John Ledford's Radiant Burner

Rich Carlstedt posted on Chaski.org

Back in 2000, at the IBLS Meet in Burnaby B.C. a fellow from New Mexico, John Ledford, had his locomotive successfully powered with ceramic burners. This was in a 7-1/2 inch gauge loco. John was a scientist at the National Lab in Los Alamos and very intelligent. The secret for heat as I recall was to use liquid propane, instead of the normal regulator air mixer method. The liquid injector looked like a hypo needle, and no flame was seen as the ceramic glowed a very bright orange/red.

John's design consisted of a stainless steel box that was mounted at the mudring and below, with NO air allowed

to come in around the box,and which had a ceramic core on it's top, in the firebox. The box had a 1 inch diameter tube introducing the gases into the middle of the box. The tube was a venturi with a hypo needle feeding liquid propane in it's center. You must have no draft! So the Petticoat pipe is eliminated and exhaust steam is piped to the top of the stack. The only oxygen is what comes in at the venturi with the propane since it is all sealed.

What was amazing was I could place my hand under the bottom of the stainless steel box and feel no heat. All the heat is radiated into the firebox and the bottom of the box is cooled by the incoming air and expanding propane (You know how the regulator in propane system gets ice cold..this expansion occurs in the bottom of the SS box).