Frosty

Naturally Aspirated Ribbon Burner. Photo heavy.

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1 minute ago, D.Rotblatt said:

Go for it!  Would love to hear how your version works!  Of course, you could do both....

I could but I'm not sure what I want to do with a really slow wide flame. I don't do much heat treatment and the other concept forge should work pretty well for that. I think I'll probably see how the round forge develops. I am NOT welding the burners to one again though! :angry:

What do you like about that big soft flame? 

Frosty The Lucky.

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On 4/26/2019 at 11:09 PM, Frosty said:

What do you like about that big soft flame? 

I'm going from stable 1450F to welding heats (Ive done a couple of welded billets 3x1.25x2" no flux), so it is very versatile with no backfiring.  I don't know if it's more efficient then a regular burner, I seem to be running it at higher pressures for welding.  I think because the heat is distributed over 6" rather then a 3" center, but for regular forging I keep it at the same 5-7 lbs.  Like all ribbon burners, it's disadvantage is it's advantage.  The heat is distributed very evenly in the forge. Sometimes I like a hot spot to work with, so a single NA burner provides that.  

One thing I'm thinking, is that I don't need as large an internal forge diameter with this burner (this forge is made from the smaller helium tank and has 1" of ceramic wool and IFB on bottom).  The flames cones are only about 3/4" long. There seems to be no back pressure problem.  I could run another 1/2-1" of ceramic fiber around the inside and I think it would make it more efficient.  I make knives and swords, so don't need a wide forge generally. I think the burner, which is coming in from the top, could be moved down closer to the bottom as well.  Actually, a square design might work well for this burner.

On 4/26/2019 at 11:09 PM, Frosty said:

the other concept forge

Do tell!  What are you thinking of (if it's not a classified secret)?

Dan R

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I'm thinking a round forge with a bowl shaped roof. Walls around 4.5" high in two halves that aren't connected to the deck or lid. The door baffles would be similar but with an ID that matches the rest of the forge body's OD. and a total length considerably longer than the openings are wide.

The ID of the forge would be around 10". The straight walls about 4.5" high.

The lid will be a shallow dome with a pair of ribbon burners across the center point. The outlets will be angled slightly to induce a horizontal vortex. The dome will angle them slightly towards each other.

The idea behind this arrangement is to let me. move the openings in relation to the burner flames. For example run long stock between the two to heat longer sections or across one flame for relatively limited heat zone. The walls can be moved around the circumference to manipulate opening size and position in relation to the burners. The door baffles will let me determine how much and where the openings are. 

I've been kicking around easy ways to corrugate the floor in a spiral like grooves on a record. The corrugations will increase the flame contact and radiant surface of the deck while allowing flame to pass under stock and help maintain the liner's heat.

Unfortunately like so many folks I keep "improving" on my ideas and keep coming back to one I've wanted to play with since before I built my first (gun burner by the way) propane forge. I keep thinking of different ways to make this with a recuperative wall liner. 

The recent experiments with 97% zircopax x 3% bentonite refractory tiles was giving me upitty ideas about a thin seriously high temp flame face with an open space between it and a second less high temp hard liner over a Kaowool insulating liner. 

The trick is inducing the fire inside the forge to exit through vents to the annulus between liners before exiting the forge completely.  Providing adequate support for the floor and lid is doable though casting them is a trick. It's venting the system to make it work that has me scratching my head. The stupid openings and baffles keep messing up MY head space. :huh:

Hmmmmm? 

Frosty The Lucky.

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Took me a few reads to get my mind around that... Lets see if i have it right.  The forge looks something like that Parthenon - a 4.5" vertical cylinder, 10" ID, with a domed top.  Two ribbon burners in the top with angled outlets to swirl the flame and focused on the center.  Curved walls that can move/rotate under circumference of the dome.  Baffles that can also move/rotate to change the size of the openings.  Not a knifemakers forge, but a blacksmiths/iron artists forge.  I like the concept.  I've heard of forges with a wide flat top and bottom but no walls, burner in the middle to allow for heating of wide items.  By containing the sides like you do, and using ribbon burners you should get really good heat.

