C21C 5/5211
In an alternating current [ac] electric arc furnace
Official title: {in an alternating current [AC] electric arc furnace}
C21C5/5211 (In an alternating current [ac] electric arc furnace) appears on 350 US grants and 287 published applications in this corpus.
Search patents in C21C- Granted patents
- 350
- Published applications
- 287
- Assignees
- 216
- Inventors
- 815
- Latest grant
- 9 Jun 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 5 | 0 |
| 1977 | 4 | 0 |
| 1978 | 6 | 0 |
| 1979 | 3 | 0 |
| 1980 | 4 | 0 |
| 1981 | 3 | 0 |
| 1982 | 3 | 0 |
| 1983 | 4 | 0 |
| 1984 | 10 | 0 |
| 1985 | 10 | 0 |
| 1986 | 6 | 0 |
| 1987 | 10 | 0 |
| 1988 | 14 | 0 |
| 1989 | 7 | 0 |
| 1990 | 6 | 0 |
| 1991 | 4 | 0 |
| 1992 | 6 | 0 |
| 1993 | 4 | 0 |
| 1994 | 9 | 0 |
| 1995 | 9 | 0 |
| 1996 | 6 | 0 |
| 1997 | 5 | 0 |
| 1998 | 9 | 0 |
| 1999 | 6 | 0 |
| 2000 | 8 | 0 |
| 2001 | 7 | 3 |
| 2002 | 14 | 6 |
| 2003 | 10 | 7 |
| 2004 | 9 | 12 |
| 2005 | 5 | 9 |
| 2006 | 1 | 6 |
| 2007 | 4 | 8 |
| 2008 | 7 | 13 |
| 2009 | 4 | 10 |
| 2010 | 7 | 14 |
| 2011 | 5 | 17 |
| 2012 | 9 | 21 |
| 2013 | 11 | 9 |
| 2014 | 7 | 18 |
| 2015 | 8 | 14 |
| 2016 | 9 | 13 |
| 2017 | 10 | 6 |
| 2018 | 10 | 10 |
| 2019 | 6 | 8 |
| 2020 | 8 | 19 |
| 2021 | 7 | 9 |
| 2022 | 9 | 11 |
| 2023 | 6 | 11 |
| 2024 | 9 | 11 |
| 2025 | 3 | 12 |
| 2026 | 4 | 10 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Biomass pyrolysis integrated with bio-reduction of metal ores, hydrogen production, and/or activated-carbon production9 Jun 2026US 12,649,959 B2Carbon Technology Holdings, LLC
- Method for simultaneously injecting a fuel gas and an oxygen-rich gas into a unit14 Apr 2026US 12,601,022 B2SMS group GmbH
- Method of operating an electric arc furnace and steel mill24 Mar 2026US 12,584,182 B2Paul Wurth S. A.
- Process for producing raw steel and aggregate for production thereof10 Mar 2026US 12,571,062 B2ThyssenKrupp Steel Europe AG
- Method for manufacturing molten iron with electric arc furnace9 Dec 2025US 12,492,439 B2Jfe Steel Corporation
- Molten steel manufacturing method and arc furnace20 Aug 2026US 2026/0242884 A1Nippon Steel Corporation
- Method for producing molten iron13 Aug 2026US 2026/0234740 A1Jfe Steel Corporation
- Method for producing molten iron6 Aug 2026US 2026/0226569 A1Jfe Steel Corporation
- Granule and/or powder solid materials injection lance for injecting solid materials in the form of granules and/or powders into a metallurgical furnace23 Jul 2026US 2026/0209875 A1Tenova S. P. A.
- Apparatus for determining energized state of electric arc furnace, operation method for electric arc furnace, and electric arc furnace23 Jul 2026US 2026/0210632 A1Jfe Steel Corporation
Most cited
By later US patents
- Scrap melter and impeller113US 6,723,276 B12004
- Adjustable momentum self-cooled oxy/fuel burner for heating in high temperature environments110US 5,199,866 AAir Products and Chemicals, Inc. · 1993
- Destruction of toxic chemicals100US 4,574,714 AUnited States Steel Corporation · 1986
- Destruction of toxic organic chemicals93US 4,602,574 AUnited States Steel Corporation · 1986
- Process and apparatus for melting a furnace charge87US 5,166,950 AL'Air Liquide, Societe Anonyme pour Etude et l'Exploitation des Procedes · 1992