Mikey98118

Burners 101

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Curing the kasto with one 1/4” Mikey burner. This forge will accommodate two 

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Looks pretty HOT from here. Nice.

Frosty The Lucky.

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Thank you Frosty. I am very happy with the build. The knowledge and eye to know what I’m looking for in a good forge and acceptable flame are greatly credited to You and Mikey’s among others experiences y’all were willing to share . Thank you. 

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What did you use for a forge shell? Do you want to describe how you choose to construct your burners? All your would-be imitators will want too know how to get such good results :D

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Burner sizes

Generally speaking, burner sizes are based on schedule #40 pipe sizes; or rather on the nominal inside diameter of their (or its rough equivalent in tubing). Classic venturi burners (AKA wasp-waist, such as Ransom burners) go by the throat diameter's (the narrowest point of their venturi’s constriction).

    One naturally aspirated 3/4” burner (that is capable of making a neutral flame) will heat 350 cubic inches of interior volume to welding temperature in a properly insulated forge (two 1” thick layers of ceramic fiber or the equivalent insulation in some other form). Add additional inches for  a burner capable of making a neutral flame in a single flame envelope (with no more than a trace of secondary flame). Below is a list showing how this will translate in other burner sizes. If you substitute schedule ten stainless steel pipe for schedule forty mild steel, you can add a little more heat forges and furnaces.

(1) A 1/4” burner or equivalent air/fuel torch should sufficiently heat a 30 cubic inch interior from a bean can or two-brick forge to welding heat.

(2) A 3/8” burner can adequately heat 60 cubic inches; enough to weld in a Coffee-can forge, or melt bronze in that size casting furnace.

(3) A 1/2” burner should adequately heat 125 cubic inches; enough to run one of the non-refillable Freon or helium cylinder mini-forges (or the equivalent size casting furnace), or mini oval forge made from half a car muffler.

(4) A 3/4” burner should heat 350 cubic inches; enough to run a refillable five gallon propane cylinder forge (or the equivalent size casting furnace).

(5) A 1” burner should heat a 600  cubic inch interior for a small pottery kiln, etc.

(6) A 1-1/4” burner should heat 1, a 1000 cubic inch kiln.

Use of a ¾” burner with a perfect flame (total combustion in a single envelope), which is mounted in an entrance port that is set up to control how much secondary air is induced into the forge by that flame, and you can add another 50 cubic inches from a 3/4” burner, for a total of 400 cubic inches. Addition of the proper heat reflection coating will raise forge or furnace temperature still further or reduce fuel used to gain yellow heat; putting it another way an optimal burner running in an optimal forge or furnace will do the same work as  average equipment with about 30% less fuel.

    So why not use cubic volumes to describe all these burner sizes? Actual numbers will vary according to burner and equipment designs. On the other hand, naturally aspirated burners all have very long turn-down ranges. If you are anxious about using a hot enough burner for your forge or furnace, use the next larger burner size, and turn it down. Later on, if you long to get the burner size just right, it’s easy to change your burner out for a smaller one.

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It should also go without saying that additional improvements in burner design, such as Another Frankenburner's 3D printed burner  can and will continue to raise flame temperatures radically upward, creating still more changes in these figures :)

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My cubic inch to burner size figures are not simply arrived at mathematically,  but are adjusted to include how burners work out in the real world, so don't be surprised if they don't mach yours; especially with miniature burner sizes.

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:rolleyes: Heh, heh, heh. I get a kick out of how many folk think I calculated all the factors to make the T burner. I had the basic ratio from the sales booklets and just experimented till it worked. Been refining the things since and those are mostly refinements in construction. Simpler, easier and less equipment, I have it down to a drill press drill bits and taps. 

I did the same basic thing with the NARB, the 1:12 ratio for enlarging the fuel air path wasn't even close. It's why my test blocks were wood and I simply bracketed too many or too few outlets and split the number till I had it. Wood blocks were fast and easy, II can drill 20 holes in maybe 5 minutes and a pair of wood screws secures it to the plenum. I could've used duct tape, it would've lasted long enough to read the flame, the wood blocks were only readable for maybe 20 seconds before they were making long yellow flames and the flames were degraded beyond evaluation.

The math I use isn't much more sophisticated than multiplication and division, area and volume. I've NEVER measured the ID of a piece of pipe I use and take the label on a package of mig tips for granted. I know when I assemble it it's going to burn rich, a few seconds burning and I have an idea how much to trim.  Math? What's math, something to eat? :huh:

That's one thing that caused Ron and I to drift off on our different trails. I did almost everything by eye and ear and he calculated everything to the nth degree. I can and do work precisely but I rarely calculate much. 

However, I'm watching folk who know how to USE math make burners that put my junkyard editions to shame. Another Frankenburner and Dan know so much more about the hows and whys of the things and are tickling the fuel air into behaving like dancers on stage. 

I'm looking forward to the day the burners on the forges used on Forged in Fire are REAL high performance wasp wasted burners instead of home made plumbing. 

Frosty The Lucky.

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Math is good. Understanding of the principles behind our equipment'a design is good; but they can only provide sign posts. Even combustion engineers must feel their way forward.

