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US 4,373,325 AGranted
Combustors
AssigneeInternational Harvester Company
InventorJack R. Shekleton
Life of this patent
Estimating the term…
Abstract
Combustors utilizable in a variety of sizes, configurations, and applications in which vortex induced centrifugal forces and hot gas recirculation are employed for flame stabilization. Both gas and liquid fuels can be burned, and low emission as well as other modes of operation are available.
Claims53
A method of effecting the stable, nonluminous combustion of a liquid fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air only after said film has been formed on the inner boundary of said annulus and so as to form a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said stratified annuli of combustion air and fuel droplets to promote the mixing and subsequent combustion of said fuel and air and then so effecting a downstream contraction of the swirling fuel-air mass as to effect 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 said stratified annuli of atomized fuel and rotating combustion air are rapidly expanded to promote the mixing of said fuel with the combustion air.
1 more element
A method of effecting the low emission combustion of a liquid fuel which comprises the steps of:
- generating an outer annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air;
- centrifuging the atomized fuel outwardly into the annulus of combustion air to evaporate said fuel and mix it with the combustion air;
- and expanding the annulus of the fuel-air mixture thus formed and igniting said mixture and then effecting a downstream contraction of the fuel-air mass to promote the formation of a recirculation zone containing hot gases which stabilize the flame generated by the combustion of the fuel-air mixture and ignite the fuel-air mixture at a location downstream from the location at which premixing of the fuel with at least that air in the outer annulus is initiated, ignition of the fuel and air being delayed until atomization and evaporation of said fuel and the subsequent formation of the fuel-air mixture are completed by so generating an inner annulus of rotating air on the inner side of the annulus of fuel after said fuel has been atomized as to isolate the fuel from the hot gases in the recirculation zone and thereby prevent ignition of said fuel until the formation of the fuel-air mixture is completed as aforesaid.
2 more elements
A method of effecting the combustion of fuel in a manner which provides a stable flame at off-design conditions and low emissions under operating conditions at or nearer the design point, said method including the steps of:
- effecting the combustion of said fuel at off-design conditions by:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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;
- combustion being effected at design and nearer design conditions by:
- generating an outer annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air;
- generating on the inner side of the annulus of atomized fuel thus formed an inner annulus of rotating air to prevent the ignition of the fuel;
- centrifuging the atomized fuel outwardly into the annulus of combustion air to evaporate said fuel and mix it with the combustion air;
- and expanding the annulus of the fuel-air mixture thus formed and igniting said mixture and then effecting a downstream contraction of the fuel-air mass to promote the formation of a recirculation zone containing hot gases which stabilize the flame generated by the combustion of the fuel-air mixture and ignite the fuel-air mixture at a location downstream from the location at which premixing of the fuel with at least that air in the outer annulus is initiated.
9 more elements
A method of effecting the combustion of fuel in a manner which provides a stable flame at off-design conditions and low emissions under operating conditions at or nearer the design point, said method including the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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;
- combustion being effected at design and nearer design conditions by so injecting fuel into said annulus of combustion air as to premix said fuel and air and subsequently expanding said annulus and then effecting a downstream contraction of the fuel-air mass to promote the formation of a recirculation zone containing hot gases which stabilize the flame generated by the combustion of the fuel and air and ignite the fuel-combustion air mixture at a location downstream from the location at which premixing of the fuel with at least that air in said annulus is initiated.
2 more elements
A method of effecting the combustion of gaseous fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of said gaseous fuel on the inner boundary of said annulus at a specified location therealong;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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.
A method of effecting the combustion of fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air;
- injecting a gas or atomized or vaporized liquid fuel into said annulus at the upstream end thereof;
- thereafter rapidly expanding said annulus to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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.
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;
- 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.
