F27B 3/04
Hearth-type furnaces: of multiple-hearth type
Official title: of multiple-hearth type; of multiple-chamber type; Combinations of hearth-type furnaces
F27B3/04 (Hearth-type furnaces: of multiple-hearth type) appears on 165 US grants and 116 published applications in this corpus.
Search patents in F27B- Granted patents
- 165
- Published applications
- 116
- Assignees
- 131
- Inventors
- 367
- Latest grant
- 23 Jun 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 1 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 3 | 0 |
| 1981 | 0 | 0 |
| 1982 | 4 | 0 |
| 1983 | 2 | 0 |
| 1984 | 6 | 0 |
| 1985 | 1 | 0 |
| 1986 | 4 | 0 |
| 1987 | 5 | 0 |
| 1988 | 4 | 0 |
| 1989 | 6 | 0 |
| 1990 | 4 | 0 |
| 1991 | 6 | 0 |
| 1992 | 3 | 0 |
| 1993 | 3 | 0 |
| 1994 | 0 | 0 |
| 1995 | 3 | 0 |
| 1996 | 5 | 0 |
| 1997 | 2 | 0 |
| 1998 | 5 | 0 |
| 1999 | 3 | 0 |
| 2000 | 5 | 0 |
| 2001 | 5 | 1 |
| 2002 | 3 | 5 |
| 2003 | 3 | 4 |
| 2004 | 3 | 7 |
| 2005 | 4 | 2 |
| 2006 | 3 | 4 |
| 2007 | 2 | 6 |
| 2008 | 0 | 7 |
| 2009 | 8 | 3 |
| 2010 | 3 | 3 |
| 2011 | 3 | 1 |
| 2012 | 2 | 1 |
| 2013 | 1 | 2 |
| 2014 | 2 | 7 |
| 2015 | 0 | 7 |
| 2016 | 6 | 3 |
| 2017 | 10 | 4 |
| 2018 | 2 | 4 |
| 2019 | 1 | 2 |
| 2020 | 4 | 13 |
| 2021 | 3 | 4 |
| 2022 | 6 | 6 |
| 2023 | 5 | 5 |
| 2024 | 7 | 7 |
| 2025 | 2 | 6 |
| 2026 | 2 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Vortex metal insertion furnace control system23 Jun 2026US 12,663,214 B2Gpre IP, LLC
- Molten metal mixing system24 Mar 2026US 12,584,189 B2Tounetsu Co., Ltd.
- Metal melting apparatus, screen plate for metal melting, and method of melting metal20 May 2025US 12,305,919 B2Tounetsu Co., Ltd.
- Smart molten metal pump1 Apr 2025US 12,263,522 B2Molten Metal Equipment Innovations, LLC
- Method for smelting low nitrogen steel using electric furnace25 Jun 2024US 12,018,341 B2Baoshan Iron & Steel Co., Ltd.
- Wet hearth melting systems and methods for melting solid metals23 Apr 2026US 2026/0110492 A1The Schaefer Group
- Melting Furnace and Method for Melting a Metal Material12 Mar 2026US 2026/0071819 A1Bayerische Motoren Werke Aktiengesellschaft
- Method for operating electric furnace18 Dec 2025US 2025/0383152 A1Hyundai Steel Company
- Melting furnace and method for melting metal by means of an electrically heatable immersion heating element11 Dec 2025US 2025/0377162 A1
- Stack melting apparatus5 Jun 2025US 2025/0180292 A1
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
- Aluminum scrap melting process and apparatus123US 6,074,455 AMetaullics Systems Co., L.P. · 2000
- Apparatus for melting metal particles122US 4,747,583 A1988
- Stirring molten metal115US 4,008,884 AAlcan Research and Development Limited · 1977