I actually built this thing a year or two ago (it consists of the minifurnace (see Furnaces), a copper tube spiral which preheats the oil and a 'hood' section which directs the vertical flames sideways to the furnace tuyere). I got some bad photos from the first burn but this more recent burn I actually got some good pics. Click most of them for full size.
Starting it up. The smoke is from flames leaking out between the top and bottom halves; why isn't it burning? Passing through the narrow gap pulls the heat out of it (conducted away by the crappy refractory) so the oil vapor is too cool to burn. Bummer, it doesn't help the smell of the foundry. :-/
On the furnace, where the tuyere enters, you can see a black patch, that's partially explained below.. the reason is the burner is just up to the furnace, no seals or piping type stuff. In the background is my burn barrel for making charcoal.
Looks good inside, doesn't it? It doesn't get real hot, only 1500°F or so, would be a lot better with a shorter furnace and better refractory. Still, melts aluminum well enough. You can see that a lot of soot comes out between the lid and furnace, it's pretty clean but that little bit of soot over time builds up and makes a mess. Unless I turn up the oil too high, then it's a black stream of smoke...
Everything's melted and the burner is off. This was scrap (plate etc.) and cutoff sprues, runners and gates from castings of similar alloy. This will go in my "general" scrap bin.
Using my patented Long Ingot MoldŽ, which is a rusty angle iron set in the dirt, :) I made a nice 4' long ingot. Those tomato cans can hold a lot of metal!
Here's a closeup of the plinth block after firing. It's an old piece, having sat around the basement for a while, waiting for some sort of burner (such as this) to put it to use. Its purpose is to elevate the crucible above the bottom floor of the furance so the flames hit the bottom corner rather than the side of the crucible, evening out the temperature on it, important with ceramic crucibles which can crack. The mixture of this is portland cement, sand and ash, wetted with thinned furnace cement. It didn't work too well, as after firing it was pretty soft.
Ok guys, here's a look inside. Now you know the secret of a good burner! Really? No, of course not. :) (Lionel's oil burner has the oil dripping into either the airstream, or the hot inside itself.) The oil comes in, metered by a needle valve, and goes from the 5/16" tubing to 1/4" ("refrigerator icemaker tubing"). I used copper because I had it, but steel would be better - handles heat and doesn't conduct heat as well (so it won't melt that solder joint you see.. 'course that could've been brazed, or some fitting instead..). It takes 2 turns around the wall then ends open (no special nozzle or anything) near the center.