burnner

[TJ Smith]

MY forge burner is a simple 8 inch piece of 1.25 black pipe. It is blown with a 65 cf fan. I don't have a nipple or small hole drilled anywhere for propane to enter. My burner is reduced in size from 2 inch to 1.25 inch and gas enters just before reduction. I have a gate valve to adjust air flow.

My forge will get to 2350 degrees.

 Why all the nipples and special flares? Do you really need them.

TJ Smith

[Charlotte]

If it works for you  and you are happy with your forge then good.!    However a lot of people use the nipples etc.  because they are using the "induction" of pressurized gas escaping from a small hole to pull ambient air into and mix with the propane with out the fan.  

I actually use a hybrid system that allows me to switch from one to the other , forced air or induction, depending on the heat that I want.  I change a couple of fitting and can force air or go induction when I want to keep temp at med orange/yellow 

[Charles R. Stevens]

No moving parts, no electrical outeges...

[Mikey98118]

Many people run induction burners in forges and casting furnaces without a flame nozzle; I've done so myself just to prove it works. So why go to all the work of building, or the expense of buying, a flame nozzle? Well, why buy a Ferrari when an old farm truck is cheaper? The answer in both cases is performance. Although a flame nozzle isn't necessary to get an induction burner to work in some heating equipment, the burner will work much better with than without one. BTW, this is also true of flan-blown burners, as anyone operating a glass-blowing furnace (day tank, glory hole, etc) could tell you. Look up more information on the kind of flame nozzles commonly used for fan-blown burners at Ward burner systems, and many other sites used by people running large burner systems for hot glass work and for large pottery kilns. But, when your hair curls at the prices quoted, just remember that you can still build and install your own stainless steel flame nozzle for a LOT less money :-)

[Frosty]

The idea of putting a flare on home made burners came about when Ron Reil and I were messing with the things. We hadn't figured out how to send pictures so all our communications were via text. A coffee shop buddy of mine had dumped a brief case size stack of literature on inducers on me. He was always searching for application patent material so he was always noodling through interesting stuff and giving me piles of interesting stuff.

Anyway there were a good dozen different inducers from what you see in weed burners, linear inducers, ejectors and amplifiers. Ron liked the linear, I like ejectors and Mr. Dyson likes amplifiers. Anywho during the conversation I told Ron the tube should be tapered but no more than 1:12 or it'd cause bad turbulence. Well, Ron either misunderstood me or knew a lot more than I did and he just put a flared end on his burner.

I started to tell him he'd screwed up but darned thing worked a treat, that was about the time we learned to attach pics and I got a look at his burners running. He refined his till he could use it as a torch outside the forge. I have an oxy propane torch so don't have an interest in running my FORGE burners outside the forge.

I messed around with flares a bit and discovered just slapping a thread protector on the end worked just fine and the threads induced a LITTLE "bad" turbulence and really improved mixing.

Some day I'd like to get a spinning lathe set up and take a lash at spinning a burner with a full length taper. Commercial burners and induction devices have full length tapers, search out "Fisher Burner" for a visual. It's the real difference between home builds and the real deal and you'd better believe it makes a difference. HUGE difference.

Frosty The Lucky.

[Mikey98118]

Frosty,

Fisher burners are the modern equivalent of old cast iron "wasp waist" burners; to me they are way out of date tech. But, you and I seem to be coming from opposite ends of the spectrum for what we want out of a burner flame. You appear to want a soft quiet slightly reducing flame well suited to forge welding. I want a fast hard flame with total primary combustion and zero CO output. I care much more about clean burning forges than scale formation. This is because, after 45 years of welding I am the canary in the mine shaft :-) It's kind of a case of apples and oranges. I'm actually glad for the difference. If we perfectly agreed, what could we possibly teach one another? I'm learning a lot from you; don't know if you're learning much from me, but I'm happy with the deal.

Should we discuss gas jets again? I have a new trick...

[TJ Smith]

i like to run a reducing flame on my forge to reduce scale.

I wouldn't call it soft or quiet. My forge sounds like a jet engine with flames coming out of both the back and front 3-4 inches.

After a few minutes of running I can get welding heat with 4 lbs of pressure. I don't think flares or mig tips are going to improve on that.

Enjoy the discussion

Take care TJ Smith

 

.

 

[Frosty]

I've always learned things talking to you Mike. I think our biggest difference is how perfect we want the things, Ron and I have the same differences. I'm not much in the search for perfection, I look for safe and good enough for tools. I tend to just mess up perfect things.

The burners in my shop forge are loud enough to hear driving up the driveway 100'+ away and my forge is in the shop. Soft is for oven enameling not my forge. Slightly reducing is the other accurate discriptor. Do you have a burner that will melt 3,000f+ hard firebrick? It's just one of 4 in the forge and a golden bullet but it melts the floor. Get a little flux on the floor and it makes an enlarging puddle.

