Frosty

Naturally Aspirated Ribbon Burner. Photo heavy.

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I haven't talked about this little project in any depth though I've mentioned it to a few folks. After reading posts by folk here who have made and use ribbon burners I started looking into them a bit more. I like the idea of more even heat and quieter. What had me baffled is all the talk about needing a high pressure blower and looked more. I downloaded the ribbon burner plans Wayne has posted on his site and ran into the high pressure thing again.

The only reason the device would actually NEED high pressure is if there weren't enough burner "nozzles" (nozzlettes?) A burner has to deliver the Fuel Air (FA) mix faster than the rate of propagation of the mix. To do so there only has to be enough pressure to overcome friction and restrictions in the system. too many nozzlettes though and the velocity falls below the flame front velocity and the system will back fire or burn back if you prefer.

Okay, that's what I was thinking when I started tinkering with a Naturally Aspirated Ribbon Burner. (NARB? :o) John's design was straight forward enough, a length of square tubing one side opened up, ends capped and a threaded intake port. (About the internal diffuser later) Then a mold to support an array of crayons to provide nozzlettes in the cast refractory. That is easy enough to understand so I gave it some thought, tweaked things a bit and started experimenting.

A NA burner doesn't produce that much pressure, volume you betcha but not a lot of pressure so I needed to find out how many holes the ribbon block needed to let a T breath. Want to guess how many ribbon blocks I had to cast before getting it right? I should make that a contest, maybe Glenn would've donated a prize. Naw, I'm about to give it away so why bother. I started with my calculator, mic and did some figuring. To keep a NA burner breathing properly you need to increase the passage volume as the distance increases, the increase in cross sectional area decreases pressure in the stream to compensate for friction while increasing induction. Well, the basic plan has a piece of 2" sq. tubing 7" long and a thread protector welded to the center of the top side. Okay, there's a big increase in volume so no back pressure problem. I started with 10 nozzlettes about 2x the cross sectional area of the 3/4" tube on the T inducer. The diffuser in the steel plenum was just a piece of sheet steel bent in a flat V and welded across the inside of the plenum chamber to deflect the FA stream towards the ends.

Put it together hooked up the gas and lit it off. No go, too much back pressure only got a sickly stream of fluttery yellow flames that looked like a demented candle. Doubling the flow path wasn't enough.

The next test block had 36 nozzlettes and lit it up. No back pressure issues but the FA velocity was too low and it backfired in about 3-4 seconds. Well, I had it bracketed I knew what was too little and too much.

The next test block had 24 nozzlettes and it performed pretty darned well but backfired in about 30 seconds. Close but no cigar.

Next one had 21 nozzlettes and it ran close to a minute so I put it in a brick pile forge and it backfired in under 10 seconds. I could smell that brass ring now! :lol:

Test fire 24 nozzlettes.jpg

Don't let the long yellow flames fool you this test block is burning nicely it's made of wood so . . . Yeah, I made all the ribbon test blocks from 2" x 4" cut to fit the plenum. The plenum end caps are 2 3/4" long and drilled so I could screw through to the test blocks. You didn't really think I was going to cast all the test blocks in refractory did you? :rolleyes: There were 6 test blocks tuning into the 19 nozzlettes in 3 rows 6" long. I don't have any pictures of the tests after I rotated the T tube 90* so the T would lay horizontal rather than stand vertical. This lets me put the burner air intake behind the forge as far from the door as possible so it can't breath exhaust, an ongoing problem with all the vertical burners I've run.

So, once I had my numbers and pattern I made the mold. It isn't nearly as nice as the one John made I used a 2" x 6" drilled for crayons and 2" x 2" for the sides. Sanded, painted in hard epoxy appliance paint. The release agent I used is spray Pledge.

I made the final mod to the plenum, welding 1" of expanded steel to the long side to act like rebar in the refractory and make for a positive bond to the refractory.

This pic is a final fitting of the T inducer before casting the block to check for clearances and other fiddly little things I was able to think might maybe could go wrong. Note the lack of a diffuser in the plenum, with or without one made zero difference in the flame size uniformity so I dropped it from the design.

Ribbon plenum horizontal T 01.jpg

Then came the setting it to the old, two pieces of 3/4" angle iron tacked to the ends set it's depth in the mold, they'll come off when it goes in the forge. There's nothing of particular iterest to say about this part. Holes drilled, crayons set plenum height set, mold sprayed with Pledge and allowed to dry.

