Steven Bronstein Posted July 15, 2016 Share Posted July 15, 2016 I have built a number of Zoeller Type side arm burners. They have all worked well. However, I am having trouble setting up my newest forge. I have run these burners through soft brick and flared the inside of the bricks to create a flame holder. I have also made kaowool forge tops and just cut a hole for the burners and have worked well without any flaring. My newest forge has two burners and the top is 12" x 17" set on top of a rectangle of soft brick. One of the burners works great, the other sputters and will not form a typical flame. I removed it and added a stainless flare. It works great on the bench but continues to sputter inside the forge. I have changed the burner depth and changed the placement of the flare. I am stumped, any suggestions? Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 15, 2016 Share Posted July 15, 2016 In my experience sputtering is either due to blockage at the orifice with roughness from drilling or pipe dope getting in the way, (teflon tape is particularly bad about this) OR alignment issues. Not flare issues Quote Link to comment Share on other sites More sharing options...
Steven Bronstein Posted July 15, 2016 Author Share Posted July 15, 2016 Another Detail, I swapped the two burners and it appears it has to do with how the kaowool is shaped inside the forge. The "Bad" burner worked fine in the other hole. I did not do anything to shape the kaowool so I am not sure what to fix.I poked through the fabric and it is a somewhat random opening, larger than the diameter of the pipe. Thomas, Thanks for your help. The burner is ok outside the forge and works when poked into a different hole. It appears something is affecting the burner as it passes through the kaowool into the forge body. I have changed the depth to no avail..... Quote Link to comment Share on other sites More sharing options...
Steven Bronstein Posted July 15, 2016 Author Share Posted July 15, 2016 Thomas, of course you were correct. I realized there was a flaw in my logic. I was switching the burners but not the gas lines with the tweco tips. I swapped out the bad burner and it is now running correctly. The last question is there is a cold spot below the burners. I would assume that means they are too close and need to be raised. The interior volume is 12" x 13" x 4.5" =702 cu. in. This burner runs successfully in a single burner -6 brick forge of the same height. I would have thought they would have needed the same height regardless of the area. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 15, 2016 Share Posted July 15, 2016 Yeah, it's too close to a perpendicular surface, back pressure is one potential issue. The cold spot means the floor is so close the fuel air hasn't had a chance to burn before being dispersed. In fact the air fuel mix is cooling the forge floor there. Forge / burner is a volume ratio not area. It's also an environment where back pressure needs to be taken into account when tuning. Tuning a burner to run well outside the forge then wondering why it doesn't work properly inside the forge is a self explanatory problem. There is no back pressure when mounted in a vise or clamped to a table. Just putting it in a chamber changes that considerably and having two burners changes it a LOT. There is not only back pressure there are currents, the flame is moving with force and two burners can interfere with each other. Typically the burner at the back suffers the most interference. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted July 17, 2016 Share Posted July 17, 2016 Why do I get the feeling that you need a smaller burner? Not two smaller burners mind, but one of the burner should maybe be changed out for the next size down. The most elegant engineering fix I've ever heard of is "just don't go there". Logically then, "if you done went there already, turn around and go elsewhere Quote Link to comment Share on other sites More sharing options...
Steven Bronstein Posted July 18, 2016 Author Share Posted July 18, 2016 Thank you all. I raised the roof slightly, so no more dark spot, and cleaned up the Kaowool around the burner port. I put in a piece of 3/4" pipe, and packed around it with kaowool dipped in rigidizer. It is a now a cleaner opening leading into the forge and the burners are now working well. The last challenge is the amount of blue dragons breath coming out the door. I am assuming it is running too rich. It is an aspirated burner so I cannot add more air. Or is it just a volume issue and need to add a needle valve to reduce the overall volume. The two burners are required to get enough btus for the volume of the forge chamber. I have the burners coming straight down from the flat top, I want to keep the flat top so it is easy to add/remove bricks but may recut the burner ports so that they enter the rectangular forge chamber at an angle. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 18, 2016 Share Posted July 18, 2016 Blue dragon's breath indicates a pretty neutral air fuel ratio, if it isn't scaling the steel IN the forge the mix is good. If you're getting too much dragon's breath turn the pressure down unless you're heating the shop too. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Steven Bronstein Posted July 18, 2016 Author Share Posted July 18, 2016 Frosty, thanks so much for all your help. I am then assuming that if I want to weld I will just have to keep the pressure up and deal with the dragons breath Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 19, 2016 Share Posted July 19, 2016 My pleasure. Yes, use the regulator like the throttle it is. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
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