Patents by Inventor Douglas W. KARKOW

Douglas W. KARKOW 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: 11953199
    Abstract: A combustion system includes a fuel and oxidant source that outputs fuel and oxidant, a first perforated flame holder, and a second perforated flame holder separated from the first perforated flame holder by a gap. The first and second perforated flame holders sustain a combustion reaction of the fuel and oxidant within the first and second perforated flame holders.
    Type: Grant
    Filed: April 6, 2022
    Date of Patent: April 9, 2024
    Assignee: ClearSign Technologies Coporation
    Inventors: James K. Dansie, Douglas W. Karkow, Jesse Dumas, Donald Kendrick, Sunny Karnani, Christopher A. Wiklof
  • Patent number: 11953201
    Abstract: A combustion system includes a distal flame holder, a pilot fuel distributor, a main fuel distributor, an oxidant source, an array of sensors, and a controller. The oxidant source outputs an oxidant. The pilot fuel distributor supports a pilot flame configured to preheat the distal flame holder by outputting a pilot fuel at least when the combustion system is in a preheating state. The main fuel source outputs a main fuel in the standard operating state. The distal flame holder is configured to support a combustion reaction of the main fuel and the oxidant in the standard operating state. The sensors are configured to sense parameters of the pilot flame and the distal flame holder and to output sensor signals to the controller. The controller executes software instructions that include adjusting the flow of the main fuel, the pilot fuel, and the oxidant responsive to the sensor signals.
    Type: Grant
    Filed: January 17, 2020
    Date of Patent: April 9, 2024
    Assignee: ClearSign Technologies Corporation
    Inventors: Douglas W. Karkow, Donald Kendrick, James K. Dansie, Christopher A. Wiklof
  • Publication number: 20230115032
    Abstract: According to an embodiment, a fired heater includes a fuel and combustion air source configured to output fuel and combustion air into a combustion volume, the combustion volume including a combustion volume wall defining a lateral extent separate from an exterior volume. According to an embodiment, the fired heater includes a boiler heater and the combustion volume wall comprises a combustion pipe defining a lateral extent of the combustion volume, the combustion pipe being disposed to separate the combustion volume from a water and steam volume. The fired heater includes a mixing tube aligned to receive the fuel and combustion air from the fuel and combustion air source. The mixing tube may be separated from the combustion volume wall by a separation volume. The fired heater includes a bluff body flame holder aligned to receive a fuel and combustion air mixture from an outlet end of the mixing tube.
    Type: Application
    Filed: September 28, 2022
    Publication date: April 13, 2023
    Inventors: DONALD KENDRICK, DOUGLAS W. KARKOW, VENKATESH IYER, JAMES K. DANSIE, JONATHAN BUCHER, AARON SALZBRUN
  • Publication number: 20230072921
    Abstract: A combustion system includes a fuel and oxidant source and a flame holder. The flame holder includes a plurality of discrete slats arranged in parallel defining combustion channels between adjacent slats. Pairs of adjacent slats may be oriented to operate substantially as a V-gutter. The fuel and oxidant source outputs fuel and oxidant into the combustion channels. The flame holder holds a combustion reaction of the fuel and oxidant in the combustion channels.
    Type: Application
    Filed: September 2, 2022
    Publication date: March 9, 2023
    Inventors: VENKATESH IYER, COLIN JAMES DELLER, JEFF LEWALLEN, DONALD KENDRICK, JAMES K. DANSIE, DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Patent number: 11460188
    Abstract: According to an embodiment, a fired heater includes a fuel and combustion air source configured to output fuel and combustion air into a combustion volume, the combustion volume including a combustion volume wall defining a lateral extent separate from an exterior volume. According to an embodiment, the fired heater includes a boiler heater and the combustion volume wall comprises a combustion pipe defining a lateral extent of the combustion volume, the combustion pipe being disposed to separate the combustion volume from a water and steam volume. The fired heater includes a mixing tube aligned to receive the fuel and combustion air from the fuel and combustion air source. The mixing tube may be separated from the combustion volume wall by a separation volume. The fired heater includes a bluff body flame holder aligned to receive a fuel and combustion air mixture from an outlet end of the mixing tube.
    Type: Grant
    Filed: June 18, 2019
    Date of Patent: October 4, 2022
    Assignee: ClearSign Technologies Corporation
    Inventors: Donald Kendrick, Douglas W. Karkow, Venkatesh Iyer, James K. Dansie, Jonathan Bucher, Aaron Salzbrun
  • Publication number: 20220299203
    Abstract: A combustion system includes a fuel and oxidant source that outputs fuel and oxidant, a first perforated flame holder, and a second perforated flame holder separated from the first perforated flame holder by a gap. The first and second perforated flame holders sustain a combustion reaction of the fuel and oxidant within the first and second perforated flame holders.
