Abstract: The arrangement comprises a swirler for producing at least one air stream for mixing with a supply of fuel but wherein the supply of fuel is initially injected into at least one zone adjacent a respective air stream but shielded (by 26) therefrom whereby fuel-rich pockets of fluid are formed in the zone(s). The pockets ensure flame stability at least at lower power settings. The zone is defined by a wall of the swirler. The fuel is injected through nozzles. Additional nozzles for supplementary supply of fuel may be provided in a block. A plate is arranged between the block and the swirler.

Abstract: A dual fuel gas generator (10) is provided with a steam injection system (48) having a bleed-off valve (66) and a steam metering valve which are controlled in concert by a controller (50) to supply steam to a steam manifold (22) for injection into the gas generator at rapidly variable rates independent of the steam supply rate from a boiler (42, FIG. 1). A proportion of the system can be reheated using a steam warm-up flow through the bleed-off valve (66). A further portion of the system can be purged and preheated using compressor delivery air to flow through a steam metering valve (80), a purge valve (74) and a drain valve (94). To control the degree of superheat at the steam manifold (22), water can be injected through a metering valve (90) and a vortex mixer (92), and to purge condensation from a gas fuel manifold (30, FIG. 7 ) of the gas generator, compressor delivery air can be allowed to flow through the manifold (30), a supply line (108) and a purge valve (112 to atmosphere.

Abstract: The purging of residual fuel. In gas turbine combustor fuel injectors is disclosed in which the fuel injector includes a fuel element having a first and second fuel passage for discharging the fuel to the combustor of the gas turbine. Upon interruption of the fuel to the fuel element, high pressure air is passed through an air passage to the first fuel passage to force the fuel in the reverse direction through the first fuel passage, through the second fuel passage, and discharge the residual fuel in each of the passages to the combustor through the second fuel passage.

Abstract: A fuel nozzle for a gas turbine includes a nozzle body having a tip portion, the nozzle body including an inner tube defining an axially extending air passage; an intermediate tube concentrically arranged and radially spaced from the inner tube and defining a diffusion fuel passage therebetween; and an outer tube concentrically arranged and radially spaced from the intermediate tube and defining a premix fuel passage therebetween. The outer tube has a plurality of radially extending injectors in communication with the premix fuel passage. The premix fuel passage is further defined in part by an outer tube wall portion formed with at least one weakened region adapted to burn through in the event of a flashback, thereby causing a substantial portion of premix fuel to bypass the injectors and to exit the nozzle body at the at least one weakened region. A related method is also disclosed.

Abstract: An air fuel mixer is disclosed having a mixing duct, a shroud surrounding the upstream end of the mixing duct in which a fuel manifold is provided in flow communication with a fuel supply and control means, a set of inner and outer counter-rotating swirlers adjacent the upstream end of the mixing duct for imparting swirl to an air stream, a hub separating the inner and outer annular swirlers to allow independent rotation of the air stream, and a centerbody located axially along and substantially the full length of the mixing duct. In order to inject one type of fuel into the mixing duct, fuel is supplied to the outer annular swirlers which include hollow vanes with internal cavities, wherein the internal cavities of the outer swirler vanes are in fluid communication with the fuel manifold in the shroud. The outer swirler vanes further include a plurality of fuel passages therethrough in flow communication with the internal cavities.

Abstract: An air fuel mixer is disclosed having a mixing duct, a shroud surrounding the upstream end of the mixing duct in which a fuel manifold is provided in flow communication with a fuel supply and control means, a set of inner and outer counter-rotating swirlers adjacent the upstream end of the mixing duct for imparting swirl to an air stream, a hub separating the inner and outer annular swirlers to allow independent rotation of the air stream, and a centerbody located axially along and substantially the full length of the mixing duct. In order to inject one type of fuel into the mixing duct, fuel is supplied to the outer annular swirlers which include hollow vanes with internal cavities, wherein the internal cavities of the outer swirler vanes are in fluid communication with the fuel manifold in the shroud. The outer swirler vanes further include a plurality of fuel passages therethrough in flow communication with the internal cavities.

