New Construction Method

[punkin]

I've just had my eyes opened by some lateral thinking in a big way! A problem i've been hashing over for months trying to solve (my double boiler) is suddenly looking acheivable thanks to a post by Myles over on HD.

http://www.homedistiller.org/forum/view ... =16&t=9250

Hi folks,
Please check with the prices where you are. I compared the price of 1 square meter of copper sheet to the price of copper tube that you would need to solder together to make a 1 square meter double walled piece with surprising results.

15 mm needs 67 x 1 meter lengths
22 mm needs 46 x 1meter lengths
28mm needs 36 x 1meter lengths

If you buy tube in 30 meter lots (or more) then 22mm tube and 0.9mm sheet work out the same price per area.

What set me off on this thought was the idea of winding a big coil, soldering it together and using it as a hollow wall for a still boiler. Would still need sheet metal for the bottom and top but you could use steam or hot water in the coil as your heat source.

OK there are lots of potential leaks, but decent soldering would sort that out. Is this a viable way of building a steam jacketed boiler or would you line it with the thinnest copper sheet you could find, just to be on the safe side?

The possibilities are just endless... i can't see another double boiler being built the traditional way again. How easy would it be to bend 3/4 copper to build a pot bottom out of it? the heat from soldering the copper to itself would be plenty enough to anneal it...


I gotta mull this over for a few days, but i'm excited...brains racing away at a million ' per sec....



Coiled copper bottom tigged to stainless sides, hooded with a stainless sheild to capture side heat...run by gas...filled with glycol....



IInvitedHimOverByTheWayPunkin

[myles]

Punkin, been thinking about this coiled bottom idea. With or without the coiled sides I recon it would be possible to set it up to circulate by convection.

Feed it in to the centre of the bottom, then take the end of the coil higher than the top rim of your boiler and back into your reservoir. Forgive the poor image but perhaps someone with CAD skills can draw a spiral. Fraid its beyond my skills.


You would need a valve to open to atmosphere once it was cooling down to quickly ballance fluid levels. Water would turn to steam in the coil and circulate. The weight of fluid in the reservoir should force the steam to go in the direction you want and not backwards to the reservoir.

Not sure it would work with glycol unless the change in density could power the circulation.

You would need a small disc above the coil because of the minimum bend radius - you cant get a coil tight enough to seal in its own diameter. And possibly a thin plate underneath to help spread the thermal transfer from your gas burner.

[Adverse Effects]

you have the flow in the wrong direction in your pic you would have the flow the other way because the liquid would be cooling down as it gives its heat to the pot so it would want to flow down hill

same effect with steam would rise up the left hand pipe start to cool and flow down the tube/pot

[trthskr4]

What about a dual reservoir system where the boiler sits close to the ground and is sealed. The steam rises up through the tubing and down the coil into another reservoir that is below the bottom coil but higher than the first reservoir then a tube from the return res. goes into the upper middle of the boiler/steam res. to refill once and if the water gets below a certain point in it. The second reservoir may even be able to be open to atmosphere to prevent pressurization. I know nothing about steam and thermodynamics, I just have been thinking about a self filling system that would recirculate back to the boiler without check valves and such.

[Adverse Effects]

I just have been thinking about a self filling system that would recirculate back to the boiler without check valves and such.

well that is what i was working on till someone in power here started to get a little power hungry and tryed to shut me down

[punkin]

I just have been thinking about a self filling system that would recirculate back to the boiler without check valves and such.

well that is what i was working on till someone in power here started to get a little power hungry and tryed to shut me down

Spose that's one way to look at what happenned....

An intensely paranoid way to look at it, but a view nonetheless...








JustSeemedLikeADisagreementToMePunkin

[trthskr4]

Ya'll just keep sitting back laughing and pointing fingers at us paranoid folks.








Who's gonna have the last laugh when the mothership shows up?

[punkin]

Not you paranoid sorts, there'll be some kind of conspiracy to leave without ya's

[Adverse Effects]

I just have been thinking about a self filling system that would recirculate back to the boiler without check valves and such.

well that is what i was working on till someone in power here started to get a little power hungry and tryed to shut me down

Spose that's one way to look at what happenned....

An intensely paranoid way to look at it, but a view nonetheless...

JustSeemedLikeADisagreementToMePunkin

In short and in order to terminate this thread,

now if that ant shuting me down what is it?

[punkin]

I'll let someone who cares decide....

[blanikdog]

This is all very confusing. Who shut down whom??

[myles]

Can we get back on topic please. By my calculations copper tube IN SOME SIZES ONLY works out cheaper by area than solid sheet in the same wall thickness.

You also get as a bonus, a hollow wall that you can use for anything you like. Ok I like the idea of steam heating but even if you use it for thermal transfer with oil , glycol, salt or whatever it could be a bonus. Direct gas heating is convenient, fast and relatively cheap. If you can transfer that energy all the way up the sides to the rim of your pot, in addition to heating the base, that has to be a good thing.

I think you will have to use a lining of 0.3mm or less copper sheet, but the thermal transfer properties of copper are so much better than stainless it has to be worth it. At the end of the day it comes down to cash. Can you build a thin sheet and copper coil wall or base, for less than a simmilar strength sheet in solid copper?

If you intend to use a coil anyway to heat your wash, why not make it a structural component of your boiler.

Copper phosporous brazing rods thast are used in flux free applications such as air conditioning coils!!!! Do these have thermal expansion coeficients that are closer to copper than silver solder. Any heating engineers out there that can advise?

[trthskr4]

Myles you could ask Tater on HD about the silver brazing rods, he's in the business. I use the silver and don't have a problem unless I want to take something apart afterwards.

[big worm]

i use them a great deal, got no math for ya but solder joints with them are hard as a rock i just dont see any flexability at all they are like steel when cool. we refer to it as hard solder it takes lots of heat to melt it and bond good.....and like truth says twice as much heat to break apart.

[punkin]

I use em a lot too. I'm not worried at all about silver solder breaking.

I could be proved wrong, but i'm thinking of coiling 3/4 or inch as a base only (filled) and i don't reckon it'll break or leak.

Wonder if you could fill it with a solid? Sand or something? then just leave a small breather?

I don't reckon you'll have to line it with sheet, but i haven't had the design clck in properly in my head yet either...guess i'll have ta sleep on it a couplea nights.

I'm definately thinking a copper pipespiralled bottom with a stainless tube tigged to it and a gal sheet shroud to gather the side heat will = a double boiler.

The stainless is cheaper and the thermal properties more suited to the sides. The shroud should take the place of insulation in capturing the energy that runs up the sides.

Just gotta get the middle of the coil fixed in my head...got some ideas, but they all leave gaps, best one so far has the middle of the coil exiting vertically and joining the expansion tank through the side of the pot half way up to complete a curcuit.