4 more elements
A gas turbine engine comprising:
- a combustor which includes:
- an elongated cylindrical casing having an upstream portion and a downstream portion;
- a fuel injector in the upstream portion of said casing;
- means forming an annular combustion air passage in said upstream portion of said casing;
- 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 configured such that said annuli of combustion air and 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;
- a compressor;
- means including said compressor for introducing combustion air into the upstream end of the combustion air passage and for effecting a flow of said air therethrough;
- and a turbine through which the hot gases generated in said combustor can be expanded to produce mechanical energy.
7 more elements
A method of effecting the stable, non-luminous combustion of a liquid fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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, the air in said annulus being rotated at a velocity which is sufficiently high that the resulting centrifugal forces will keep the hot evaporated fuel in the annulus thereof formed on the inner boundary of the combustion air annulus by evaporation of the fuel as aforesaid from moving radially outward into the combustion air annulus.
1 more element
A method of effecting the stable, non-luminous combustion of a liquid fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air which contains not less than the stoichiometric amount of air needed for combustion of the fuel or air in excess of that amount;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect the formation of a recircualtion 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.
1 more element
A method of effecting the stable, non-luminous combustion of a liquid fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- and thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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, the amount of air present in said annulus of combustion air being less than the stoichiometric amount for combustion of the fuel, thereby maximizing the range of operation of the combustor in which the method is carried out and/or minimizing the conversion of fuel-bound nitrogen in the fuel being burned to NO.sub.x and said method also including the step of introducing additional air into the combustor in which the method is carried out to complete the combustion of said fuel, said air being added in a manner which is effective to keep it from penetrating to said recirculation zone.
1 more element
A method of effecting the stable, non-luminous combustion of a liquid fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and the formation of a swirling annulus of burning gases and then effecting a downstream contraction of the swirling annulus of burning gases to effect 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, the annulus of burning gases being so expanded in promoting the mixing of said air and fuel as to generate an inner recirculation zone surrounded by said flame and an outer recirculation zone surrounding the annulus of combustion air and extending downstream from the location at which the expansion of said stratified annuli of combustion air and fuel is initiated.
1 more element
A method of effecting the stable, non-luminous combustion of a liquid fuel which comprises the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air to effect 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;
- and, during light-off, directing an air pump-generated, high velocity stream of air into contact with said fuel film to promote the atomization of said fuel.
2 more elements
A method of effecting the low emission combustion of a liquid fuel which comprises the steps of:
- generating an outer annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air;
- generating on the inner side of the annulus of atomized fuel thus formed an inner annulus of rotating air to prevent the ignition of the fuel;
- centrifuging the atomized fuel outwardly into the annulus of combustion air to evaporate said fuel and mix it with the combustion air;
- expanding the annulus of the fuel-air mixture thus formed, igniting said mixture, and then effecting a downstream contraction of the fuel-air mass to promote the formation of a recirculation zone containing hot gases which stabilize the flame generated by the combustion of the fuel-air mixture and ignite the fuel-air mixture at a location downstream from the location at which premixing of the fuel with at least that air in the outer annulus is initiated;
- and, during light-off, directing an air pump-generated, high velocity stream of air into contact with said fuel film to promote the atomization of said fuel.
4 more elements
A method of effecting the combustion of fuel in a manner which provides a stable flame at off-design conditions and low emissions under operating conditions at or nearer the design point, said method including the steps of:
- effecting the combustion of said fuel at off-design conditions by:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contration of the swirling fuel-air mass to effect 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;
- combustion being effected at design and nearer design conditions by:
- generating an outer annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air;
- generating on the inner side of the annulus of atomized fuel thus formed on inner annulus of rotating air to prevent the ignition of the fuel;
- centrifuging the atomized fuel outwardly into the annulus of combustion air to evaporate said fuel and mix it with the combustion air;
- and expanding the annulus of the fuel-mixture thus formed, igniting said mixture, and then effecting a downstream contraction of the fuel-air mass to promote the formation of a recirculation zone containing hot gases which stabilize the flame generated by the combustion of the fuel-air mixture and ignite the fuel-air mixture at a location downstream from the location at which premixing of the fuel with at least that air in the outer annulus is initiated;
- and, during light-off, directing an air pump-generated, high velocity stream of air into contact with said fuel film to promote the atomization of said fuel.