Abstract: A combustor for a gas turbine having primary and secondary combustion zones. The combustor has a centrally disposed dual fuel nozzle that can supply a fuel rich mixture of either liquid or gaseous fuel to the primary combustion zone. The combustor also has primary gas fuel spray pegs for supplying a lean mixture of gaseous fuel to the primary combustion zone via a first annular pre-mixing passage and secondary dual fuel spray bars for supplying a lean mixture of either gaseous or liquid fuel to the secondary combustion zone via a second annular pre-mixing passage. The dual fuel spray bars are aerodynamically shaped and have passages for distributing gas and liquid fuel to a number of fuel discharge ports. The gas fuel discharge ports are formed in two rows on either side of the spray bar. The liquid fuel discharge ports are formed by a row of spray nozzles arranged along the downstream edge of the spray bar.

Abstract: A fluidic nozzle which is flown through by a singular injection jet and which periodically deflects the injection jet. The nozzle has a nozzle channel, whose cross section is expanded in relation to the injection jet, and with control openings opening into the nozzle channel downstream close to the neck of the nozzle for injecting a control fluid that brings about the deflection of the jet. The nozzle channel has a channel cross section, which is two-dimensionally expanded in height and width in relation to the cross section of the jet, with a cross-section contour corresponding to the desired distribution cross section, and it is provided with a number of control openings. The control openings are arranged offset in relation to one another in the circumferential direction of the nozzle channel and are activated one after another in sequence to generate a jet movement rotating along the circumference of the nozzle channel.

Abstract: A combustor for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone.

Abstract: A fuel injector includes outer and inner coaxial shells spaced radially apart to define a flow channel therebetween having an inlet and an outlet. A strut extends radially outwardly from the inner and outer shells at leading edges thereof and is fixedly joined thereto. An annular lobed mixer is disposed coaxially in the channel and includes a leading edge, a trailing edge spaced from the channel outlet to define a mixing nozzle, and a plurality of circumferentially spaced apart lobes increasing in radial height from the leading to trailing edges of the mixer. The lobes defines with the outer and inner shells corresponding pluralities of outer and inner chutes for separately channeling respective portions of inlet air. The fuel is injected into the lobed mixer forming a fuel and air mixture in the mixing nozzle for discharge through the channel outlet into a combustor.

Abstract: A fuel injector for a gas turbine conbustor, the injector operating on gas and liquid fuels selectively. The injector has a central liquid fuel duct and jets, an annular gas duct and gas jets, and an outer annular combustion air duct. Operation on the liquid fuel tends to cause combustion products to be ingested into the gas orifices so impeding efficient gas combustion. The invention provides apertures (17) between the outer air duct and the intermediate gas duct whereby during operation on liquid fuel air bleeds into the gas duct and purges the gas orifices. As an added advantage, in a transition from liquid fuel to gas, the gas pressure is increased to a point where the air bleed is reversed and gas bleeds into the air duct. The pre-mixed gas/air is then emitted from swirlers surrounding the ring of gas jets. More efficient gas combustion results.

Abstract: The present invention relates to a system for cooling a high power fuel injector of a dual fuel injector wherein the system comprises a first fuel supply circuit having a first conduit connecting a fuel feed supply and the high power fuel injector, the first conduit having a terminal end adjacent to a distal end of the high power fuel injector, and a second conduit connecting the terminal end of the first conduit to the low power fuel injector such that all of the fuel supplied to the low power injector first passes through the high power fuel injector. The system also has a second fuel supply circuit, separate from the first fuel supply circuit, which comprises a third conduit connecting the fuel feed supply and the fuel injection orifices of the high power fuel injector so as to supply fuel to the fuel injection orifices.

Abstract: A gas turbine fuel nozzle and method of fuel flow provide resistance to coking of the fuel by means of a multiple passage heat transfer cooling circuit. Fuel streams to primary and secondary sprays of pilot and main nozzle tips are arranged to transfer heat between the pilot primary fuel stream and each of the main secondary fuel stream and the pilot secondary fuel stream. This protects the fuel in the streams from coking during both low flow, lower engine heat conditions and high flow, high engine heat conditions. This nozzle and flow can protect engines with both single tip and dual tip nozzles.

