F23J REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES (combustion apparatus for consuming smoke or fumes, e.g. exhaust gases, F23G7/06)
Description
F23J covers technologies for managing exhaust gases, particulates, and residual matter generated by combustion processes, along with the flue systems that transport these byproducts. This includes dust collectors, ash removal equipment, scrubbers, and related treatment systems for both solid and gaseous combustion residues. The classification encompasses flue design, draft control, and ancillary equipment that processes or directs combustion products from furnaces, boilers, and other combustion apparatus. Related dust separation and air pollution control measures are included where integral to combustion residue management.
Filing statistics
CPC subclass F23J recorded 23,943 patent applications worldwide between 2013 and 2023. Annual filings grew from 1,318 in 2013 to 2,351 in 2023 (+78%), peaking at 3,207 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
15 direct subcodes
Child Classifications
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- F23J 1/00 Removing ash, clinker, or slag from combustion chambers ( devices for removal of material from the bed of fluidised bed combustion apparatus F23C10/24)
- F23J 11/00 Devices for conducting smoke or fumes, e.g. flues (chimney stacks E04H12/28; removing cooking fumes from domestic stoves or ranges F24C15/20 )
- F23J 13/00 Fittings for chimneys or flues (side-supporting means for chimney stacks E04H12/20; ladders permanently attached to chimneys E06C9/00; draught-inducing apparatus associated with chimneys or flues F23L17/00; tops for chimneys, terminals for flues F23L17/02)
- F23J 15/00 Arrangements of devices for treating smoke or fumes
- F23J 2211/00 Flue gas duct systems
- F23J 2213/00 Chimneys or flues
- F23J 2215/00 Preventing emissions
- F23J 2217/00 Intercepting solids
- F23J 2219/00 Treatment devices
- F23J 2700/00 Ash removal, handling and treatment means; Ash and slag handling in pulverulent fuel furnaces; Ash removal means for incinerators
- F23J 2900/00 Special arrangements for conducting or purifying combustion fumes; Treatment of fumes or ashes
- F23J 3/00 Removing solid residues from passages or chambers beyond the fire, e.g. from flues by soot blowers
- F23J 7/00 Arrangement of devices for supplying chemicals to fire
- F23J 9/00 Preventing premature solidification of molten combustion residues
- F23J 99/00 Subject matter not provided for in other groups of this subclass
Top Applicants
Top 10 applicants by patent filingsfor class F23, 2013–2023, worldwide · Source: EPO PATSTAT
- GE (GENERAL ELECTRIC COMPANY) US 2,581
- UNITED TECHNOLOGIES CORPORATION (UTC) US 1,180
- SIEMENS DE 1,157
- GE (GENERAL ELECTRIC COMPANY) 994
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 769
- MITSUBISHI HEAVY INDUSTRIES JP 701
- MITSUBISHI HITACHI POWER SYSTEMS JP 695
- RAYTHEON TECHNOLOGIES CORPORATION US 587
- NINGBO FOTILE KITCHENWARE COMPANY 543
- GENERAL ELECTRIC TECHNOLOGY CH 490