Burners 101

[Candidquality]

Yep, working through prototypes now with 3d printed burners.  Once I get something feasable, I'll print a mold for a castable refractory for the final just so I don't have to worry about heat ever again.  Honestly I could make that a production rig and be very comfortable that it would be isolated enough it would remain out of harms way, but sending it to the masses would be riddled with issues.

Have a testing rig for adjusting the position on the jet down the burner tube which is also printed.  So once I find the sweet spot I can either lock it in place there, or decide to create an adjustable version for trimming at altitude.   

[Mikey98118]

7 hours ago, Candidquality said:

So once I find the sweet spot I can either lock it in place there, or decide to create an adjustable version for trimming at altitude.

By "trimming" did you mean "adjusting for" altitude? I'm not trying to be picky (this time :-). "T" burners are tuned by trimming back their MIG contact tip's lengths.

[Frosty]

Modern regulators use ambient pressure to regulate PSIG. They do NOT produce absolute PSI. 

If the regulators we use produced "absolute" psi they would NOT have diaphragms. Ambient pressure on one side and adjusted desired psi on the other. 

I don't know how many years I thought barometric pressure affected burners. I was wrong, so soooooo wrong.

Frosty The Lucky.

[Mikey98118]

And so we come back to the often disputed question of whether and how much altitude affects these burners. I think the ayes have it. But I also think it takes a lot more altitude than people worry about.

[Candidquality]

Yes Mikey, 

Adjusting for altitude.  Been reading too many t- burner posts and it's stuck in my head.   Will have to see how it goes after the design is finished.

Test burner designs cost almost a whole quarter to print.   Mostly my design time in cad. 

Frosty,

Good to know a rain storm is nothing to worry about.  Just have to keep my eyes peeled for tornados....

[Frosty]

Altimeters come in different types most common for general aviation are baroid (barometric) and need to be corrected for ambient barometric pressure, ask a pilot.

Unless you're on low ground rain storms shouldn't be a problem but YES always watch out for twisters.

Frosty The Lucky.

 

[Mikey98118]

Except for those little twisters that you can create inside your burner

[Frosty]

You want to watch for them, you wouldn't want to miss out.

Frosty The Lucky.

[Mikey98118]

Slide-over stepped flame retention nozzles

These nozzles consist of one pipe or tube, called a spacer ring, fitted into an outer stainless steel pipe or tube. You are likely to have to power sand the outer or pipe or tube, or the spacer ring, to get them to fit together. You might even end up slitting the spacer ring lengthwise, and tapping it into the outer tube. Or, you could just as easily slit the spacer tube, and spring it apart, to provide a snug fit to the outer tube, and a sliding fit on your burner’s mixing tube.

    The spacer ring can be made of either stainless steel or mild steel, to suit your convenience. But the outer tube must be made of stainless; #316 stainless is better for the purpose than #304, as it does not oxidize away under high heat and live flame conditions as fast. However, #316 doesn’t last enough longer than #304 to put up with the high prices some sellers feel you should pay for it—just say NO!

Note: These nozzles are kept in position with stainless steel socket-head screws. Do not use mild steel screws; they will “freeze” in place after a few heats.

Caution: Stainless steel flame retention nozzles on a good burner design, will get to yellow heat in ambient air, burning propylene, and will quickly melt down in a forge. The same nozzle will get to orange heat in ambient air, burning propane, and will melt down in a forge, if they are not recessed back at least one-inch into the burner portal; do not position them close to the forge’s swirling super-heated atmosphere!     

 

[Mikey98118]

So far, stepped flame retention nozzles do a much better job of controlling the flames of thigh speed air/fuel burners than tapered nozzles ever did.      

 

[Mikey98118]

 

              A different stepped flame retention nozzle design

But what about burner designs with softer flames? Amal burners came up with a unique solution to the problem. What problem? That slide-over step nozzles don't work very well on burners with softer flames, like "T" burners and Amal burners. Instead of a spacer ring between the burner's mixing tube and the outer tube of the flame retention nozzle, Amal uses an internal tube, which has twice the mixing tube’s internal diameter for its length, with a chamfered rear edge. check out their drawing at Amal's website.

