Burners 101

[671jungle]

I meant to say ejector. It’s a take on the Mikey burner. So are Mikey’s And Frosty T’s burners ejectors? And the Ron Reil burners linear inducers? But all of them are venturies?

[671jungle]

As I suspected the scale on the nozzle expanded the I.D. Causing the flame to lift. I tried to drill it out to a operatable (<is that even a word) size for a small improvement but not enough. One seriously needed changing anyway so I sprayed the nozzles with some rust loose stuff and twisted’em off but I also warped one of the little 1/4” mix tubes. So I went to the local plumbing supply and got a couple 1/4” couplings that I have been using as nozzles and pipe to replace the one I warped. Got home and realized I had bought the wrong length of pipe. Tomorrow I will trade them in for the proper length. But I am pretty sure the problem is the nozzle was all scaled up, almost to the same I.D. as the mix tube. I will take the time to make a more detailed build plan for anyone interested in smaller burners when constructing tomorrow. 
you can tell which burner was running lean. One of the nozzles is just pinched from the vice trying to get it off the mix tube. 
Oh and I meant contracted the I.D. causing the flame to lift, not expanded.

[Another FrankenBurner]

The way I understand it is inducers induce, injectors inject, ejectors eject.  It's very complicated.    Inducers are drawing something in.  Ejectors and injectors are inducers.  Ejectors are inducing something to spit it out of somewhere.  Injectors are inducing something to push it into somewhere.  

I've also run into the term inspirator which was defined as a device which fuel pressure is used to draw in atmospheric air to mix it with the fuel at precise ratios for burning purposes.  

A Venturi is a cone shaped constriction in a fluid flow system to temporarily speed up the flow and lower it's pressure.  The lower pressure can be used to draw things in.  Carburetors use this restriction in the air flow to draw in fuel.  Some burners, in part, use this to draw in air.  In a Mikey burner, there is no constricting point.  

[Mikey98118]

I hope you will post a photo of the burners, once they're repaired. Any working 1/4" burner is probably of interest, whatever its design.

[Frosty]

Other than to clarify what a poster means I've stopped worrying abut what one of these things is supposed to be called. I call them: Linear inducers and Jet ejector, inducers. Nothing we build at home has a venturi in it that I'm aware of though commercial inducers sure do. I don't argue though, it's a wide wide world and who knows how a term translates into their language, then they start making them and selling them back so another transliteration is applied. 

One of my favorite stories about transliterations is the one about "water sheep." After engineers and upper management had scratched their heads raw someone called the company advertising "water sheep" in an engineering magazine. Transliterated to their language, "hydraulic" means of or by water and Ram is a male sheep. Transliterated back it equaled Water Sheep. 

The worlds a fun place.

You know Jungle, that's pretty darned ambitious making 1/4" burners this early out of the gate but the results are impressive. I'm thinking you're a budding burner guru.

Frosty The Lucky. 

[671jungle]

 

Thanks for the input everyone! I did not get any pics, but I changed out the nozzles on the existing tubes and it ran much better than in the previous video. The warp in the tube is still effecting performance to a very noticeable degree compared to when they were first built. Also the angle the burners come in still need adjusting. Today I will try to make the time and put another one together from scratch and document. I believe I made a mistake several months ago stating I used 6" long mix tubes when it should have been 5" lengths. My apologies to anyone who followed those instructions. One could have made the jet longer to meet the intakes but I think the extra drag in such small EDM tubes would result in malfunction.

 

[Mikey98118]

 

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Posted 23 hours ago

Other than to clarify what a poster means I've stopped worrying abut what one of these things is supposed to be called. I call them: Linear inducers and Jet ejector, inducers. Nothing we build at home has a venturi in it that I'm aware of though commercial inducers sure do.

 

I've had to pay attention to the labels, both 'official' and otherwise that various salesman and tool room aficionados have plastered on tools, etc., and found that the only excuse for their choices are how descriptive they are. I wholeheartedly accept your definitions; they work, and that's as good as things get

El Mikey

[localsmith]

I just want to personally thank both you (Mikey) and Frosty for all of your posts and knowledge that you have put free of charge on this forum. Thanks to both of you, I figured out that my forge was running inefficient over this past year and I was able to build my own burner that is literally twice as efficient as my first burner.

