Jump to content
I Forge Iron

Burners 101


Mikey98118

Recommended Posts

  • Replies 3.6k
  • Created
  • Last Reply

Top Posters In This Topic

Okay, this time I got the homepage and the ad was right there. So, what do I make of it? If it were an attempt at building a Mikey burner I would be unimpressed; but he stated that It was designed to be as good a burner as possible for a price tag of $50; figuring that in, I consider the design ingenious. He used my design where it made sense, and only departed from it where it also made sense. I'm impressed :) 

Link to comment
Share on other sites

Tapers new and old

My first burners used cold hammered stainless steel flame retention nozzles, which I formed over a pipe (held in a vice), to Increase the nozzle diameter about 1/8" over a length of 1-1/2" length; that produced roughly the recommended taper on burners in those bygone days. Then I found out that Larry Zoeller Forge was selling those same slide-over taper nozzles for about ten bucks, and never bothered to make another tapered nozzle. This old formula worked well on most burner designs of the day; I have a suspicion that a "T" burner would be enhanced with a little more taper).

One of the other guys on IFI came up with the turn "slide-over"; it's an elegant description, because the ability to change the amount of overhang a flame retention nozzle has (past the end of the burner's mixing tube) is as important as anything else about its design; something that screwed on pipe fitting nozzles simply can't provide.

I needed something stronger than a taper nozzle for Mikey burners because their gas/air mixture flow speed was much too fast for those tapered nozzles to work properly. I also wanted a design that people constructing their first burner could make easily and surely. And so the stepped slide-over nozzle came to be.

These two designs seemed to cover the range of burner slow speeds well enough for many years. However, in the last couple of years, tapered nozzles of more radical designs have come into the marketplace. I think of them as trumpet shaped, because they have a much greater diameter formed in a much shorter length, Trumpet nozzles seem to work well enough on high speed burner designs, but less than perfectly. However I viewed a flame photo of a nozzle with as wide a taper diameter, but with double the distance, creating a perfect flame on a high speed burner design. So how would a newbie make one? Well, if you buy one of these inexpensive trumpet-horn  nozzles online, heat up one end, insert a drift pin in it, and give a sharp hammer blow, I'm thinking you'd have the right taper on you new flame retention nozzle...

Link to comment
Share on other sites

changing subject just slightly, I made a 1/2" T burner , details on request, that had a severe lifting flame . I had a 1/2" coupling on the end. after removing the threads from the inside It decided to light. I cut a 10° taper on the inside of the coupling and once again it would not stay lit. Obviously I do not understand everything I know about this but I had thought a drop in pressure at the end would improve my lifting flame problem. Any comments? 

Link to comment
Share on other sites

Sounds like a question for Frosty; did you ask it on his "T" burner thread? I welcome mentions of new and different burners, including "T" burners in smaller sizes, but I think you will get much better answers talking to the burner's designer, and I don't think it is quite fair to be asking him to answer questions here that he could be answering there.

Link to comment
Share on other sites

Lifting flames

When describing his burner problem, one guy wrote " I am getting a lifting blue flame, which of course, will not stay lit." First, let us rejoice in a nifty new descriptive turn for a common form of unstable flame :)

"Lifting flames" are also the easiest problem to fix; it is caused by a faster flow speed of gas/air mixture than the flame's combustion speed can keep up with. The most common fix is to increase the amount of overhang in (a slide-over flame retention nozzle) passed the end of the burner's mixing tube. With a screw on nozzle it becomes necessary to slow down the burner's flow speed; usually by increasing the gas jet's orifice diameter a few thousandths of an inch.

Off center flames

Flames that are tilting off to one side, instead of running axially true to the burner, are the second most common form for lifting flames; how far they have to tilt before blowing out depends on how fast the burner's flow speed is. Sometimes the problem is a flame retention nozzle that is tilted out of alignment with the mixing tube's axis; this is a common problem with threaded parts. It is unlikely that the mixing tubes thread will be wrong. It is quite common for the reducer fittings thread to be tilted.

Less obvious is a canted flame do to a gas jet that simply isn't centered in the mixing tube, or is properly positioned but is itself tilted out of alignment with the mixing tube's axis.

