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: 9388981
    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: June 16, 2015
    Date of Patent: July 12, 2016
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Igor A. Krichtafovitch, Christopher A. Wiklof
  • Patent number: 9377190
    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: June 16, 2015
    Date of Patent: June 28, 2016
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Igor A. Krichtafovitch, Christopher A. Wiklof
  • Publication number: 20160161115
    Abstract: A burner includes a flame position actuator configured to control a location at which a flame is held. Combustion supported at a first location corresponds to high fuel dilution. An electric charge is applied to the fuel stream. If electrical power is lost or removed, the flame is shifted to a location corresponding to a lower fuel dilution.
    Type: Application
    Filed: October 23, 2013
    Publication date: June 9, 2016
    Applicant: ClearSign Combustion Corporation
    Inventors: IGOR A. KRICHTAFOVITCH, JOSEPH COLANNINO, DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Publication number: 20160091200
    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: Application
    Filed: May 12, 2014
    Publication date: March 31, 2016
    Inventors: JOSEPH COLANNINO, DOUGLAS W. KARKOW
  • Publication number: 20160046524
    Abstract: A rotary kiln includes a stationary fuel nozzle and a perforated flame holder positioned within an inclined rotating shell. The flame holder includes a plurality of perforations that collectively confine a combustion reaction of the burner to the flame holder to shift most heat transfer from the combustion reaction from radiation heat transfer to convective heat transfer.
    Type: Application
    Filed: August 11, 2015
    Publication date: February 18, 2016
    Inventors: JOSEPH COLANNINO, DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Publication number: 20160040872
    Abstract: A swirl-stabilized burner includes a charge source configured to apply a majority charge to a combustion reaction and at least one stabilization electrode configured to apply electrical attraction or repulsion to the majority charge to control position or stability of the swirl-stabilized combustion reaction.
    Type: Application
    Filed: March 20, 2014
    Publication date: February 11, 2016
    Inventors: JOSEPH COLANNINO, DOUGLAS W. KARKOW, IGOR A. KRICHTAFOVITCH, CHRISTOPHER A. WIKLOF
  • Publication number: 20160025333
    Abstract: A perforated flame holder and burner including a perforated flame holder provides reduced oxides of nitrogen (NOx) during operation. The perforated flame holder includes a pattern of elongated apertures extending between a proximal and a distal surface of the flame holder relative to a fuel nozzle. The perforated flame holder can provide a significantly reduced flame height while maintaining heat output from the burner.
    Type: Application
    Filed: February 14, 2014
    Publication date: January 28, 2016
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, IGOR A. KRICHTAFOVITCH, ROBERT E. BREIDENTHAL, CHRISTOPHER A. WIKLOF
  • Publication number: 20160025374
    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: Application
    Filed: July 28, 2015
    Publication date: January 28, 2016
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, CHRISTOPHER A. WIKLOF
  • Publication number: 20160025380
    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. A controller variably controls a flow of fuel to the nozzle according to a temperature of water in the tank.
    Type: Application
    Filed: July 28, 2015
    Publication date: January 28, 2016
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO
  • Publication number: 20160018103
    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: March 27, 2014
    Publication date: January 21, 2016
    Applicant: ClearSign Combustion Corporation
    Inventors: DOUGLAS W. KARKOW, CHRISTOPHER A. WIKLOF
  • Publication number: 20160003471
    Abstract: A furnace has a fuel and oxidant source to create a flow of combustible fuel and oxidant mixture, a perforated flame holder on which the flow impinges, and a support structure to support the perforated flame holder in a position where it at least partially contains combustion of the fuel and oxidant mixture. The support structure mechanically engages with the interior of the furnace to support the perforated flame holder, which may be movable within the furnace via a mechanism to optimize combustion or reduce NOx. The support may contain fluid coolant. The perforated flame holder may be moved into and out of a combustion region.
    Type: Application
    Filed: July 7, 2015
    Publication date: January 7, 2016
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, ROBERTO RUIZ, NICHOLAS S. BROMER, CHRISTOPHER A. WIKLOF
  • Publication number: 20150369477
    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: February 14, 2014
    Publication date: December 24, 2015
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, IGOR A. KRICHTAFOVITCH, CHRISTOPHER A. WIKLOF
  • Publication number: 20150362178
    Abstract: A burner supporting primary and secondary combustion reactions may include a primary combustion reaction actuator configured to select a location of the secondary combustion reaction. A burner may include a lifted flame holder structure configured to support a secondary combustion reaction above a partial premixing region. The secondary flame support location may be selected as a function of a turndown parameter. Selection logic may be of arbitrary complexity.
    Type: Application
    Filed: February 14, 2014
    Publication date: December 17, 2015
    Inventors: DOUGLAS W. KARKOW, IGOR A. KRICHTAFOVICH, JOSEPH COLANNINO, CHRISTOPHER A. WIKLOF
  • Publication number: 20150330625
    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: Application
    Filed: September 23, 2014
    Publication date: November 19, 2015
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, ROBERT E. BREIDENTHAL, CHRISTOPHER A. WIKLOF
  • Publication number: 20150316261
    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: Application
    Filed: February 14, 2014
    Publication date: November 5, 2015
    Applicant: ClearSign Combustion Corporation
    Inventors: DOUGLAS W. KARKOW, ROBERT E. BREIDENTHAL, JOSEPH COLANNINO, CHRISTOPHER A. WIKLOF
  • Publication number: 20150285491
    Abstract: A combustion system outputs fuel gas from a plurality of fuel ejectors toward a forward end of a burner wall and preheats a perforated flame holder by sustaining combustion reaction of the fuel gas at combustion zone between the burner wall and a perforated flame holder. The combustion system then outputs fuel gas from the fuel ejectors onto the perforated flame holder and sustains a combustion reaction of the fuel gas within the perforated flame holder.
    Type: Application
    Filed: June 16, 2015
    Publication date: October 8, 2015
    Inventors: DOUGLAS W. KARKOW, ROBERT BREIDENTHAL, JOSEPH COLANNINO, CHRISTOPHER A. WIKLOF
  • Publication number: 20150276217
    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: Application
    Filed: June 16, 2015
    Publication date: October 1, 2015
    Inventors: DOUGLAS W. KARKOW, ROBERT BREIDENTHAL, JOSEPH COLANNINO, CHRISTOPHER A. WIKLOF
  • Publication number: 20150276212
    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: June 16, 2015
    Publication date: October 1, 2015
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, IGOR A. KRICHTAFOVITCH, CHRISTOPHER A. WIKLOF
  • Publication number: 20150276220
    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: Application
    Filed: June 16, 2015
    Publication date: October 1, 2015
    Inventors: DOUGLAS W. KARKOW, ROBERT BREIDENTHAL, JOSEPH COLANNINO, CHRISTOPHER A. WIKLOF
  • Publication number: 20150276213
    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: June 16, 2015
    Publication date: October 1, 2015
    Inventors: DOUGLAS W. KARKOW, JOSEPH COLANNINO, IGOR A. KRICHTAFOVITCH, CHRISTOPHER A. WIKLOF