Dear,
This is my first post. I have been reading lately on this forum and learning many new things, but as it typically happens, first you build then you try to solve issues. So, this build I am posting is done before most of my reading. This is my second forge, first one was a soft firebrick one made from a block of autoclaved cellular concrete. It was OK, but with every forge the inner chamber got smaller and smaller due to the concrete erosion. So, I've built one from hard firebrick (refractory), the material used for stoves. Dimensions of a brick are: 250x124x30 mm, so it's close to 1.25" thick, similar to what I've seen some other forge builds. I glued the pieces and spaces in between with refractory cement, rated to 1200C.
Now, the burner. I've built it as an atmospheric one with a MIG welding tip, 0.8mm, that's 0.03". Pipe is 3/4" with a flare at the end of 1", larger would have been better. This burner ran on propane in my soft firebrick forge without issues, maybe a bit of dragon breath. I use a propane/butane tank. In my country these are sold at gas stations for cooking ovens, it's the only type I can find without going really into professional shops for welding. So far so good, I've made a few knives, pair of tongues, other decoration items from wrought iron and high carbon steel. I got them to non magnetic, quenched, had success.
But, with the new forge I thought of going for a double burner. Before completely building a new one I thought of trying to split the existing one in two, still having just one injector. On the tank I use an adjustable pressure regulator from 1-7 bar, same as in my old forge. I've tested the new setup outside of the forge and it runs well, stable but I believe there's not enough pressure. There is no backfiring to the air inlet. My tank is now probably only 30% full, so pressure is not optimal ... maybe. Once I put the burner in the forge it runs well for the first 3-5 mins and then it starts choking. I'm thinking it could be exhaust running in the inlet. The two pipes that I put the burner in have no screws yet, rather I let the burner hang in there. Protrusion of the flares in the forge is about 10mm. The pipes are really tight to the flares but definitely not sealed.
I took pictures and I hope you guys can help me. I could build two separated burners. I tries to search if somebody else had this crazy idea and I'm thinking it could be it's so bad nobody took pictures of it. I'm thinking that also forced air could be a solution, like stacking a hair drier like blower in the inlet.
The welding and pipe cuts are unfinished work, once I have it running properly I will dress it up. Please excuse the mess.
I'm looking for advice on the burner, starting with fixing the current solution if it's not totally idiotic to building two separated ones. Thank you in advance!