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Naturally Aspirated Ribbon Burner. Photo heavy.


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On 7/26/2019 at 11:02 PM, Howling dog forge said:

Any thoughts on pulverizing the castable to make it flow into the form easier?? Any thoughts on using something else??

Just used some Mizzou for a burner head.  Because the aggregate makes it very very difficult to put between the sprues, I sifted it out with a screen.  A little of the aggregate went through.  I did the first layer without aggregate, and then added a little to the rest except the last layer.  I mixed small amounts at a time.  I'll let you know how it holds up.

The aggregate in Mizzou is really hard stuff - maybe ceramic or firebrick or a hard high temp stone.  Either way, morter and pestle didn't do squat, metal tube with a 1" steel bar did some, but had to do so little at a time it wasn't worth it,  finally relied on pounding some with a hammer to pulverize it - but it flew all over.  Pain in the rear!  I ended up with a bit of smaller stuff, which I used in small amounts.  

I thought of using some other material which is smaller.  I have several grades of fused silica for ceramic shell, but I didn't want to add something that might be a lower temperature melting point.  Also tried breaking up a IFB, but it mainly powdered, and I wanted small bits of aggregate rather then the larger ones in the Mizzou, so that was a bust too.  I'll have to test the fused silica and see if it slumps at high heat.  

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DanR

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ARGHHH! I remember Howling dog's question now I just forgot to answer. My bad, sorry.

I sifted the aggregate out to get the refractory to flow between the crayons more easily. 

A pretty good replacement reinforcement might be Kaowool fibers. OR crush Kastolite 30 after it sets but before it's cured to full hardness and sieve it through the screen. Without the larger aggregate gradation the mix is more of a grout than a refractory "concrete." (Any new guys reading this do NOT mistake "refractory concrete" for any type of Portland cement mixture!) Concrete refers to aggregate that has been cemented together to form a contiguous mass. The asphalt macadam on your road is technically asphalt bound concrete. People will just look at you funny if you call it that though.

My first burner block got Kastolite as it comes and I had to rod it down between the crayons. It was a PITA but has stood up well. My second block got sifted Kastolite and I was able to vibrate it into the mold by LIGHTLY tapping the sides of the mold with a hammer. I made double sure there were no voids by rodding between the crayons with an old butter knife.

It's held up nicely as well, I have one small crack in the first block but it hasn't spread or caused a problem.

Frosty The Lucky.

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8 minutes ago, Frosty said:

OR crush Kastolite 30

Is kastolite 30 similar to greenlite 30?  Either way, I’ll try it next time I do this. Hopefully my burner will set fine and I won’t have to redo. Took about an hour to put all those sprues in place.

DanR

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I don't know though IIRC I used greenlite (90?) on an earlier set of forge mistakes but I'm not very sure. 

On further thought about a suitable but crushable aggregate we can produce I was thinking of high temper ceramics than Kaowool. I wonder how friable ceramic crucibles and muffle furnace dishes and cups are. Ash correction cups took high yellow heat in the muffle furnaces at the lab though they vitrified and slumped when the furnace was maxed. Not part of the tests but it happened.

I'm in awe at your burners, I can hardly imagine setting all those sprue waxes but it's darned tempting. 

I'm thinking my next burners will get much of the aggregate replaced with zircopax. Maybe order a pound of coarse grain and one of flour for flame face wash. 

Frosty The Lucky.

 

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9 hours ago, Frosty said:

much of the aggregate replaced with zircopax. Maybe order a pound of coarse grain

Where do you find coarse grained zircopax?  It's generally used as a glaze opacifier, so I've only seen it as a flour.  Took a quick look again, but no love from google :(  

Thank you Frosty!  Very kind.  I was able to get the mizzou between the sprues, just took patience.  I sifted out the aggregate, smashed some of it up, and then added the smaller pieces back in in smaller amounts.  Just mix it a cup at a time, sprinkle it in little bits over the sprues and push it down then mix some more.  That way I was not sweating that it was all setting up.  Next time the first layer will have no aggregate.  Maybe it took an hour to cast the refractory in place, another hour to place all the sprues.  Curious George is using 1/8" cocktail straws - they may work better since they are stiffer.  He'll let us know I'm sure!

Since a 3/4" burner works for 124 holes, I'm thinking making an adapter and putting on a 1" or 1.25" burner as an injector on this one as an injector.  The advantage of he forced air injector is I can turn it really low (if the fan will do that), while the NA injectors stall out a 1/2 lb or so (they just don't pull any air anymore and the flame goes to all propane).  

DanR

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Seattle Ceramics (or Pottery) Supply is where Tristan bought it. There were different grades available but it's been better than a year. Mikey should know the name of the place, it's his area. 

I lent Tristan a small rock tumbler that may work for crushing up aggregate sifted out of commercial hard refractories. I just never remember to pick it up if I'm in Anch when he's home. 

