Flared Ribbon Burner Ports?

[Peppie]

Was reading a post from 2016 last nite. A member here related to a ribbon burner manufacture mentioned a flare at the end of each burner port . Seems easy enough to do...But he also mentioned that the length of the port and the depth and diam of the flare was important.  He did not offer any numbers. Maybe a trade secret??

Would there be a big difference in burner performance?  Or am I just splitting hairs as a hobbiest? 

Peppie

[Peppie]

No one has gone down this path?

I just bought 60 Bic ink pens. The cap to these is about 1/32 larger in diameter of the pens body. Wonder how deep the pen lid should be set into the burner?  1/8" ? 1/4" ?

[wpearson]

look at pine ridge burners

[D.Rotblatt]

A flared nozzle slows the speed of the gas so the flame stays on or in the end of the nozzle rather then blowing off, but also this makes the flame closer to, if not inside the end of the nozzle.  My thinking is that this is the opposite of what we want in a ribbon burner.  The main issue in the ribbon burner is the face gets too hot and the flame can then backburn at low pressures into the plenum.  We want the burner block to be cooled by the gasses flowing through the block, not heated by having a flame burn inside the block.  If one was to try to experiment with a change in the nozzle shapes, I think trying the opposite of a flare, a constriction at the end of the nozzle to speed up the gas and push the flame a little away from the block.  Bottom line, what is good for a single burner in open air, may not be good a ribbon burner in a forge.

Dan R

[jwmelvin]

Based on Dan R’s comment to an earlier post where I showed a mold core with flared outlets, I redesigned with straight 3 mm outlets for the nozzle I just cast. I haven’t tried it yet but will report once I do. 

[D.Rotblatt]

On 5/6/2019 at 4:17 AM, jwmelvin said:

but will report once I do

I'll be interested to see.  My comments are a hypothesis at this point, the one data point I have is that I tried to flare the nozzles a bit on a ribbon burner to get it to burn better out of the forge, and it did, but seemed to have poorer characteristics at low pressures in the forge (easier backfire)...but I didn't take down notes or anything, just casual observation.

Dan R

[jwmelvin]

On 5/12/2019 at 1:34 AM, D.Rotblatt said:

I'll be interested to see.  My comments are a hypothesis at this point, the one data point I have is that I tried to flare the nozzles a bit on a ribbon burner to get it to burn better out of the forge, and it did, but seemed to have poorer characteristics at low pressures in the forge (easier backfire)...but I didn't take down notes or anything, just casual observation.

I fired up my ribbon nozzle for the first time last night. The small outlets seem to work well for low pressures, so I'm glad I didn't flare them. It wouldn't burn in free air (blew the flame out) but did once installed in the forge. I put all the details in my thread.

[MCalvert]

On 5/6/2019 at 12:53 AM, D.Rotblatt said:

.  If one was to try to experiment with a change in the nozzle shapes, I think trying the opposite of a flare, a constriction at the end of the nozzle to speed up the gas and push the flame a little away from the block.  Bottom line, what is good for a single burner in open air, may not be good a ribbon burner in a forge.

Dan R

I am currently doing this, and I am hopeful it will improve low pressure performance.

[D.Rotblatt]

1 hour ago, MCalvert said:

I am currently doing this, and I am hopeful it will improve low pressure performance

It will be interesting to see!  I'm looking forward to your results.

Dan R

[jwmelvin]

Do you intend to improve backfiring? Or heating of the block? I’m wondering what advantage constructed outlets have over smaller-diameter straight outlets. 

[MCalvert]

Backfiring elimination (maybe/hopefully) via velocity increase 

[jwmelvin]

I can understand that motivation. My thought is that smaller outlets overall have a chance of getting down to the quench diameter, which would protect against backfiring through a separate mechanism. 

[D.Rotblatt]

On 5/20/2019 at 6:37 AM, jwmelvin said:

My thought is that smaller outlets overall have a chance of getting down to the quench diameter, which would protect against backfiring through a separate mechanism.

