CactusBob Posted February 11, 2018 Share Posted February 11, 2018 I have spent the last two or three hours looking through IFI and cant find a definitive answer to tuning. I fired up my TEE burner to fire the Rigidized wool insulation and cannot keep the burner lit unless I cover the air inlets almost completely. Completely closed at low pressure (1-3 psi) gives a gentle flame with no roar, open the air inlet up a little and it starts to roar. By turning the pressure up (I have a 0-40 psi regulator) to 40 psi I can open the air ports all the way and it will stay running. My tee is a 3/4 X 3/4 X 1/2 T, 4" nipple with a .024 mig tip If this is running too lean wouldn't shortening the mig tip cause more air to enter ultimately making it leaner? or should this issue be fixed by adding covers to the inlets and letting it run at low pressure? or a bigger mig tip? Tonight I will get some flame pics, its just too bright today to see the flame The refractory has not been put in yet, that will be tonight, this firing was just to dry and harden the rigidized wool Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 12, 2018 Share Posted February 12, 2018 I wish you guys would get off this run at low pressure thing. It SHOULD roar, if it isn't, it isn't running properly. Your parts list sounds okay, within the ball park anyway. Your jet is off center in the pic. It probably isn't inducing enough air because you're running it at too low PSI. I've never built a T that ran that low, mine typically run between 9 and 20 psi. Not counting the NARBs those are a whole different critter. The T burner is the simplest easiest to make jet ejector type burner I could come up with. As such they're harder to tune and have a much narrower operating range than others. Mike's are much more adjustable but require a higher level of shop skill and precision work. It's in the trade off. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
CactusBob Posted February 12, 2018 Author Share Posted February 12, 2018 42 minutes ago, Frosty said: I wish you guys would get off this run at low pressure thing. It SHOULD roar, if it isn't, it isn't running properly. No sir, I'm not trying to run it at low pressure, that's just where I tried to light it. My problem is I can barely keep it lit at 40 psi. I'm just trying to figure out how to get it to run at any pressure. It seems like its getting way to much air so if I shorten the tip I would think it would pull in more air. So should I block off some of the air or shorten the tip? how would I determine which way to go The Kast-O-Lite was applied late this afternoon so either tomorrow night or Tues I'll try re-firing it Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 12, 2018 Share Posted February 12, 2018 4 hours ago, Frosty said: I wish you guys would get off this run at low pressure thing. It SHOULD roar, if it isn't, it isn't running properly. Yes; turbulent type burners must roar because it is due to flame noise. You then silence the roar in the way you make a forge's openings; they['re called baffle walls. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted February 12, 2018 Share Posted February 12, 2018 13 hours ago, CactusBob said: I fired up my TEE burner to fire the Rigidized wool insulation and cannot keep the burner lit unless I cover the air inlets almost completely. Since you're trying to fire the insulation I assume this was with the burner mounted in the forge. Typically with a T burner I get burning in the tube with that pulsing chirping sound at too low pressure (not the same psi for every burner). Raising the pressure a little will get a burn at the end of the burner tube, but too much pressure when cold will blow the flame off the end of the burner, even in the forge. I believe someone else mentioned that when firing a wet blanket the burner may not function well and you may have trouble keeping it lit due to the amount of water vapor created by firing the blanket. I've never had a situation where I couldn't keep the burner lit at a lower pressure, but higher pressure would keep it burning, so the wet blanket could be the "wet blanket" with your burner. In your photo it's clear your fitting isn't lined up with the burner tube, but it looks like the mig tip could be. I've had enough of my own pictures look different than I knew them to be, but if your jet is not somewhere near centered with the burner tube that will affect performance for sure. 14 hours ago, CactusBob said: My tee is a 3/4 X 3/4 X 1/2 T, 4" nipple with a .024 mig tip If this is running too lean wouldn't shortening the mig tip cause more air to enter ultimately making it leaner? or should this issue be fixed by adding covers to the inlets and letting it run at low pressure? or a bigger mig tip? I use a 0.023 mig tip in my 1/2" T burner and it works well, so I don't think the orifice size is a big part of your problem. You are correct that shortening the tip should result in more air drawn in, but your flame blowing out is not necessarily a fuel to air ratio issue. Even if the fuel/air ratio is perfect with a jet that is perfectly centered in a tube the perfect length you can still blow the flame off the end of the burner if you turn the pressure up enough where the fuel/air velocity is faster than the flames can burn the fuel. A flare can help with this issue even in a forge. However, usually we can keep these burners lit without a flare at a moderate pressure until the forge starts to glow then we can turn them up as far as we want without the flame blowing itself out. My guess (and it is only a guess) is that you have a combination of the wet blanket and a jet that is off center contributing to your issue. Quote Link to comment Share on other sites More sharing options...