 

[Mikey98118]

                                                        On tuning

In reply to a recent post, Frosty gave the following advise concerning his "T" burners.

"Try turning the pressure up and putting it IN the forge, it's hard to tune a T burner properly in a different place than it's intended to run. Think of it like adjusting a carburetor at sea level to run the Pike's Peak race." Hmmmm?

I  prefer tuning "Mikey" burners (and every other high speed burner I have played with) out in the open air. The advice given in this thread has seldom mentioned the great differences that mixture flow speed can make in various burner designs; that was a mistake. Different burner designs must be tuned individually.

Frosty has mentioned that his burner was designed to be slow speed, to get the most heat transfer out of its flame, before it exits the equipment via an exhaust opening.

I designed my burners to give the highest speed possible, and counted on sufficient swirl in the exhaust path to slow that high speed flame down, increasing hang time; differing paths to similar goals.

 

[Frosty]

Actually I'd been using the T burners for years before I saw one of yours and the difference in flame velocity. A fellow in Talkeetna had a type 3 in his only NA forge. But it was taking the route I did when Ron and I were messing with the things when the internet went public and I got to join. 

In truth it wasn't till much later before I started noticing how much flame was burning OUTSIDE other folk's forges and I started thinking about flame velocity. My intent wasn't to build fast or slow, my intent was to deliver as much flammable fuel/air to the forge chamber per second as possible. An old coffeeshop buddy delivered a bunch of literature about various induction devices hoping I'd come up with a good idea for an application patent and make us some money. 

That was the last time I messed with a linear inducer burner. Jet ejectors are IIRC 27x as effective as inducers so it was a piece of cake to detune the device to under 17:1 and make an effective burner. Getting a jet ejector to function well as a burner is so easy it's almost cheating. And THAT changed my goal to making an effective burner anyone with basic shop skills and minimal equipment could make for under $7.00. (1984 money) Even now one will cost under $20 unless you have to buy the taps, drill bits, etc. Not counting regulator, hose, shut off valves, etc.

While they do the very same thing a Mikey and T burners are very different machines. 

Last of all burner and furnace, be it forge, melter or pottery kiln or whatever are two components in one machine and need to be matched to work up to potential.

And here's a secret. Mike didn't make a mistake, he just pretends to now and then to make all of us feel better. 

Frosty The Lucky.

[Mikey98118]

3 hours ago, Frosty said:

A fellow in Talkeetna had a type 3 in his only NA forge.

Oh yes; back when I was still numbering the changes. I suppose we would be up to type six or seven by now, if it mattered at all...

What I like to see is people coming along, and completely upsetting all the apple carts, including mine. May AFB and all his fellow travelers be forever blessed

[Frosty]

As I recall you were only marking a new "type" for significant improvements and major changes plateaued around there. I know I haven't made a change in the T burner itself in I don't remember how long. Refining the way I mounted the mig tip I think. The last actually good thing I came up with was using a floor flange to jig in a drill press to make keeping everything aligned easy. 

I don't count NARB as a T burner improvement, NARB will work with any kind of driver, NA, or Gun. It's a diffuser, certainly not a retention nozzle even IF it does a marvelous job of retaining the flame. In the forge.

I love seeing new ideas, burners and whatever. Can't upset the T burner applecart, no matter what someone comes up with it's unlikely to be easier or more forgiving to make and work well.

Maybe sometime we'll meet up and come up with a really different burner. How about a Gatling burner? several burners rotating around a common axis and only burn one at a time? No, nevermind that'd be too easy, we'll have to come up with something else interesting to play with.

Frosty The Lucky.

[Mikey98118]

41 minutes ago, Frosty said:

How about a Gatling burner?

I already did that with a bong, forty some years back. Ah, misspent youth. How did I survive?

[Frosty]

Have pictures?

How did any of us survive? 50 years ago I thought 30 sounded like an unlikely old age.

Frosty The Lucky.

[Mikey98118]

6 hours ago, Frosty said:

Have pictures?