That has worked well on my 1/8"x122 nozzle burner.  No backfire, down to 0 pressure (after over an hour of forge welding at 2400F+).  0 pressure is a flame so low it won't pull oxygen into the tube, just propane.  Quench diameter is around .11" for propane, so .125 seems to work.

On the other hand, a larger nozzle with restricted end may allow for less friction, more cooling, or other advantages (or disadvantages) that we don't foresee.  I think it's definitely worth a try!

Dan R

[Old Crew]

Dan and Frosty

Your experimentations have set me on a path, the harder but more rewarding path.

Yesterday I built 2 Frosty T Burners  Today with 1 of those I test fired my 112 x 1/8" flared orfice NARB which I also built today.

It is nor cast  I drilled a 2800F brick 

Here is the drill bit I used.  It was not long enough to drill through the 2-1/2 " brick with a clean 1/8 " hole but the shoulder had a taper. I drilled the brick and the pushed the taper into the brick which compressed and flared the top 1/4 inch. 

Here a couple pictures of it burning

This at about 5psi

another at 5 psi

[Old Crew]

Here is a picture after several minutes of run with the tapered portion of the office incandescent this is at 2 psi

When I shut it off there was a very small back fire.

 

I haven't built the forge(any forge-ever)  yet but will continue playing with it tomorrow . I have a bunch of old AP Green fire brick so  I will try it out on a brick pile set up to see how it does. 

The fire brick is set into the plenum and has kaowool packed around it for testing. the tapered orfice is facing the hot side. Do you think that It would be of any benefit to flip the brick over so the taper to face the plenum. Maybe accelerate the gas flow?

Regard less I am stoked by my results!!!

Bear in mind that I have never forged anything and am greener than a Leprechaun's balls! as regards forging

[D.Rotblatt]

Good start!  And good use of some AP Green bricks, I have a lot of those!  

On 5/24/2019 at 6:31 PM, Old Crew said:

Do you think that It would be of any benefit to flip the brick over so the taper to face the plenum.

WTH - flip the brick and see if there is any difference.  You have nothing to loose, I doubt it will accelerate the gas much, but you will be able to see the difference between taper and no taper.

It appears in the last pic that the flames are inside the tapers, which I think is not an advantage since it will heat the block more.  The problem with backfiring that people have with the regular ribbon burners is after about an hour of running the face gets hot and allows the flame face to burn back into the plenum.  In this case, the smaller holes should prevent this, so we are on virgin ground here.  You won't know how it acts until it is in a forge and has run an hour or so.

On 5/24/2019 at 6:31 PM, Old Crew said:

I will try it out on a brick pile set up to see how it does. 

Absolutely!  All these burners work differently inside a forge then they do outside.  

It's hard to see what the individual flames cones really look like because the pics are so small.  Very promising start though.  

Dan R

[Old Crew]

On 5/27/2019 at 2:57 AM, D.Rotblatt said:

Good start!  And good use of some AP Green bricks, I have a lot of those!  

WTH - flip the brick and see if there is any difference.  You have nothing to loose, I doubt it will accelerate the gas much, but you will be able to see the difference between taper and no taper.

It appears in the last pic that the flames are inside the tapers, which I think is not an advantage since it will heat the block more.  The problem with backfiring that people have with the regular ribbon burners is after about an hour of running the face gets hot and allows the flame face to burn back into the plenum.  In this case, the smaller holes should prevent this, so we are on virgin ground here.  You won't know how it acts until it is in a forge and has run an hour or so.

Absolutely!  All these burners work differently inside a forge then they do outside.  

It's hard to see what the individual flames cones really look like because the pics are so small.  Very promising start though.  

Dan R

Dan

Here are 2 of the same pictures in larger format . You are correct about the flame being inside the taper.