Abstract: A dual fuel mixer is disclosed having a mixing duct, a shroud surrounding the upstream end of the mixing duct having contained therein a gas fuel manifold and a liquid fuel manifold in flow communication with a gas fuel supply and a liquid fuel supply, respectively, and control means, a set of inner and outer annular counter-rotating swirlers adjacent the upstream end of the mixing duct, where at least the outer annular swirlers include hollow vanes with internal cavities and fuel passages, all of which are in fluid communication with the gas and liquid fuel manifolds to inject gas and liquid fuel into the air stream, and a hub separating the inner and outer annular swirlers to allow independent rotation thereof wherein high pressure air from a compressor is injected into the mixing duct through the swirlers to form an intense shear region and gas and/or liquid fuel is injected into the air stream from the outer annular swirler vanes so that the high pressure air and the fuel is uniformly mixed therein so as

Abstract: An improved airblast fuel injector for a gas turbine engine wherein the injector comprises an inner air discharge chamber, a first fuel discharge chamber disposed outboard of the inner air chamber, an intermediate air discharge chamber disposed radially outboard of the first fuel chamber, a second fuel discharge chamber disposed radially outboard of the first outer air chamber, and an outer air discharge chamber disposed radially outboard of the second fuel chamber. The fuel flow from the first fuel discharge chamber is subjected to inner and outer atomizing air flows from the inner and intermediate air chambers. The fuel flow from the second fuel discharge chamber is subjected to inner and outer atomizing airflows from the intermediate and outer air discharge chambers. The individual fuel flow streams discharged from the first and second fuel discharge chambers provide an aggregate, high mass flow of fuel necessary for engine operation.

Abstract: A fuel control system for a gas turbine aero engine comprises a first metering valve 22 which is controlled by a feed back loop 43 in flow series with a manually operated metering valve 34. A pressure drop regulator 31, 39 regulates the pressure drop across the series connected valves 22, 34. In this way response of the control system is directly influenced by movement of the manual valve 34 and the automatic valve 22 stabilizes the fuel flow rate in response to monitored operating parameters of the engine.

Abstract: A gas turbine combustor comprises a cylindrical outer casing having one end closed by a header plate. A combustor liner provided with an inner combustion chamber which is divided into a first-stage combustion region on a side of the header plate and a second-stage combustion region formed on a downstream side of the first-stage combustion region. A first-stage fuel supply unit mounted to the header plate for injecting a first-stage fuel to the first-stage combustion region and a second-stage fuel supply unit mounted to the header plate for injecting a second-stage fuel previously mixed in a lean fuel state. The first-stage fuel supply unit includes a first-stage fuel nozzle assembly, which supplies the first-stage fuel, formed by combining a diffusion combustion nozzle and a pre-mixture combustion nozzle.

Abstract: The fuel nozzle includes an annular chamber defined between a housing and a central tube. At the downstream end of the tube, inner and outer swirlers are provided in communication with the upstream chamber and a combustion zone downstream of the swirlers. When fuel gas is supplied the inner swirler, a portion of the air flowing through the chamber mixes in the inner swirler with the supplied fuel for holding a diffusion flame in a downstream diffusion mixing cup. The balance of the air flowing through the chamber through the outer swirler is segregated from the air supplied the inner swirler by a circumferentially extending splitter vane. At an upstream portion of the chamber a plurality of spokes pass into the chamber for supplying fuel gas to the chamber when the nozzle operates in a premix combustion mode. When operating in a premix combustion mode, fuel gas is cut off from the inner swirler and supplied to the spokes.

Abstract: Past fuel injection nozzles have attempted to provide a structure to reduce exhaust emissions, generally NOx using water injection. Such nozzles have failed to attain adequate reduction of exhaust emissions. The present fuel injector structure has resulted in reduced NOx emissions. The structure includes a combustor having an axis a first air flow passage, a second air flow passage, a first annular fuel passage and a second annular fuel passage. Positioned in the first air flow passage is a directing device through which water is introduced in a swirling manner and mixed with the air in the first air flow passage. Fuel is introduced into the first and/or second annular fuel passages and mixed with air in the second air flow passage. The mixtures of air and water, and fuel and air are mixed prior to entering the combustion section. The unique structure swirls the air and fuel and the air and water prior to their meeting and mixing.

