Patents by Inventor Narendra D. Joshi

Narendra D. Joshi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5680766
    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.
    Type: Grant
    Filed: January 2, 1996
    Date of Patent: October 28, 1997
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Paul R. Angel, James M. Caldwell, Paul V. Heberling, Anthony J. Dean
  • Patent number: 5675971
    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.
    Type: Grant
    Filed: January 2, 1996
    Date of Patent: October 14, 1997
    Assignee: General Electric Company
    Inventors: Paul R. Angel, James M. Caldwell, Paul V. Heberling, Anthony J. Dean, Narendra D. Joshi
  • Patent number: 5638682
    Abstract: An air fuel mixer is disclosed having a mixing duct, a set of inner and outer counter-rotating swirlers adjacent the upstream end of 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 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. In addition, the mixing duct of the mixer includes slots, preferably with flares associated therewith, at its downstream end which modify the shape and direction of mixing eddies emanating therefrom.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: June 17, 1997
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Michael J. Epstein
  • Patent number: 5613363
    Abstract: An air fuel mixer having a mixing duct, a set of inner and outer counter-rotating swirlers at the upstream end of the mixing duct, and means for injecting fuel into the mixing duct is provided, 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 fuel nozzle by means of a plurality of fuel spokes 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 said mixing duct into the combustor and ignited.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: March 25, 1997
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Michael J. Epstein, Michael E. Ewbank
  • Patent number: 5596873
    Abstract: An annular combustor with an air fuel mixer is disclosed including a plurality of mixing tubes having a forward end and an exit end, wherein a longitudinal axis through the exit end for each mixing tube is at both an axial angle and a radial angle to the centerline axis of the mixer. A fuel injector for providing fuel to the forward end of each mixing tube, a fuel manifold in flow communication with each of the fuel injectors, and a fuel supply and control means are provided. High pressure air from a compressor is injected into the mixing tubes and fuel is injected into the mixing tubes from the fuel injectors, wherein 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 tubes into the combustor and combusted. The mixing tubes preferably impart a swirl to the fuel/air mixture as it exits into the combustor.
    Type: Grant
    Filed: September 14, 1994
    Date of Patent: January 28, 1997
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, John M. Koshoffer
  • Patent number: 5590529
    Abstract: An air fuel mixer having a mixing duct, a set of inner and outer counter-rotating swirlers at the upstream end of the mixing duct, and means for injecting fuel into the mixing duct is provided, 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 fuel nozzle by means of a plurality of non-linear fuel spokes 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 said mixing duct into the combustor and ignited.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: January 7, 1997
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Michael J. Epstein, Michael E. Ewbank
  • Patent number: 5511375
    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
    Type: Grant
    Filed: September 12, 1994
    Date of Patent: April 30, 1996
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Edward E. Ekstedt
  • Patent number: 5351477
    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
    Type: Grant
    Filed: December 21, 1993
    Date of Patent: October 4, 1994
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Eric J. Kress
  • Patent number: 5323604
    Abstract: In accordance with one aspect of the present invention, a combustor is disclosed having three separate domes, each dome having disposed therein a plurality of circumferentially spaced mixers for uniformly mixing air and fuel. The combustor utilizes a high percentage of the total available combustion air at the dome area in order to maintain a lean mixture of air and fuel during all levels of engine output. Besides providing an unobstructed area in the diffuser dump region upstream of the mixers for the combustion air, sealing means is included to prevent cooling air from entering the combustion chamber until downstream of the primary combustion zone. Heat shields having radial centerbodies are also included between each dome to isolate each primary combustion zone.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: June 28, 1994
    Assignee: General Electric Company
    Inventors: Edward E. Ekstedt, Narendra D. Joshi, Adrian M. Ablett, Timothy R. Gresla, John M. Koshoffer, William F. Burke
  • Patent number: 5251447
    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.
