F23H GRATES; CLEANING OR RAKING GRATES
Introduced: September 1968
Classification Context
- Section:
- MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- Class:
- COMBUSTION APPARATUS; COMBUSTION PROCESSES
- Subclass:
- GRATES; CLEANING OR RAKING GRATES
Description
F23H covers mechanical grates used in combustion apparatus and devices for their maintenance. This classification encompasses fixed and moving grates designed to support fuel in furnaces, boilers, and fireplaces, as well as mechanisms for cleaning, raking, or removing ash and clinker from grate surfaces during operation. The scope includes grate constructions, support structures, and powered or manual cleaning systems integrated with or retrofitted to combustion equipment. Related combustion apparatus classifications (such as F23B for furnace structures) are distinguished by their focus on the overall combustion chamber rather than the grate element itself.
Filing statistics
IPC subclass F23H recorded 2,855 patent applications worldwide between 2013 and 2023. Annual filings grew from 165 in 2013 to 226 in 2023 (+37%), peaking at 388 applications in 2020. The most active applicants in class F23 are GE (GENERAL ELECTRIC COMPANY) (2,124 applications), XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY (1,369 applications) and NINGBO FOTILE KITCHENWARE COMPANY (1,363 applications).
Source: EPO PATSTAT, worldwide filings
In class comparison
F23H ranks 12th of 12 subclasses with filings in F23, with 2,855 applications between 2013 and 2023, 0.9% of the class. Annual filings grew 37% from 2013 to 2023, below the class as a whole (+76%).
| Rank | Subclass | Title | Applications | Share |
|---|---|---|---|---|
| 1 | F23J, Removal or Treatment of Combustion Products or Combustion Residues; Flues | Removal or Treatment of Combustion Products or Combustion Residues; Flues | 62,845 | 20.9% |
| 2 | F23G, Cremation Furnaces; Consuming Waste or Low Grade Fuels by Combustion | Cremation Furnaces; Consuming Waste or Low Grade Fuels by Combustion | 62,605 | 20.8% |
| 3 | F23D, Burners | Burners | 48,008 | 15.9% |
| 4 | F23L, Supplying Air or Non-Combustible Liquids or Gases to Combustion Apparatus in General; Valves or Dampers Specially Adapted for Controlling Air Supply or Draught in Combustion Apparatus; Inducing Draught in Combustion Apparatus; Tops for Chimneys or Ventilating Shafts; Terminals for Flues | Supplying Air or Non-Combustible Liquids or Gases to Combustion Apparatus in General; Valves or Dampers Specially Adapted for Controlling Air Supply or Draught in Combustion Apparatus; Inducing Draught in Combustion Apparatus; Tops for Chimneys or Ventilating Shafts; Terminals for Flues | 24,279 | 8.1% |
| 5 | F23C, Methods or Apparatus for Combustion Using Fluid Fuel or Solid Fuel Suspended in Air | Methods or Apparatus for Combustion Using Fluid Fuel or Solid Fuel Suspended in Air | 19,304 | 6.4% |
| 6 | F23R, Generating Combustion Products of High Pressure or High Velocity, e.g. Gas-Turbine Combustion Chambers | Generating Combustion Products of High Pressure or High Velocity, e.g. Gas-Turbine Combustion Chambers | 17,458 | 5.8% |
| 7 | F23K, Feeding Fuel to Combustion Apparatus | Feeding Fuel to Combustion Apparatus | 17,228 | 5.7% |
| 8 | F23N, Regulating or Controlling Combustion | Regulating or Controlling Combustion | 15,400 | 5.1% |
| 9 | F23Q, Ignition; Extinguishing Devices | Ignition; Extinguishing Devices | 12,442 | 4.1% |
| 10 | F23B, Methods or Apparatus for Combustion Using Only Solid Fuel | Methods or Apparatus for Combustion Using Only Solid Fuel | 9,943 | 3.3% |
| 12 | F23H | Grates; Cleaning or Raking Grates | 2,855 | 0.9% |
Source: EPO PATSTAT, worldwide filings
Related Keywords
9 direct subcodes
Child Classifications
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- F23H 1/00 Grates with solid bars
- F23H 11/00 Travelling grates
- F23H 13/00 Grates not covered by any of groups
- F23H 15/00 Cleaning arrangements for grates; Moving fuel along grates
- F23H 17/00 Details of grates
- F23H 3/00 Grates with hollow bars
- F23H 5/00 Double grates
- F23H 7/00 Inclined grates
- F23H 9/00 Revolving grates; Rocking or shaking grates
Top Applicants
Top 10 applicants by patent filingsfor class F23, 2013–2023, worldwide · Source: EPO PATSTAT
- GE (GENERAL ELECTRIC COMPANY) US 2,124
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 1,369
- NINGBO FOTILE KITCHENWARE COMPANY 1,363
- SIEMENS DE 997
- UNITED TECHNOLOGIES CORPORATION (UTC) US 937
- GE (GENERAL ELECTRIC COMPANY) 898
- VATTI 815
- CHINESE ACADEMY OF SCIENCES 719
- RINNAI COMPANY 708
- MITSUBISHI HITACHI POWER SYSTEMS 670