Abstract: A fuel injector 28 utilizing air, a liquid fluid and a gaseous fluid is disclosed. Various construction details are developed to enhance mixing and reduce carbon monoxide emissions for a given level of nitrous oxide emissions. In one detailed embodiment, the fuel nozzle 28 has two radially spaced passages 68, 104 for air having swirlers 86, 114, a liquid fluid passage 57 for water therebetween and a gaseous fluid fuel passage 118 which injects fuel into one of the air passages.

Abstract: A self-purging fuel injector for a combustor of a gas turbine engine wherein the fuel injector comprises an injector body having first and second air discharge orifices for discharging air to the combustor and first and second fuel passage means having respective first and second fuel discharge orifices for discharging fuel to the combustor. The first and second fuel passages are in communication upstream of the fuel discharge orifices. The first air and fuel discharge orifices have a relationship to establish a pneumatic pressure at the first fuel discharge orifice and the second air and fuel discharge orifices have a relationship to establish a different pneumatic pressure at the second fuel discharge orifice such that, in the event the supply of fuel to the first and second fuel discharge orifices is interrupted, the fuel residing in the fuel passages between the first and second fuel discharge orifices is subjected to a pressure differential effective to purge the resident fuel into the combustor.

Abstract: A combustor for a gas turbine having primary and secondary combustion zones. The combustor has a centrally disposed dual fuel nozzle that can supply a fuel rich mixture of either liquid and gaseous fuel to the primary combustion zone. The combustor also has primary gas fuel spray bars for supplying a lean mixture of gaseous fuel to the primary combustion zone via a first annular pre-mixing passage and secondary gas fuel spray bars for supplying a lean mixture of gaseous fuel to the secondary combustion zone via a second annular pre-mixing passage. In addition, the combustor also has a plurality of liquid fuel spray nozzles for introducing a lean mixture of liquid fuel into the secondary combustion zone via the second annular pre-mixing passage. The liquid fuel spray nozzles are disposed in fan shaped channels that are arranged in a circumferential array and that are connected to the second annular pre-mixing passage.

Abstract: A fuel nozzle for gas turbine combustors reduces combustion instabilities by injecting purge air into the combustor angularly instead of axially. The fuel nozzle has a substantially cylindrical body with a number of internal passages. One of the passages provides premix gas fuel to a plurality of fuel injectors attached to the fuel nozzle. The remaining passages can be for diffusion gas, atomizing air and liquid fuel. One or more of the remaining passages is connected to a respective group of discharge orifices formed in the cylindrical side surface of the nozzle body. During low NO.sub.x operation, premix gas is introduced through the fuel injectors, and the remaining passages are all purged with air to prevent the ingress of flame gases from the combustion chamber. The resulting jets of air emitted from discharge orifices formed in the side surface will disrupt or break-up spanwise vortices shed from the bluff end of the fuel nozzle, thereby reducing combustion instabilities.

Abstract: Fuel injection nozzles used for reducing NOx in gas turbine engines have incorporated a variety of expensive and complicated techniques. For example, systems use schemes for introducing more air into the primary combustion zone, recirculating cooled exhaust products into the combustion zone and injecting water spray into the combustion zone. The present dual fuel injector reduces the formation of carbon monoxide, unburned hydrocarbons and nitrogen oxides within the combustion zone by providing a series of premixing chambers being in serially aligned relationship one to another. During operation of the dual fuel injector the premixing chambers have a liquid fluid and air or water and air being further mixed with additional air or a gaseous fluid and air. The liquid fluid and the gaseous fluid can be use simultaneously or individually depending on the availability of fluids.

Abstract: Fuel injection nozzles used for reducing NOx in gas turbine engines has incorporated a variety of expensive and complicated techniques. For example, systems use schemes for introducing more air into the primary combustion zone, recirculating cooled exhaust products into the combustion zone and injecting water spray into the combustion zone. The present fuel injector (60,166) reduces the formation of carbon monoxide, unburned hydrocarbons and nitrogen oxides within the combustion zone by controlling the premix air/fuel ratio and more explicitly by controlling the air portion of the air/fuel ratio over the entire operating range of the engine (10).

