Combustors

Claim 1

A combustor comprising: an elongated, cylindrical casing having an upstream portion and a downstream portion; a fuel injector in the upstream portion of said casing; means for forming an annular combustion air passage in said upstream portion of said combustor in surrounding relationship to said injector; means for introducing combustion air into the upstream end of said passage and for effecting a flow of said air therethrough; means for imparting a rotational component to the air flowing through said passage, whereby said combustion air will be formed into and exit from said passage and the upstream portion of said casing in the form of a rotating, axially moving annulus; and fuel supply means for so providing an annulus of liquid fuel at or toward the downstream end of said injector that said fuel will be inhibited against mixing with said combustion air and will form into a thin, stratified film on the inner boundary of said combustion air annulus and subsequently be atomized by the air making up said annulus; the downstream portion of said casing being of sufficiently large diameter that said annuli of combustion air and atomized fuel can so expand thereinto as to reduce the centrifugal forces on, and promote the mixing and subsequent combustion of, said fuel and air and the formation of a recirculation zone containing hot gases which stabilize the flame generated by the combustion of the fuel and air and so ignite the fuel as to effect evaporation and heating of the fuel before it is mixed with the combustion air, said injector having a fuel flow passage extending therethrough and constituting a component of said fuel supply means, a first atomizing air passage surrounded by said fuel flow passage, and a second atomizing air passage surrounding said fuel flow passage, said combustor further including means for directing air at high velocity through one or both of said first and second atomizing air passages against said annulus of fuel to assist in atomizing said fuel.