Seeking info

[ajoeiam]

snip
P.S. I appreciate the "art" of good welding, although few elevate it to that level. I never could.

Its called practice and do and practice some more and do some more - - -
it only takes time (with the odd bit of advice from someone at one's elbow)

(Not meant to be a drag - - - but its how I learnt)

 

[Lloyd-ss]

Its called practice and do and practice some more and do some more - - -
it only takes time (with the odd bit of advice from someone at one's elbow)

(Not meant to be a drag - - - but its how I learnt)

Hi Joe, my welding is a couple of times a year, and I quickly grind it down and put some spray paint on it so that no one can see my actual weld, LOL.

Before retirement I worked for a defense contractor that made the hydraulic system for the steering gear for a certain class of ships. An 8" diameter double acting cylinder to turn the rudder, that operated at up to 4,000 psi hydraulic pressure. That group bent and welded all the stainless steel piping for the pumps and cylinders and tanks and back-up systems, etc. I would occasionally look at the TIG fillet welds they did on the pipes and fittings. I swear, they were so pretty, they almost brought tears to my eyes. I know that some of you understand. It's a guy thing, LOL.

 

[skyline1]

Hi everyone, I am really late to the party on this one and have to admit that I know nothing about boilers except that the potential energy contained inside one is something that must be understood, and treated with great respect.
I am very curious about copper as the material choice. Cost and strength are a couple of negatives. Aesthetics, heat transfer, and maybe authenticity are a couple of pluses. I know that if I hunted around in previous threads I might find the answer, but it seems like there are some seasoned veterans right here, and I am hoping to learn. And sutty, with your extensive welding background, you could have been working with a material you had lots of experience with, so there must be so good motivation for using copper. There is definitely some good advice in this thread, and I am not at all questioning the material choice, I am just curious.

Hi Lloyd you are right even small boilers DO contain high potential energy and as you rightly say need to be treated with respect

But they need not be treated with fear, Start with a simple design like a little cylindrical pot boiler and work from there If in doubt Hydraulic test is your friend !
Personally I prefer copper and silver solder but the many techniques discussed here are equally valid.

I have made many boilers over the years along with my late father who despite not being a professional engineer, had an innate knowledge of these things.

All my boilers are silver soldered copper and whilst fairly simple (and some a bit elderly) none of them have EVER failed either hydraulic or steam test.

He was not keen on steel boilers despite the fact that most full size ones are. (some of them have copper fireboxes though)

He said "Always use copper for a boiler 'cos it's "stretchy" like a balloon

I think he was right. Copper is great material for pressure vessels that need to work in high temperature differences (like a steam boiler)

and it has one other trick of it's sleeve, it work hardens (actually i believe work toughens )

Ask anyone here who has made a copper boiler, lots of heating up and annealing needed

 

[Lloyd-ss]

Skyline, Thanks for all that info. For the time being, I will treat copper boilers with grave respect, but no fear.....
well, maybe just a teeny tiny bit of fear.

 

[ajoeiam]

Hi Joe, my welding is a couple of times a year, and I quickly grind it down and put some spray paint on it so that no one can see my actual weld, LOL.

Before retirement I worked for a defense contractor that made the hydraulic system for the steering gear for a certain class of ships. An 8" diameter double acting cylinder to turn the rudder, that operated at up to 4,000 psi hydraulic pressure. That group bent and welded all the stainless steel piping for the pumps and cylinders and tanks and back-up systems, etc. I would occasionally look at the TIG fillet welds they did on the pipes and fittings. I swear, they were so pretty, they almost brought tears to my eyes. I know that some of you understand. It's a guy thing, LOL.

I is truly a beautiful thing when the welds 'look' gorgeous.
(Even better when the x-ray is also that way!!!)

4k psi is still pretty much 'normal' hydraulic cylinder pressures.
Now when you're wanting to spec 10k psi - - - -that's when my posterior develops serious twitching (LOL).
Even so - - - careful work using good procedures - - - its all doable.