Abstract: A fuel nozzle assembly is provided having the capability of burning either gaseous or liquid fuel, or both simultaneously, along with steam injection. The nozzle has a nozzle body that is attached to a nozzle cap by inner, outer and middle sleeves. The sleeves form inner and outer concentric annular conduits between themselves for directing the flow of gaseous fuel and steam from the fuel and steam inlet ports to the outlet ports. In addition, the inner sleeve forms a central chamber in which an oil fuel nozzle is disposed. Radial passages in the nozzle body allow cooling air to flow over the oil nozzle and through the oil outlet port, thereby preventing coking at the nozzle tip. The fuel nozzle assembly is originally built, and the nozzle cap is replaced, by sliding the sleeves forward and aft on the assembly so as to gain access to the next innermost sleeve.

Abstract: An ultra-low NOx gas turbine combustor having a dual fuel capability. The combustor has a pre-mixing zone and a downstream combustion zone. The pre-mixing zone has three concentric annular passages that surround a central diffusion-type dual fuel nozzle. A gas fuel manifold distributes gas fuel around the inner and outer passages. A plurality of dual fuel nozzles are disposed in the middle passage to distribute either gas or oil fuel around the middle passage. The distribution of fuel around the passages allows the formation of lean fuel/air ratios, thereby lowering NOx formation. In addition, swirl vanes are arrayed around the inner and outer passages and around each of the fuel nozzles. A step increase in the flow area in going from the pre-mixing zone to the combustion zone creates vortices that tend to anchor the flame.

Abstract: A breech loaded fuel nozzle cartridge assembly is provided for use with a fuel nozzle capable of use with gaseous or distillate fuels. The cartridge assembly includes an elongated water delivery pipe having an interior through passageway extending from a rearward open end to a forward open end. A mounting coupling is fixed to the exterior of the pipe adjacent its rearward end for use in mounting the cartridge assembly within the rearward end of a fuel nozzle body. The forward end of the cartridge pipe is provided with an interior water swirler and an exterior distillate fuel swirler, while the forward end of the fuel nozzle body is provided with an air swirler so that at the fuel nozzle tip, an outer conical air spray, an intermediate distillate or gaseous fuel spray and an inner conical water spray combine to provide a homogenous mixture at the point of combustion.

Abstract: A dual fuel mixer is disclosed having a mixing duct, a shroud surrounding the upstream end of the mixing duct having contained therein a gas fuel manifold and a liquid fuel manifold in flow communication with a gas fuel supply and a liquid fuel supply, respectively, and control means, a set of inner and outer annular counter-rotating swirlers adjacent the upstream end of the mixing duct, where at least the outer annular swirlers include hollow vanes with internal cavities and gas fuel passages, all of which are in fluid communication with the gas fuel manifold to inject gas fuel into the air stream, the vane cavities also having liquid fuel passages therethrough in fluid communication with the liquid fuel manifold, and a hub separating the inner and outer annular swirlers to allow independent rotation thereof, the hub having a circumferential slot in fluid communication with the liquid fuel passages which injects liquid fuel into the air stream, wherein high pressure air from a compressor is injected into the

Abstract: A combustor apparatus is provided for a gas turbine engine including a circumferential ring of injectors. A fuel manifold provides a source of fuel for the injectors. The combustor apparatus includes a plurality of first fuel flow paths between the manifold and all of the injectors. Fuel is provided to all of the injectors via these first flow paths. At least one second fuel flow path including an electronically switchable valve is coupled between the manifold and a selected one of the injectors to provide additional fuel thereto at certain times when special engine operating conditions, such as demand for initial ignition, crossfire and altitude relight are sensed.

