Internal Water Tube Patents (Class 122/140.1)
Having water tube in flue (Class 122/140.2)
Longitudinal
Return fire tube (Class 122/142)
Spur (Class 122/143)
Subjacent firebox (Class 122/144)
Transverse (Class 122/145)
Water firebox (Class 122/148)
  • Method for low NOx fire tube boiler
    Patent number: 10359213
    Abstract: A fire tube boiler includes a perforated flame holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).
    Type: Grant
    Filed: July 20, 2016
    Date of Patent: July 23, 2019
    Assignee: CLEARSIGN COMBUSTION CORPORATION
    Inventors: Douglas W. Karkow, Joseph Colannino, Igor A. Krichtafovitch, Robert E. Breidenthal, Christopher A. Wiklof