Mangled flames

This is the least likely problem and the easiest to fix; it is do to an obstruction in the mixture's flow path. first look for a burr inside of, or on, the end of the gas jet orifice. Hold the mixing tube up to a light source and look down its barrel to inspect for internal obstructions, Make sure that any thread end is filed smooth from any burr or narrowing from the pipe cutter.

 

Link to comment
Share on other sites

Answering T burner questions in this thread is fine with me, it's on my follow list like a number of others so I get email notices of posts. I read all the posts here.

I messed with machining tapers for T burners but stopped as it didn't work any better than a thread protector. 12* is the number, rather than 10*. a T will support a larger taper ratio than most linears and I haven't messed with a Mikey so can't say. 

Did you machine the taper while it was attached to the tube? I machined the taper into the end of the taper for good measure. I even tried just cutting the threads out of a thread protector to no good purpose.

The threads actually seem to improve performance, I believe the flow over them causes a barrier layer, reducing friction, increasing speed and lowering pressure. When I was still using my lathe to make the things I was tempted to cut rope threads the full length of the tube to see if my thoughts were right. If you're wondering search "rope thread, drill tool, rods." Images will draw the picture. Basically they're smooth rounded threads like you'd wrapped rope around a rod.

I never did it though, I had all the burners I needed and stopped playing with improved performance. I switched my target to easy to make with minimum tooling and shop experience. Hence the drill press + floor flange construction method.  

I've only gave tuning advise to a couple guys who made 1/2" burners, I've never made one. Guys are having good luck with 0.023" mig contact tip jets. I like the lock screw method of mounting them but it's generally 2 additional steps and needs higher shop skills so it doesn't really fit the model.

I never discourage tinkering though, I keep learning cool stuff from you guys.

Frosty The Lucky.

Link to comment
Share on other sites

4 hours ago, Frosty said:

The threads actually seem to improve performance, I believe the flow over them causes a barrier layer, reducing friction, increasing speed and lowering pressure.

A barrier layer seems to make since to me.

Glad you feel that way about taking the time to write technical explanations about "T" burners here, since I love getting technical :D

There are no tapers involved in Mikey burners because all swirling of the air gas mixture is created from the air making a right angle turn as it enters the mixing tube from air entrances cut into the tube's wall. I suspect that a similar swirling motion is created by opposing air flows meeting at the center of a Tee pipe fitting. A linear burner features a cone or pipe reducer to engender swirl through vortical movement I believe creation of a stronger vortex is why a larger reducer will create a faster flame from a burner; not because it "gathers more air". The Hybrid burner design uses a combination of side air entrances and a reducer to create a very strong air swirl, and other advantages of vortical flow. Mikey burners simply improved the shape of the air entrances to increase swirl to the point that the reducer wasn't needed. BUT, the reducer is what gives vortical flow; side air entrances can't do so.

Link to comment
Share on other sites

If you like the "lifting flame " thing feel free to use it . HVAC term for a flame that floats and is unstable, generally caused by lack of combustion air.

I thought we could discuss the burner tip and the effect it had on the burner I don't see why that would be a great difference between one burner and another, am I wrong? And the removing the threads does not seem to fit your model and more surprisingly the taper did not improve things but , in fact made it decidedly worse. I must admit, the whole thing is a bit confusing. 

I have a couple more questions  on this subject and your comments but I will carry them over to Frostys thread

Link to comment
Share on other sites

We're talking about it here Howling dog, no need to change threads in the middle of a conversation.

Mike: you know your experience with rectangular air intakes compared to round ones has led me to wonder about making a T burner with square or rectangular tubing, I collected a bunch a few years ago and it's just . .  there calling to me.

I thought we were talking about the outlet flare, I was. I don't think reducers of either kind have a place in NA burners, intake or outlet. That they work on linear burners as well as they do is testimony to how easy it is to get linear amplifiers to work reasonably well. 

I don't know how well a bell reducer generates a vortex on the intake end, their shape is poor. Toilet bowls are designed to create a vortex when flushed but bell reducers are designed to maintain a fairly linear flow in a line. An induction device is a different device of course but if we want to induce a strong vortex it needs to be a different shape. It needs to be a trumpet bell shape like the old type linear burners. 