Abstract: The burner assembly includes a flow body 12 having a central liquid fuel injection nozzle 14, inner and outer concentric passages 24 and 26, respectively, and a flow duct comprising a venturi downstream of the liquid injection nozzle. The inner passage 24 communicates air and gaseous fuel into the flow duct 16. Swirlers 30 and 38 are provided at the exit ends of the inner and outer passages, respectively, to create counterrotating flows which form a shear layer at the exit of the burner assembly body. The extent of the flow duct 16 facilitates liquid fuel atomization and vaporization, while affording sufficient time for gaseous fuel/air pre-mixing. The arrangement creates a recirculation zone 40 and a shear layer 42 at the exhaust of the burner assembly body which affords flame stabilization.

Abstract: A fuel/oxidizer pre-mixing combustion chamber for a turbojet engine is disclosed in which the pre-mixing device is incorporated into the upstream end wall structure of the combustion chamber. The upstream end portion of the combustion chamber, which is in communication with the oxidizer, has a plurality of generally radially extending, "V"-shaped members oriented such that the vertex of the "V" shape faces in an upstream direction. These members extend generally radially between the inner and outer walls which define the boundaries of the combustion chamber. The members define upstream edges and downstream edges which are axially the upstream edges. Fuel injectors extend radially inwardly between these members and are axially positioned between the locations of the upstream and downstream edges so as to spray fuel onto the adjacent sides of each of the members.

Abstract: A gas turbine combustor for a gas turbine power plant comprises a combustion liner connected to a turbine and provided with a main fuel nozzle assembly and a sub-fuel nozzle assembly for jetting fuel to an inside of the combustion liner through nozzle holes, a base fuel supply line, a main fuel line for supplying a fuel to the main nozzle assembly for premixing an air with the fuel jetted through the nozzle hole for carrying out a lean burning in the combustion liner, and a plurality of sub-fuel lines for supplying the fuel to the sub-fuel nozzle assembly for mixing the fuel with a combustion air for carrying out a diffusion burning in the combustion liner. The main and sub-fuel lines branch off a front end of the base fuel supply line.

Abstract: The known control systems for reducing NOx in the combustion systems of past gas turbine engines has incorporated a variety of expensive and complicated techniques to reduce the NOx level. The present apparatus reduces the formation of NOx within the combustion zone by controlling the air portion of the air/fuel ratio. The present apparatus includes a device for controllably varying the quantity of compressed air directed into a manifold resulting in controlling the air to a plurality of injection nozzles and into a combustor. A throttling mechanism moves between an open position and a closed position varying the flow rate of compressor air to the combustor apparatus provides an economical, reliable and effective method for reducing and controlling the amount of nitrogen oxide (NOx) carbon monoxide (CO) and unburned hydrocarbon (UHC) emitted from the gas turbine engine.

Abstract: A hot gas generator includes a dual fuel injector (42) having spaced fuel discharge nozzles (48, 60) on the longitudinal axis (28) of a vessel (18) having a narrow inlet (22), an opposite narrow outlet (14) and an intermediate, enlarged chamber (24) which serves as a combustion chamber. The nozzle (60) injects a spray cone (64) of fuel in a cone angle that is sufficiently wide that a large angle exists between the fuel spray and the path (54) of high velocity combustion gases moving toward the outlet (14) to achieve excellent vaporization of fuel at fuel rich conditions without causing carbon buildup and/or the generation of black smoke in the exhaust.

Abstract: The present system or structure for cooling a combustion end of a fuel injection nozzle is accomplished by providing a cooling passage for skin cooling of the portion of the nozzle directly exposed to the combustion flames. A twofold path is provided through which cooling air can enter cooling passages and cool an end portion of a second member and a tip. A first flow path is intended to primarily cool the tip and further cool the end portion. A second flow path is intended to ensure primary cooling of the end portion Thus the combustor end of the fuel injection nozzle is maintained at a temperature low enough to prevent failure of the combustor end through oxidation, cracking and buckling. Both the cooling flow paths dump the spent air in a cavity formed between the injector nozzle and a combustor. The spent cooling air becomes a part of the main combustion air and, therefore, does not adversely affect the combustion process in general and NOx and CO emissions in particular.

