D21F 1/68
Using hydrocyclones
Official title: using hydrocyclones
D21F1/68 (Using hydrocyclones) appears on 8 US grants and 3 published applications in this corpus.
Search patents in D21F- Granted patents
- 8
- Published applications
- 3
- Assignees
- 6
- Inventors
- 12
- Latest grant
- 11 Mar 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 1 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 1 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 1 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 1 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 1 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 2 |
| 2023 | 0 | 0 |
| 2024 | 1 | 0 |
| 2025 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Method for suppressing sedimentation of suspended substance, method for suppressing pitch trouble, and method for detecting sedimentation of suspended substance11 Mar 2025US 12,247,354 B2Kurita Water Industries Ltd.
- System for managing solids in papermaking whitewater23 Jul 2024US 12,043,961 B2
- Pulp fractionation using centrifugal cleaners and power screens with multi-layer headbox and deaeration tank3 Jun 2008US 7,381,295 B2Metso Paper, Inc.
- Process for recovering raw materials from paper industry mechanical waste sludge27 Mar 2001US 6,207,015 B1Omya AG
- Clarifying suspended solids from liquid process streams17 Oct 1995US 5,458,738 AKamyr, Inc.
- Method for suppressing sedimentation of suspended substance, method for suppressing pitch trouble, and method for detecting sedimentation of suspended substance13 Oct 2022US 2022/0325473 A1Kurita Water Industries Ltd.
- System for managing solids in papermaking whitewater23 Jun 2022US 2022/0195668 A1
- Method and Equipment for pulp fractionation in a paper or board machine12 Feb 2004US 2004/0026050 A1Metso Paper, Inc.
Most cited
By later US patents
- Hydrocyclone removal of sticky contaminants during paper recycling33US 5,131,980 AKamyr, Inc. · 1992
- Hydrocyclone deinking of paper during recycling26US 5,069,751 AKamyr, Inc. · 1991
- Process for recovering raw materials from paper industry mechanical waste sludge10US 6,207,015 B1Omya AG · 2001
- Clarifying suspended solids from liquid process streams8US 5,458,738 AKamyr, Inc. · 1995
- Downflow control system for web making machines7US 3,960,653 ADominion Engineering Works Limited · 1976