CPC technology class · F23
F23C — Methods OR Apparatus FOR Combustion Using Fluid FUEL OR S…
Methods or apparatus for combustion using fluid fuel or solid fuel suspended in ; a carrier gas or; air. 1,571 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.
- 1,571
- US patents granted
- F23
- Parent CPC class
- 20
- Active assignees
- -29%
- 5-yr velocity
CPC subclass F23C — METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN ; A CARRIER GAS OR; AIR — covers 1,571 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records. This subclass sits within the broader CPC class F23 (COMBUSTION APPARATUS; COMBUSTION PROCESSES), one of roughly 250 top-level technology categories in the Cooperative Patent Classification system jointly maintained by the USPTO and the European Patent Office. At the subclass level, four-character codes like F23C give the most practical resolution for tracking a specific technology domain without losing sight of adjacent filings. Every grant here has been classified by a USPTO examiner based on the technical disclosure in the patent specification.
The competitive landscape in F23C is shaped by 20 distinct companies actively filing in this space. General Electric Company leads with 85 patents, followed by GENERAL ELECTRIC TECHNOLOGY GMBH at 670 grants and ANSALDO ENERGIA SWITZERLAND AG at 179. Concentration at the top of the leaderboard indicates whether this technology area is dominated by a handful of incumbents or fragmented across many filers — a useful signal for investors evaluating competitive moats and for product teams mapping freedom-to-operate risk.
Filing trajectory matters as much as static counts. The yearly series on this page plots grants from 2015 through 2025, highlighting whether innovation in F23C is accelerating, plateauing, or cooling. Technology areas with rising post-2020 activity often reflect emerging markets or new platform shifts, while declining filings can signal mature domains where incremental improvement has slowed. Researchers, licensing professionals, and competitive-intelligence teams use these patterns — together with the top-assignee distribution — to decide where to invest, where to license, and where to avoid entanglement. All counts on this page come directly from USPTO PatentsView and reflect US granted utility patents only.
Is F23C innovation accelerating?
US utility-patent grants per year in F23C, 2015–2025 — recent five years are down 29% versus 2015–2019.
Who leads F23C?
The 12 most active assignees in METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN ; A CARRIER GAS OR; AIR — wider bars mean more grants
- Clearsign Combustion 81
CLEARSIGN COMBUSTION CORPORATION
81 patents
- General Electric Tech…
GENERAL ELECTRIC TECHNOLOGY GMBH
670 patents
- Ansaldo Energia Switz… 179
ANSALDO ENERGIA SWITZERLAND AG
179 patents
- Exxonmobil Upstream R…
EXXONMOBIL UPSTREAM RESEARCH COMPANY
841 patents
- Ifp Energies Nouvelles
IFP ENERGIES NOUVELLES
870 patents
- Alstom Technology
ALSTOM Technology Ltd
352 patents
- Ener-core Power 25
Ener-Core Power, Inc.
25 patents
- Air Products And Chem…
AIR PRODUCTS AND CHEMICALS, INC.
353 patents
- Clearsign 28
ClearSign Technologies Corporation
28 patents
- 8 Rivers Capital 109
8 Rivers Capital, LLC
109 patents
- Delavan 180
Delavan Inc.
180 patents
- EberspÄCher Climate C… 78
EBERSPÄCHER CLIMATE CONTROL SYSTEMS GMBH
78 patents
What this shows General Electric is the most active filer in F23C, holding 85 of the 1,571 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.
View data table
| Rank | Company | Patents in F23C |
|---|---|---|
| #1 | CLEARSIGN COMBUSTION CORPORATION | 81 |
| #2 | GENERAL ELECTRIC TECHNOLOGY GMBH | 670 |
| #3 | ANSALDO ENERGIA SWITZERLAND AG | 179 |
| #4 | EXXONMOBIL UPSTREAM RESEARCH COMPANY | 841 |
| #5 | IFP ENERGIES NOUVELLES | 870 |
| #6 | ALSTOM Technology Ltd | 352 |
| #7 | Ener-Core Power, Inc. | 25 |
| #8 | AIR PRODUCTS AND CHEMICALS, INC. | 353 |
| #9 | ClearSign Technologies Corporation | 28 |
| #10 | 8 Rivers Capital, LLC | 109 |
| #11 | Delavan Inc. | 180 |
| #12 | EBERSPÄCHER CLIMATE CONTROL SYSTEMS GMBH | 78 |
| #13 | The Babcock & Wilcox Company | 62 |
| #14 | TOTAL RAFFINAGE CHIMIE | 58 |
| #15 | Sumitomo SHI FW Energia Oy | 17 |
| #16 | TOTAL SA | 187 |
| #17 | GAS TECHNOLOGY INSTITUTE | 128 |
| #18 | Linde GmbH | 382 |
| #19 | NORITZ CORPORATION | 184 |
| #20 | Valmet Technologies Oy | 103 |
About This Class
CPC subclass F23C belongs to class F23.
1,571 patents were granted in this class between 2015 and 2025.
20 companies actively patent in this space.
Classification System
Cooperative Patent Classification (CPC) is a hierarchical patent classification system used by the USPTO and EPO.
Frequently Asked Questions
What is CPC class F23C?
How many patents have been filed in F23C?
Which company holds the most patents in F23C?
How is patent data for F23C collected?
What is the difference between CPC class and subclass?
Learn More
Explore the patent dataset
Read our methodology — how this data is sourced, computed, and verified.