I discovered an interesting thing mixing the Kast-O-Lite 30. I used the mold to measure the Kast-O-Lite beforehand and added about 25% more so as to have enough and not waste too much. I mixed it in two batches, the first batch was about 1/4" depth and I added about 25% Zircopax. This section is the flame face so I armored it up a little. Test coupons performed satisfactorily so this is the mod I made to the refractory in the mold. I then mixed the rest and discovered adding water reduced the volume significantly and had to mix a third batch to make up the difference. About then I was kicking myself heartily for not weighing the refractory.

Here's a little tip I one of the guys at Bartells passed to me and I confirmed. When you mix this stuff add water VERY SLOWLY and kneed it like you were mashing peanut butter. It will seem VERY dry but when little pellets start to look wet you're about there. Mash it into a corner between the side and bottom of the container, then turn it out cut it up and mash it in again. It will begin to stick together and it's into the add water by the drop not drizzle. Suddenly it will start loosening up and will quickly become soft and pliable, work it more and it'll become liquid. It's weird stuff but be patient it'll become workable. Too much water and it'll flow like paint and it looses strength and it's thermal properties.

This pic is of the vibrator I made to settle the refractory into the mold and the expanded sheet thoroughly. It's just a piece of 5/16" rd. with about 4" bent 90* at the end. With the drill turning at a moderate speed it vibrated every bubble out quickly and also quickly produced free moisture at the top of the mix and through a joint under one end of the mold. Darned stuff was still too wet and I had to spoon it into the mold and mash it in with a butter knife. It's weird stuff.

Not a whole lot for pictures happened next, I put a magnetic engine heater on the plenum to keep the refractory in the 80f range and wrapped in it Kaowool to insulate it. Then I left it over night, and gave it a little quick scratch test to see how it was setting. Hard as a rock so I cracked the mold and gave a side under the mold a scratch. Ditto, HARD set. ow for the 100% humidity cure time a set of directions called for. It went into a coffee can with a little water and the magnetic engine heater stuck to the outside to keep it wet. I left it at 100% humid for a day and a half before trying to melt out the crayons. I don't k now what they're putting in crayons anymore but they don't melt easily at all

Vibrating refractory in mold.jpg

mix set and eng heater.jpg

Out of mold.jpg

 

After a couple days warm and wet I discovered I was out of propane! I was expecting a local fellow who wanted to give smithing a shot so I loaded up my 100lb. tank, got it filled ad had help dragging it into the shop and hooking up my new ribbon burner. I'd stacked up a brick pile forge with a chamber volume of about 365 cu/in and lit it up. :)

The first pic is just after lighting it, you can just barely see the top of the T behind the plenum. It's running a little rich but not terribly.

Refractory NA ribbon block in pile 01.jpg

This is running at 2 PSIG. None of my T burners run at 2 PSIG. :lol:

Refractory NA ribbon 2 PSIG.jpg

 

Refractory NA ribbon 10 PSIG.jpg

 

This is 10 PSIG.

Refractory NA ribbon 10 PSIG.jpg

 

This last pic is 20PSIG. The forge was running into yellow heat in about 5 minutes and she's quiet, roars but quietly.

Refractory NA ribbon 20 PSIG.jpg

And that ladies and gentlemen, is a Naturally Aspirated Ribbon Burner. Driven by an off the page Frosty T induction device.

I am not displeased. :wub:

Frosty The Lucky.

 

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Excellent experiment, Frosty! I find this all very interesting.

Do you feel that having the T-inducer enter the plenum at 90 degrees to the 'nozzlettes' (instead of directly in line with them) helped reduce the need for a diffuser?

As to the Kast-O-Lite, I noticed the same phenomenon: At some point in mixing, adding just a tiny amount of water induced a significant change in the fluidity of the mixture. I've noticed similar effects with some masonry mortars that I've used in the past.

Steamboat

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I stopped experimenting with the vertical inducer so I don't know if the diffuser is necessary there. The crayons are under about 3/8" dia so individual nozzlettes don't offer a lot of volume less than 1/10 the inducer tube and friction is logarithmic, 1/2 the dia. = 1/4 the area but still 1/2 the circumference. This means 2x the friction for the volume carried comparatively.

Having the inlet 90* to the nozzlettes eliminated the need for a diffuser for all practical intents and purposes. There is a slightly shorter flame length from the nozzlettes on the very ends. Just those two, not the ones 1/2" closer to the center, just the very ends. There may be a little crud caught in them because they're at the ends OR there may be an eddy current that close to the end caps that lowers the FA pressure over those two. It's not a big deal and heck it may even out once everything cleans out.

