only comes from the top with ethanol as well then maybe there is no point as not getting more liquid vapour interaction from the bottom to the top of the pool. Will ponder some more before committing to an upcomer design.

Went and took some more pics so here is the tray with the downcomer in place.

[ant]

Also brazed the inlet pipe from the keg into the bottom of the ball. No problem at this stage. Just more of the same.

Got to finish brazing the top to the collar. Finish and install the tray into the bottom then attach the top to the bottom. Wish I could think of a way to make that last stainless to stainless joint demountable for access. Bit big for a swing clamp though. Also odd size.

[YHB]

Ant

Great progress.

It looks like you are on a roll, after the bubble ball the rest will be a walk in the park.

Have you seen the sight glasses from Still Draggon? they are around 4 USD - I do not know what you are paying for casserol lids but it must be close to that. But there again it's much more fun trying to drill holes in glass.

Keep the pictures coming, even the blurry ones are good?.

[ant]

Thanks YHB. Sorry for the blurry pics, I discard the worst of them but the camera phone is not a great lens.

The column should be straightforward enough Though after pulling a 2" dimple in the bottom bowl I am wondering if I will be able to do the same in the 4" stainless filter housing I am using for the head. It was hard and the housing will be harder. Thicker metal.

Plus the small matter of making an automated SPP machine.

As for the pyrex lid it was 10p from a charity shop so although $4 is a very reasonable price for a sight glass I'll spend a similar amount on buying a cutter locally and maybe buy up some more lids while they are available. At several glasses per lid it works out a lifetime supply Even if I suddenly decided I wanted a flute.

Not to be I think, though I do find Joe rednose's original small commercial work that OD bounced off, interesting reading. Not sure why Joe gets less recognition than OD who did great work but is unjustly credited with being the originator rather than a developer.

More creativity adapting Joe's work to our scale than my ball which is only a version based on the work of VB/Fester and more recently PP. But it all links up, Lwtcs made the bubble ball seem like a good idea because he had already shown that an inline thumper is a good thing. If you go back far enough the Charles 803 fuel still was using an inline thumper in the 80's for the same reasons and the very development of a thumper goes back into the mists. Anyway I am rambling so I'll stop.

[ant]

Update on the mesh skirt. After leaving the prototype in the jar with water I went back to it days later to show my nephew what I had been doing. When I puffed with the rubber ball on the end of the tube a cloud of tiny bubbles erupted from all around the skirt. Blowing hard produced a combination of big bubbles and tiny ones. It seems having time to become properly wetted has changed something. Some kind of surface tension effect I assume. The exact performance is obviously pressure dependant so I need to measure the pressure that is producing the cloud of bubbles and calculate the pressure in each of the seven upcomers to compare the two and have some prediction of how the 30 mesh skirt will behave in practice. I was just about to buy a small amount of 20 mesh to try but, if the pressures match, the 30 mesh is fantastic once wetted.

My friend has built and programmed a more modern version of the Russian electronic pressure sensor and added control capabilities so that it can turn off the heater if the pressure gets too high in the column. An anti flood/puke measure.

He lives in another town but he has finished it now so I need to get it from him as a use for it has become evident and imminent. Scared to have it posted as royal mail has just lost the last parcel I was expecting. Bit dear to drive up there to get it but I might have to do that or take a deep breath and risk the post again.

[YHB]

Your presure sensor / switch sounds highly desirable, looking forward to seeing the results / details.

I found it amazing when building a relativly simple Bok how many completly different elements needed to be addressed to produce the final device. You are adding many more to your build, but when they all come together it will be worth it.

[Phantom]

I must be really thick! I've read through and thought about the pic's included, but still can't mentally visualise how it might look when finished.

I'm still (slowly but surely) working out where to get parts and materials for "something".

Perhaps I should ask Jimmy to change my username to "Procrastination Man"

[ant]

Well I took a lot of time gazing at the stuff I had lying around before I started anything. In the end the kick came from finding the coper jug in a charity shop. That set the dominoes falling.

I have finished brazing the top on the collar now so here is a pic of it all sat on the keg. The bottom and top are just pushed together and the tray is not inside but it should help you see what it looks like.


I was ok at brazing a few years ago but this is the first project in awhile and I had forgotten the edge of what I knew. Relearning and remembering as I go. I do aim for a capillary joint as well as the visible silver. Strength comes from a capillary joint. The visible stuff is just doubling up against leaks. Or inevitable side effect of troweling on the flux. When brazing stainless the bench grinder and the Dremel are your friend. Don't think clean the surface, think resurface. Expose new metal and use borax based flux with the silver solder. In the pics of something being brazed, note the use of strategically placed fire bricks to reflect heat back to the joint being made.

