REGULATING OR CONTROLLING COMBUSTION (control devices specially adapted for combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles F23C10/28; condition responsive controls for regulating combustion in domestic stoves with open fires for solid fuel F24B1/187)

Description

F23N covers devices and methods for regulating and controlling combustion processes in furnaces, boilers, burners, and other combustion apparatus. The classification includes fuel supply control systems, air/oxygen supply regulation, flame monitoring and safety devices, and automatic control mechanisms that adjust combustion parameters to maintain stable operation. Typical applications encompass ignition control, fuel flow modulation, excess air management, and feedback systems for industrial heating equipment. This class excludes the combustion apparatus itself (covered in F23D, F23H) and specific fuel supply systems when not integrated with combustion control (covered in F23K).

Filing statistics

CPC subclass F23N recorded 13,537 patent applications worldwide between 2013 and 2023. Annual filings declined from 1,173 in 2013 to 1,139 in 2023 (-3%), peaking at 1,525 applications in 2020. The most active applicants in class F23 are GE (GENERAL ELECTRIC COMPANY) (2,581 applications), UNITED TECHNOLOGIES CORPORATION (UTC) (1,180 applications) and SIEMENS (1,157 applications).

Source: EPO PATSTAT, worldwide filings