Howling Dog: There are many different types of induction devices, only two are used for naturally aspirated burners. The linear like you see on the forges on Forged In Fire is one general type. You see them under your gas stove feeding multiple outlet burners. The other type is the "Jet ejector." they weren't developed for burners they're generally used commercially for generating vacuum. They make nice home built burners because they're so efficient our slop detunes them enough to make good fire.

 I find it's easy to tune a T burner so it runs a hair rich at any psi in it's range without a flare or especially a choke. 

In general a flare is to increase induction by reducing pressure on the exhaust end of the burner tube. Basically a limited volume of fuel air mix has to fill a larger volume causing a pressure and velocity drop. Flares may act as "flame holders" but that isn't their purpose, they're there to increase performance and stability. 

I put thread protectors on the T burners I build so they're easy to mount and as disposable nozzles. That they improve performance means I have to tune the burner differently to keep it right. I make flanges to weld on the thread protector so the burners stand on end in my too large shop forge. I weld thread protectors into the inlet port on the NARB so I can just screw the T inducer on. There are pics of this in the NARB LIVES thread.

I discovered machining couplers in different ways didn't improve things over plain internal tapered pipe threads of the protector. Pipe couplers cost something like $7.00+ each here but thread protectors can be had for nothing by the bucketfull at real plumbing supplies. Forget big box stores, you need a real plumbing or HVAC supply. I'm lucky I have a good one just up the road and they like me. :)

Being a likable bull shooter is like a super power if you play it right. ;)

"Lifting flame" is now part of my vocabulary, thank you. It shouldn't be long and it'll be part of most everybody's It's beautifully descriptive.

Frosty The Lucky.

Link to comment
Share on other sites

Lifting Fame is "beautifully descriptive" and is now part of my vocabulary too; it is nice to now its an "official" description, but it would have gone viral on this group regardless; it's just too handy not to :)

55 minutes ago, Frosty said:

Mike: you know your experience with rectangular air intakes compared to round ones has led me to wonder about making a T burner with square or rectangular tubing, I collected a bunch a few years ago and it's just . .  there calling to me.

Well, that is about reducing drag made by a fluid passing over a rounded edge; how a square passage. like in a 1" square tube would affect a fluid passing along it isn't down to me. I do know of a commercial forge builder who featured burners constructed of square tubing; he claimed they were superior, but never provided a flame photo... 

 

1 hour ago, Frosty said:

thought we were talking about the outlet flare, I was. I don't think reducers of either kind have a place in NA burners, intake or outlet. That they work on linear burners as well as they do is testimony to how easy it is to get linear amplifiers to work reasonably well. 

Since I recently started working with linear burners again, I have noticed that they are far more forgiving and easy to get along with than jet-ejectors. For years I took it as an article of faith that they just weren't as powerful as jet-ejectors, but I begin to wonder if their problem all along has been that they are too forgiving, thus allowing people to settle for building "just good enough" burners, instead of pushing for darn good burners. It was said back in the sixties that the big difference between an old Ford and an old Chrysler was that the Ford would run without much tuning but the Chrysler had to be tuned just right to run; so old Chryslers ran like tops, and old Fords--not so much. 

Link to comment
Share on other sites

  • 1 month later...

I just answered a question on flame nozzles for a guy who plans to mount three of Frosty's "T" burners in a Majestic forge.

"You don't need a flame retention nozzle to get a stable flame in forges; they do improve the flame, but in "T" burners least of all, because this burner series makes softer flames, which are therefore shorter then most other burners put out. In other words, you would be "gilding the Lilly" to invest the effort; just don't go there."

I am a fan of "T" burners in box forges because they make hot flames that are also much softer than other burner designs. When placed in the top of box forges and facing down, soft flames tend to be shorter than hard flames, which is especially important in that forge design.

A ribbon burner will do the job even better.

Link to comment
Share on other sites

On ‎9‎/‎14‎/‎2018 at 10:34 PM, Frosty said:

I don't know how well a bell reducer generates a vortex on the intake end, their shape is poor. Toilet bowls are designed to create a vortex when flushed but bell reducers are designed to maintain a fairly linear flow in a line. An induction device is a different device of course but if we want to induce a strong vortex it needs to be a different shape. It needs to be a trumpet bell shape like the old type linear burners. 