Next time I mix up a batch of Kast-O-Lite I'm weighing everything, I hope I don't need my old Triple Beam Balance It's long gone. Vibrating it had so much effect I'm tempted to just put the dry mix and a little water in a container and vibrating it. Oh that's just silly, nevermind. :rolleyes:

I really needed some cheering up, it's been kind of a depressing week. Today I made a new friend, did a little smithing and the NARB worked better than I'd hoped. Now I need to decide how to mount it in it's new forge.

Frosty The Lucky.

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Very interesting Frosty and very interesting.  I like it.  I doubt that most of the rest of us have the patience to do all that testing and experimenting.  If anyone wants a different size burner I would think that they would need to use this as a basis and experiment from there.  I expect that getting just the right number of holes will be essential and that the na burner would be more temperamental as far as controlling the temperature and flame qualities (reducing, natural or oxidizing).  If you are planning to do fluxless forge welds you will need a reducing flame (about 6" of dragon's breath).

Thanks Frosty and I will be putting this in my notes.

Wayne.

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6 hours ago, WayneCoeArtistBlacksmith.c said:

Very interesting Frosty and very interesting.  I like it.  I doubt that most of the rest of us have the patience to do all that testing and experimenting.  If anyone wants a different size burner I would think that they would need to use this as a basis and experiment from there.  I expect that getting just the right number of holes will be essential and that the na burner would be more temperamental as far as controlling the temperature and flame qualities (reducing, natural or oxidizing).  If you are planning to do fluxless forge welds you will need a reducing flame (about 6" of dragon's breath).

Thanks Frosty and I will be putting this in my notes.

Wayne.

It kept me off the streets and out of trouble. You know how it is when something doesn't jibe in your mind and gets your stubborn up. This thing kept me fiddling for quite a while. Yes it's running rich, more so that I'd like but I think in a larger chamber it'll lean out some. Maybe I'll have to give a fluxless weld a shot though I flux very lightly now. I didn't do a build how to, I used equipment not everybody has. I fileted  the sq tubing in my band saw in cut off configuration. With a new blade and it cuts straight and clean.

Well, actually I have so many sketches, drawings and templates laying around it'd be hard pressed to put a how to together. I think my only (sort of) new idea was using lumber as test ribbon blocks.

I replied to your Email and attached the post in "Word." Let me know if there's a problem and I'll try a cut and paste.

Frosty The Lucky.

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I'm looking forward to running it in a proper forge it'll destroy the soft fire bricks in that brick pile and they're too expensive to destroy just because. I hope I can get something put together in time for the meeting. I really want to show this baby off, I am SOOOOO pleased. B)

Frosty The Lucky.

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37 minutes ago, Frosty said:

I'm looking forward to running it in a proper forge it'll destroy the soft fire bricks in that brick pile and they're too expensive to destroy just because. I hope I can get something put together in time for the meeting. I really want to show this baby off, I am SOOOOO pleased. B)

Frosty The Lucky.

Once again, I'm impressed. Not only because it works, but also because it appears to work at a wide range of gas flow rates, which I would think should give you excellent temperature control. Would you say that the 2 psi rate would be akin to an "idle" setting? It was inspiring enough that I went out and got back to work on my current gas forge project, which has been on the 'back burner' for the past few days.

Steamboat

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1 hour ago, Steamboat said:

Once again, I'm impressed. Not only because it works, but also because it appears to work at a wide range of gas flow rates, which I would think should give you excellent temperature control. Would you say that the 2 psi rate would be akin to an "idle" setting? It was inspiring enough that I went out and got back to work on my current gas forge project, which has been on the 'back burner' for the past few days.

Steamboat

You and me both, it performs WAY better than I expected, I don't kn ow how low I can turn it down. I don't know why you couldn't use an idle circuit, I have no idea what range a different burner will have. I've only made this one and a single sample isn't enough to determine general characteristics. This one may be a golden BB and the only one with such a wide range.

Frosty The Lucky.

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As another data point, and not to minimize the importance of Frosty's testing in any way, Ransome style NA burners have been used with multi port burner heads for many years .  Please see Dudley Gibberson's site for more detail.

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5 hours ago, Latticino said:

As another data point, and not to minimize the importance of Frosty's testing in any way, Ransome style NA burners have been used with multi port burner heads for many years .  Please see Dudley Gibberson's site for more detail.

Shhhhhhh:ph34r:, don't tell the guys I spent a bunch of time looking at commercially made NA ribbon (multi port) burners will ya! That's one of the reasons only 1 test firing had a diffuser in the plenum.

What I did is just a refinement of John Emmerlings ribbon burner plans published in "The Hammer's Blow" I believe it was several years ago. I just adapted a proven device a little.