Thought: If I'm thinking of this right, why not make the walls fixed with large openings (and your moveable baffle doors) and have the the top able to rotate 90 degrees?  An external metal ring around the top and above the walls would allow this and would allow you to change the orientation of the ribbon burners.  That way you won't have to deal with moving walls and baffles, which, I agree, is mind boggling to figure out. 

And then there is the whole recuperative liner part...I'd need a diagram or pic to see what you are talking about that.  

Sounds interesting, does get the gears turning!

Dan

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On 4/28/2019 at 12:03 AM, D.Rotblatt said:

One thing I'm thinking, is that I don't need as large an internal forge diameter with this burner

In line with my earlier thought, I added an inch of ceramic fiber to my forge reducing the interior to about 4.5" wide and high.  The burner is actually about an inch higher since the brackets didn't allow it to be lowered too much.  Since the forge is 8" long, that gives it an internal size of around 180 square inches.  Maybe smaller since the top is rounded (kind of...it's an odd shape now). Runs fine with the NA 1/8" ribbon burner, no problem with back pressure.  Definitely getting hotter easier and quicker. 

Choke wide open.  5lbs = 1950, 10lbs = 2150, 15lbs = 2250, but didn't go up much at 20 lbs.  So I closed off the top 1" of the door with some ceramic fiber and the temp jumped up to 2300.  Then I played with he choke on the burner (it's a standard Reil burner going into the plenum), and closed it down about 60-70% and the temp went up to 2370.  

Two lessons learned: 1) a lot of heat leaves out of the top of a high door, 2) a reducing flame seems to be hotter in this forge or with this ribbon burner.

Dan R

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3 hours ago, D.Rotblatt said:

The forge looks something like that Parthenon

Good visual, you have the basics down. The burners aren't focused on the center their focus is mid point between the wall and center. This will make a "hallway" of double burner heat IF you're running both burners. I'll work out the details of angle & just how far apart to mount the burners with a brick pile as per usual.

The only things attached are the burners, everything else can be moved. Move the main walls till they touch in the rear for a 9"-10" opening, adjustable with the baffles. Rotate the dome and you have a sheet of flame for more localized heats. Lift it off and use fire brick or even a couple baffles and you have a large surface heater say for oh hollow forming 1/4" plate with a jack hammer or sledges. 

The dome's flame face sort of makes a parabolic reflector. . . well radiator maybe focused on the center of the floor. Maybe a good thing maybe insignificant but what the hey. The main reason for dome is it's far more structurally sound than a flat roof, Kastolite is strong in compression, a dome transfers bending force to downward force on the rim. See dry laid masonry: bridges, vaults, domes, etc. 

I've been giving serious thought about the shell, I have a goodly amount of salvaged 16ga. stainless. However this forge would have way too much exposure to dragon's breath even if it's minimal dragon's breath, heck just the exhaust is hot enough to warp sheet steel. I'm thinking it'd be easy enough to put a coat of Kastolite on the outside and not care about how hot it gets. It'd take care of a rim to keep the lid from shifting easily. 

I can't find the patent documents  for recuperative wall furnaces I found years ago, it's nothing but an ad storm anymore. <sigh> The basic concept is a furnace in a furnace. The inside chamber is the work volume, exhaust is directed into the space between the work chamber and the insulated outer chamber, thus heating the radiant inner liner from both sides.

You see them or versions for glass works but not the above type. Mostly anymore recuperative is used to preheat combustion air and fuel. 

A double wall recuperative forge would be easy enough with a single outlet burner(s), had that one designed and planned a long time ago but that method wouldn't be a good thing with a multiple outlet burner. The trick is making the exhaust circulate through the space between walls. Easy enough with gun burners but not so with NA. It's not hard though, stop the burner's nozzle just before it reaches the inner wall. The burner port in the inner wall is larger than the flame so they make an inducer drawing exhaust through the annulus and back into the main chamber.

Where you put the vents/ports to allow the flame in the main chamber into the annulus between walls will be a matter of strategy. Brick pile time. 

