F25J 3/04454
A main column system not otherwise provided
Official title: {a main column system not otherwise provided, e.g. serially coupling of columns or more than three pressure levels}
F25J3/04454 (A main column system not otherwise provided) appears on 54 US grants and 28 published applications in this corpus.
Search patents in F25J- Granted patents
- 54
- Published applications
- 28
- Assignees
- 21
- Inventors
- 86
- Latest grant
- 9 Dec 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1978 | 1 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 1 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 2 | 0 |
| 1985 | 1 | 0 |
| 1986 | 1 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 2 | 0 |
| 1993 | 0 | 0 |
| 1994 | 2 | 0 |
| 1995 | 1 | 0 |
| 1996 | 2 | 0 |
| 1997 | 4 | 0 |
| 1998 | 0 | 0 |
| 1999 | 3 | 0 |
| 2000 | 1 | 0 |
| 2001 | 6 | 0 |
| 2002 | 3 | 2 |
| 2003 | 2 | 1 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 1 |
| 2009 | 0 | 1 |
| 2010 | 0 | 1 |
| 2011 | 0 | 2 |
| 2012 | 1 | 2 |
| 2013 | 2 | 3 |
| 2014 | 0 | 2 |
| 2015 | 2 | 0 |
| 2016 | 1 | 2 |
| 2017 | 2 | 2 |
| 2018 | 0 | 1 |
| 2019 | 3 | 0 |
| 2020 | 1 | 0 |
| 2021 | 0 | 2 |
| 2022 | 0 | 1 |
| 2023 | 2 | 3 |
| 2024 | 2 | 0 |
| 2025 | 2 | 2 |
By publication year. Applications have been published since 2001.
Recent patents
- Process and plant for low-temperature separation of air9 Dec 2025US 12,492,863 B2Linde Aktiengesellschaft
- Carbon-based oxygen-enriched combustion method for recirculation of flue gas from cement kiln24 Jun 2025US 12,339,062 B2Hangzhou Turning Energy Technology Development Co., Ltd.
- Method and apparatus for producing high-purity nitrogen and low-purity oxygen21 May 2024US 11,988,446 B2L Air Liquide, Societe Anonyme Pour L'Etude et L'Exploitation des Procedes Georges Claude
- System and method for recovery of nitrogen, argon, and oxygen in moderate pressure cryogenic air separation unit19 Mar 2024US 11,933,538 B2Praxair Technology, Inc.
- Method and unit for low-temperature air separation19 Dec 2023US 11,846,468 B2Linde Aktiengesellschaft
- Apparatus and process for providing nitrogen and oxygen18 Sep 2025US 2025/0290692 A1Air Products and Chemicals, Inc.
- High-purity oxygen production method, and air separation device for producing high-purity oxygen12 Jun 2025US 2025/0189218 A1L Air Liquide, Societe Anonyme Pour L'Etude et L'Exploitation des Procedes Georges Claude
- Process and plant for low-temperature separation of air9 Feb 2023US 2023/0038170 A1Linde Aktiengesellschaft
- Energy-efficient process for preparing nitrogen and oxygen for glass melting furnace2 Feb 2023US 2023/0034371 A1Hangzhou Turning Energy Technology Development Co., Ltd.
- Carbon-based oxygen-enriched combustion method for recirculation of flue gas from cement kiln2 Feb 2023US 2023/0034842 A1Hangzhou Turning Energy Technology Development Co., Ltd.
Most cited
By later US patents
- Triple column distillation system for oxygen and pressurized nitrogen production46US 5,341,646 AAir Products and Chemicals, Inc. · 1994
- Cryogenic air separation with cold argon recycle38US 4,533,375 A1985
- Production of ultra-high purity oxygen from cryogenic air separation plants31US 5,049,173 AAir Products and Chemicals, Inc. · 1991
- Air separation with medium pressure enrichment30US 4,433,989 A1984
- High purity nitrogen and oxygen gas production equipment29US 4,853,015 ADaidousanso Co., Ltd. · 1989