I'm just silly, happy dance pleased with how well this one worked. I have my fingers crossed it's a design trait rather than a one time fluke.

Thanks for the "multi port" term I've seen it before but I keep blanking on terms. There really isn't much limit to the shape these things can take and "ribbon" is a specific shape. It would have to turn into a pretty clunky phrase to describe a ring burner say. Seriously the shapes are darned near unlimited, with a little more material research a person could turn the forge liner into a plenum with burner ports everywhere. The whole forge could be the burner.

Multi port is so much more appropriate. I'll have to write it on a Postit and stick it to my computer to remember it till it's well enough burned in but it's in the book thank you.

Frosty The Lucky.

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Hey frosty how long is the nipple your using for the mixing tube? 6in right? As in you just screwed you tee burner in as basicly a new "flare". And the "flare" being the "multi-port" burner?

 

Why isnt this in the gas forge section?

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T inducer has a 6" tube, screws into a thread protector that's welded to the center of the plenum. No flare, I don't bother with flares.

Why isn't this in the burner section? Burners are a vice of mine? I think I sent Admin a message asking to move it to the gas burner section but that was only last night and I couldn't get a "Report This Post" button anywhere on the thread. I see one now I'll ask them again.

Frosty The Lucky.

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41 minutes ago, Frosty said:

T inducer has a 6" tube, screws into a thread protector that's welded to the center of the plenum. No flare, I don't bother with flares.

Why isn't this in the burner section? Burners are a vice of mine? I think I sent Admin a message asking to move it to the gas burner section but that was only last night and I couldn't get a "Report This Post" button anywhere on the thread. I see one now I'll ask them again.

Frosty The Lucky.

Gottcha this is to likely be a near future project for my extra materials 

And sorry for the need of clarification.... the op was clarification enough i just needed to give it a second look

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Nothing to be sorry about, if a person needs clarification s/he needs clarification. I'm sort of a rare bird not putting a flare on NA burners. At least you didn't put a forge burner in the vise section. :o  Admin has moved it for me, thanks for pointing it out. I'm following the thread so I don't look at the section it's in, it's just THERE.

Frosty The Lucky.

 

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3 hours ago, Frosty said:

Nothing to be sorry about, if a person needs clarification s/he needs clarification. I'm sort of a rare bird not putting a flare on NA burners. At least you didn't put a forge burner in the vise section. :o  Admin has moved it for me, thanks for pointing it out. I'm following the thread so I don't look at the section it's in, it's just THERE.

Frosty The Lucky.

 

Yea i read that you were gonna try to make one and didnt see it here then just stumbled across it 

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Just too darn cool for words!

So, how do we keep this great post from vanishing from convenient view? Will you post it to Burners 101, or create a new thread (maybe Ribbon Burners 201)? Either way works in my world:rolleyes:

By the way, congratulations big time for doing it and posting it; that is the first majorly cool thing posted here since the half muffler oval forge (and you know good what a picky butt I am).

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Since Latticino pointed out the correct term (Thanks again) I'll have to start calling them "Multi Port" burners. The "ribbon" is only the first shape I want to play with. A friend wants to make a round one and seeing as he lives 10 minutes from here . . . 

I'm still in the process of making a new portable forge for the Ribbons, the second one is curing in the mold right now and I'll see in a day or two if running so well is a design trait or a fluke. What I post for how tos, etc. will depend on how reliably repeatable the performance is. For example I never would've published the T burner if it hadn't turned out to be so easy to make and reasonably effective.

The ribbon burner directions posted on Wayne Coe's site show how to make the burner mold though I didn't do it quite that way. The other major difference is not including a diffuser in the plenum and tailoring the nozzlettes to optimize fuel air mix velocity minimizing back pressure on the T inducer and maintaining enough velocity to prevent back firing.

Other than that it's nothing special. I'll have to wait till I get them installed in the multi port forge to have an empirical report on how the method I'm trying to "plaster" the Kaowool with the Kast-O-Lite 30 + Zircopax works.

This is still very much an experiment in progress, I'm just pretty darned happy about how it's going so far and have my fingers crossed I can pull it off before the next club meeting.

Frosty The Lucky.

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I lit burner #2 today and it's not a fluke this one is almost as sweet as the first one!! I'll have to run them both side by side to see just how they compare but this one turns down below 2 PSIG and above 20 PSIG and burns smooth as silk.

I don't know what kind of margin of error there is between this type home build but they're close enough as to make no difference in a home forge.

As hard as it is to believe I'm even happier. :D The shell for the new forge is cut out, fitting the burners is the next step then I weld it together, line it and see how it works.

Frosty The Lucky.

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