I may have to try cocktail straws next time. Regular plastic straws tended to collapse if I didn't fill them with sand so I went back to crayons.

Frosty The Lucky. 

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  • 1 month later...

Dan or others, You guys have a guess at what the ideal spacing should be between holes?   If I’m doing 1/8th” holes, should they be separated with a 1/4” of material between them?   Worried that if it gets to less than that, it’ll become weak without enough structure.  What spacing are you using?   Factory burners are way tighter, but obviously they use finer material and much more refined processes.

 

 

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When I arranged my outlets I placed them in as even a pattern as would fill the mold with space for good bonding contact for the plenum. If I had a kiln I might experiment with high temp ceramics as densely packed as a commercial multi outlet burners but when I look at the asking price for used kilns and power bills. . . 

I'm good with large outlets in a NA burner.  Sorry Mike, I'm no help here, I'd have to start building and experimenting to be any.

Frosty The Lucky.

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On 10/28/2019 at 3:16 PM, Whiskeymike said:

it looks like his spacing might be 3/16 or so

Pretty close.  Looks like .1675, but 3/16 is fine.  Making them close together is really an issue of getting th refractory in between the sprues.  I had lots of problems with the sprues bending.  One person making them used steel rods dipped in crisco - said they pulled out easily and stayed straight.  I'd suggest you try that.  i'm actually considering trying one that uses smaller then 1/8" holes.  We'll see when the muse hits...want to play with some actual pounding of hot steel now!

BTW: NA or Forced air?

DanR

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On 10/31/2019 at 4:09 PM, D.Rotblatt said:

Pretty close.  Looks like .1675, but 3/16 is fine.  

BTW: NA or Forced air?

DanR

Yea, I’m going to go with Tig rod and see how it goes.  I’m going with NA.  If I end up having problems, I figure I can add a blower and cap the other side of the T.

Do you have a theory of why smaller holes are better?  In looking at the pro ribbon burners, they seem to have very small holes, but all require blowers.  Concerns that we may get to a point of having to much back pressure for the NARB.    I did some quick napkin calculations and at 1/8”, I’m already reducing hole flow area from the 1” pipe by 50%.  I’d have to get them much closer together or go much wider to approach a similar area.

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4 hours ago, Whiskeymike said:

I did some quick napkin calculations and at 1/8”, I’m already reducing hole flow area from the 1” pipe by 50%.  I’d have to get them much closer together or go much wider to approach a similar area.

Odd...my figures show the opposite.  How many holes are you planning to use?  My burner head with 122 holes @.125" gives an area of 1.5" (.012 x 122), while a 1" burner pipe gives an area of .79".  That's almost double the area of a 1" burner.  Now, I'm using a 3/4" burner not a 1" burner, so its more like triple.  The 122 holes worked well for any of my 3/4" burners.  If you are going to use a 1" then you might need more holes.

If you are using a 1" burner, try the Frosty test: Take a block of wood and drill 125 or so 1/8" holes in it, then tape it to the plenum and see how it works.  You get about 15-30 seconds before it starts to burn.  Keep adding holes until the flame looks good - ignore yellow flames, that's burning wood, but you can see the flame shape and whether it holds to the burner or not.  It's an open air test, so it will work better in the forge, but it will give you an idea of how it'll work, and it's pretty easy to do if you have a drill press.

DanR

4 hours ago, Whiskeymike said:

Do you have a theory of why smaller holes are better?  In looking at the pro ribbon burners, they seem to have very small holes,

Look on page 22 of this thread for discussion on the theory.  JWMelvin refers to an article about hole size and prevention of flame propagation that is interesting.

Pro ribbon burners are the reason I tried the small holes.  There was backfiring issue on the crayon sized burners when they heat up for a few hours - you have to turn the gas pressure up to keep it from happening.  It seemed to me that many pro burners have small holes, and everybody seemed to be using the crayons just because that's what originally worked.  My 1/8" is working like a champ, good even heat, low consumption, no backfire even at pressures too low for the gauge.

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Hi Dan.  First time on ifi in a long time.  So I just converted my home built slot forge to blown ribbon and now I'm looking to change over my portable.  It currently uses a single zoeller type propane  3/4" n.a. burner.  In your opinion would this burner convert to run a ribbon head?  

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Welcome back J. glad to see you again. A 3/4" T powers NARB nicely though it has crayon dia. outlets. I have no doubt one of Larry's will work a treat, +/- a crayon size outlet. I can't say about one of Dan's 1/8" dia. outlet burners I haven't played with them myself.

Frosty The Lucky.

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Dan, 
I've been re-reading this thread to find some more exact dimensions on your setup in hopes of recreating them using my 3/4 Frosty T burner.  I actually found some dimensions in a different thread.  My apologies if you already detailed these but again, I did my best to search (including going post by post).