I also removed the junk depot store refractory that I used on my forge that would puff up 1" when first heated and reduced the internal dimensions of my forge and it would flake off and need periodical repair and I replaced it with Kastolite and my forge works like a charm now giving me a much more durable forge and a forge that has larger internal dimensions since the Kastolite does not puff up when heated. 

I have to say, once I started getting into building burners and playing around with forge designs I started to become addicted to making the most efficient burner and forge I could possibly come up with. Kudos to both of you gentlemen and thanks again for how much I have learned off of both of you!

[Frosty]

You know, becoming addicted to how these things work and tinkering is how you end up an Iforge guru, don't you?

We got us another one Mike! 

Frosty The Lucky.

[ThomasPowers]

The Emperor will be pleased!

[Mikey98118]

Good one, Thomas

Frosty,

The people's pool always has more room down at the deep end

Localsmith,

You brought your rubber ducky along, right? Dive right in; the water's fine

[Frosty]

Oh yeah, the more people who can make effective burners the less I have answer the same questions.  Better yet, we keep seeing newer better designs and mods.

Frosty The Lucky.

[Alphafarrier]

Question:  What are some of the basic factors that affect how quickly a forge comes up to temperature?

 

 

Background: I’ve been running two prototype forges for about 6 months now.  I found that high temperature firebrick takes FOREVER to get up to temp, even though it’s only 1.25” that I had lining the floor over refractory.  I replaced with high alumina kiln shelf, and that has been much better.  
 

I have two Mikey burners powering these forges.  The heat is concentrated, and does eventually spread out, and get very hot, but it does take longer than a traditional Venturi burner to come up to temp.

[ThomasPowers]

Size, thermal mass, insulation properties,  burners and how they are positioned: BTUs in and "hang time" in the forge, forge design (how large the doors, etc).  Are some of the factors.

 

[Mikey98118]

I think you need to spend some time reviewing re-emission; commonly termed heat" reflection." Don't bother changing out your firebrick floor, at first; coat it, and every other internal surface with Plistex; it isn't the very best solution, but it is more than good enough, and the cost is minor. You can order it at the top of the group page.

Once you get that done, we can move on to easy fix number two.

[Alphafarrier]

Too late!  I already put Kiln shelf in.  It works much better.  And I’ll coat it with Plistex.  What next?

[Mikey98118]

Step number two is to get control of the amount of secondary air that those high velocity burner flames will induce into your forge. The easy way is to stuff some left over ceramic wool between the burner and the wall of the portal; this allows guys to see the benefit before going through the bother of constructing variable secondary air chokes with large flat washers with nuts  silver brazed on, etc. /various pipe fittings and conduit fittings can serve the same purpose.

Step three is to construct a baffle wall in front of the main exhaust exit; not right against the opening but about 1" away from it. Most guys start out with bricks, just to assure themselves that this is worthwhile, and then move on to more elaborate schemes. Coat the side of the brick that faces the forge with Plistex, so that you aren't leaking all kinds of radiant energy out the exhaust opening.

Get back to us with your thoughts after stage two, and again after stage three. With these things done, we can help fine tune your burner; by then your forge should be four to six hundred degrees hotter already

[Mikey98118]

So, why have variable chokes to regulate secondary air induction into the forge? because most burners NEED a little secondary air to burn their secondary flames thoroughly.

But excess secondary air, simply cools the forge, will contributing to scale build up on the work; a loses lose proposition.

So, secondary air is just another factor to be balanced, just like gas pressure, and the amount of primary air being induced inside the burner.

[Mikey98118]

Good point; didn't know that.

6 hours ago, ShaunAnderssen said:

Another question I have is on say, Forged in Fire, they're able to heat their steel to a nice bright yellow hot enough for forge welding, I've even seen them get their metal TOO hot. But when I look up the temperature output for a propane forge, it's only listed around 2,000 degrees.

That's a good question. The answer involves one of my pet peeves.

There are a number of way that flame temperatures are measured. The ultimate possible temperature of any given fuel gas can be calculated mathematically, and such numbers, both for air-fuel flames and oxy-fuel flames are listed. Air-propane flames have an ultimate possible temperature of around 3600 F give or take 50 degrees (it's been about fourteen since I last looked this up). In practice you would need something as complex as a jet engine to reach this goal

There are optical comparitors (spelling?) that can measure flame temperature accurately, for a whole lot of bucks, and a steep learning curve.

