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I Forge Iron

gas burners problem!


kilemnik

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Hi everyone,

I just build 2 propane burners. They seems to work well outside the forge housing at horizontal position but- When I insert them inside the forge there is no premixed flame as should be.

I thought maybe its because the change to vertical position? or maybe related to the inner dimensions of my forge? Someone have any idea?

Im attaching here some videos showing the problem.

Thank you for helping!

Jonathan 

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No; those burner are not working well outside the forge. You have weak heavily reducing flames in both. First, try closing the choke plates; this kind of burner has a sweet spot that is likely to be a lot narrower opening than you'd expect. How come such a thing? Moving the choke plate closer will actually increase swirl in the incoming air. The hole point of those reducers is to add swirl; not to act as some kind of "air scoop" :)

For maximum benifit, you will probably also need to make some changes in your gas orifices. So, how about laying some more information on us, so we can help with that?

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Is that hard firebrick too?  If so it's a real heat hog. I strongly suggest a kaowool lined forge.  I also do not like vertically oriented burners due to their proclivity to re-run exhaust and so spike CO levels---as well as chimney effect issues once you shut them down.

Can you stop by my smithy and I can show you what I am using?

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The video that you added show one definite problem, and a second likely problem. You definitely have some kind of blockage in your gas system; most likely in the MIG tip, but we've seen these blockages come from as far away as the fuel hose (that is rare). The likely problem is that you also need to increase gas pressure. While you have the gas tubes and MIG tips out for cleaning, how about a photo, and description of part sizes? Once you resolve your immediate problems, you will be left with a design problem, unless we can address it at the same time.

Look; you have built a nice pair of burners. Why stop halfway?

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Thank you!

I replaced the burner ending with a 3/4 to 1 1/4 reducer, earlier it was a 1.9'' steel pipe. Is it looks better ? 

Still, when the burner inside the forge I have this jumping on and off problem especially when the back of the forge is closed or half closed. I added another video about that.

Gas pressure is 0.5 bar (~7 psi)   

Part sizes are in the drawing blew. 

Thanks !!!

 

IMG_0883.JPG

IMG_0886.JPG

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Yes, the flames up much improved.

As to the pulsing problem, back-pressure has two aspects; one of them is the flames strength (push power). So, turning down the burner to avoid too much back-pressure will become counterproductive if the flame becomes too feeble. Turn UP your gas pressure; lets hear those flames roar.

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The proper ratio of mixing tube length to ID is 8:1 and 8 x 3/4" is NOT 8". YOur mixing tube should be 6", not counting flare, etc. 

Yes, it should be uncomfortably LOUD. You can hear one of my T burners inside the closed shop from the front door of the house and that's about 130' away. When it's running near neutral it almost screams, I wear ear plugs. NARB 2 burner is a whisper compared to one straight 3/4" T burner.

Frosty The Lucky.

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Why I tell students to learn to tune "by ear and by eye": loudest is the most balanced mix and the brightest wall glow at the impingement is most balanced.  So I generally tuned my old burners to max and then rich them up a bit to do knives with less scaling.

I have a blown ribbon burner already and hope to have electricity to the shop by Christmas! (If not sooner!)

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