I built a rudimentary brick pile forge and was successful in reaching bright orange with an old bull pin (1-1/4 headed pin with a taper about 7" long) which i proceeded to beat on with glee!

The burner created a loud howl/harmonic hum while the forge was coming up to temperature when it reached temp the noise stopped. I ran it for over an hour mostly at 10 psi and It never burned back into the plenum. I ran it down as low as the gauge would read and then up at several increments to almost 30psi when I reached there the flame went out and even though the burner face was incandescent it would not self re-ignite. The burner assembly was simply resting on top of the brick pile with bricks pushed up to it. The burner housing / plenum was cool to the touch after turning the gas off,  so I made the mistake of removing the burner. The face was still incandescent , I set it down on its back and soon heard a small pop. I believe the burner was thermally shocked from being removed from the forge. So i put it back in the forge. Several hours later when it had cooled i removed it and it had a small crack across one of the lines of holes.

I believe that the 1/8 holes  work like  you said and keep the fuel from burning back.

[Old Crew]

The first brick pile was with the AP Green brick and it took a long time to get up to temperature. So I stacked it up again with the few K2800 bricks that I bought and it was much better.

Even with the partial crack in my burner block I was able to remove it from the plenum turn it over so the taper side faced the plenum and re-pack into the plenum with kaowool.

When I light it outside of the brick pile the flames were not as stable with the straight sided 1/8 holes as it was with the taper on the burner face. Maybe the 1 to 12 taper ratio that Frosty mentioned in one of his posts?   I am to inexperienced to know. I reinstalled the burner in brick pile version 2.0 and fired it up. It again had the odd harmonic noise but only for a minute or so before burning quietly. This was much faster than with the taper facing the burner side.

I don't think i have the t-burner tuned quite right yet, but up to now I have just been tinkering not testing. I probably need to do some more research before i move to testing.

I believe with a little more work the Drilled NARB  might be a viable burner.

It may just need to be perfected by one of the masters

David

[Old Crew]

       

 I ran it for over an hour and it was very stable I don't think it is  burning as hot as it should though. The interior volume is about 240 cubic inches. Very slight pop at turn off. This was at 15 psi. I believe I need to play with the tip length in the t-burner

David

[D.Rotblatt]

8 hours ago, Old Crew said:

The burner created a loud howl/harmonic hum

I get that on mine, the musical forge.  The best description was like blowing over the mouth of a bottle.  Lasts for a couple of minutes until it gets up to heat.  If I damp down the burner intake to create a reducing flame it stops.  

7 hours ago, Old Crew said:

the flames were not as stable with the straight sided 1/8 holes as it was with the taper

This is exactly what I'd expect, as the taper slows the gas speed and brings the flame closer to or into the nozzle.  Inside the forge you don't need as stable a flame, and once the burner face heats up the flames are more stable anyway.  I think with a ribbon burner they are all right less stable because if one would blow out, the one next to it relights it, and I like the face of the burner to stay cooler (that's relative since it will still be red hot).

6 hours ago, Old Crew said:

The interior volume is about 240 cubic inches. Very slight pop at turn off. This was at 15 psi.

Mine is on a 200 cu in forge, and I weld at about 12-15 lbs.  All the bricks you make the forge from should be insulating fire bricks, the light ones, not the heavy ones.  I'm guessing your ap green bricks are the heavy bricks and the K2800 are light insulating bricks?  Either way, it obviously works!  Cant tell the temps from pictures, but looks good from here!

Flames look OK, but I'd see what Mikey or Frosty say on that.  You should be getting a little dragons breath from the forge mouth.  Always hard to tell at first cause of stuff burning off the new bricks or burner.

I'm a big proponent of results, and yours works!  The only question now is how the brick will hold up to repeated thermal cycles.  Those IFB tend to degrade quickly.