That would be like the air intake shapes used on Ransom burners? Giberson offers them on his Joppa Glass website, but he also offers burner intakes that are bowl shaped. For me the jury is out. I am still considering what  makes the best possible intake shape on a linear burner, and have been for more than five years so far.

Giberson Burner heads

Back in 1999 I ran across "A Glassblower's Companion" by Dudley F. Giberson Jr, the inventor of a multi-flame  refractory burner head  clear back in the seventies. If you you ribbon burner fans want to know the answers to what kind of hole configurations are practical on what kind of of burner, and on how small a piece of heating equipment, you can find it on his Joppa glass website in the small burner head section. You can also find lots of technical information there too. Giberson is into hot glass work, so just substitute "forge" in your mind for "small glory hole."

Gentle hint; he uses his heads on both fan-blown and naturally aspirated burners.

Link to comment
Share on other sites

Please note that I am NOT suggesting that anyone buy his ceramic heads for work in a forge, without first asking him if he can recommend them for use in equipment with rapid heating and cooling cycles. Glass working uses slow heating and cooling cycles, so the refractory in his multi-flame heads might not stand up well in a forge. But his site has abundant free technical information which ribbon burner fans can use to pioneer with :)

Link to comment
Share on other sites

I located a good example on the Ward burner page, first burner by Ransom manufacturing. Yes, that's the trumpet shape intake I'm referring to.  Until we started trying to make the things so we could afford a burner that shape intake was about all that was on the market. 

The Joppa Glass and other sites is where I gleaned information for making the NARB. If a person is interested in building burners, single or multi orifice it's an excellent place to research.

Frosty The Lucky.

Link to comment
Share on other sites

  • 2 weeks later...

A storm in a teapot

One of the several ways of describing flames is as non-contained ongoing, minor explosions; an ongoing series of explosions that are occurring so rapidly that the sound of each explosion is shared by the sound of the next, and so on.

This is true of both soft laminar, and hard turbulent flames. Oxy-fuel flames can be laminar or turbulent,  just as air-fuel flames are. Furthermore, these two flame types don't constitute an either/or choice; there is a whole range of flames between one kind and the other. The "T" burner puts out a very soft turbulent flame, while a Mikey burner puts out a very hard turbulent flame; one flame isn't superior to the other; they both have their uses, which intersect nicely. But understanding their differences can fine tune your burner choices to best serve in your forge.

Speaking of tuning, we often come down to a crises of belief--not in fact. When finishing up the construction of a high speed tube burner, commonly dubbed a Mikey burner, some pretty wild symptoms can occur, including backfiring, which can be caused by the smallest leak between the burner's gas tube and gas jet; it can more rarely occur from having too small an orifice size in the MIG tip chosen; or it can occur from a combination of the two. An off-center flame, which is a mere annoyance in a slower burner can become so destabilized in a high speed burner that it blows out.

These things should be understood as symptoms pointing out the path to perfect performance; not problems. If you find yourself at this stage, know that what you are seeing is an embarrassment of riches to be sorted out; not a crisis to be endured!

On the other hand, it is is common to find someone building a smooth running burner, sans problems, which unfortunately simply won't get hot enough to do the job...

It doesn't take much of that to change your whole outlook about high speed burner 'problems' does it?

Link to comment
Share on other sites

Welcome to IFI DirtyDusty... have you read this yet? It will help you get the best out of the forum. https://www.iforgeiron.com/topic/53873-read-this-first/

I don't think there is a free PDF for the book. I've been looking for one a long time and found like you the only one's I've found are on suspicious sites I'm not willing to open.

Link to comment
Share on other sites

Hi Mikey: I' am new here and just getting into forging. I built a gas forge this summer and have been practicing forge welding. Even made an attempt at damascus. I wonder if you can help with a problem with my forge. It is a duel burner, and for some reason after I light the front burner and turn up the valve, it's like its blowing itself out. There's no more blue flame. I try to adjust the air inlet with no luck. I seem to have good pressure but maybe too much. I put a .30 mig tip in but it doesn't help either.The back burner works better for some reason. The two burners are exactly the same. My hose line is one into two.  I 'd like to read your book on this subject if I can find it. Thanks in advance.

Grinder

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...