CactusBob Posted February 13, 2018 Author Share Posted February 13, 2018 13 hours ago, Buzzkill said: I believe someone else mentioned that when firing a wet blanket the burner may not function well and you may have trouble keeping it lit due to the amount of water vapor created by firing the blanket. Possible, but it sat over 24 hours and daytime temps were about 80 prior to firing. I'll try again after the refractory is all in. 13 hours ago, Buzzkill said: Even if the fuel/air ratio is perfect with a jet that is perfectly centered in a tube the perfect length you can still blow the flame off the end of the burner if you turn the pressure up enough where the fuel/air velocity is faster than the flames can burn the fuel. I took my hand and covered the air inlets and it would fire and run with a roar at all most any pressure, the higher the pressure the more air inlet I was able to uncover. With the air inlet fully uncovered it would just run at max pressure 40 psi. It seems to be drawing too much air. I will straighten the tip and try it again after the refractory is dry. Hopefully with everything dry it will run better. Thanks for the info Bob Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted February 13, 2018 Share Posted February 13, 2018 2 hours ago, CactusBob said: I took my hand and covered the air inlets and it would fire and run with a roar at all most any pressure, the higher the pressure the more air inlet I was able to uncover. With the air inlet fully uncovered it would just run at max pressure 40 psi. It seems to be drawing too much air. I will straighten the tip and try it again after the refractory is dry. Hopefully with everything dry it will run better. Covering the air inlets does decrease the amount of air being drawn in of course, but it also has the effect of slowing the fuel and air stream inside the tube so it's slower exiting the burner. Less velocity at the end of the burner will keep the flame there without blowing it out. That doesn't mean your fuel and air ratio is correct when you cover the inlets. You're most likely causing a very rich burn when you do that. I am a bit puzzled by the flame becoming more stable at higher pressures though. Perhaps when you turn it up that high you create enough back pressure within the forge to offset the greater velocity of the fuel and air mixture. Once again that's just a guess though. I rarely run my 1/2 inch T burner past 20 psi, and it's only close to that pressure if I'm forge welding. With my burner in my forge I keep the pressure around 5 to 6 psi when starting cold and turn it up after the shell gets hot. If I try to turn it up to something like 15 psi right away it will blow itself out. What works with my setup may not work with yours though. It's just to give you a ballpark idea of what my experience is with that size and style of burner. Quote Link to comment Share on other sites More sharing options...
Binesman Posted February 13, 2018 Share Posted February 13, 2018 Do you have a coupler on it as a flame retainer? Been a while since i read the tburner instructions and i believe frosty taks about it and says it is unnecessary. However in your case it sounds like it is needed. Quote Link to comment Share on other sites More sharing options...
CactusBob Posted February 13, 2018 Author Share Posted February 13, 2018 On 2/11/2018 at 6:31 PM, Frosty said: The T burner is the simplest easiest to make jet ejector type burner I could come up with. Thank you for coming up with it and sharing it. I know myself and probably others wouldn't be doing this without designs and ideas like yours. The simplicity of this design is what made me realize I can build this and despite being knotheaded at times this baby will be heating steel before long. Thanks again Bob Quote Link to comment Share on other sites More sharing options...
CactusBob Posted February 26, 2018 Author Share Posted February 26, 2018 I finally have the refractory in and cured, it sat about a week before I could get back to it, ran it through a few cycles of getting hotter and letting it cool down. Yesterday I fired it and let it run for about 30-40 minutes. After lighting I noticed it started purring at about 5 psi and was definitely roaring at 10 psi, 20 was a fire breathing dragon that was not a happy camper , definitely a roar. Here are flame pictures at 5 and 10 psi and right after shutdown. I have to puit the IR coating on and finish the burner holder. Does this look like its running right or is more tuning required Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted February 27, 2018 Share Posted February 27, 2018 Pictures of the flame burning inside the forge would give us more information to work with. Some of the refractories, like Kastolite, tend to change the flame color to decidedly orange for several forging sessions. From what I can see it looks like you are getting quite close to where you want to be though. Keep in mind that in these pictures you have extra space around the burner as it enters the forge. This can allow additional air to be pulled into the forge. You may have to do some final tuning after installing your burner mount, especially if you eliminate that extra space. The bottom line is if it does what you want it to do and how you want it done then it's good, or very close to it. Quote Link to comment Share on other sites More sharing options...
CactusBob Posted February 28, 2018 Author Share Posted February 28, 2018 7 hours ago, Buzzkill said: Pictures of the flame burning inside the forge would give us more information to work with. Here's a couple of the pics looking in the forge, I believe it was running about 10 psi at this time. It seemed to take awhile to heat a piece of scrap steel. I will have to time it this week and see how long it actually takes Bob Quote Link to comment Share on other sites More sharing options...
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