 

[sutty]

Hello guys, hope all are well . we've been busy, made up a burner that seems to work OK, had a bit of an issue getting fibreglass wick so I made some from fibreglass fire door rope, seems to work ok, gash built a fuel tank to see if my idea of a chicken feed worked to stop over feeding and flooding, and it does so we'll be making a proper one.
The burner seems to work ok, the fuel feed pipe stays cool so that's a good sign, we're getting a good flame that has some swirl on it.
Here's some pix, feel free to pick the knits out of it,
We've also made a water feed pump from a design we found on the web.

Best regards sutty

 

[Lloyd-ss]

Sutty,
SWEET ! Nothing like playing with fire to get the heart pumping!
Seriously, though, very nice work although I have never tried anything like that except for changing jets on a cook top, and installing a propane burner in a fireplace. Nothing built from scratch like yours. But attention to detail is always number one when working with flammables or compressibles.
Thanks for doing the video, too. Is the fuel propane (LPG) or something else? I see the square tank, which I guess you pre-fill from the dead-end line with the shut-off and compression fitting?? Then the line exiting the tank along the board, thru the shut-off valve, and then thru a cylindrical gizmo with some circular fins. What is that? Then on to the burner with some air-mixing passages?? Got any marshmallows before it has to start working to heat the boiler?

I enjoy following the process on things I am not familiar with. I don't have enough knowledge to offer any critique, but plenty of good folk around like steamchick and more to keep a watchful eye over your shoulder.
Lloyd

 

[sutty]

Lloyd, Ok , the fuel is methalayted spirits, the tank has two levels, the top level feeds the bottom tank through a small pipe, that pipe is set at a distance from the bottom of the tank, as the fuel flows to the burner the level in the bottom tank drops and uncovers the bottom of the pipe and allows fuel to pass from the top tank to the bottom tank until the pipe is covered and creates a vacuum in the top tank stopping the flow, works fine.

the burner has a reservoir at the bottom fed from the bottom fuel tank, the valve shuts off the fuel and the burner extinguishes.
there are 3 wicks that feed from the reservoir and heat the top vaporiser tank which stands on 3 hollow legs mounted on the reservoir that allow vapour to rise into the top tank and out through the 6 x 1mm jets and gives a good flame.

sutty

 

[sutty]

Lloyd, this might explain it better, the finned discs are heat sinks but the pip didn't get warm at all.

regards sutty

 

[ajoeiam]

Hello guys, hope all are well . we've been busy, made up a burner that seems to work OK, had a bit of an issue getting fibreglass wick so I made some from fibreglass fire door rope, seems to work ok, gash built a fuel tank to see if my idea of a chicken feed worked to stop over feeding and flooding, and it does so we'll be making a proper one.
The burner seems to work ok, the fuel feed pipe stays cool so that's a good sign, we're getting a good flame that has some swirl on it.
Here's some pix, feel free to pick the knits out of it,
We've also made a water feed pump from a design we found on the web.

Best regards sutty

Hmmmmmmmmmm - - - the burn3.jpg - - - that is the flame at a low level of 'burn' - - yes?

(Looking at pics is more than somewhat different than 'being there' - - - sorry.)

 

[Steamchick]

Hi Sutty, just remember that when "inside the firebox" the burner will perform completely differently for a couple of reasons.
In the open air, you are sucking-in a lot of side air to keep the flame clean and burning - Inside a firebox this rarely can happen. All the air usually comes up through the centre of the burner....
Inside the firebox, the outside of the "combustion zone" is copper with cold-ish water behind it, so flames stop when the get below around 350degC. even when the water is at 150deg.C. so you want a more compact flame, so it has burned all the fuel before it gets to the firebox walls.
The flue tubes (full of hot exhaust gas) rely upon the hot gas to be developing a pressure to push the flue gases up the lum, and therefore there is a back pressure affecting how much air is drawn into the burner.


