Can someone help me with my burner?

tomh

tomh

Joined
Oct 3, 2005
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411
I built my first venturi forge. I am having trouble getting it to burn completely. Big yellow flame coming out the front, only getting up to 1500F
My burner tube is 12" long 1" pipe, bell reducer is 1.5", orifice is #53 drill bit size. 6 psi on the propane regulator.
orifice is shoved as far as I can get it in the bell. It burns worse the more I slide the orifice out of the bell.
I think I need it to pull more air, or reduce my orifice size.
Will a bigger bell reducer give me more or less air flow/velocity?

I can't wait to get this going good, it has such a nice swirl going on!

Any help is appreciated!
 
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Hey Tom, Just thought's, but most body tubes are 3/4" and there's some thought that a 'flare' at the end is more efficient. Big yellow flame and cool forge sounds like too much gas. I'd leave everything as is, and turn down the psi to maybe 3psi. and see if you can get the flame down to maybe 6-8" out the front. If it helps a little, then turn down volume with your shut off valve. You might test if you're getting too much air by closing off the intake with duct tape temporarily (try 2/3). With the large 1" tube though your velocity may go down and the burner huff a bit.

Good luck, and hopefully a burner expert can help, Craig
 
On a venturi burner, I would use a 3/4" tube.
The air is drawn by the gas injection ( venturi principle) and there needs to be a good alignment of the jet. If the hole is not clean and smooth, it will make turbulence, and won't draw air right. This is why many folks use a welding tip (#30? IIRC) or a gas jet (from the plumbing and heating shop) to inject the propane.These are made for the job.
You didn't say how the injection was being done on your burner (photos always help) , but the injection point often needs to be tweaked a bit. If you are using an 1/8" pipe with a drilled cap for the injector (try the above mentioned tips, instead of the cap), it has to be moved in and out of the bell/tube junction to find the perfect venturi point.

A note:
When I got a new stove, there were six burner jets in a bag that came with the stove. These were for changing the jets if the stove was going to run on propane, and not natural gas. Now I thought, what do I do that needs a propane gas injector nozzle ???I have only used one of them, but it worked like a champ.
I bet any appliance store that does the installation of stoves has a bin full of them, and they would give you a couple.

Stacy
 
propane is a richer fuel than natural gas. I would stick with the proven 3/4" side arm burner, mine works wonderfully.
 
Looks like everything is too big. I am using a drilled cap on a 1/4"nipple. Guess I need to downsize everything and save these parts for a bigger forge. Thanks!
 
true! but i never seem to learn my lesson until I screw the project up first!
 
Hi Tom

i've built some venturi's that worked well and others that i just couldn't figure out why they didn't ...

keep trying... but if your behind on work... just duct tape a hairdryer to it and a pot/speed controler on the wire... to control air flow... as a real temporary fix till you figure out the bugs...

i have to say... the 1inch pipe is abit big for the venturi... i believe that is what i use on my furnace to melt steel...:eek:
 
Tom, here's the plumbing for a burner I built with parts from Lowes. The piece holding the mig tip I made but later found that a brass plug, drilled and tapped worked better. The plugs from Lowes were milled on thwe thread side and it was really east to center the drill bit for accurate drilling. I then tap , I forget the size..10/28 mebbe. and install the mig tip.
 

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Tom,

A lot of things can be made to work if some of the basics are right. A 1" tube is 33% bigger than a 3/4" tube. A 0.035" tip is "right" for a 3/4" tube. I'd try a tip 33% bigger... or about 0.047". The length of the tube should work (3/4" is 8" to 9" and a 1/2" will run on a shorter tube). Check to see if the tip looks centered in the tube. Get the tip about in the center of the air intake to start. Try 7 to 10psi range to start. Tune burner out of the forge. If you can get it to roar, move the tip in and out a little looking and listening for better burning. One of the basics is forge volume... usually in cubic inches. Volume of the forge drives burner size and number of burners needed for forging temp. or welding temp.


Anyhow, what you really out to do is go here... http://www.zoellerforge.com/

If you look around on the three burner links, the "gas forge parts" link, the "FAQ" link, there is a lot of atmospheric forge information.

Larry Zoeller is a great guy to work with. I've e-mailed him back and forth on a number of atmospheric forge topics. Sometimes it takes a while to get an answer but I've always gotten one and always gotten all the help I needed.

On the 'gas forge parts' page, there is a book by Michael Porter. Inter-library loan is the way I accessed it. The book was over my head but I got stuff out of it.

Searching "atmospheric burner(s)" will lead you to Ron Reil and "T-Rex" burners, among others. I like Larry Zoeller for all-around-easy for me to deal with mentally.

It may seem like a lot money for some plumbing parts but either of Larry's "Z Burner" or "Modified Side-arm Burner" are a good deal if you add your time into it.

When we started into building an atmospheric forge for both forging and welding, we were "persons unclear on the concept". 6" x 24", 3- 3/4" burners, no flares. One burner would run, two were marginal, no way all three would run at the same time without a lot of huffing and/or blowing the flame off a burner tip. By the time we got done, we had flares, better gas control, and the understanding we were "over burnered" (two would have worked for the volume)... Now, when we crank the psi to all three, you can feel the earth move... =]

It's a learning curve... they always flatten out in time.

Mike
 
I was mistaken on my tube diameter. It is 3/4 inch pipe, so I am going to use a 1/2" pipe and play with that. got a new cap to drill a smaller orifice if I can make it run on the one I have now.
 
Unless you need a small burner, stick with the 3/4".
The best solution is a blown burner. They are so much easier to run....from a whisper to a roar. Cost is nearly the same for the burner. A blower for a small forge can be found in many things or bought for very little.
Stacy
 
Tom
You should be able to make this work. Regardless of what some may think it isn't that hard. If you are using a small tank with an OPD type valve on it then that is your biggest problem. They will not allow enough volume. The jet should be near the mouth of the bell to drag in enough air. You will not need a flare on the flame end except to run the burner outside of a forge, the forge body will create the pressure drop needed. I built myself both a forge with a fan burner and one with two venturi burners, I like them both. In addition to the regulator I use a needle valve on each burner to fine tune. On my venturi forge I can use it with both burners or just one by shutting off the needle valve and closing off the burner with a "choke" type plate.
Hang in there you will figure it out. If you post some pics it may help with diagnosis.
Have Fun
Alden
 
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