10 more elements
A method of effecting the combustion of fuel in a manner which provides a stable flame at off-design conditions and low emissions under operating conditions at or nearer the design point, said method including the steps of:
- generating an annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets which resist centrifuging into the swirling annulus of combustion air;
- thereafter rapidly expanding said annuli to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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;
- combustion being effected at design and nearer design conditions by so injecting fuel into said annulus of combustion air as to premix said fuel and air, subsequently expanding said annulus, and then effecting a downstream contraction of the fuel-air mass to promote the formation of a recirculation zone containing hot gases which stabilize the flame generated by the combustion of the fuel and air and ignite the fuel-combustion air mixture at a location downstream from the location at which premixing of the fuel with at least that air in said annulus is initiated;
- and, during light-off, directing an air pump-generated, high velocity stream of air into contact with said fuel film to promote the atomization of said fuel.
3 more elements
A gas turbine engine comprising:
- a combustor which includes:
- an elongated cylindrical casing having an upstream portion and a downstream portion;
- a fuel injector in the upstream portion of said casing;
- means forming an annular combustion air passage in said upstream portion of said casing;
- 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 form into a thin, stratified film on the inner boundary of said combustion air annulus and be atomized by the air making up said annulus, the downstream portion of said casing being configured such that said annuli of combustion air and 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;
- a compressor;
- means including said compressor for introducing combustion air into the upstream end of the combustion air passage and for effecting a flow of said air therethrough;
- a turbine through which the hot gases generated in said combustor can be expanded to produce mechanical energy;
- and a pump operable independently of said compressor for supplying air to said combustor.
7 more elements
A gas turbine engine comprising:
- a combustor which includes:
- an elongated cylindrical casing having an upstream portion and a downstream portion;
- a fuel injector in the upstream portion of said casing;
- means forming an annular combustion air passage in said upstream portion of said casing;
- 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 form into a thin, stratified film on the inner boundary of said combustion air annulus and be atomized by the air making up said annulus, the downstream portion of said casing being configured such that said annuli of combustion air and 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;
- a compressor;
- means including said compressor for introducing combustion air into the upstream end of the combustion air passage and for effecting a flow of said air therethrough;
- and a turbine through which the hot gases generated in said combustor can be expanded to produce mechanical energy, said combustor having means for forming between said annulus of fuel and said recirculation zone an inner, rotating annulus of air which is effective to insulate the fuel from the hot gases in said zone and delay the ignition of said fuel, thereby allowing said fuel to be centrifuged outwardly into the annulus of combustion air and to be evaporated and mixed with said air and subsequently ignited, thereby providing a low emission mode of operation, and said engine further including means which are selectively activatable to block the flow of air to said second air annulus forming means and thereby increase the range of efficient operation of the combustor and to make air available thereto to thereby drive the combustor into the low emission mode of operation.
6 more elements
A method of effecting the stable, non-luminous combustion of a liquid fuel which comprises the steps of:
- generating a first annulus of axially moving, rotating combustion air;
- forming a thin, uniform film of fuel on the inner boundary of said annulus at a specified location therealong;
- atomizing said fuel by contact between said fuel and said combustion air and thereby forming a stratified annulus of small fuel droplets;
- inhibiting the centrifuging of said fuel into said first rotating annulus of combustion air by sandwiching the annulus of fuel between the latter and a second, inner, axially moving, rotating annulus of air which contains only a fraction of the amount of air contained in said first annulus;
- thereafter rapidly expanding said annuli of air and fuel to promote the mixing and subsequent combustion of said fuel and air and then effecting a downstream contraction of the swirling fuel-air mass to effect 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.
2 more elements
Dependencies are inferred from the claim text.