Multistage fuel burner having a helically rising column of air-fuel mixture

摘要

Disclosed is a fuel burner comprising a nozzle for ejecting fuel, an inner tube having an inlet end for receiving the fuel from the nozzle. The inner tube has first and secod air inlet ports adjacent to and located in positions spaced longitudinally apart in the direction of axis of the inner tube and angularly apart about said axis for introducing primary air into the inner tube so as to produce a helically rising column of air-fuel mixture and providing primary combustion at the outlet end thereof. An outer tube coaxially surrounding the inner tube has secondary air inlet ports for introducing secondary air thereinto to provide secondary combustion at an outlet end. A sensor is located between the outlet ends of the inner and outer tubes for detecting the presence of the primary combustion.