Not hardly! Those were wild days in old Seattle town, but I was never dumb enough to document things.

[Frosty]

You sure do  know how to keep a secret Frosty whispers to Mikey on the world wide web. 

I think you and I are both well past the "statute of give a darnedness.

Frosty The Lucky.

[Mikey98118]

Exactly; otherwise Mikey would still have nutten to say

[Frosty]

I don't remember anything worth talking about.

Maybe one day we'll get a chance to sit down with a beverage and talk about old time, times.

Frosty The Lucky.

[Mikey98118]

                                                  Burner sizes needed for forge sizes

(1) A 1/8” burner’s nozzle size is 0.493” I.D; this is sufficient to heat 22 cubic inches on naturally aspirated burners.                       

(2) A 1/4” burner’s nozzle is 0.622” I.D.; this is sufficient to heat 44 cubic inches on naturally aspirated burners.                       

(3)  A 3/8” burner’s nozzle is 0.824” I.D.; this is sufficient to heat 88 cubic inches                       

(4) A 1/2” burner’s nozzle is 1.049” I.D.; this is sufficient to heat 175 cubic inches on naturally aspirated burners.                           

(5) A 3/4” burner’s nozzle is 1.315” I.D.; this is sufficient to heat 350 cubic inches on naturally aspirated burners.                             

(6) A 1” burner’s nozzle is 1.61” I.D.; this is sufficient to heat 700 cubic inches on naturally aspirated burners.

    The number of cubic inches that can be brought to welding temperature in a properly built forge, or the number of cubic inches in a casting furnace that can be brought to iron casting temperatures (from an air-propane burner with a neutral flame), depends on the inside diameter of its flame retention nozzle; this is limited by the diameter of a burner’s mixing tube, in naturally aspirated burners, but nozzle diameters on fan-induced burners must be larger, when the fan is running at full power, and the fuel gas is increased to match its increased air induction, so the amount of cubic inches a fan-induced burner will sufficiently heat depends on the internal diameter of its flame retention nozzle; not on its mixing tube diameter.

Note: “Sufficient to heat” means that it can raise a properly built forge interior of those cubic inches to welding heat, or melt cast iron in an equal size casting furnace. Are these figures legitimate? In fact, they are under stated; not over reaching. What about the optional second (larger) flame retention nozzles on fan-induced burners? Whatever inside diameter is used with one of them, with the gas pressure turned up to match the fan running at full speed, can be considered as producing a flame equal to that nozzle size in a naturally aspirated burner. You can more than match the maximum output on the next larger size naturally aspirated burner.

That would be cool, Frosty. My beverage of choice is coffee, although tea is pretty good too

[Frosty]

I'm a plain old black coffee kind of guy though I'm a fan of green tea hot or iced Lipton. It's been a long time since I was in Seattle. I'm thinking the last time I had a favorite coffee shop it was in Everett, about 2 blocks from the hospital where I was born and one in Stanwood, just before you cross to Camano Island. 

Anywhere works for me though, I hit coffee shops for conversation so if conversation's already lined up I'm set.

Frosty The Lucky.

[Mikey98118]

You may find this strange, but the proliferation of drive-up kiosks and the pandemic mess didn't do regular coffee shops any favors. Normally, I just go to a restaurant to have a coffee sit down. In Seattle these days, it would probably be easier to find the coffee shop experience in a tea shop; weird huh?

[Frosty]

I used to be a regular counter culture member at the local restaurant / cafe but covid stopped most early opening, hardly anybody opens before 7:30 and nobody close has a counter I think there's only one 24 hour restaurant within 50 miles and that's a bit far.

There used to be and heck might still be a group that held "meetings" Wednesday evenings in the conference room of the local restaurant and discussed all sorts of stuff. Alien tech, gvt. conspiracies and such. I knew most of the gang but never attended a meeting. 

I LOVE the regular's table at local coffee shops, restaurants, etc. They're the place to find out what's what when you're traveling. 

Are tea shops good for meeting the local characters and solving the problems of the world?

Frosty The Lucky.