I mentioned the Fisher burner as an easily found and understood of a full length tapered induction device it's certainly not current, heck it's gotta be at least 80 years since it was current. Still, it's a perfect example of how a full length taper makes a much more robust flame at a lower final velocity.

That's desirable because it doesn't blow so much heat out of the furnace. It's also desirable because the increased induction allows larger jets and puts more fuel:air in the furnace. More heat in the contact zone and less blown out the doors. There's a darned good reason full length tapers are industry standard.

One of these days I'll get a spinning lathe up and we'll see how "perfect" I can get the things.

Jets, Yes, jets are good what you got for me?

Frosty The Lucky.

[Mikey98118]

Frosty,

Alas, it's too late for a rousing debate between us, because of my own ambivalent feelings. I've run full circle, and just as I come up with a wonderful new burner, find this inconvenient reasonableness greatly increasing my respect for the other guy's viewpoint. It takes a lot of the joy out of my present book plans. But, on the other hand, should do a lot to improve the book that these Vortex burners have interrupted, once I can get back to it. You will remember that my very first burner change was installation of MIG tips on old Aussie style burners; it is still included in Ron's burner pages. But, straight tube flame nozzles with spacer rings wasn't. When the MIG tips are combined with larger reducer fittings they jump mixture feed up enough to allow the straight nozzles to work on these old burners, producing a performance leap in a simple to construct burner. But, due to circumstances beyond my control, I never got to point that out at the time. And, in any case, older burner designs have their own advantages.

Blunt tip stainless steel Luer-lock dispensing needles come in both plastic hubs (unsafe) and metal hubs (recommended); they can be found in many orifice sizes from McMaster-Carr, eBay, and many other sources. These needles come in perfect orifice sizes for maximum flame performance on any burner. You cannot order by gauge size, because inside diameters of the same gauge can vary several thousandths of an inch depending on wall thickness, so you must look for I.D. listings. Dispensing tips are also available through eBay, and Amazon.com. Luer-lock dispensing needles mount on nickel plated brass or stainless steel male adapters (plugs) that are combined with various connector fittings in both threaded and barbed ends.

By varying length and orifice sizes on the needles I have been able to eliminate the need for 3" and 4" long gas tubes on burners up to 3/8" pipe equivalent size (included in a publisher's update of the original book), and expect to continue this happy practice with all the burner sizes, as time permits more experiments.

[Mikey98118]

Your point about not blowing the heat right out of the forge is well made, and I believe that is what ribbon burners are all about. Still, it will be interesting to see your results.

[Mikey98118]

So, speaking of employing other kinds of burners, I collected a bunch of lab burners to try rebuilding into something a little heartier than low pressure gas heaters for chemistry tubes. It turns out that the first wasp-waist burners were used this way; they can be had on the cheap used through eBay. If you want to rebuild one to use higher pressure propane

[Frosty]

I had to look them up. What's the advantage of Luer-lock dispensing needles over mig contact tips? I see a larger variety in ID but do folk really build such a wide range of burner sizes?

How are you mounting them in the burner? Are fittings between the Leur locks and standard pipe/hose fittings available? (called "subs" by drillers) I find it very simple and easy to tap a 1/8" pipe x 1/4" flare fitting 1/4-28 to accept mig tips. From there it's just 1/4" copper tubing to the ball valve at the reg or manifold. A lot of guys sub from 1/8" pipe to 1/4" pipe and connect directly to the hose.

Below is my main shop forge in it's 3rd incarnation. The pic's only reason here is to show how bad a place it is for rubber supply hose. The manifold and hose fitting is above the jack on the right. I've only had all 4 burners running at the same time to test and on a couple occasions when there were 4 of us using it. the new forge is much MUCH smaller.

Frosty The Lucky.

 

7 hours ago, Mikey98118 said:

Your point about not blowing the heat right out of the forge is well made, and I believe that is what ribbon burners are all about. Still, it will be interesting to see your results.

I was going to mess with a naturally aspirated chip forge but decided I had better things to do and you run into a similar situation with a ribbon though it's a lot more possible. You just need to continuously increase the cross sectional area as you move out the burner so if you put enough crayon size nozzles in the ribbon it should work fine.

Even so a gun is so much easier I don't think I'm going to mess with developing a NA ribbon let alone a chip forge.

The tapered tube is industry standard for induction devices of all kinds. Look under the hood of your gas range in the kitchen or if you get the chance one of the vacuum trucks used to clean storm drains. Both use jet ejector induction devices, one to mix methane and air in the proper ratio regardless of primary pressure, the other develops enough vacuum at high volume to suck boulders out of storm drains from 30' down. The one in the range operates on pressures you need a manometer to measure, the one in the Aquatech uses 30cfm. @ 130 psig. The same darned device though, different size and a little different shape but the same thing.

