Built my own burner....need help tuning

[savageironwerx]

So burner starts as second image.  Nice roaring blue flame but then turns to image one especially if I try to fire up more burners.

.030 welding tip as orifice going down to a .023 made no difference.

If I increase gas pressure or open the needle valve more the flame "pops" and runs up inside the burner.

Any suggestions?  Anyone around Calgary or Hanna?

[savageironwerx]

Burner outside of forge

[Irondragon Forge ClayWorks]

Welcome from the Ozark mountains. I'm concerned about what looks like un-coated ceramic wool in your forge. It should be rigidized and a castable refractory coated. It is a safety factor and we are strong on safety. Might take a look at this thread.

https://www.iforgeiron.com/topic/53239-ceramic-wool-insulation-safety-alert/

If you post better pictures of your burner I'm sure the burner guys can help with tuning it. Who's directions did you follow when building it?

[Frosty]

Welcome aboard savageironworks, glad to have you. If you put your general location in the header you'll have a better chance of meeting up with members living within visiting distance and many questions / answers have a strong location component. 

The first issue I see with your forge has already been mentioned, it really is a serious safety issue. Your burner is running VERY rich, right now it's unsafe to run in an enclosure even if it's well ventilated.

We need more information to be able to provide meaningful help. Who's plans did you use? A picture of the entire burner, in through the air intake if possible and a list of the parts and sizes you used, we'll get it performing for you. Hopefully that won't mean a do-over but it happens.

You might want to do some reading in Forges 101, there are literally thousands of posts discussing the whats, hows and whys of building effective forges and bare ceramic blanket is in the red flag don't do that category.

Frosty The Lucky.

 

[Mikey98118]

You're right that you need help with that burner. Irondragon is right that we need photos of the burner to know what needs changing.

[savageironwerx]

To address the safety concerns, the Kaowool was rigidized and coated with 2 layers of ITC100HT.  I do hope that's enough if not please let me know and I'll put more refractory medium in there.  The exception to that being the door that was rigidized only.

Burner tube is 10" pipe is 3/4 upper is 1.5 to 3/4 cross over 

Edited December 4, 2022 by Mod30
Remove @name tag

[Mikey98118]

Your reducer is too small, and this deficiency is aggravated by a mixing tube that is to long. The easiest fix is to reduce the diameter of the burner's mixing tube. But first, cut the new pipe nipple to nine times the the replacement pipe's inside diameter, and be sure to include a internal bevel on its threaded end. Also grind an internal bevel on thread reducer, that you'll need, between the smaller pipe and the original pipe reducer.

Next, lift out your cross pipe, and tap a 1/4-27 threaded hole were you drilled have a hole for a gas orifice, and screw a Tapered 1-1/2" long MIG contact tip for .023" welding wire into it.

[Mikey98118]

Lest you should get discouraged by our comments, I should like to point out that your forge, even with a weak burner is reaching orange heat; a very good sign

[Irondragon Forge ClayWorks]

If you read through this thread, it will explain better than I can about refractories. I just know that ITC 100 HT is not suitable in a propane forge.

 

[Frosty]

Tagging people with the  @  symbol causes this operating software problems, it's not social media it's a forum. If you wish to address someone specifically just use their log on name or nick name. I'm just talking to you because there's almost no chance of me talking to someone else. Yes? Same for quotes lot's of Iforge members live in countries without broad band connections and they're paying data charges on dial up connections. We try to save them as much bandwidth as possible. Don't sweat it, you aren't in trouble even if you get a note from a moderator, it's just part of the learning curve. 

Please don't take this wrong but you've made some fundamental errors and parts will probably need to be replaced completely. 

Ah, there's Mike. Yes, 8 or 9 x the mixing tube ID, splitting the difference between the two says the tube should be 6" long. Any flare you wish to use doesn't effect this length unless you get silly carried away.

Making that change alone will improve performance. However there is another serious mistake, the diameter of the propane supply pipe that has the jet drilled in it is WAY too large, it's blocking a significant portion of combustion air. If you choose to supply the gas in this way find the smallest diameter pipe you can. That coupled with a bell reducer that as Mike has said is significantly too small. Is this what you refer to as the "1.5 - 3/4 cross over"?  I'm not familiar with that term. A 3/4" x 2" "bell reducer" is a proven effective fitting for the air intake. 

Mike and I are going to diverge some here I highly recommend changing the propane final supply pipe with as I said above to the smallest you can find, drill and tap. I also favor a size larger mig contact tip that doesn't extend so deeply into the burner. Moving the tip of the gas jet farther from the mixing tube increases how much combustion air the propane stream induces. Being as it draws more air for the same volume of propane you can either use lower PSI or a larger diameter mig tip jet. 

There are up and down sides to how I do it. It requires the maker to balance fuel and air during the build which can get a little finicky if you haven't done it before. The upsides, yes two, are, 1 A larger mig tip needs less PSI and still provides more "neutral" fuel air mix per second burning in the forge. #2 the flame exiting the burner is traveling at a lower velocity so it stays IN the forge longer, transferring energy to the forge walls to be radiated as infra-red on your stock to do work for you. 

Back to the downside, balancing the higher volume of propane and air means a little trial and error. Remember the farther back the end of the mig tip is from the mixing tube the more the gas stream induces. A new mig tip typically is too deep in the forge so it needs to be shortened a LITTLE at a time. Light the burner, evaluate the flame and if necessary trim it again until you've sneaked up of a neutral flame. In this process trim it a little less each time so you don't pass the right length. 

I've probably rambled on more than is helpful. I do that. Don't let me or anybody discourage you, you're on your way we'll help get you there.

Frosty The Lucky.

