LeeHene Posted February 26 Author Share Posted February 26 Frosty, These pictures give a better example of how it fits in the burner tube. Mikey, I do agree that simplicity and repurposed parts would be excellent, but I've come to a point with my current forge and blower where nozzle design has to be balanced with efficiency of flow. Quote Link to comment Share on other sites More sharing options...
LeeHene Posted February 26 Author Share Posted February 26 I cranked it up a bit. Thd picture doesn't do it justice. Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 27 Share Posted February 27 The real trick for home build ceramic burners will be a suitable high temp ceramic a person can fire in a hobby shop or afford to have fired at a ceramic shop after forming it. This is a subject I haven't given much thought to the how to of it. I think we have a long thread on just this idea Mike. Lee: I'm not picturing what if any questions you have about your burner and am having trouble asking good questions. Maybe I'm tired or maybe it's blood sugar but I'm drawing a blank on what you mean by balancing flow . . . efficiency. It's just not making sense to me right now. Maybe if you reword or maybe my brain will be engaging better when I come back but right now I'm at a loss. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 27 Share Posted February 27 Lee, Repurposing is just one goal. We all do what we can to simplify burner construction. Meantime, we do what we can, never knowing who in the wide world will come up with a better plan Quote Link to comment Share on other sites More sharing options...
LeeHene Posted February 27 Author Share Posted February 27 Frosty, sorry my comment about balancing flow with efficiency wasn't more clear. What I meant was due to having a less than stellar blower and a small forge, I'm having to strike a balance of spreading my flame out for the desired even coverage without causing a restriction that creates too much resistance to flow. The only way I can overcome restrictions is by increasing velocity, but that comes at the expense of efficiency because some propane escapes out the front before it has the chance to burn completely. It's not nearly as much of an issue if I'm running the forge at the higher end of the heat range, but for the majority of the work my son and I do with 1/2" or under mild steel, that much heat is not required and eats a lot of propane. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted February 27 Share Posted February 27 On 2/24/2024 at 7:15 PM, LeeHene said: Introducing... The HALO burner! Love the flame shape. That looks awesome! I haven't fired up my forge much in the past few months, but now I'm gonna have to resist going into tinker mode when I get back out there. Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 27 Share Posted February 27 Thanks for the clarification Lee, I wasn't too sharp yesterday for some reason. The issue is perfectly clear. The lowered efficiency of excessive flame out the doorways you describe is commonly called "dragon's breath" and I'm with you all the way! It lowers efficiency by burning fuel outside the furnace, whatever kind it is. Next to adjusting to a neutral fuel air ratio, lowering flame velocity is the easiest way to reduce dragon's breath I know of. I'd like the halo if it weren't quite so wide myself and have a couple ideas but would hate to maybe destroy the cone if it's not easily replaced. Have another one? Preferring a slightly more narrow halo I'd start putting a round grind on the inside edge of the cone to encourage the flame to wrap around the edge and not spread as far. Putting a hollow grind on the inside edge of the tube orifice should help. If I wanted a wider halo I'd put the convex edge on the tube outlet's ID edge and a concave on the cone. Being aware that this will thin the cone's edge and make it more vulnerable to heat damage. Same thing for the tube edge if widening the flame. For a general idea the curved sections are wave lenses like an airfoil. Any fluid flowing over a curved surface accelerates and creates a low pressure zone at the surface contact area. "Bernoulli's principle." If you've ever watched jets take off on cool humid days you can see how the air flows over the wings and the vortices generated at the tips. Wing tip votrices are the reason for the little winglets on jet wingtips. They redirect them downwards for a bit more lift and less drag. That's my thought for shaping the halo more finely while keeping drag through the gap as low as reasonably possible. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
LeeHene Posted February 28 Author Share Posted February 28 Frosty, Thank you for the idea. To be honest, the shape does look awesome (if I may say so) and it does heat most of the forge very evenly. HOWEVER, at my normal working setting (valve positions marked based on my favorite burner) it still leaves a cooler spot in the center, right where I normally put my work. I've been trying to figure out how to overcome this and was leaning toward going one size down with the bolt head. If I can evenly modify the edge like you mentioned to help pull the flame in, that might just work! Pouring a floor with a smooth transition out of cast-o-light rather than using a cut-down firebrick would probably help some too. I'll still probably make another one. The internal spacer still blocks more flow than I'd prefer. ...I'm really getting nitpicky about it, but I already have a great working burner that's a pair of channel locks away to swap out of something doesn't work. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 28 Share Posted February 28 If you set up the forge as a radiant oven, than perhaps nothing will be lost by the "cold spot," where you might continue to set your work. For, it would not remain cold, but would remain unlikely to be impinged by the burner's flames, and therefore unlikely to contribute to scale on work surfaces. Just a thought. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted February 28 Share Posted February 28 1 hour ago, LeeHene said: it still leaves a cooler spot in the center, right where I normally put my work. I've been trying to figure out how to overcome this The easiest solution may be just a hole in the center of your bolt head to allow a small amount of fuel air mixture through. Quote Link to comment Share on other sites More sharing options...