Finally, we mere mortals are reduced to looking at sales literature, and comparing one claim with another; this rapidly leads to the conclusion that, while every last salesman on earth may possibly not be a compulsive  liar, most heads of advertising departments probably are. The second conclusion reached is that most of the 'facts' they use boils down to one talking head imitating another

When I first started looking up propane flame 'information' (AKA outright lies) on flame temperature, most 'experts' claimed 2200 F for air propane flames from their various torches. During the following two years those claims reached 2450 F; when some of them started claiming 2600 F I gave up.

So, what can we rely on as closer to the truth than sales BS? First, forge temperature cannot exceed flame temperature; it works the other way around. Two different guys on IFI claimed their forges had registered temperatures of 2750 F with my burners. Aside from flattery, what evidence is there to support this?

Air propane flames have a spike in No production between 2800 F and 3200 F. The smell is unmistakable. Not every Mikey burner can produce it, but I have tested more than one burner that did.

Before you think this is a brag fest, let it be known that Dr Frankenburner, on this very group has come up with a burner design that blows mine right off the road

I have looked over the burners they advertise on the Forged in Fire, and have no reason to doubt their claims, or to think they aren't worth every penny they ask. Hope these answers help; they're the best I can do.

That should have read "NOx"

Nitrogen oxides are produced in combustion processes, partly from nitrogen compounds in the fuel, but mostly by direct combination of atmospheric oxygen and nitrogen in flames. Nitrogen oxides are produced naturally by lightning (Wikipedia quote).

[Alphafarrier]

Is a stepped burner nozzle or tip on a frosty burner a contradiction?  Is a stepped burner nozzle a high speed burner thing, and the frosty burner a lower speed burner?

[Frosty]

No. Lots of guys are making T burners with all sorts of nozzles and some are a lot more effective than what I build. I developed the burner to be as simple as possible, requiring the minimum shop tools and skills. It's no surprise, folk with better than beginner level skills can improve on the basic bit of plumbing. A number from dumb luck. 

As it turned out the thread protectors I use on my personal burners as an easy way to mount them, turned out to be a step nozzle. Discovered that after Mike started describing the things. The T burners without a thread protector are higher speed burners and more dragon's breath.

Frosty The Lucky.

[ThomasPowers]

I have accidentally melted steel in my propane forge and lots of people forge weld in theirs.  When folks tell me that propane forges don't get as hot as coal forges; I tell them that "I've melted steel in mine---how much hotter does it need to be?"

I think the real issue is that people mean that THEY can't get higher temps in THEIR propane forge; not that it can't be done.  Rather like saying cars can't go faster than 100 mph because my old 66 Volkswagen beetle couldn't.

[Mikey98118]

And since we are looking for proof, what do I base this conclusion on? Well, a properly constructed Mikey burner's flame retention nozzle will reach bright orange heat out in the open air, when burning propane. The same burner will reach yellow heat on propylene. Propylene burns about six hundred degrees hotter than propane in an oxy-fuel torch. I think it is safe to estimate four hundred degrees hotter in an air-fuel burner. I consider this sufficient proof to conclude his flame are above 3200 F. We should ask him if he gets an ozone smell from his burners. I'm betting he doesn't 

Him who? AnotherFrankenburner.

[Frosty]

OZONE from an air fuel burner, Mike?

NOX smells a LOT different, sort of like taking a sniff of battery acid in my experience.

Frosty The Lucky.

[Mikey98118]

Gas valves

There are three kinds of gas valves that matter to you; needle valves, ball valves, and variable pressure regulators. Ball valves are meant to start and stop flow. In a burner system, they’re mainly used as emergency cutoff in case of fire; they are also used to rapidly divert flow from one pipe system to another. They can be used to control flow, but not in a satisfactory way.

    Needle valves are best used to quickly fine tune flow in a gas system that has a variable pressure regulator. A good quality valve, which is new, can be used to stop flow completely, but it will begin to leak flow, eventually. What about air-propane cylinder mount torches; they only have a needle valve, right? Expect them to eventually develop small leaks.

    Variable pressure regulators limit the amount of pressure in a burner system to a little higher than the desired range you want to use; this allows rapid fine tuning of the burner with a needle valve, while protecting the hose and pipe connections from possible damage and leaking, from constant exposure to full cylinder pressure. Yes, it is possible to use the regulator to fine tune your burner, but if you have very much hose in your burner system, every change will be slow.