Recuperative walls in the Parthenon forge are just random noodlings on my part, I can't help it. But BOY wouldn't it be cool in a HOT way. B)

 

2 hours ago, D.Rotblatt said:

Two lessons learned: 1) a lot of heat leaves out of the top of a high door, 2) a reducing flame seems to be hotter in this forge or with this ribbon burner.

Agreed, a multiple outlet burner's low flame velocity tends to vent more at the top of the openings. Higher velocity burners tend to vent more heat at floor level through the openings. I didn't think about that but looking at early pics of NARB when the calcite in the refractory was making so much orange flame I see it's venting more out the top. Good observation, one more for my files.

Is the hotter flame actually reducing or more neutral? The dragon's breath is often the refractory burning off calcite and doesn't represent burner ratios.

Frosty The Lucky.

 

 

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8 hours ago, Frosty said:

Is the hotter flame actually reducing or more neutral?

The flame may be leaning down as I turn up the pressure, thus I am actually getting a more neutral flame at ~70% closed.  That would make sense.  With the damper closed down I'm getting 6-8" of yellowish dragons breath at 15 lbs.  I seem to recall reading that the flame mixture in a RA burner changes a bit at different pressures, and the ribbon burner end may cause it to lean up more then normal. 

8 hours ago, Frosty said:

The only things attached are the burners, everything else can be moved.

Got it.  That makes sense.

8 hours ago, Frosty said:

The burner port in the inner wall is larger than the flame so they make an inducer drawing exhaust through the annulus and back into the main chamber.

So in essence, the end of the burner is like the nozzle in a NA burner, pulling air in around it.  Easy with a single burner, hard with any type of ribbon - slower flame, much larger hole.  Especially two ribbon burners.  Once more, ingenious idea (or application).  

I've got the idea now, I like it!  

8 hours ago, Frosty said:

I'm thinking it'd be easy enough to put a coat of Kastolite on the outside and not care about how hot it gets.

Will you be using ceramic fiber inside it, or just a cast wall?  

8 hours ago, Frosty said:

it's nothing but an ad storm anymore. <sigh>

I'm with your there!  I remember taking an education class around '94 and learning how to research the web.  All sorts of cool stuff, mostly from universities.  No ads, only a few commercial sites. Then again, around that time I used to love spending the weekend at the UCLA research library tracking down primary sources for medieval metal technology in those square things some people may remember as being called "books".  That'll be a lost art!  

Dan R

 

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4 hours ago, D.Rotblatt said:

The flame may be leaning down as I turn up the pressure, thus I am actually getting a more neutral flame at ~70% closed.  That would make sense.  With the damper closed down I'm getting 6-8" of yellowish dragons breath at 15 lbs.  I seem to recall reading that the flame mixture in a RA burner changes a bit at different pressures, and the ribbon burner end may cause it to lean up more then normal. 

Right, the higher the pressure the leaner, normal. Any burner that needs the choke closed 70% is screaming to me for a large jet. You have 70% excess air available for combustion why not increase the fuel to match? Yellowish dragon's breath says rich but not being able to see it myself I can't say for sure. All NA burners operate on an induction curve, the flatter the better. Tuned close enough and there isn't enough difference between low and high to need any adjustment. 

 

4 hours ago, D.Rotblatt said:

I've got the idea now, I like it!  

Yes, the burner nozzle is the jet in an inducer that draws exhaust gasses from the flame chamber through the annulus between chamber walls. The patent drawings I looked through made it clear. Multiple outlet burners have, I believe, too low a flame velocity to make it work well if at all.

4 hours ago, D.Rotblatt said:

Will you be using ceramic fiber inside it, or just a cast wall?  

Yes, I think I'll just replace the steel shell with a layer of Kastolite, maybe reinforced with hardware cloth. It'll be a sandwich with rigidized Kaowool the goody in the middle: Kastolite, Kaowool, Kaowool, Kastolite, kiln wash. 

