F27B 3/00
Hearth-type furnaces
Official title: Hearth-type furnaces, e.g. of reverberatory type (F27B9/00, F27B11/00, F27B13/00, F27B14/00, F27B15/00, F27B21/00 take precedence); Electric arc furnaces {; Tank furnaces}
F27B3/00 (Hearth-type furnaces) appears on 1,404 US grants and 1,086 published applications in this corpus.
Search patents in F27B- Granted patents
- 1,404
- Published applications
- 1,086
- Assignees
- 687
- Inventors
- 2,732
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 18 | 0 |
| 1977 | 14 | 0 |
| 1978 | 11 | 0 |
| 1979 | 10 | 0 |
| 1980 | 14 | 0 |
| 1981 | 12 | 0 |
| 1982 | 21 | 0 |
| 1983 | 28 | 0 |
| 1984 | 29 | 0 |
| 1985 | 26 | 0 |
| 1986 | 18 | 0 |
| 1987 | 35 | 0 |
| 1988 | 16 | 0 |
| 1989 | 25 | 0 |
| 1990 | 19 | 0 |
| 1991 | 19 | 0 |
| 1992 | 19 | 0 |
| 1993 | 20 | 0 |
| 1994 | 21 | 0 |
| 1995 | 35 | 0 |
| 1996 | 34 | 0 |
| 1997 | 23 | 0 |
| 1998 | 48 | 0 |
| 1999 | 46 | 0 |
| 2000 | 37 | 0 |
| 2001 | 33 | 14 |
| 2002 | 37 | 24 |
| 2003 | 26 | 25 |
| 2004 | 32 | 28 |
| 2005 | 18 | 19 |
| 2006 | 6 | 28 |
| 2007 | 17 | 31 |
| 2008 | 13 | 39 |
| 2009 | 24 | 41 |
| 2010 | 33 | 35 |
| 2011 | 21 | 40 |
| 2012 | 32 | 46 |
| 2013 | 32 | 51 |
| 2014 | 25 | 44 |
| 2015 | 34 | 56 |
| 2016 | 38 | 60 |
| 2017 | 44 | 40 |
| 2018 | 41 | 46 |
| 2019 | 41 | 44 |
| 2020 | 38 | 58 |
| 2021 | 36 | 51 |
| 2022 | 46 | 52 |
| 2023 | 39 | 56 |
| 2024 | 47 | 55 |
| 2025 | 34 | 57 |
| 2026 | 19 | 46 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- F27B 3/10Details, accessories or equipment1,127
- F27B 3/08Heated electrically, with or without any other source of heat446
- F27B 3/04Hearth-type furnaces: of multiple-hearth type165
- F27B 3/06Hearth-type furnaces: with movable working chambers or hearths121
- F27B 3/02Hearth-type furnaces: of single-chamber fixed-hearth type23
- F27B 3/002Siemens-martin type furnaces2
Recent patents
- Induction coils as non-contact temperature boosters and flow boosters for ferrous and non-ferrous materials in a furnace6 Oct 2026US 12,753,973 B2Inductotherm Corp.
- System and method for measuring cooling plate thickness in a blast furnace25 Aug 2026US 12,716,717 B2Paul Wurth S. A.
- Metallurgical furnace11 Aug 2026US 12,704,326 B2Metso Metals Oy
- Converter device and electric power supply apparatus4 Aug 2026US 12,698,937 B2Danieli Automation S.P.A.
- Non-water cooled consumable electrode vacuum arc furnace for continuous process14 Jul 2026US 12,680,758 B2
- Tuyere for a metallurgical furnace1 Oct 2026US 2026/0297694 A1Paul Wurth S. A.
- Hearth mixture for disposing on the hearth bottom of an electric arc furnace, use of a hearth mixture for disposing on the hearth bottom of an electric arc furnace, electric arc furnace, method for disposing a hearth mixture on the hearth bottom of an electric arc furnace and use of magnesia spinel used in a lining of a cement rotary kiln24 Sep 2026US 2026/0287256 A1Refractory Intellectual Property GmbH & Co.KG
- Molten steel manufacturing method and arc furnace20 Aug 2026US 2026/0242884 A1Nippon Steel Corporation
- Melting furnace13 Aug 2026US 2026/0235363 A1Kubota Corporation
- 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
- Metal scrap submergence system128US 6,217,823 B1Metaullics Systems Co., L.P. · 2001
- Method for producing hydrocarbon gas from waste126US 5,395,405 AMolten Metal Technology, Inc. · 1995
- Method and apparatus for injection of a liquid waste into a molten bath124US 5,436,210 AMolten Metal Technology, Inc. · 1995
- Aluminum scrap melting process and apparatus123US 6,074,455 AMetaullics Systems Co., L.P. · 2000
- Apparatus for melting metal particles122US 4,747,583 A1988