Multi tube condenser ideas

[Julian]

Been playing today.

I was quite disappointed that the multitube condenser I posted on the VOD a few years back came to nothing due to the cost of suitable tube, but the tube plate idea has been swimming around in my head ever since.

Now with the 3D printer (yes, I can hear the groans and Tony muttering "when you have a hammer ..."), but I think these ideas may be worth persuing.

Normally I'd advance the design much further, I have many ideas filed in the aging cranium, but as it's a bit quiet I though I'd post a couple of test pieces and see if any one comes up with anything.  I'm thinking around a rain water down pipe as the body, plumber's delights for the tubes and plenums top and bottom.

One major issue with printed plastic is it's low melting point.  No an issue for the bottom plate and I'm having thoughts on insulating the top with thinned silicone calking or Oogoo (Google it!) both of which I've been playing with recently.


First idea is for the tube plate to body joint.  Printed plastic with a recess filled with silicone, top and bottom clamped with studding.  Could possibly press the body into the silicone whilst it's still wet.




Second idea was to use an O ring.  Nitrile has excellent resistance to methanol.  This ring was from one of those red boxes containing various sizes.  Say it myself the fit is amazing and would certainly seal perfectly for the duty we want.







If the design can be economically printed I'd be happy to consider producing it for members if there's a demand.

[Tony]

Interesting.

One situation where temperature is not an issue is drywashing.

At the moment many of us use one 110mm drainpipe, which has two problems:

- first flush has to be recirculated until the dust is re-trapped by the wood shavings
- it's always the inlet bit that clogs with soap first, so changing the lot wastes some of the potential of the shavings near the outlet

I've long thought some solution with four smaller bore (43mm?) waste pipes in series would be a good solution, you could slowly cycle them taking turns as to which one is on inlet duty, and when replacing the sawdust only do it to the inlet tube so dust is trapped by the three downstream.

I've no idea how best to implement this, but a 3d printer would potentially change the landscape of possibilities.

Do we know how well the plastic resists bio long term?  Some of the plastic parts on my drywash tower have split after a couple of years of use (I think they may be black ABS).

[Julian]

That sound like a good project ... do you want to have a think and sketch up some ideas just a scan of a fag packet design will do to start.  Push fit waste pipe fittings use O rings, just need to make sure they don't pop off under pressure!

I've tried PLA with methanol and it seems OK short term... perhaps I should do some long term tests. 

[Julian]

More thoughts ... would fire cement be a suitable, moldable insulator for the top tube plate?

And would heat conducted along the tubes be a problem for the plastic?

[Tony]

It's a shame K.H's clamp-top drywash tower failed under pressure.  Still, it was an interesting experiment.  I'll have a think Julian.

[Julian]

I wonder if the second test piece could be modified to take components from a push fit plumbing fitting?

That would be good for the water connections, condense and vapour outlets ... more playing tomorrow me thinks, (provided my new filament arrives).

[Julian]

My tower is leaking like a sieve.  I think it's down to the gasket under the screw cap/s.

The solution I came up with was to put it inside my second settling tank ... it can leak all it likes now!

[Tony]

I wonder if the second test piece could be modified to take components from a push fit plumbing fitting?

That would be good for the water connections, condense and vapour outlets ... more playing tomorrow me thinks, (provided my new filament arrives).

That sounds like an excellent plan.  Push fit is pretty clever stuff.

My tower is leaking like a sieve.  I think it's down to the gasket under the screw cap/s.

The solution I came up with was to put it inside my second settling tank ... it can leak all it likes now!

Mine sits in a bucket I have to periodically empty...

[Julian]

Just pulled a Speed fit fitting apart.  Incorporating it's parts looks completely doable.

Screwfix do 5 off 15mm Ts for 10 quid, so circa 67p per connection!

[Julian]

He, he, Plumbcenter do the collets and O rings as spares for 37p and you get the insert O ring too!  Just need the backing ring which is easy to print.



http://www.plumbcenter.co.uk/en/speedfit-15mm-epdm-o-ring-15-epr-62944?top_category=18233

and 22mm at 57p ...

http://www.plumbcenter.co.uk/en/plumbing/fittings/plastic-fittings/jg-speedfit-plastic-fittings/jg-speedfit-22mm-epdm-o-ring-22-epr-each-62916

[Tony]

Eminently doable then

EPDM would turn to squishy mush in short order, though I expect they are sizes readily available in Viton/Nitrile.

[Julian]

Eminently doable then

EPDM would turn to squishy mush in short order, though I expect they are sizes readily available in Viton/Nitrile.

EPDM is fine with methanol I believe.  I found this    http://www.biodiesel.org/docs/ffs-performace_usage/materials-compatibility.pdf?sfvrsn=4    which states it's "fair" and "usually OK for static seal" have you had bad experiences with EPDM?

If fact there's quite a lot of good info in that pdf, it might be worth plagiarising it for the wiki!

Nitrle O rings the same size as my test piece, (the Speed fit one is a bigger cross section, but it will make little difference to the cost) are about 17p in reasonable numbers.  Viton a little more, so not really an issue.  The critical bit is the collet which would be impossible to print.

[Julian]

Just tried the little flange with the silicone filled groove on a bit of 22mm pipe and that too seem to work well.

[Julian]

There you go Tony ... a 40mm waste to 15mm push-in fitting in section.



Didn't have any 40mm pipe just fittings (which is where the O ring came from), but the 15mm end seems to work reasonably well ... might need to increase the diameter of the O ring housing a shade, but the collet mechanism appears to hold well.

As I type I noticed I made the groove for the big O ring too deep so that will need changing too.

As for fixing it to the 40mm pipe, I had thoughts on a double split clamp with serrated teeth grafted on to 40mm end with a couple of bolts to pull it up tight on the pipe.

Is this along the line you're thinking?

[Julian]

For those interested, here's a graphic ...