[ant]

Been slow progress and not much to report even now. Reason being I have decided I want the ball to open up easily and can't afford a 7" tri clamp with two 7" ferrules. Or even just the clamp. Only cheap solution I can think of is to cut flanges out of sheet, braze them on the halves and clamp them together with cleco clamps. The side pinch clamps like bulldog clips on steroids. 70lb or 31.75kg of clamping force per clamp.

Started one flange but having tried the feel of it after cutting it and putting the since acquired micrometer on it, I think it should be a dummy run as it seems too thin (.7mm) to me. Perhaps I could reinforce it but I would rather get something thicker, if I can, and start again.

The methodology seems to have been good though so I will share what I have done and perhaps someone will have some feedback to inform my next move.

First I drew some circles in thick blue marker for the inner and outer dia.

Then, using a shallow punched centre I used my gasket cutter to scribe an exact circle, for each marking, in the blue marker and the steel below.


Then I cut out the centre with a small angle grinder.


Then freed the flange from the sheet (old butchers tray) also with the angle grinder.

I left plenty of margin inside and outside the scribed lines. The angle grinder is not a precise tool.

Then I used the bench grinder to grind the outside of the flange down to the scribed line. I was not too worried about ultra precision as this is not a critical cut.

Then I put the flange in the vice and used the dremel with a cylindrical grindstone to grind to the inner scribed line.

This is a fairly critical cut as it has to slide snugly over the ball half and braze solidly on.

Well that's all until I can find better stock to work with. 1mm or better seems like it might be enough. I could double this stuff up but too much of a fudge I think. Time to hit the charity shops for a couple of 8" or bigger stainless pans perhaps. Use the thick bases. Harder work than what has turned out to be a practice run but should be doable.

[ant]

After stalling on the flange for some time I have now made some progress. I gave up waiting for some thicker stainless to turn up and made flanges from 10mm copper pipe. Then I went on to make a triclamp from plywood with a nice thick oak face. Offcuts from some uber expensive laminate flooring. Not finished yet but enough progress to be worth reporting.
10mm pipe annealed and wound around the fire extinguisher the stainless ball bits came from.
annealing again to get the fit as close as possible.
Coils cut free and brazed.
Flange beaten flat against the ball half.
View from the other side
The two halves flanged and sat together
Marking two concentric circles across the two halves of 22mm ply with a 5mm oak face.
semicircle cut out on the table saw and smoothed down with a surform and then a rotary sanding cylinder in the battery drill.
Internal semicircle removed with the battery drill and a small hole cutter. Internal surface of clamp smoothed the same way as the outer.
Starting the groove with a slitting saw in the dremel
Then a cone shaped burr
Then a cone shaped grindstone

In reality it took several passes with each of these tools in various turns to get a good fit on both flanges. I'm sure there is a tool out there that would just do it great in one pass but with what I have I just carved it to fit with successive alterations.


Finished profile of the groove
Clamp in place with the stainless hinge showing.
Still need to fit the swing bolt but the hard part is done now.

May need to adjust the groove some more when the silicone gasket (from cookie sheet) is in place but feel like it is working so far.

Thanks to YHB for pointing me to the easy easy flange.

Thanks also to YHB for the inspiration to consider wood in the build. His wood clad boiler with wooden clamps for the lid of a water urn is a work of art.

[YHB]

Great work Ant.

A project like this with many different elements can seem to take for ever, with little apparent progress. Then one activiy comes along that allows the several individual elements to be linked and suddenly progress is very apparent.

It looks as though it is moving on quickly now - keep the ball rolling.

Brian

[ant]

Somewhat belatedly the ball has rolled once more. More or less finished.

Once I got some time to dust it off the shelf the first thing I did was discard the stainless plate I was using and redo it in copper. Once again Pics will tell the story but any questions gladly answered.



Acquired copper plate with nice galleon pic for better rum making. First rough snip.



centre drilled. mounted on mandrel in pillar drill. File used to finnes the size down to a good fit reasonably still round.



Centre popped ready for drilling as I did the first time round.



Holes drilled.




bottom view with the caps and downcomer all sat on a flat surface while I soft soldered them in place. That way they are all at the same height later.



finished plate sat in the bottom half of the ball.



Swing bolt exhaust clamp off some kind of VW.



Bits left over after cutting it in half and drilling out the spot welds to remove them.




Screwed to my previously made clamp using the spot weld holes and six of those nice self drilling wood screws they make nowadays.



The finished clamp.Tightens up with an allen key and works a treat.

Well that is it for now. I still need to seal a site glass to it and make a silicone seal between the halves but both tasks are trivial.

I expect the gauze skirts to be sensitive to fouling and only suitable for well cleared sugar wash but it is now easy to separate for cleaning and if they don't work or are too much of a PITA to work with or clean then they can be replaced easily enough. Such is the nature of experiment.

I'm working on an SPP machine at the moment. Pics after I finish for that one I think. Then you won't have to wait two years for the end of the story.