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).

  • Publication number: 20190113224
    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: Application
    Filed: December 12, 2018
    Publication date: April 18, 2019
    Inventors: DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Publication number: 20190107331
    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: Application
    Filed: October 22, 2018
    Publication date: April 11, 2019
    Inventors: DONALD KENDRICK, JAMES K. DANSIE, DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Publication number: 20190093886
    Abstract: A combustion system includes a perforated flame holder, a camera, and a control circuit. The perforated flame holder sustains a combustion reaction within the perforated flame holder. The image capture device takes a plurality of images of the combustion reaction. The control circuit produces from the images an averaged image and adjusts the combustion reaction based on the adjusted image.
    Type: Application
    Filed: November 29, 2018
    Publication date: March 28, 2019
    Inventors: JOSEPH COLANNINO, DOUGLAS W. KARKOW, ROBERT GEIGER, CHRISTOPHER A. WIKLOF
  • Patent number: 10240788
    Abstract: A combustion system includes an electrically actuated flame location control mechanism.
    Type: Grant
    Filed: August 17, 2018
    Date of Patent: March 26, 2019
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Igor A. Krichtafovitch, Robert E. Breidenthal, Christopher A. Wiklof
  • Publication number: 20190049107
    Abstract: A method of operation of a burner system includes introducing a fuel stream into a perforated flame holder, combusting the fuel stream, with a majority of the combustion occurring between an input face and an output face of the flame holder, and producing a heat output from the combustion of at least 1.5 kBTU/H/in2.
    Type: Application
    Filed: October 15, 2018
    Publication date: February 14, 2019
    Inventors: JOSEPH COLANNINO, DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Patent number: 10190767
    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: March 27, 2014
    Date of Patent: January 29, 2019
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Christopher A. Wiklof
  • Publication number: 20190024887
    Abstract: A combustion system such as a furnace or boiler includes a non-planar perforated flame holder configured to hold a combustion reaction.
    Type: Application
    Filed: September 20, 2018
    Publication date: January 24, 2019
    Inventors: JOSEPH COLANNINO, DOUGLAS W. KARKOW, JAMES K. DANSIE, CHRISTOPHER A. WIKLOF
  • Publication number: 20190011123
    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: July 12, 2018
    Publication date: January 10, 2019
    Inventors: JAMES K. DANSIE, DOUGLAS W. KARKOW, JESSE DUMAS, DONALD KENDRICK, SUNNY KARNANI, CHRISTOPHER A. WIKLOF
  • Publication number: 20190011124
    Abstract: A cracking furnace includes a combustion volume defined in part by a burner wall having a refractory lining. A plurality of perforated flame holders is arranged in an array that is spaced away from the wall, with fuel input faces facing the wall. Each of a plurality of fuel nozzles is positioned and configured to emit a fuel stream toward the input face of a respective one of the plurality of perforated flame holders. Combustion reactions, supported by the fuel streams emitted by the fuel nozzles, and held by the flame holders, release heat, which is emitted by the flame holders as thermal (blackbody) radiation, a portion of which impinges upon, and heats the inner face of the refractory lining. Thermal radiation from the flame holders and the wall impinges upon a load positioned in the approximate center of the combustion volume, between burner walls.
    Type: Application
    Filed: September 13, 2018
    Publication date: January 10, 2019
    Inventors: JOSEPH COLANNINO, DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Publication number: 20190003705
    Abstract: According to an embodiment, a combustion system is provided, which includes a nozzle configured to emit a diverging fuel flow, a flame holder positioned in the path of the fuel flow and that includes a plurality of apertures extending therethrough, and a preheat mechanism configured to heat the flame to a temperature exceeding a startup temperature threshold.
    Type: Application
    Filed: August 20, 2018
    Publication date: January 3, 2019
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, IGOR A. KRICHTAFOVITCH, CHRISTOPHER A. WIKLOF
  • Publication number: 20180372314
    Abstract: A combustion system includes an electrically actuated flame location control mechanism.