Therefore, I suggest you make a simple model of the firebox (from old tin cans) and the flue tube, and play around with the burner inside there, before you finally decide upon the design of burner. - It will probably need some tweaking to get the best from the burner.
K2

 

[sutty]

Cheers ken, I'm not sure if the burner is too close to the bottom of the firebox so I think I'm going to raise the boiler up on feet, that will give an air gap all round the base of the boiler, that might improve airflow, not sure what distance the burner should be from the bottom tubes .
I was getting Edd to start thinking things through and work bits out, he's shown interest in the chicken feed fuel supply system and siphon effects.

best regards and keep the help coming. sutty

 

[Steamchick]

Hi Sutty, my 'weekly' idea to take you another step forward?
Considering combustion: as well as fuel and air you need heat, well the heat isn't correct, as "heat'" is energy flow. What you need to do is control,the heat so different parts are at different temperatures. The heat source = flames = combustion. I.E. the release of the stored chemical energy when "hot" molecules breakdown and recombine, making different molecules. The more intense this reaction the higher the temperature , because, assuming the heat flows out under the same conditions, to move more energy from hot zone to cooler zone needs more temperature difference.
Your meths burner will supply lots of heat energy, but a higher temperature will improve combustion and efficiency of getting the released energy into the water in the boiler.
Too much air will cool the flames, so needs to be limited to "just enough" air. - not too much, nor too little.
Rapid mixing of fuel vapour and air will speed up combustion.
Concentrating the combustion in a small zone will raise temperature, but not the overall amount of energy available. One idea to help these latter ointment is using a turbulent flow device. E.g. Some baffle causing fuel and air to mix more rapidly. E.g. Some wire mesh from a stainless steel pan scourer. Costs pence, and can be pulled around to make whatever shape seems to work best.
Mounted so it sits right where all the flames are may give you a visible improvement in concentrating the combustion. The wires will glow dull to bright red showing you hot and not so hot positions.
Try it and see?
K2

 

[Lloyd-ss]

Fascinating.The internal wire mesh as a sort of temperature indicator is very clever. I know zero about boilers but have worked with many kinds of wood stoves and have observed their response with fiddling around with the air supply.
This leads to a recent odd reference in a couple of places on U-tube that may be of interest. They were about fabricating smokeless burn barrels for use out in the country. They were basically a barrel inside a barrel with a small gap all around including at the bottom. There were carefully planned holes around the bottom and top of both barrels. Primary combustion air in at the bottom, but then the secondary air at the top kind of super-heats the final bits of remaining fuel before it escapes as what would normally be smoke.
I just thought the principle seemed rather intuitive once it was explained and then demonstrated.

 

[sutty]

Thanks guys, even more to think about now, we were going to put a series of holes around the base of the boiler and have a sliding choke to control airflow. Busy re-making the fuel supply tank now I know it works and Edd is still turning the Phos /bronze bushes up as well as making up the water feed pump mount .

Best regards sutty

 

[Steamchick]

Hi Sutty. You can make a throw-away test firebox by taking a tin - From tinned fruit, pess, beans or whatever is the right size. I.E. the same as the ID of the firebox tube. Cut a small hole in one end equal to the size of the flue ID. Leave the other end fully open. Position the burner at the height from the end with the flue hole as per dimensions in the boiler. Prop the whole thing up on small spacers to permit air to be drawn in at the base as per the boiler.
Rub soap in lines all over the outside of the tin. When lit, the soap will turn black where hot enough for the boiler. It may even glow red in parts. Where the soap does not char, it is cold and can be below the firebox as there is no heat to transfer to the boiler.
And you can see how much fuel will be trying to burn up the flue tube, because some flame will come out of the top.
Then try with some wire wool and see if less flame comes out of the top?
Record results, fiddle and adjust and try again.
A good exercise for Edd?

Cheers
K2

 

[Lloyd-ss]

Hi Sutty. ............
................................Rub soap in lines all over the outside of the tin. When lit, the soap will turn black where hot enough for the boiler.........................
.................................Record results, fiddle and adjust and try again.
........................

Cheers
K2

K2,
I am not trying to embarrass you, but some of the tricks you have up your sleeve impress me to the point that I just shake my head and chuckle. You are quite the scientist and inventor. My hat is off to you, good sir.
Lloyd

 

[sutty]

Cheers Ken, I need to finish the fuel tank and solder up the wick holders on the burner reservoir then we’ll knock up a dummy firebox, we have a strip of copper, we have some slip rolls,

regards sutty

 

[Steamchick]

Glad you laugh, Lloyd.
I call it "experience". The stuff to be shared on this website.
And I am glad someone reads it and smiles!
K2

 

[sutty]

Ken, experiences are everything, I’m gagging to pass on over 50 years of experience before I shuffle off. It’s harder to teach than learn !

regards sutty