Goods Posted February 28 Share Posted February 28 You could even place two holes from opposite sides of the bolt, starting at the taper, angled to the front center of the bolt. When to holes are aligned towards the ends of the forge, it may direct some of the FAM away from the doors to the center cool spot. Keep it fun, David Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 28 Share Posted February 28 Coming back to the thread some ideas are gelling. I think losing the firebrick floor and replacing it with a mix of 80%+ zirconia flour, 20% silica bubbles and the remaining 10% bentonite. Bringing it to a good working moisture content will require patience but that's bentonite for you. I'd ram it maybe 1/2" thick on the floor and 1/4" for walls and roof. With a smooth transition between walls and floor the flame should circulate pretty evenly through the entire forge. Another thought is similar to George's but I think I'd saw some slots in the edges of the cone to allow flame to blow through to the center. I'm not crazy about it but if you have enough it's an experiment that might work. A last general thought is turn your forge on end, widen and shorten it to maybe 8-10" high. Then grind a series of slots at an angle in the inside of the tube, think STEEP rifling to induce spin in the flame. Hopefully the vertical cylinder would be filled with spinning flame. Put the exhaust port in the center bottom with a piece of kiln shelf on stand offs say 1/4" - 3/8" high to keep things from falling through. I realize the kiln shelf floor vent is just a blue sky idea but here is my reasoning. The center of a cyclone wind is the low pressure zone, low pressure is what generates them in nature and your bath tub. Draining water = low psi = whirlpool it's a conservation of angular momentum thing. Anyway, the exhaust will NOT want to exit the center of the round floor and will have to shed MORE energy if it is forced to. energy the forge liner will absorb and re-radiate as IR radiation. I've given the cyclonic forge some thought using either 3 or so small dia burners or a pair of multiple orifice burners aimed to induce the cyclone for some time but I haven't actually built a forge in some time so I just think about it. I can't help it the voices won't stop! I've come up with a couple ideas for exhausting the forge gasses in a reasonable manner. An exhaust stack extending out the bottom of the forge, gentle 180* turn and up through the roof. Refractory for the 180 and stove pipe on up. The trick will be getting the flow moving up the stack. So keep the door baffles closed until there is hot gasses in the stack might work. A jet of compressed air aimed up the center of the stack will work like a NA burner. That will work. Using an air jet would allow the smith to turn up the air so he could open the doors without too much dragon's breath. The cyclonic forge and a HALO burner have the voices excited. Thoughts? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
LeeHene Posted April 16 Author Share Posted April 16 Just an update, I went back to my previous burner that uses a smaller diffuser cone, but I placed the burner further up in the tube. It still sends gas and air down around the walls, but also allows some to evenly spread back to the center. (I think Mikey had suggested trying that a good while back. Works near perfect! (Sorry it's been a little while. My 13 year old boy decided to make money building bird houses. We're up to 28 of em' and still have orders coming in.) Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted April 16 Share Posted April 16 Nice one, Lee. Tell us a little bit about the bird houses. I for one, am interested. We have a garden, a bird bath, loads of birds, and three trees to place them in; but no bird houses. Quote Link to comment Share on other sites More sharing options...
LeeHene Posted April 16 Author Share Posted April 16 They are sized for bluebirds and similar. Assembled strong and true, held together with Titebond III and trim nails. They are available to be painted any number of different colors, by request. He's been selling them for $25 each. (We are making him cover the cost of material and supplies.) Quote Link to comment Share on other sites More sharing options...
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