Abstract: Dual fuel/air injectors are provided, including a conventional central diffusion flame fuel nozzle 12. A fuel injector 14 for pre-mixing fuel and air for low emissions combustion and coaxial to the central nozzle includes a plenum 30 about the central injector having an air inlet 32, an annular pre-mix chamber 34, a fuel injection region 36 between the pre-mix chamber and air inlet 32 and an outlet 40 defined in part by swirler vanes 38. Radially projecting fuel spokes 46 extend into the plenum 30 and are supplied fuel from a manifold 44. Apertures 52 in the spokes supply fuel in a circumferential direction to the incoming air. The spokes in the plenum define throat areas T which, in the aggregate, define a minimum cross-sectional area of the plenum 30. Differential air flows through the throats provide inverse differential fuel distribution in the throats whereby a uniform fuel/air mixture strength distribution occurs at the throats.

Abstract: Past systems have attempted to cool the combustor end or tip of fuel injection nozzles, however, such methods have failed to attain adequate cooling and life. The present system or structure for cooling a tip or combustion end of a fuel injection nozzle is accomplished with a twofold structure. First, a plurality of openings being acutely positioned in the combustor end about a plurality of base circles provide effective air-sweep cooling. Secondly, the convection cooling of a back face and a combustion face provides effective convection cooling. The two structures are combined to provide an effective, efficient cooling of the combustor end or tip. The combustor end of the fuel injection nozzle is maintained at a temperature low enough to prevent failure of the combustor end through oxidation, cracking and buckling and the air-sweep avoids carbon deposits on the combustor face.

Abstract: In a gas turbine (10), a plurality of combustors (14), each having a plurality of fuel nozzles (32) arranged about a longitudinal axis of the combustor, and a single combustion zone (70), each fuel nozzle having a diffusion passage (74) and a premix passage (60), the premix passage communicating with a plurality of premix fuel distribution tubes (66) located within a dedicated premix tube (46) adapted to mix the premix fuel and combustion air prior to entry into the single combustion zone (70) located downstream of the premix tube (46).

Abstract: An air fuel mixer is disclosed having a mixing duct, a shroud surrounding the upstream end of the mixing duct having contained therein a fuel manifold in flow communication with a fuel supply and control means, a set of inner and outer counter-rotating swirlers adjacent the upstream end of the mixing duct, hollow vanes in at least the outer swirler having passages therethrough in fluid communication with the fuel manifold to inject fuel into the mixing duct, and a hub separating the inner and outer swirlers to allow independent rotation thereof, wherein high pressure air from a compressor is injected into the mixing duct through the swirlers to form an intense shear region and fuel is injected into the mixing duct from the swirler vanes so that the high pressure air and the fuel is uniformly mixed therein so as to produce minimal formation of pollutants when the fuel/air mixture is exhausted out the downstream end of the mixing duct into the combustor and ignited.

Abstract: A gas turbine fuel nozzle assembly having a replaceable nozzle cap. The nozzle assembly is comprised of a base portion and a nozzle cap. The nozzle base is secured to a combustion system and contains inlet ports for receiving either gas and oil fuel or gas fuel and steam, depending on the nozzle assembly configuration. The nozzle cap has outlet ports for injecting either gas and oil fuel or gas fuel and steam. The nozzle cap is connected to the nozzle base by inner and outer sleeves that form an annular conduit by which the gas flows from an inlet port in the base to an outlet port in the cap. In addition, the inner sleeve, which has an expansion joint formed therein, forms a central cavity that either holds an oil spray nozzle or forms a steam passage, depending on the nozzle assembly configuration. The nozzle cap is detachably coupled to the base by first and second threaded joints formed in the inner and outer sleeves, respectively.

Abstract: A fuel injector is disclosed for injecting fuel into a combustion chamber a gas turbine engine which includes an injector nozzle having a central axis, first and second fuel injection paths in which one of the fuel injection paths supplies fuel to the injector nozzle while the other fuel injection path has an outlet displaced from the axis of the injection nozzle, a single fuel supply conduit which supplies fuel to both of the fuel injection paths, and a metering device which controls the flow of fuel from the single fuel supply conduit to the first and second fuel injection paths. The metering device may be a fuel metering valve assembly which has a piston defining a fuel metering orifice biased against a valve seat around an opening which communicates with the single fuel supply conduit. The piston is biased into engagement with the valve seat by a resilient bellows attached between the piston and a fixed structure.