I went online as soon as the net went public and it was heaven. Within hours I'd discovered theforge list and the old Artmetal list by sticking my nose into a discussion between Chris Ray and someone else about treadle hammers. I'd just started. after about two days Chris tld me my emails weren't coming in on either email list then had to explain them to me and helped me join. I found myself surrounded by kindred spirits and more knowledge, experience and ideas than a boy could dream about.

I also learned there were different patent servers that used different search parameters and how to search all 3 at once. Suddenly I had more patent docs about self contained power hammers than I dreamed existed. The earliest control valves were unbelievably simple but to take out a patent you have to have enough difference or improvement to qualify so every year the valves got more complex till now they have half a dozen ports with multiple channels on spool valves to do what the original did with essentially a ball valve.

I can't gripe about people figuring out how to make a living off the net but now it's mostly just infomercials obscuring real info. Now you have to solve maze after maze to answer a question. Brick and mortar libraries are looking better all the time till you find mostly net connections and computers. I hit the library book sales when I see them. 

I love my Kindle arthritis is making my thumb joints hurt but I still love the feel of a book and pages. 

Frosty The Lucky.

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DIY forge / NARB update.

Initial Forge Shell 1

Forge_Shell1.thumb.jpg.4c1a221ec6b2b2b6d24b32dfa941b2f8.jpg

 

Initial Forge Shell 2

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Spraying rigidiser 1

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Spraying rigidiser 2

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Second layer rigidised

Forge_2nd_layer_Rigidised.thumb.jpg.c473e509b4822cc60bf67c83f766efc4.jpg

 

Initial NARB lit to cure Colloidial Silica slurry / Zircopax Hotface.

Forge_HotFace_Curing1.thumb.jpg.a9d24b9536d81f8703bdbcd7b45893b9.jpg

 

Curing Hotface 2

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Curing Hotface 3

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Curing Hotface 4

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Dan's (@D.Rotblatts) Colloidial Silica slurry / Zircopax mix seems to work very well as the Hotface coating.

I've probably mixed too thick a solution of the coating initially, but the Ceramic Wool, the NARB flame face and the Insulating Fire Brick (IFB) took the Hotface
coating well, in fact the IFB & NARB have a near-glazed appearance.

I will be adding some extra layers with some glass bubbles in it at the weekend, as well as a few tweaks to prevent flame leaks around the ends of the IFB. 

I will also be making a raised floor to reduce the working volume for smaller jobs.

Very pleased with it so far.

Tink!

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On 4/30/2019 at 12:14 AM, Frosty said:

Any burner that needs the choke closed 70% is screaming to me for a large jet.

It's a 25 year old Reil burner with a #60 drill hole in the side of a 1/4" pipe...standard old construction.  I think at lower pressures it runs ok, but now I will need to check the most efficient damper placements at different temperatures.  Then I'll have to see how that relates when the same burner has a regular nozzle rather then the ribbon burner.... 

10 hours ago, tinkertim said:

DIY forge / NARB update.

looking truly excellent!  Glad the hot facing is working well.  I'll be interested to see what the glass bubbles do.  Nice idea using the bucket!  

Dan R

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That looks great. You guys here are an inspiration and such a rich source of info. Thanks @tinkertim and @timgunn1962 for all the time and kind advice. I am starting my burner build now after being a bit dissatisfied with the commercial venturi styled ones (not referring to the Amal, not tried that yet, about to incorporate it into a NARB). Ig

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I attempted my first casting. I printed a new core because I wanted to include the outer mold along with it, with a ledge to support the steel frame:

62DC4B54-8EFD-4201-BD14-0DABCA19DEA7.thumb.jpeg.55abc817cfab6c21d1f130410e2c9e33.jpeg

I’m a bit careless and used a heat gun to quickly clean up the stringing that the 3d printed left behind but it softened the core pins and they got a bit wonky. I straightened them as much as possible but couldn’t bear to repeat the 20+ hour print. 

