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Burner trouble shoot


Michael Pikula

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Ok guys, I have tried just about everything that I can, I have tried several different combinations to get my burner to work and I don’t know if it is acting weird because it is being fired cold outside of the shell or if I am really screwing something up. Yesterday I was getting the main cone jumping from greenish to blue, a really choppy burn, today I got it closer to what I feel is a consistent burn, but still am not convinced. I could be wrong since I have never worked with forced air propane burners….

 

I am have been trying to build a burner as per Don’s site, Kevin Cashen, and Tim Zowada.

 

I am running a blower that is borrowed from my coal forge, it is a centaur forge blower with motor attached, the 3inch outlet runs through some duct work to a 1.5inch valve, to a 1.5 inch nipple, to a 1.5 inch tee, the side opening has a 1.5 to .5 inch bushing that has a .5 inch nipple that goes to a valve and gas is coming in. After the tee I have a 1.5 inch nipple, a 1.5 inch 90 degree elbow, 1.5 inch nipple, 1.5 to 1.25 reduction with a 1.25 to 1 inch bushing with a 1 inch nipple. (I couldn’t find a 1.5 – 1) Also I tried using a 1.25 to .75 bushing with a .75 nipple.

 

I couldn’t get either of these configurations to stay burning with out a flame source, so I added an .25 enlargement to the tip and it stayed burning, but still had some flame chop, all though these seemed to be the best combinations, seeing this flame outside of the shell I am not too convinced that this will get me the nice even welding heats that I need.

 

I am including a picture of the burner assembly with the 1 inch opening, and two short video clips of the burner burning with and without the flared tip.

 

Any advise, flaming with a good flame, or comments with a swift kick to the butt would be greatly appreciated.

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100_2910.MOV

Edited by Michael Pikula
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Centaur Forge Blower

Is this the blower that you are using? If so, 500cfm of air is ten times the volume that Don mentions on his forge page.

Forge

 

~Bruce~

“All work is empty save when there is love, for work is love made visible.” Kahlil Gibran

"It is easier to fight for one's principles than to live up to them." - Alfred Adler

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Centaur Forge Blower

Is this the blower that you are using? If so, 500cfm of air is ten times the volume that Don mentions on his forge page.

Forge

 

~Bruce~

 

Very true, however I am running it on a very low setting since I have it hooked up to adjust the air flow, so I am not pushing anywhere near 500cfm. The blower is running on a very low speed, I have been playing with the blower speed as well as the two flow gates. I don't know how I can measure it to get and exact figure.

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Hi Michael.

 

I think also that all that air is too much...Velocity of gas and air is bigger than velocity of burn.

In mid air i have found that blower burners dont run ...they need forge back preasure...venturi also...but not that much, Becourse of flame holder.

Blower burner dosent need same typ flame holder.

 

I just test run my gas forge ( based in Don´s / Jesus) desing...it didint run first....Mig tip 0,8 mm was way too small...small tip makes ( I think) gas race way and combustion whit air is not good. I drilled hole 2,5mm and now it runs like devil him self...

 

I also have WAY too big blower but I can control air amount.

 

I did also redused indiam of burner head...it was too big ( my bad) now it´s 25mm ( 1") and it slitelly slows velocity of mix.

 

I hope you get forge running :)

 

 

BR

 

Niko

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Blown burners reach forging temps. at low gas pressures, usualy 1/2 pound of gas. The 50 cfm blower Don recommends has to be almost entirely choked off in this situation. When welding, higher gas pressures are used, along with more air. Full out, running about 15 psi of gas, you will need the 50 cfm, possibly more if the interior volume of the forge is large. Even choked back, a blower that puts out 500 cfm will be too much for normal forging. The blower you have is capable of supplying multiple forges and is overkill in almost any other situation. What works best for forges is a blower that moves large volumes of air at low pressures. Unfortunately, that is not what industry supplies us with. Burden Surplus is all out of the 50 CFM blowers (they do have an inexpensive 100 CFM blower that would work great for a large welding forge) but, here is a link to one on ebay. It is not nearly as inexpensive as a surplus one but, you could look around, never know what you'll find.