    Type: Application
    Filed: August 17, 2018
    Publication date: December 27, 2018
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, IGOR A. KRICHTAFOVITCH, ROBERT E. BREIDENTHAL, CHRISTOPHER A. WIKLOF
  • Patent number: 10156356
    Abstract: A combustion system includes a perforated flame holder, a camera, and a control circuit. The perforated flame holder sustains a combustion reaction within the perforated flame holder. The image capture device takes a plurality of images of the combustion reaction. The control circuit produces from the images an averaged image and adjusts the combustion reaction based on the adjusted image.
    Type: Grant
    Filed: April 19, 2016
    Date of Patent: December 18, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Joseph Colannino, Douglas W. Karkow, Robert Geiger, Christopher A. Wiklof
  • Patent number: 10139131
    Abstract: A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: November 27, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Christopher A. Wiklof
  • Patent number: 10125983
    Abstract: A method of operation of a burner system includes introducing a fuel stream into a perforated flame holder, combusting the fuel stream, with a majority of the combustion occurring between an input face and an output face of the flame holder, and producing a heat output from the combustion of at least 1.5 kBTU/H/in2.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: November 13, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Joseph Colannino, Douglas W. Karkow, Christopher A. Wiklof
  • Patent number: 10125979
    Abstract: A combustion system includes a combustion fluid charge source and a start-up flame holder configured to attract the charge and hold a flame when the combustion system is cool and allow the flame to lift when the combustion system is warmed up.
    Type: Grant
    Filed: May 12, 2014
    Date of Patent: November 13, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Joseph Colannino, Douglas W. Karkow
  • Patent number: 10119704
    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: August 15, 2016
    Date of Patent: November 6, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Joseph Colannino, Douglas W. Karkow, James K. Dansie, Christopher A. Wiklof
  • Patent number: 10088154
    Abstract: A down-fired flame burner includes a flame holder positioned below the burner. The flame holder includes a plurality of perforations that collectively confine a combustion reaction of the burner to the flame holder.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: October 2, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Joseph Colannino, Douglas W. Karkow, Igor A. Krichtafovitch, Christopher A. Wiklof
  • Patent number: 10088153
    Abstract: A cracking furnace includes a combustion volume defined in part by a burner wall having a refractory lining. A plurality of perforated flame holders is arranged in an array that is spaced away from the wall, with fuel input faces facing the wall. Each of a plurality of fuel nozzles is positioned and configured to emit a fuel stream toward the input face of a respective one of the plurality of perforated flame holders. Combustion reactions, supported by the fuel streams emitted by the fuel nozzles, and held by the flame holders, release heat, which is emitted by the flame holders as thermal (blackbody) radiation, a portion of which impinges upon, and heats the inner face of the refractory lining. Thermal radiation from the flame holders and the wall impinges upon a load positioned in the approximate center of the combustion volume, between burner walls.
    Type: Grant
    Filed: November 8, 2016
    Date of Patent: October 2, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Joseph Colannino, Douglas W. Karkow, Christopher A. Wiklof
  • Patent number: 10077899
    Abstract: According to an embodiment, a combustion system is provided, which includes a nozzle configured to emit a diverging fuel flow, a flame holder positioned in the path of the fuel flow and that includes a plurality of apertures extending therethrough, and a preheat mechanism configured to heat the flame to a temperature exceeding a startup temperature threshold.
    Type: Grant
    Filed: February 14, 2014
    Date of Patent: September 18, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Igor A. Krichtafovitch, Christopher A. Wiklof
  • Patent number: 10066835
    Abstract: A combustion system includes an electrically actuated flame location control mechanism.
    Type: Grant
    Filed: November 10, 2014
    Date of Patent: September 4, 2018
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Igor A. Krichtafovitch, Robert E. Breidenthal, Christopher A. Wiklof