The tapered tube not to exceed 12:1 ratio increases induction and reduces exhaust velocity. I've got the papers that explain this somewhere in the basement but . . . <sigh>

Frosty The Lucky.

[Mikey98118]

Frosty,

That's a lot of questions at once, but the answer to most of them is simple :-)

I left the gas burner book with 1/2" burners as the smallest size because MIG contact tips only go down to 0.031" orifices as the minimum. The ideal orifice for a gas accelerator on a 1/2" pipe burner would be 0.028".  While 0.031" orifices are barely serviceable, less than the best possible performance is aggravating to me (as you pointed out). So, I recommended employing torch tips for miniature burners, and listened to a lot of criticism about their prices.

The only practical answer for constructing smaller burners was to employ capillary tubing. Back in 2004 heavy wall gauge tube and other sources of capillary tube were cheap and easy to obtain, but in following years their sources dried up quite a lot. So, the search for easy sources continued. The point of Luer-lock dispensing needles is that they are an industrial standard supply for dispensing solder, glue, etc.; thus, their continued supply is as assured in the marketplace as anything.

You can find brass and stainless steel Luer-lock adapters with many common thread sizes on their attached connector fittings , along with barbed ends for direct  connection to gas hose, you can find both 1/8" and 1/4" pipe  thread. One of the available thread sizes is 10-32, so they can easily be threaded into existing bases, like those found on lab burners, with a little drilling and re-threading: http://www.mcmaster.com/#luer-fittings/=zy9a6c  Scroll down to the bottom of the page.

Which brings us to, why 3/8" and 1/4" burners anyway? 3/8" burners will run two-gallon forges and casting furnaces. How well? A 3/8" Mikey burner will turn two-thirds of the enterior on a two-gallon forge yellow-white hot without producing exit flames from its exhaust openings, or two of them running at half power will heat the complete enterior white hot if you want to work on a sword. At a casting party my buddy Dan Brewer borrowed my two-gallon casting furnace, stuffed a #8 crucible in it, and brought a load of brass to  pouring temperature from a cold start in fifteen minutes flat; the burner that powered it was 3/8".  A 1/4" burner will heat a bowl shaped chip forge for silver brazing large parts on air-propane. And of course both sizes are great to use for hand torches.

But, in all this we see my bias towards more and ever more concentrated power. Perhaps a rebuilt Meeker burner with a Luer-lock gas accelerator used to power a coffee-can sized knife forge could be equally impressive in a much quieter way...

[Mikey98118]

 if you would like to discuss the forge more, I think it would be fascinating for many of us. After all, brick forges are configurable, and I don't know of any other forge that can do that trick.

[Mikey98118]

Also, a 1/4" burner is the perfect size for powering a coffee-can casting furnace or knife forge. But so would a rebuilt Meeker burner, and a one pound propane canister would probably run it for up to half an hour for off-site demos. There is a lot of metal work done by jewelers and others who heat materials for many purposes.

[Mikey98118]

Frosty,

All that information and I didn't directly answer your questions. Yes, different burner sizes are that important to people working other aspects of the metal hobbies. But, the main thing about Luer-lock dispensing needles is that between the gauge sizes available and the changes in orifice diameters because of wall thickness an exact match between gas accelerator and burner can be made. This will allow the long gas tubes to be deleted from jet ejector burners. I like compactness in  a burner.  

[Frosty]

No problem Mike I got it, I have a bit of a leg up on most you know. I didn't reply to some of your points either. I run 0.023" mig contact tips in 1/2" burners though I don't know if they make smaller. ).023" is really common size anymore.

Still, next time I'm near McMaster Carr I'll check out the Luer-lock needles. As it stands if someone wants to make a forge smaller than a bean can forge I recommend a Bernzomatic torch.

I don't see the significance of long vs. short jet tubes other than to tune my version burner. I have to fess up, I've never read your book so if I ask really basic questions about your method . . . there it is.

The T works I wasn't going to "fix" it. I'll just go sit in my corner now.

Frosty The Lucky.

[Buzzkill]

I'm still having trouble with the idea that water vapor is a major player here. The oxidation of hydrogen to produce H2O gives off more heat than it absorbs or hydrogen wouldn't work as a fuel.  When water vapor condenses to a liquid it also gives off heat. What I'm trying to wrap my head around is the role that the water vapor plays in the decreased heat output.

You mentioned before that only about 20% of methane is consumed in the primary flame, with most of the remaining 80% being consumed in the secondary flame. What occurred to me is that perhaps a comparison would be along the lines of using a hundred butane cigarette lighters compared to one torch using the same amount of the same fuel.  The same total heat output is obtained (assuming complete combustion of all fuel in both cases), but the lighters won't reach anywhere near the high temperature of the torch.