Abstract: In order to reduce emissions of NO.sub.x, CO and unburned hydrocarbons, the flame temperature must be kept between 2500.degree.-2800.degree. F. Premixing combustor tubes are used to premix the fuel and air before the mixture is burned in the combustion chamber. The tubes are flashback resistant due to the flow of the fuel and air mixture through them. If it is desired to reduce the load operation of the combustor to substantially below 100% of its maximum load operation, as is the case during off-peak hours, the fuel and air flow rate can be regulated to reduce the load operation while still keeping the low emissions and the low flame temperature.

Abstract: A breech loaded fuel nozzle cartridge assembly is provided for use with a fuel nozzle capable of use with gaseous or distillate fuels. The cartridge assembly includes an elongated water delivery pipe having an interior through passageway extending from a rearward open end to a forward open end. A mounting coupling is fixed to the exterior of the pipe adjacent its rearward end for use in mounting the cartridge assembly within the rearward end of a fuel nozzle body. The forward end of the cartridge pipe is provided with an interior water swirler and an exterior distillate fuel swirler, while the forward end of the fuel nozzle body is provided with an air swirler so that at the fuel nozzle tip, an outer conical air spray, an intermediate distillate or gaseous fuel spray and an inner conical water spray combine to provide a homogenous mixture at the point of combustion.

Abstract: The known systems and injector nozzles for reducing NOx in the combustion systems of past gas turbine engines has generally failed to effectively and efficiently reduce the NOx level. The present system reduces the formation of NOx within the combustion zone by controlling the air/fuel ratio and more explicitly by controlling the air portion of the air/fuel ratio. The present injector nozzle includes a device for introducing a primary supply of air through the injector nozzle which is sized to have a predetermined cross-sectional area. The injector nozzle further includes a device for introducing a secondary supply of air through the injector nozzle which is sized to have a predetermined area. A device for introducing a primary supply of air through the injector at a controlled rate and a device for passing a main source of fuel through the injector nozzle at a controlled rate relative to the quantity of primary supply of air.

Abstract: A gas turbine combustor is provided with a premixer in which an oxidant and fuel is mixed and caused to flow to the combustion zone past two or more arrays of convex members positioned transverse or canted to the flow. The convex members introduce turbulence and include a plurality of openings to introduce one or more additional fuels into the premixed oxidant and fuel flow. Parallel, annular and radial arrays, or combinations thereof, may be provided. The downstream array is V-shaped in cross section and provides flame holding capability while the upstream array principally provides additional mixing of fuel and oxidant.

Abstract: A dual mode, dual stage low NOx combustor, includes a primary combustion chamber and a secondary combustion chamber separated by a throat region of reduced diameter. Fuel is input into the primary combustors by an annular array of diffusion type nozzles whereas in accordance with the invention, fuel is input into the secondary combustor by a central combination premix and diffusion nozzle. A premix swirler annulus is located upstream of a plurality of fuel distribution tubes of the combined premix and diffusion nozzle.

Abstract: A fuel vaporizer is formed from two concentric tubes. A mixture of fuel and air having a high proportion of fuel passes along the annular space between the two tubes while air alone passes along the inner tube.

Abstract: This burner arrangement has a main feed channel (2) for a fuel-air mixture, which channel discharges into a combustion chamber (1). A swirler, which is provided with swirl vanes (5), is penetrated by a burner lance (3), and into which exit openings for the fuel feed discharge, is provided in this main feed channel (2). The aim is to create a burner arrangement in which it is impossible for undesired instances of ignition of the fuel-air mixture to occur outside the combustion chamber (1). This is achieved in that the exit openings are constructed as nozzles (9) which discharge into a region between the swirl vanes (5). In this regard, at least one nozzle is provided between two neighboring swirl vanes (5).

Abstract: High temperature deterioration of an injector 34 for a gas turbine including a compressor and a turbine wheel 10, 14, 30 is avoided through the use of swirler blades 60 that form a forced vortex adjacent the ends 52, 58 of fuel and oxidant injection tubes 38, 40 to prevent separation of the mixed stream thereby eliminating backflows or eddies of burning fuel.