Ebay New 50 CFM Dayton Blower

 

~Bruce~

“All work is empty save when there is love, for work is love made visible.” Kahlil Gibran

"It is easier to fight for one's principles than to live up to them." - Alfred Adler

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Just had a thought. You could always detach the blower you have and pull it back a little and try your burner to see if it will work with less air. If that works you could divert what air you need for your blower and pipe the rest to provide an "air curtain" for the door(s) like Don talks about.

 

~Bruce~

“All work is empty save when there is love, for work is love made visible.” Kahlil Gibran

"It is easier to fight for one's principles than to live up to them." - Alfred Adler

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So I must be misunderstanding the basic principle of this blower. When the motor is running at less then 10% of its speed, and the blades are spinning at less then 10% of their speed, I am still getting 500cfm? I can feel a great difference in the sound and amount of air coming out of the blower when I adjust the speed of the motor, so I thought that by running the motor slower I am reducing the cfm....

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Yes. You are reducing the CFM but, not enough. At best, you are dropping it down to 50 CFM and for normal forging you only need a fraction of that. That is why I suggested diverting some of your air supply, to provide a test to determine if this is the problem.

 

~Bruce~

“All work is empty save when there is love, for work is love made visible.” Kahlil Gibran

"It is easier to fight for one's principles than to live up to them." - Alfred Adler

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Another good fan is a simple bathroom vent fan. I've got a 100CFM fan from Surplus Supply and I had to choke all but about 1 square inch of the intake off to get my burner to run. A gate valve between the fan and the burner is another, better option, or a smaller fan.

 

Geoff

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

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My 90 CFM has to be gated down to one third the flow for regular forging. As the forge interior heats up I have to back it off more or it gets too lean and hot. And that is with a 2.5 cubic foot forge interior.

Edited by B Finnigan

Everything I need to know I learned from the people trapped in my basement.

 

 

I'm out of my mind but feel free to leave a message.

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Hey guys, update. I got the shell about 85% done and mounted so I thought I would do a little test fire to see what I could find out. After playing with the blower intake size, blower output, the valve for air, the valve for gas, the gas pressure.... I was finally able to get something that I consider to be a decent burn. The sound is still a little choppy, but the inside is glowing pretty consistent, the flames that come out the door when tuned to a reduced atmosphere are consistent, so over all I am pretty pleased.

 

I'm posting two pics, one of the flame in what I think is a neutral atmosphere, the other reduced. In the neutral atmosphere there are almost no flames coming out the door, which if I am right means that the burner is just the right size for the burn chamber.... then when I turn the air gate closed a few turns I start to get flames out the door. I suppose I will have to see how scale forms, or doesn't form on a clean surface to determine where I want my forge welding settings to be, but I will leave that for tomorrow when I finish insulating and do the final burner mount. I will also switch out the blower for a smaller one when I get the funds to do so. At the moment I'm a little on the poor side so if I can get by with the current blower turned way down and intake cover almost all the way closed then I'll be happy since I can forge :)

 

Thanks for the help and advise, let me know if my thoughts on the atmosphere in the pictures is right or if I need some more learning. I am just starting to get into gas after nothing but coal so please forgive my ignorance!

 

btw first image if of the reduced atmosphere, I think, after adding air I get the second image, no flames out the door, neutral?

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Edited by Michael Pikula
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On my blown forge I used to blower out of a discarded dryer. They operate at relatively low pressures, and fairly high volumes. I'm not sure what that volume is, but it's plenty to get oxidizing flames at 15psi of gas pressure. The best part of using a dryer motor is that they are designed to be run in fairly warm environments. They are also already set up to be conencted to felxible ducting.

 

If you check our craigslist, you'll likely be able to find one for free. Search for "dryer" or "scrap" or something similar. They are on there all the time in the free section.

 

Good luck

Have you ever thought about the life of steel? It's interesting to think that you can control the fate of a piece of metal.

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