Ulric Posted November 12, 2010 Share Posted November 12, 2010 Started with a 12" black iron pipe (1" diameter), cap and 1"-1 1/4" flare... Thought the nipple, tip wouldn't be much a problem to find locally... uhg. You can find a brass one, but forget sch 80 black... welding tips, just the small, blunt mig tips. Found out in my search, that many of the small supply shops have closed up and disappeared in the current ecoomic situation. So I sallied forth... went with the brass nipple, and dug up a # acetelyne tip cut it down... threaded the nipple and the cut tip. I had originaly drilled and cut 4 slots at 1/2 x 1 1/2 in approx (cut with an angle grinder) after cutting the pipe down to 9 inches.. That seemed to..run oddly, so I cut 2 pieces out, making 2 large (and rough) slots. Smoothed them out a bit as best I could. Unfortunately ignition is 1-3 inches into the pipe instead of the flare. Was...interesting to play with and try to build, think I'm going to order a couple nipples and tweco tips online. Pics are included for the heck of it, 1 P1 @ zero register of guage, 2 & 4 at 5psi, pic 3 approx 1.5-2psi Quote Link to comment Share on other sites More sharing options...
Dodge Posted November 13, 2010 Share Posted November 13, 2010 Started with a 12" black iron pipe (1" diameter), cap and 1"-1 1/4" flare... Thought the nipple, tip wouldn't be much a problem to find locally... uhg. You can find a brass one, but forget sch 80 black... welding tips, just the small, blunt mig tips. Found out in my search, that many of the small supply shops have closed up and disappeared in the current ecoomic situation. So I sallied forth... went with the brass nipple, and dug up a # acetelyne tip cut it down... threaded the nipple and the cut tip. I had originaly drilled and cut 4 slots at 1/2 x 1 1/2 in approx (cut with an angle grinder) after cutting the pipe down to 9 inches.. That seemed to..run oddly, so I cut 2 pieces out, making 2 large (and rough) slots. Smoothed them out a bit as best I could. Unfortunately ignition is 1-3 inches into the pipe instead of the flare. Was...interesting to play with and try to build, think I'm going to order a couple nipples and tweco tips online. Pics are included for the heck of it, 1 P1 @ zero register of guage, 2 & 4 at 5psi, pic 3 approx 1.5-2psi The second pic looks great!! You say that it is burning inside the pipe as well?? How big is the orifice? I would be curious to see pics of your acetylene tip orifice. Did you have a problem using blunt mig tips? That's all I have used with no issues. I used them in atmospheric burners as well as my forced air burner. Quote Link to comment Share on other sites More sharing options...
pkrankow Posted November 13, 2010 Share Posted November 13, 2010 I had pre-ignition problems and took a torch file set and cleaned up the orifice exit to have a nice sharp edge. Since you say you cut down the torch tip you may want to start with this as it is simple. Phil Quote Link to comment Share on other sites More sharing options...
Ulric Posted November 13, 2010 Author Share Posted November 13, 2010 I have no clue on the actual orifice size of the tip... was one we dug up out misc collection of stuff at a cousins. In order to use the blunt mig tips, I either had to use a compression fitting or fab something to hold it... they're too small to fit the brass nipple. I'm kicking around the idea of cutting off 2-3 inches off the 1" pipe, putting on a reducing bell and going to a 3/4 pipe and see how it goes/what happens. We... played around with it a tad last night, cousin wanted to see it in action. Used it to heat of a brand he had, and branded some picnic tables & benches he'd made. On a whim, I took the 'flare' off and ignition point was within 1/16-1/8th the end of the pipe. Quote Link to comment Share on other sites More sharing options...
kcrucible Posted February 10, 2011 Share Posted February 10, 2011 I know I'm late to the show here (and you're probably not reading this...) but I had basically the same design and same initial problem (though I left my pipe at 12".) In fact, the design is so similar I'd guess your build is based on mine. Ultimately, the burnback rate exceeds the exit gas rate and so it enters the tube and keeps burning down until it hits a turbulance point that can slow down the gas and hold the flame in place (around the air intakes.) The solution is a flare or flame holder. I've found that a 1 1/4" -> 1" pipe coupler with the threads tapered down on the 1 1/4" side work quite nicely. Creates a nice little pocket where the flame sits. I'd guess that the roughness of the air intake, shorter tube, and not using the tapered tip is causing slower exit velocity, accounting for the performance difference. All of my edges (tapered output, air intakes, etc) are very smooth via Dremel. The air intakes are bevelled-in to reduce drag and make it easier for the air to flow around the tip. It's possible that the flare isn't needed if I hadn't removed the "lip" from the 12" pipe where it tapered in, initially. I never went back and tried it again with a fresh pipe. The problem: http://kcrucible.wordpress.com/2010/08/11/firing-up-the-burner/ The fix after some experimentation: (note that I DID grind down the threads, and it DID improve things) http://kcrucible.wordpress.com/2010/08/20/burner-modifications/ And then the burning: http://kcrucible.wordpress.com/2010/08/23/firing-up-the-burner-pt-2/ Quote Link to comment Share on other sites More sharing options...