In one thread, you provided dimensions for your plenum as  2.5" x 8".  Is 2.5" both the width and height?
You just previously posted that your holes are 1/8 (.125) and about .1675 (say 3/16) apart (good timing, thank you).
Do your holes begin about 1/2" from the edge of the plenum (so a 1/2" border of no holes)?
How thick is your refractory burner head? (I know there is discussion of going thinner)
How deep did you submerge your plenum into the refractory mold?

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10 hours ago, J.Gonzalez said:

In your opinion would this burner convert to run a ribbon head?

Refer to Frosty on this, he worked out how to make a NARB (THANKS FROSTY).  I took his burner and changed it by making more and smaller holes.  If you are using 1/8" holes, I find that kind of head is very forgiving on the type of burner that runs it.  I've put in a Reil, a Mikey, an experimental hybrid, and my new cast burner and they all work just as well from the point of the burner head.

44 minutes ago, MattP said:

n one thread, you provided dimensions for your plenum as  2.5" x 8".  Is 2.5" both the width and height?
You just previously posted that your holes are 1/8 (.125) and about .1675 (say 3/16) apart (good timing, thank you).
Do your holes begin about 1/2" from the edge of the plenum (so a 1/2" border of no holes)?
How thick is your refractory burner head? (I know there is discussion of going thinner)
How deep did you submerge your plenum into the refractory mold?

The basic construction is just as Wayne Coe outlined.  Same form made out of 1x2, etc.  

***I don't think the dimensions matter so much.  It can be wider and shorter, or a bit longer.  That's the beauty of the ribbon burner!  But as to the one I built here's the specs and pics.

The plenum is a piece of 2" x 2.5" tubing.  It's about 6" long.  There are 124 holes (I think, you can count them if you want B)).  

The refractory block is 1.5" thick, since I used 1x2 for the form.  On the plenum, when you cut out the side that the refractory is on, leave an edge of about 1/8" so it will lock into the refractory.  The plenum is sunk into the refractory around 1/4" - 1/2" - hard to tell when you are doing it.  Don't know about making it thinner or thicker, this is what I did, and it worked.

As you can see from the picture, the holes have a 1/2" border.  So the area with holes is about 1" x 5".  

The burner is set up into the ceramic fiber about 1/4+".  There's a pic below.

The forge itself is very small, maybe 225 cu inches.  I added a layer of ceramic fiber and changed the shape of the original forge to a kind of truncated triangle shape with the floor 5" wide.  Since the burner has such small holes, the flames are only about 1" long, it's not like a 3/4" burner that the flame hits the floor. It would easily power a larger forge, but being small, its really efficient.  I'm forging at 4 lbs (with .040 jet), when I used to forge at 7 lbs.

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General pics:

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Multi port head comes out of mold.  I used 1/8" aluminum tig rod scraps dipped in grease.  Worked better than I expected.  90 odd holes.  If the n.a. burner head won't run it I'll try widening a few holes.  

Thanks for the input frosty and dan.

20191105_090901.jpg

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Thank you very  much for your thorough explanation Dan.  Coincidental timing that J built one using TIG rod - I plan to do the same soon but using ER70S-2 rather than aluminum.  Just need to determine the dimensions, and first finalize what I want to use as the shell for my forge.

Edit: Also curious to See J's setup running in a forge.  if 90 works well, that saves me 30 holes plus allows for additional spacing.

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1 hour ago, MattP said:

if 90 works well, that saves me 30 holes plus allows for additional spacing.

You're welcome Matt.  It was a two-for!  When I went down to take pics, I realized I had a knife tempering in the oven...oopppps!  It got a good 5 hour temper! 

I went with 124 holes because it was a more stable flame out of the forge.  Wasn't able to try it in the forge, so we'll see how J's works with 90.  It might solve the magical organ tone at startup!  

Anything you can dig up works for a shell.  From bending sheet metal into a tube, I made a road find of a stainless stove chimney which became my new forge, party helium tanks are great, stop by a HVAC shop (auto or home) and see if you can snag some of their empty disposable tanks.  Anything around 9" in diameter.  Doesn't have to be thick.

DanR

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Just tried the burner out in an old forge shell.  Extremely stable flame at least for the 15 minutes of run time my near dead empty 20 pounder afforded. I will go pull the spare off the camper later and post pictures or a short video. 

Flame was a little reducing which I suppose could be addressed by modifying the reil type burner's air intake size.  

The flame was perfectly stable and very quiet over a wide range as well.  

I wish I had the time to change out my production slot forge from blown to n.a.  

Thanks again for sharing your discoveries.

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On 11/3/2019 at 2:05 AM, D.Rotblatt said:

Odd...my figures show the opposite. 

DanR

Look on page 22 of this thread for discussion on the theory.  JWMelvin refers to an article about hole size and prevention of flame propagation that is interesting

My bad.  I had laid out the pattern with fusion 360 and had halved the number of holes I’ll actually run.  Thanks for the spot check.  Looks like I should be good.

 

I’ll check out the thread.  Thanks.

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