[savageironwerx]

Gents, the help both forge and forum wise is greatly appreciated as I am learning at both.

Hitting the welding and plumbing store tomorrow to get some parts.

[Latticino]

Also: 

1. Burner mixing tube is mounted too far into your forge.  Edge of mixer should be in the insulation layer, not in the forge cavity.  Dark circle on the floor of your forge indicates that too much of the flame is hitting the floor, and moving it back will help the flame develop more fully (and save you mixing tube from scaling away).  Ideally the cast refractory inner shell protects the end of the burner and provides an integral flare.
2. Burner orientation is not optimal.  It is best to promote a swirl of flame along the wall by entering at a tangent to the inner wall rather than perpendicular.
3. Make sure on your updated build that the gas supply tube doesn't obstruct the air inlet as much as currently (if you increase the reducer size that will likely help.
4. Alignment of the gas orifice is critical.  It should be centered and in parallel with the mixing tube for max effect.
5. Appreciate your polite response to assistance.  Goes a long way to getting additional help.  

[savageironwerx]

Latticino,

Thank you for the added tips.

Specifically with regards to point 2.  Should the flame hit the wall or the intersection of the wall and floor?  I have a bunch of room to change the angle of the burner in relation to the forge body.

MM

All,

Is it worth taking the time to grind out the threads on the bell reducer (heading to buy a new ones) or just leave it well enough alone?

[Latticino]

[Frosty]

I've tried turning the threads out of a bell reducer and noticed no difference in burner performance. Not that there wasn't a change, it just wasn't noticeable. At that time I was judging by how fast it brought the forge to temperature and what color it finally hit. That was my first propane forge and it had 3/4" thick hard refractory flame face backed by 1" of Kaowool so it took quite a bit of time and fuel to heat up. 

Please do NOT take the description of my first forge as a good way to build one, with a little tweaking yours will be far FAR better. I only bring it up to describe how and what with I judged my old burner's effectiveness. I measured efficiency by how long a 20lb. tank lasted feeding the forge from start to empty tank. 

Have you looked at the T burner build instructions here?  https://www.iforgeiron.com/topic/43976-t-burner-illustrated-directions/

You don't need a lathe my last update to the build instructions is near the end of the thread. I use a floor flange and close nipple clamped on my drill press table to drill and tap the T and fittings. 

The T burner is NOT the most effective burner, there are many better ones. What it is, is a reasonably effective burner that requires minimal shop equipment and skills. I developed it so guys could make a fire without having to spend a bunch of money find a machine shop or spend a lot of time. If you decide to make a T burner, PLEASE use these directions and ask me any questions. I honestly regret having my name attached to so many utterly incompetent how to videos online. Most of those clowns don't have a clue about ho burners work but can slop something together that sort of works. Of course I designed the thing to be easy to build but. . .<sigh>

Frosty The Lucky.

[savageironwerx]

In reading a little of Mike's book and the comments here I get the impression that the burner is basically a propane carburator with the bell reducer providing a stable air mass for the burner to draw from, similar to an airbox.

I have a reasonable amount of tools but apparently just enough knowledge to literally be dangerous.....It would have been cheaper to pick something off Amazon but I would not have learned anywhere near as much 

Thank you again all.

[Mikey98118]

5 minutes ago, savageironwerx said:

with the bell reducer providing a stable air mass for the burner to draw from, similar to an airbox.

Some people might assume that the reducer is some kind of air scoop; this is wrong; it is a funnel shape, and its main function is to create swirl in the incoming air. The rotating air current is sped up all the way through the reducer, providing much better mixing of the fuel gas and oxidizer. This isn't the only thing this shape in an air opening does, but it is the main thing.

[Frosty]

If you mean it in a very general way carburetor is an okay analogy just don't let it fool you into trying carburetor tricks on a linear or jet ejector induction device.

Hey, if we didn't like doing dangerous things we'd all be collecting stamps instead of playing with fire and hitting HOT things with hammers. 

You have the skills, you just didn't know quite how to apply them, try it again I'll bet you get it soonest.

Mike made a good observation that was too easy to take for granted, a forge and burner aren't two separate things, they are a machine that needs to be designed and built to work together like one. THEN you start getting effective and efficient.

We'll be around to lend a hand if you need it. 

Frosty The Lucky.

[Latticino]

31 minutes ago, Mikey98118 said:

its main function is to create swirl in the incoming air

Mike,

Respectfully disagree.  I see it's main function to allow acceleration of the relatively static environmental air up to closer to the velocity of the gas exiting the orifice for efficient induction and mixed flow.  Any swirl or turbulence after this mixing resulting from the shape of the air inlet is a benefit, but the induction function is the critical one IMHO. 

[Mikey98118]

I think you disagreed quite respectfully

As to your viewpoint, I have no intentions of nay-saying it. I suspect that we may be in the position of "blind men describing the elephant." Furthermore, you just said something very smart. Rather than saying "no, no, no; it's half a dozen," I'm going to suck every advantage I can from your viewpoint. Every little glint of light has potential in burner design

 

[savageironwerx]

Well xxxx if that isn't 1000x better .  Gents thank you so very much for all of the help.  Forge roars and gets yellow in minutes you all are awesome.

Edited December 21, 2022 by Mod30
Language

[Mikey98118]

Oh, dang; it "gets yellow in minutes." Well, this one got away looooong before we could drag him down to the deep end of the people's pool

[savageironwerx]

Mikey, I am just starting out on this adventure and have tons to learn.  Thank you for your help thus far 

[Mikey98118]

Oh, good! There is still a chance to get you so into this stuff that you get too excited to sleep. I am a determined sleep thief 

Yes, its a dirty job, but somebody's gotta do it (and I love the work)