Either way it seems that low pressure natural gas in a blown burner is suitable for producing temperatures needed for forging, glass blowing, etc. Is there something significantly different about the combustion between a NA burner and a blown burner using methane or is it simply a matter of burning more fuel in the same amount of time with forced air than you can with a NA burner?

[Frosty]

I enjoy and learn a lot reading discussions here but often we have our heads stuck in what we "know" rather than what is. Most of the questions asked so far can be covered easily with a simple web search. I Yahoo'd "Fuel gas comparison chart." The better hit would've been to search "Fuel comparison chart". Sometimes specificity isn't helpful. this is what I think is the first good hit. https://www.propanecarbs.com/propane.html

Looking at other charts you'll see ALL natural gasses, (yes Propane is a natural gas) vary considerably depending on a lot of factors the most significant seeming to be: place of origin and refinery.

Frosty The Lucky.

[Buzzkill]

Frosty,

As I said before, I'm not challenging the information that Mikey provided as far as his conclusion goes.  I have done several searches and have not seen anything conclusive on a couple issues:

1) The cooling effect of water vapor formation with methane compared to propane in NA burners, and

2) Reasons why a NA burner using "high pressure" methane cannot reach forging temperatures.

Since both propane and methane produce water vapor when burned I'm curious as to why the combustion of methane is more susceptible to any issues with water vapor than propane.  A blown low pressure methane burner can achieve forging temps, so is this just a case of burning more fuel in a shorter time to hit those temps or is there some other reason. 

Mikey seems to have a handle on these issues, and so far I haven't found a better source to explain these things in terms I can understand.

[Charlotte]

You need to read physical chem books and Organic chem books and you will understand.  Just because you think things are the same they are not. The interaction of fuels Oxygen and Nitrogen in a furnace are complex and not straight forward.  Just think about this carbon carbon bonds produce more heat when broken and combined with Oxygen than Oxygen combining with hydrogen after breaking the carbon hydrogen bond.  The actual process is hugely complex at the molecular level and not everything we know about it well understood despite the calculations we know how to do. One of the nasty things that water vapor does <aka Steam> is combine with iron molecules to produce black oxide iron oxide and hydrogen  which then combines with atmospheric oxygen.   In days to Steam power  some terrible explosions were tied to the production of hydrogen from the contact of steam with red hot Iron.  The reaction of steam and Iron is one of the reasons it is hard for a gas forge to produce the nice slick looking forge work that is so easy to produce with out thought in a solid fuel forge.

[Charlotte]

 

Frosty, I've had good success drilling iron hardware store nails with number drills and silver soldering them into open copper  or stainless steel tubing.

[Frosty]

1 hour ago, Charlotte said:

 

Frosty, I've had good success drilling iron hardware store nails with number drills and silver soldering them into open copper  or stainless steel tubing.

Are you talking about making jets? I started using mig tips so I wouldn't have to make jets, it eliminates levels of complexity from the devices.

Of course I may have missed your point, I wouldn't be surprised.

Frosty The Lucky.

[Buzzkill]

Charlotte, I appreciate that it's not super simple, but I don't think digging out my old organic and p-chem books is going to explain why there would be a significant difference in the effect of water vapor produced by methane compared to water vapor produced by propane using a NA burner in a forge. That's a very specific set of circumstances.

All of the other things you mention should be present regardless of which of those 2 fuels is burned.  There is water vapor produced by burning both.  There is heat produced by burning both. There is carbon dioxide (possibly some carbon monoxide) produced by both. There is red hot or hotter iron present in both.  There is nitrogen present in both. There is no carbon-carbon bond to break in methane.  That could account for some of the reduced heat production, but it still doesn't answer the question of the more significant role of water vapor when burning methane compared to propane. All the other variables are the same.  The only difference is the starting fuel.  Both of the fuels we are discussing are in the same family.  I understand that at the atomic and molecular levels it's a many step process to go from the starting fuel to the exhaust gases rather than just a simple combination immediately producing the end products, but again it's the same for both of those fuels with the exception of the carbon-carbon bond that is present in propane and not in methane.

Why does the water vapor produced by burning methane cool the flame and/or the forge more than the water vapor produced by burning propane if both are using naturally aspirated burners?  That's what I'm trying to understand here.  I'm not saying it doesn't happen. Water vapor is water vapor no matter where it came from, just as CO2 is CO2 regardless of the source.  Doesn't matter if it's a human exhaling or a vehicle burning gasoline, carbon dioxide has certain properties and behaviors regardless of its origin. If water vapor absorbs a certain amount of heat per molecule, it will do that whether derived from methane or propane. Since there is nothing different about the substance itself then what causes the difference?  Is it quantity?  Is it location?

[Charlotte]

Enough !  You remind me of one of my partners Dutch uncles " I'm not going to believe it until I'm convinced, but I'll be goll-darned if I'm going to be convinced!"