    Type: Grant
    Filed: October 1, 1992
    Date of Patent: October 12, 1993
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Edward E. Ekstedt, Michael J. Epstein
  • Patent number: 5165241
    Abstract: A mixer having a mixing duct, a set of inner and outer counter-rotating swirlers at the upstream end of the mixing duct, and a fuel nozzle located axially along and forming a center-body of the mixing duct is provided, 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 fuel nozzle 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 said mixing duct into the combustor and ignited.
    Type: Grant
    Filed: February 22, 1991
    Date of Patent: November 24, 1992
    Assignee: General Electric Company
    Inventors: Narendra D. Joshi, Edward E. Ekstedt
  • Patent number: 4928481
    Abstract: In a staged low NOx lean premix hot wall gas turbine combustor, the interior wall of the combustor is maintained at or near the flame temperature to provide stable operation over a wide range of heat release values. One or more stages of the staged combustor includes a Stirred Reactor region followed by a Plug Flow Reactor region. In one embodiment, a lean premixture of fuel and air is inducted tangentially into an annular intake manifold for inducting a cyclonic flow of the premixture into the combustion chamber. In another embodiment, the Stirred Reactor region is developed by colliding, preferably head-on, a plurality of jets of lean premixture within the combustion chamber.
    Type: Grant
    Filed: July 13, 1988
    Date of Patent: May 29, 1990
    Assignee: PruTech II
    Inventors: Narendra D. Joshi, Frederick E. Moreno
  • Patent number: 4912931
    Abstract: A staged low NO.sub.x gas turbine combustor includes a refractory fibrous thermally insulatively lined primary combustion chamber, operating fuel-rich, and exhausting through a throat into a metallic secondary combustion chamber containing a fuel-lean secondary combustion zone in which combustion is completed. A radiation cooling zone is provided intermediate the throat and secondary combustion zone for cooling of the primary combustion products before quick quench in the secondary combustion zone. The fibrous lining of the primary combustion chamber is densified at its interior surface with a refractory such as zirconia or silicon carbide to inhibit flame erosion. The liner is wrapped with a supportive compliant blanket of fibrous refractory insulation. Air cooling of the metallic wall of the secondary chamber surrounding the radiation cooling zone is intensified relative to the remainder of the secondary combustion chamber.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: April 3, 1990
    Assignee: PruTech II
    Inventors: Narendra D. Joshi, Frederick E. Moreno, Creighton D. Hartman
  • Patent number: 4910957
    Abstract: In a staged lean premix low NOx gas turbine combustor, the inside of the combustor is lined with a low density refractory thermal insulator for maintaining the hot face of the lining at or near the flame temperature, i.e., within 200.degree. F. and preferably within 50.degree. F. The heat release value in the first stage is held at a maximum value consistent with low NOx emission while decreasing the heat release value in the second or third stage to achieve a wide range of turndown. The flame temperature in the respective stages are maintained between a low of 1700.degree. F. and a maximum of 2700.degree. F. The flow of compressed air into the combustor is maintained generally uniform over the entire operating range of 5 to 1 turndown.
    Type: Grant
    Filed: July 13, 1988
    Date of Patent: March 27, 1990
    Assignee: PruTech II
    Inventors: Frederick E. Moreno, Narendra D. Joshi
  • Patent number: 4860533
    Abstract: A gas turbine combustor is ignited by a torch igniter. The ignition chamber of the torch igniter receives a swirled stream of air into which is injected atomized fuel. The mixture of fuel and air is ignited by a spark plug in the ignition chamber. The combustion products and igniter flame are exhausted from the ignition chamber through a gas passageway penetrating through the sidewall of the gas turbine combustor to ignite a flame in the combustor. The igniter flame and the combustion flame are detected by a U.V. detector looking through aligned igniter air inlet and igniter exhaust passageways into the combustor. A U.V. transmissive window is disposed in the air inlet passageway to isolate the detector from the pressure of the igniter and combustor. A swirler in the air inlet tubulation supplies a flow of air across the window to inhibit deposit of combustion products thereon.
    Type: Grant
    Filed: September 17, 1987
    Date of Patent: August 29, 1989
    Assignee: Prutech II
    Inventor: Narendra D. Joshi