To cast, I used 3 pints of Wayne Coe’s ribbon-burner refractory #2. I started to tamp it between the core pins but then I tried vibrating and it seemed to work perfectly. As soon as I vibrated, the refractory turned liquid and filled the mold with a level top; after about another 30-60 seconds, the little bubbles stopped, so I think it was pretty effective. I used an angle grinder with a small piece of metal drilled offset to create the vibration. 

65483348-23FE-423D-924F-F9F08FA2F7EB.thumb.jpeg.fa0494be654f6e6e68240a04e1a9f4b8.jpeg

I’m still working on getting the forge ready, which I will need to burn out the core. 

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That is very impressive. 

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8 hours ago, Irondragon Forge & Clay said:

Welcome to IFI...I always suggest reading this to get the best out of the forum. READ THIS FIRST

Thanks, done. Making some progress with the build.

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Might want to look at the beginning of the thread for the reasoning for not using a diffuser in the plenum and how I prevent the plenum from breaking away from the outlet block.

Frosty The Lucky.

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I’ve been talking with my aerodynamicist brother about the best way to expand the flow from the mixing tube to the ribbon block to get even pressure distribution at the block. We will see how it works out. 

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Frosty & tinkertim thanks,  I might have missed some info in the beginning... I would be surprised TBH if it works at the first try anyway. I’ll have to drill out the diffuser if it doesn’t work, or worse re-cast, all part of the fun.

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I'm not saying you're wrong I just thought it might save you some time. I put diffusers in my first couple test burners but found mounting the inducers 90* did a better job. 

John Emerling's original ribbon burners has a reputation of the outlet block and the plenum breaking where they met. So I added a little reinforcing that spread the difference in COE rates.

Other than those little things I discovered multiple outlet burners are surprisingly agreeable to working well in wildly different configurations and constructions. 

Tagging people is not considered good Iforge etiquette and it does some oddness thing in the OS. Just names please. No sweat, it's part of the ever changing learning curve of the OS.

Frosty The Lucky.

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Great, thanks Frosty. The burner is working  and I am on a high... Can anyone tell me what high temp thread sealant I should use close to the burner please (UK)? Grateful, Ig

 

345B12A5-A4EB-4203-A337-BD8CBCCF7A24.jpeg

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I was about to get my forge working with my single burner (is that a "jet burner"?) and use it to burn out the PLA core for my ribbon burner:

2044368472_ribbon-burnerblockfired.thumb.jpg.4d9da17973b6011fb9ac9f5f7aa0ebbe.jpg

I think it came out pretty clean; I'll update as I make a plenum to feed it.

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i like this concept of a ribbon burner butt i'm wondering if one could use the burner to make a foundry burner? i have this idea in my head for a forge for dual use. a foundry that you can tip over and would become a forge. anyone familiair with the concept or is it just a mad idea? i'm just thinking i could be a good concept as u would have 1 forge instead of 2 bulky forges that would take a lot of valuable space. and if it cuts back on noise and gas usage it would be very nice indeed. or is this just ramblings of a mad man :) 

this i just a rough crappy sketch

IMG_20190507_081523.jpg

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20 hours ago, ilknives said:

Can anyone tell me what high temp thread sealant I should use close to the burner please

NO thread sealants on the burner! Gas rated paste type on the fuel lines but nothing on the burner that includes the jet threads, if it leaks a little who cares it's IN the burner and will just burn.

1 hour ago, ADHD-forge said:

could use the burner to make a foundry burner?

Sure you CAN but a foundry needs a different fire than a forge. If you use a ribbon burner in a foundry too much heat will be directed at the top of the crucible. Directing the flame around the bottom of the crucible means it MUST travel up the sides in a strong vortex. This keeps the flame in the melter longest to transfer the max heat to the crucible.

Laying a melter on it's side will direct the flame in a strong vortex in the back end of the "forge". Sure it will get to the front in a strong vortex but the hottest zone will be farthest away from the doorway.

Frosty The Lucky.

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I finally managed to build a plenum for my ribbon nozzle and fire it up for the first time. The results were encouraging. I posted the details in my forge thread; I won't repeat here, but I'm happy to discuss here or there. I appreciate any thoughts you may have. 

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