    Type: Application
    Filed: April 6, 2022
    Publication date: September 22, 2022
    Inventors: James K. DANSIE, Douglas W. KARKOW, Jesse DUMAS, Donald KENDRICK, Sunny KARNANI, Christopher A. WIKLOF
  • Patent number: 11435143
    Abstract: A combustion system includes a fuel and oxidant source and a flame holder. The flame holder includes a plurality of discrete slats arranged in parallel defining combustion channels between adjacent slats. The fuel and oxidant source outputs fuel and oxidant into the combustion channels. The flame holder holds a combustion reaction of the fuel and oxidant in the combustion channels.
    Type: Grant
    Filed: October 22, 2018
    Date of Patent: September 6, 2022
    Assignee: Clearsign Technologies Corporation
    Inventors: Donald Kendrick, James K. Danise, Douglas W. Karkow, Christopher A. Wiklof
  • Patent number: 11313553
    Abstract: A combustion system includes a fuel and oxidant source that outputs fuel and oxidant, a first perforated flame holder, and a second perforated flame holder separated from the first perforated flame holder by a gap. The first and second perforated flame holders sustain a combustion reaction of the fuel and oxidant within the first and second perforated flame holders.
    Type: Grant
    Filed: July 12, 2018
    Date of Patent: April 26, 2022
    Assignee: ClearSign Technologies Corporation
    Inventors: James K. Dansie, Douglas W. Karkow, Jesse Dumas, Donald Kendrick, Sunny Karnani, Christopher A. Wiklof
  • Patent number: 11248786
    Abstract: A method for a combustion system includes outputting fuel from an adjustable-position fuel nozzle onto a perforated flame holder, the fuel being directed for mixture with an oxidant en route to the perforated flame holder. A combustion reaction of the fuel and the oxidant is supported within the perforated flame holder. A position of the adjustable-position fuel nozzle may be changed relative to the flame holder. A first flow of fuel may be output when the adjustable position fuel nozzle is in an extended state, and a second flow of fuel may be output when the adjustable-position fuel nozzle is in a retracted state.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: February 15, 2022
    Assignee: CLEARSIGN TECHNOLOGIES CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, James K. Dansie, Jesse Dumas, Donald Kendrick, Christopher A. Wiklof
  • Patent number: 11221137
    Abstract: A flame holder system includes a support structure configured to support a plurality of burner tiles within a furnace volume. The support structure includes a frame supporting a support lattice. A number of burner tiles are arranged in an array on the support lattice. The support structure is configured to be assemblable without tools inside the furnace volume, using components that are sized to fit through an access port in a wall of the furnace.
    Type: Grant
    Filed: September 3, 2019
    Date of Patent: January 11, 2022
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Jonathan Bucher, Donald Kendrick, James K. Dansie, Douglas W. Karkow
  • Patent number: 11156356
    Abstract: A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).
    Type: Grant
    Filed: May 13, 2019
    Date of Patent: October 26, 2021
    Assignee: CLEARSIGN TECHNOLOGIES CORPORATION
    Inventors: Douglas W. Karkow, Robert E. Breidenthal, Joseph Colannino, Christopher A. Wiklof
  • Publication number: 20210310650
    Abstract: A furnace includes a perforated flame holder formed from an array of tiles. The perforated flame holder is stabilized by a support member extending between at least adjacent tiles. Elongated support members may be positioned to extend through each of the tiles in a respective column of the array of tiles.
    Type: Application
    Filed: February 19, 2019
    Publication date: October 7, 2021
    Inventors: DOUGLAS W. KARKOW, DONALD KENDRICK, JOSEPH COLANNINO, JESSE DUMAS, JONATHAN P. DEES, JAMES K. DANSIE, CHRISTOPHER A. WIKLOF
  • Publication number: 20210239317
    Abstract: A low emissions modular flare stack includes a plurality of flare stack burner modules, each including a main fuel source configured to selectively deliver a main fuel stream for dilution by a flow of combustion air, a main igniter configured to cause ignition of the main fuel stream emitted from the main fuel source, a distal flame holder configured to hold a combustion reaction supported by the main fuel stream when the distal flame holder is at or above a predetermined temperature, and a pre-heating apparatus configured to pre-heat the distal flame holder to the predetermined temperature. The low emissions modular flare stack includes a common combustion air source configured to provide combustion air to each of the plurality of flare stack burner modules, and a wall encircling all of the plurality of flare stack burner modules, the wall being configured to laterally contain combustion products corresponding to all of the plurality of flare stack burner modules.
    Type: Application
    Filed: February 5, 2020
    Publication date: August 5, 2021
    Inventors: COLIN JAMES DELLER, MATT HOSIE, DOUGLAS W. KARKOW, DONALD KENDRICK, CHRISTOPHER A. WIKLOF
  • Patent number: 11047572
    Abstract: A burner includes a porous flame holder configured to support a combustion reaction to achieve a very low output of oxides of nitrogen (NOx).