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I use math to help make burners.  The math I actually use for burners regularly is area and volume.  Basic trig for angles a few times.  

I finally got my head wrapped around 

P+\frac{1}{2}{\mathrm{\rho v}}^{2}+\rho \text{gh}=\text{constant,}

Which can break down to A₁V₁ = A₂V₂ for our understanding.  As area decreases, velocity increases.  More importantly, velocity and pressure being inverse, as area decreases so does pressure.  We want that lower pressure to pull in all the fresh air we need.  This is part of why we want a reducer at the beginning of the works.

Have I ever used these formula's to calculate anything burner related, nope.  In reality, we are dealing with compressible, viscous, turbulent fluids which complicate the math.  I learned this math to understand the basics of what I am doing and why, not to attempt to calculate some perfect burner.   My inducers have required experiments.  Lots of them.

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Numbers letters and symbols in a sentence. Passwords to the knowledge locker? :ph34r:

Frosty The Lucky.

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Does anyone have an opinion on recuperative burners ? I have an old ABANA forge I built 30 years ago setting on a shelf. It's a clever little box with a pretty cool door, the refractory was nothing to brag on when it was built and the burners were a disappointment by modern standards. I can't decide if I should leave it on a shelf, give it away or upgrade it with new refractory and better 1/2" burners.

I guess the deciding factor is, does the recuperative burner concept make enough difference to make it worth the effort??

 

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Are you asking about the Sandia recuperative forge? It did exactly what the fellows who designed it wanted. What they didn't foresee was what happened when it got warmed up. About the time it was getting to forging temperatures the burners would get hot enough to pre-ignite IN the burners and it got hot in the wrong places. IIRC they tried to come up with various ways to divert ad vent exhaust away from the burners to prevent pre-ignition but it kept getting more and more complicated.

I haven't read anything about the Sandia recuperative forge in years and my memory is suspect they may have worked out the issues.

Air propane tends to have an ignition temperature around 1,000f. It's just really easy to get burners that hot.

Frosty The Lucky.

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That is the only recuperative gas forge I've heard about. There are some examples of recuperative blue flame oil burners, and of course kerosene and gas blowtorches use the flame's heat to vaporize their fuel...

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On 6/14/2019 at 3:40 PM, Mikey98118 said:

My cubic inch to burner size figures are not simply arrived at mathematically,  but are adjusted to include how burners work out in the real world, so don't be surprised if they don't mach yours; especially with miniature burner sizes.

 The wish to end up with the perfect burner match by consulting a list of burner sizes for the perfect fit with  your equipment size is just another newbie fantasy, like building your first forge big enough for all your future needs; it tends to work out badly.

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Keep us posted please.

Frosty The Lucky.

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So, is anyone experimenting with ribbon burners in semi open equipment to heat sheet metal parts? Seems about time for someone to try that :)

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Do you remember Chris Ray, Mike? He did a lot of hot work on sheet and light plate. He built a table forge with a spittoon shaped chamber flush with the top. The burner was mounted tangentially in the bottom round section. The flame formed a strong vortex in the "pot" and spread with the bell at the top. 

He was able to heat large areas of sheet and light plate by covering the top with a ceramic wool blanket.

I believe his work is archived at ChrisRay.com or he should show in a search. Chris passed away around 2000, I really miss Chris. :(

Frosty The Lucky. 

 

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I remember, but tiny multiple flames should save as much fuel in this application, compared to single flames, as in more enclosed forges?

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On 6/13/2019 at 9:30 PM, Mikey98118 said:

What did you use for a forge shell? Do you want to describe how you choose to construct your burners? All your would-be imitators will want too know how to get such good results :D

im back, life got heavy for a bit.

The shell: 1 gallon mini keg with a half circle cut out of one side, the other end had a 1 1/2" hole where the tap was. I placed the burner ports towards the back (for max swirl) and lined up with the corner of the half circle. Instead of drilling the ports, I cut flaps that I can anchor the small 1/4" burners to. I then lined this small sun with 2 inches of wool on the roof and filled the bottom with wool scraps and topped with a blanky. Made a fumed silica+water bath and soaked/drained everything. used one 1/4" burner to rigidize. Then coated inside with kasto 30.

The burner jet: .025 mig tip with thread turned down enough to be pressed into a 1/4" female hose barb. the mig can then be fitted with an EDM tube. I used .015 orifice for my 1/4" burner.

The mix tube: 6" x 1/4" pipe with 3 holes measured 4" from one end. (when drilling, try to angle holes toward the flame end.) start with  smaller holes than you would think and enlargen from there, always clean burrs and check flame after every adjustment.

The nozzle: 1/4" coupling with threads cleaned out of one side. this too must be tuned by checking on the flame after every scoring.

NOTES: I tuned the system rich by ENLARGING INTAKE SIZE FIRST with raw coupling attached. Once i got the flame to stay on the end, I cleaned out the threads in the coupling causing the flame to lean out and allowing the psi to be turned up.

Also the hoses have been changed to proper propane hoses.

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the stand is just a base of some sort with square tubing for the neck. the tube is split at the top and splayed out to accommodate the forge shell. It is just wired together.

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