 

Dan R

 

[Old Crew]

Dan

I ran the brick narb in the brick pile for about 1.5 hrs today with the same burner adjustments as in previous trials. In my first run with only AP Green bricks in the pile it didnt heat very fast, so I shut it down after about 30 min let it cool and rebuilt with the k2800 at the flame faces. I then ran it with the taper part of the hole at the flame face for over an hour at different PSI. It got hot but not as hot as i felt it should. After I shut it down i pulled the burner at which point it developed the partial crack.

Today I flipped the burner brick over and ran it  for about 1.5 hours it ran better and hotter with the straight part of the hole on the hot side.  After it cooled I inspected it, the crack didn't spread and there is no degradation to the flame face on either side. I believe that if the burner is allowed to gradually cool  and that if it is locked in place into the burner plenum with castable that it might be long lasting. I will be drilling a new block and casting it into the plenum next. I am also going to do a run test on the current burner, let it burn for many hrs and see how it holds up even with the crack.

As i have said I am a novice. In the last picture with the steel  at a bright orange/yellow at the end I am able to work the steel  (to my limited abilities). Is it hot enough to forge weld ?

With the burner faced taper side in it didn't get this hot, the k2800 brick on the floor didn't get discolored from the steel.  This time it was hot enough that those bricks had some brown discoloration    on them from the steel.

As for the IFB breaking down I had thought about trying to coat the flame face with ITC 100 or one of the home brewed coatings. Plug the holes with something which has been greased lightly and paint it . Any thoughts on coating your burner face , be it cast NARB or drilled NARB ?      Any one tried it?

David

[D.Rotblatt]

On 5/27/2019 at 6:27 PM, Old Crew said:

coat the flame face with ITC 100 or one of the home brewed coatings. 

I did that on my cast one, because why not?  I use a home brew with zirconium flour and colloidal silica. I talk about it here on this forum page 44 or so:

 I coat all ceramic wool and an IFB brick I use as the floor. It seems to protect the floor from cracking and so far from a little flux (I try not to use it in the forge but sometimes....). It does glue and bond the cracks in the brick, and it is a thin coating so it won’t clog the holes. It may be a good solution for your burner face. 

A pint of colloids silica is around $15 shipped, zircopax (zircon flour) is about the same. Mix just enough to use, about a quarter cup. Start with powder, add liquid a capful at a time until you get a latex paint mixture. Butter brick face(wet it with spray bottle) and paint on layer. Blow out holes if necessary. Cure with propane torch till red (no need to let dry). Repeat to maybe 3 layers. Mix slurry often as zircon settles quickly and cakes. 

On 5/27/2019 at 6:27 PM, Old Crew said:

Is it hot enough to forge weld ?

No way to tell colors with photos. Put a little flux (20 mile team borax from market) on it. In forge it is welding heat when it is bubbling vigorously. Flux will melt IFB so the floor should be protected by a removable kiln shelf. 

On 5/27/2019 at 6:27 PM, Old Crew said:

With the burner faced taper side in it didn't get this hot,

That’s what I hoped would happen. Interesting to see the hypothesis seems to be correct...at least one data point. 

Dan R

[tinkertim]

Dan's Colloidal Silica / Zircopax slurry has worked well on my Drilled-IFB NARB hotface, as well as on the Ceramic blanket on the walls, and IFB on the floor.

 

Definitely hot enough to weld I think!

 

Tink!

[D.Rotblatt]

Think, that’s looking really nice!

Dan R

[Old Crew]

Tink

I agree it looks good and it looks hot.

if I recall your set up is blown. That is the direction i was planning on going at first. After I read and re-read Frostys Narb thread with all its helpful Info from him and others . I decided to try  and go all natural no blower. I will coat the flame face of the next Drilled  Narb and see how it holds up and how hot it is. I have all my supplies to build my forge now and know how I want to build it (small and sensible) Unfortunately I will be out of town most of the next 2 weeks so I can't play.

Congratulations on your build and your Tinkering

David