F23N 2221/00
Pretreatment or prehandling
F23N2221/00 (Pretreatment or prehandling) appears on 286 US grants and 258 published applications in this corpus.
Search patents in F23N- Granted patents
- 286
- Published applications
- 258
- Assignees
- 207
- Inventors
- 762
- Latest grant
- 22 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 4 | 0 |
| 1978 | 1 | 0 |
| 1979 | 4 | 0 |
| 1980 | 2 | 0 |
| 1981 | 3 | 0 |
| 1982 | 0 | 0 |
| 1983 | 1 | 0 |
| 1984 | 7 | 0 |
| 1985 | 2 | 0 |
| 1986 | 4 | 0 |
| 1987 | 6 | 0 |
| 1988 | 2 | 0 |
| 1989 | 5 | 0 |
| 1990 | 6 | 0 |
| 1991 | 6 | 0 |
| 1992 | 5 | 0 |
| 1993 | 4 | 0 |
| 1994 | 6 | 0 |
| 1995 | 2 | 0 |
| 1996 | 5 | 0 |
| 1997 | 4 | 0 |
| 1998 | 4 | 0 |
| 1999 | 1 | 0 |
| 2000 | 10 | 0 |
| 2001 | 3 | 3 |
| 2002 | 4 | 4 |
| 2003 | 5 | 3 |
| 2004 | 11 | 10 |
| 2005 | 4 | 4 |
| 2006 | 3 | 4 |
| 2007 | 4 | 14 |
| 2008 | 6 | 5 |
| 2009 | 5 | 15 |
| 2010 | 8 | 20 |
| 2011 | 6 | 16 |
| 2012 | 5 | 17 |
| 2013 | 13 | 13 |
| 2014 | 12 | 12 |
| 2015 | 8 | 17 |
| 2016 | 12 | 8 |
| 2017 | 11 | 7 |
| 2018 | 3 | 11 |
| 2019 | 8 | 11 |
| 2020 | 8 | 8 |
| 2021 | 8 | 12 |
| 2022 | 6 | 10 |
| 2023 | 9 | 14 |
| 2024 | 11 | 13 |
| 2025 | 9 | 5 |
| 2026 | 8 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- F23N 2221/10Analysing fuel propertiesIndexing code150
- F23N 2221/08Preheating the airIndexing code61
- F23N 2221/12Recycling exhaust gasesIndexing code48
- F23N 2221/04Preheating liquid fuelIndexing code18
- F23N 2221/06Preheating gaseous fuelIndexing code15
- F23N 2221/02Pretreatment or prehandling: using belt conveyorsIndexing code9
Recent patents
- Methods and systems for mixing fluids22 Sep 2026US 12,742,545 B2Ekona Power Inc.
- Method and kiln for the firing of substantially flat base ceramic articles8 Sep 2026US 12,729,855 B2Sacmi Forni & Filter S.P.A.
- Method for regulating a pellet-fired burner and corresponding installation25 Aug 2026US 12,716,585 B2N2Air
- Systems and methods for operation of a flexible fuel combustor25 Aug 2026US 12,716,589 B28 Rivers Capital, LLC
- Measuring instrument for determining the gross or net calorific value of a hydrocarbon-containing fuel gas21 Jul 2026US 12,687,496 B2Siemens Aktiengesellschaft
- Processes for Managing Combustion of a Fuel Gas Supplied to a Combustion Zone5 Mar 2026US 2026/0063294 A1
- Coal conveying control system and method for thermal power plant29 Jan 2026US 2026/0029122 A1Huaneng Chaohu Power Generation Co., Ltd.
- Combustion system able to operate with recycling of the combustion gas27 Nov 2025US 2025/0362016 A1Carbodown
- Sensor-Driven Variable Gas Flow Burner System18 Sep 2025US 2025/0290631 A1
- Heating device, heating apparatus and apparatus for providing a flow of gaseous hydrogen18 Sep 2025US 2025/0290665 A1ROLLS-ROYCE plc
Most cited
By later US patents
- Variable heat generating method and apparatus129US 4,622,007 AAmerican Combustion, Inc. · 1986
- Dynamic control system and method for catalytic combustion process and gas turbine engine utilizing same90US 6,095,793 AWoodward Governor Company · 2000
- Method and apparatus for generating highly luminous flame78US 4,797,087 AAmerican Combustion, Inc. · 1989
- Methods and systems for improving thermal efficiency, determining effluent flows and for determining fuel mass flow rates of a fossil fuel fired system61US 5,790,420 A1998
- Combustion control system58US 4,749,122 AThe Foxboro Company · 1988