    Type: Grant
    Filed: September 23, 2014
    Date of Patent: June 29, 2021
    Assignee: CLEARSIGN TECHNOLOGIES CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Robert E. Breidenthal, Christopher A. Wiklof
  • Publication number: 20210190310
    Abstract: A burner includes a distal flame holder, first and second fuel nozzles, a fuel and oxidant source, and a mixing tube disposed upstream from the distal flame holder. Fuel emitted from the first fuel nozzle mixes with oxidant from the oxidant source to form a fuel and oxidant mixture to support combustion in the distal flame holder. A non-reactive fluid source such as recirculated flue gas provides a non-reactive fluid for dilution of the fuel and oxidant mixture to prevent flashback.
    Type: Application
    Filed: January 30, 2020
    Publication date: June 24, 2021
    Inventors: Colin James Deller, Donald Kendrick, Venkatesh Iyer, Douglas W. Karkow
  • Publication number: 20210164652
    Abstract: A combustion system includes a distal flame holder, a pilot fuel distributor, a main fuel distributor, an oxidant source, an array of sensors, and a controller. The oxidant source outputs an oxidant. The pilot fuel distributor supports a pilot flame configured to preheat the distal flame holder by outputting a pilot fuel at least when the combustion system is in a preheating state. The main fuel source outputs a main fuel in the standard operating state. The distal flame holder is configured to support a combustion reaction of the main fuel and the oxidant in the standard operating state. The sensors are configured to sense parameters of the pilot flame and the distal flame holder and to output sensor signals to the controller. The controller executes software instructions that include adjusting the flow of the main fuel, the pilot fuel, and the oxidant responsive to the sensor signals.
    Type: Application
    Filed: January 17, 2020
    Publication date: June 3, 2021
    Inventors: DOUGLAS W. KARKOW, DONALD KENDRICK, JAMES K. DANSIE, CHRISTOPHER A. WIKLOF
  • Publication number: 20210063086
    Abstract: A combustion system includes a fuel and oxidant source, a first distal flame holder body, a second distal flame holder body, and a thermal load. The fuel and oxidant source outputs fuel and oxidant. The first and second distal flame holder bodies simultaneously or alternately hold combustion reaction portions of the fuel and oxidant and/or of combustion products. The thermal load receives thermal energy from the first and second combustion reaction portions.
    Type: Application
    Filed: September 8, 2020
    Publication date: March 4, 2021
    Inventors: DOUGLAS W. KARKOW, JAMES K. DANSIE, VENKATESH IYER, DONALD KENDRICK, COLIN JAMES DELLER, CHRISTOPHER A. WIKLOF
  • Patent number: 10823401
    Abstract: A combustion system such as a furnace or boiler includes a non-planar perforated flame holder configured to hold a combustion reaction.
    Type: Grant
    Filed: September 20, 2018
    Date of Patent: November 3, 2020
    Assignee: CLEARSIGN TECHNOLOGIES CORPORATION
    Inventors: Joseph Colannino, Douglas W. Karkow, James K. Dansie, Christopher A. Wiklof
  • Publication number: 20200340664
    Abstract: According to an embodiment, a fired heater includes a fuel and combustion air source configured to output fuel and combustion air into a combustion volume, the combustion volume including a combustion volume wall defining a lateral extent separate from an exterior volume. According to an embodiment, the fired heater includes a boiler heater and the combustion volume wall comprises a combustion pipe defining a lateral extent of the combustion volume, the combustion pipe being disposed to separate the combustion volume from a water and steam volume. The fired heater includes a mixing tube aligned to receive the fuel and combustion air from the fuel and combustion air source. The mixing tube may be separated from the combustion volume wall by a separation volume. The fired heater includes a bluff body flame holder aligned to receive a fuel and combustion air mixture from an outlet end of the mixing tube.
    Type: Application
    Filed: June 18, 2019
    Publication date: October 29, 2020
    Inventors: DONALD KENDRICK, DOUGLAS W. KARKOW, VENKATESH IYER, JAMES K. DANSIE, JONATHAN BUCHER, AARON SALZBRUN
  • Patent number: 10808925
    Abstract: A combustion fluid flow barrier includes an aperture to control combustion fluid flow. The combustion fluid is charged by a charge generator. The combustion fluid flow barrier includes at least one flow control electrode operatively coupled to the aperture and configured to selectively allow, attract, or resist passage of the charged combustion fluid through the aperture, depending on voltage applied to the flow control electrode.
    Type: Grant
    Filed: December 12, 2018
    Date of Patent: October 20, 2020
    Assignee: CLEARSIGN TECHNOLOGIES CORPORATION
    Inventors: Douglas W. Karkow, Christopher A. Wiklof