Ulric Posted February 10, 2011 Author Share Posted February 10, 2011 We're using it for general other uses now after/with playing with it a bit. Ie: Heating branding irons, burn out wasp nests and other misc. :-) Took off the 1" -> 1x1/4" bought 2 1"x3/4" & 1"x1/2" reducers and 2" nipples (3/4" & 1/2") Tie and $ permitting I'll play with it more, those things have just been...lacking a tad as of late. Quote Link to comment Share on other sites More sharing options...
DClaville Posted February 16, 2011 Share Posted February 16, 2011 (edited) good first try at a burner i've build a few handfuls of burner playing around and such what i have found to be very important is 1. make it long 12" is good but only as the main burner tube 2. the far back part where the air slots are should always be larger then the main tube size so for a 1" burner you should have a 1 1/4" tube for the air intake part ( this is to aid the venturi effect)have the gas inlet about 1/4 inch (mig tips tip) infront of the start of the air slots (this is most likely the main problem you have in the burner show in post 1 ) the gas need to pas by the air intake slots to be able to use its own speed and drag in air along with it and speed up even more as it flows down the burner tube and are forced in trough the step down in size to enter the main burner tube for a 1" burner a 1 or 1,2mm mig tip should be ideal for the easiest way to rig it up is to have a small pipe or brass fitting and just tread it so the mig tip fits, the ones i use have 6mm metric size tread if you having a hard time hold the flame where you want it still the use a smaller size gas inlet (mig tip) and higher pressure venturis need fast gas flow to draw in air, to make speed in the venturi the step uo in dia. should be at least 5mm for it to hold any flame no mater how strong ill try to get some photos up good luck with it stay safe. Just realised how old this is hehe well i hope this helps :) Edited February 16, 2011 by DClaville Quote Link to comment Share on other sites More sharing options...
Job R Posted February 23, 2011 Share Posted February 23, 2011 Helps me , I just got a small single burner. Homemade and second hand . I am doing some tooning. The odd thing about mine is the flame points at the ceiling, is that wrong or just different? Quote Link to comment Share on other sites More sharing options...
kcrucible Posted February 23, 2011 Share Posted February 23, 2011 Helps me , I just got a small single burner. Homemade and second hand . I am doing some tooning. The odd thing about mine is the flame points at the ceiling, is that wrong or just different? It should be a jet out of the tube. Probably you have insufficient gas pressure. If you're cranked up as far as you can go, then it may be a low pressure gas regulator. You want one that is adjustable between 0 and 20/30 psi (and high pressure hose to match... don't take chances.) I list my parts with some links here: http://kcrucible.wordpress.com/2010/08/11/firing-up-the-burner/ Similar kits can be found elsewhere. Quote Link to comment Share on other sites More sharing options...
Job R Posted February 24, 2011 Share Posted February 24, 2011 It should be a jet out of the tube. Probably you have insufficient gas pressure. If you're cranked up as far as you can go, then it may be a low pressure gas regulator. You want one that is adjustable between 0 and 20/30 psi (and high pressure hose to match... don't take chances.) I list my parts with some links here: http://kcrucible.wordpress.com/2010/08/11/firing-up-the-burner/ Similar kits can be found elsewhere. i have run up to 15 psi but i will try more i guess my question was regarding the orientation of my burner in the chamber it points upwards toward the ceiling. unlike most i have seen which point at the floor. here is a photo worth more words Job Quote Link to comment Share on other sites More sharing options...
kcrucible Posted February 25, 2011 Share Posted February 25, 2011 i have run up to 15 psi but i will try more i guess my question was regarding the orientation of my burner in the chamber it points upwards toward the ceiling. unlike most i have seen which point at the floor. here is a photo worth more words Job Oh, I misunderstood the question. Orientation of the burner really shouldn't matter much. You're just trying to deposit heat into the cavity. Most point down so that nothing can fall into the burner tube I expect. So the answer to the original question would be "just different." I thought the question was about a lazy flame that just drifted up from end ends of the burner tube (when held horizontally.) Quote Link to comment Share on other sites More sharing options...
Job R Posted February 25, 2011 Share Posted February 25, 2011 Thanks for the reply , it's always harder to type what I mean than to speak and mime what I mean. I was all set to make changes, just to make it the same as most the others. Quote Link to comment Share on other sites More sharing options...
DClaville Posted February 25, 2011 Share Posted February 25, 2011 Job the answer to your low flame is in my post further up the thread your burners burner tube is way too short to get a good mix and lacks the size stepdown from air intake champer to main burner tube to get speed on the gas/air mix its no problem that the burner points up inside the forge it might even be better if you want to avoid the "hotspot" where the flame is good luck with it and stay safe :) Quote Link to comment Share on other sites More sharing options...
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