US4921616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alveolar ceramic filters for high melting metals
Assignee: Ceramiques et Composites SA
•
Filing: 1988-11-10
•
Granted: 1990-05-01
•
Expires: 2008-11-10
Abstract
Abstract Shaped, porous filter members having a size and shape adapted for the filtration of liquid metals, e.g., the configuration of a honeycomb, are comprised of a porous alveolar ceramic material including from 10 to 20% SiO2, from 50 to 60% Al2O3 and from 20 to 40% ZrO2, each percentage being by weight with respect to the total weight of said oxides, said Al2O3 and SiO2 being present in the form of mullite, 3Al2O3/2SiO2, and the combined weight of the zirconia and mullite comprising at least 90% by weight of said alveolar ceramic material.
Inventors
- 👤 Louis Minjolle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:18
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2093; B01D39/2072; B01D39/2075; C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/185; C04B38/00; C04B38/0006; C04B38/06; C04B38/0615; C22; C22B; C22B9/00; C22B9/02; C22B9/023; C04B2111/00; C04B2111/00474; C04B2111/00793; C04B2111/0087; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3231; C04B2235/3244; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
149 words
A shaped, porous filter member having a size and shape adapted for the filtration of liquid metals, which comprises a porous alveolar ceramic material including from 10 to 20% SiO 2 , from 50 to 60% Al 2 O 3 and from 20 to 40% ZrO 2 , each percentage being by weight with respect to the total weight of said oxides, said Al 2 O 3 and SiO 2 being present in the form of mullite, 3Al 2 O 3 /2SiO 2 , and the combined weight of the zirconia and mullite comprising at least 90% by weight of said alveolar ceramic material wherein said porous alveolar ceramic material has a coefficient of linear expansion of less than 6.5×10 -6 /° C. at a temperature of from 20° C. to 1,000° C., an open porosity of 0 to 30% and an apparent density of about 2.6 to 3.8.
Claim 2
Dependent Claim
149 words
A shaped, porous filter member having a size and shape adapted for the filtration of liquid metals, which comprises a porous alveolar ceramic material including from 10 to 20% SiO 2 , from 50 to 60% Al 2 O 3 and from 20 to 40% ZrO 2 , each percentage being by weight with respect to the total weight of said oxides, said Al 2 O 3 and SiO 2 being present in the form of mullite, 3Al 2 O 3 /2SiO 2 , and the combined weight of the zirconia and mullite comprising at least 90% by weight of said alveolar ceramic material wherein said porous alveolar ceramic material has a coefficient of linear expansion of less than 6.5×10 -6 /° C. at a temperature of from 20° C. to 1,000° C., an open porosity of 0 to 30% and an apparent density of about 2.6 to 3.8.
Claim 3
Dependent Claim
19 words
The porous filter member as defined by claim 1, having a face surface porosity of from 50 to 80%.
Claim 4
Dependent Claim
18 words
The porous filter member as defined by claim 2, having a thickness of from 5 to 15 mm.
Claim 5
Dependent Claim
14 words
The porous filter member as defined by claim 2, comprising a honeycomb shaped article.
Claim 6
Dependent Claim
53 words
The porous filter member as defined by claim 4, wherein said honeycomb shaped article further comprises a perforated structure of polygonal geometrical shape comprising from about 35 to about 50 pathways per cm 2 , said pathways being square in section and having side dimensions of from about 1 to about 5 mm.
Claim 7
Dependent Claim
15 words
The porous filter member as defined by claim 1, wherein said liquid metal comprises steel.
Claim 8
Dependent Claim
18 words
The porous filter member as defined by claim 1, wherein said liquid metal comprises spheroidal graphite cast iron.
Claim 9
Dependent Claim
46 words
The porous filter member as defined by claim 1, wherein said ceramic material comprises 17% SiO 2 , 52% Al 2 O 3 and 30.5% ZrO 2 , said combined weight of the zirconia and mullite comprising about 100% by weight of said alveolar ceramic material.
Claim 10
Dependent Claim
32 words
The porous filter member as defined by claim 1, wherein said filter member is suitable for filtering a liquid metal which is poured at a temperature of about 1650° to 1800° C.
Claim 11
Dependent Claim
29 words
A process for the filtration of a liquid metal having a high melting point, comprising filtering such liquid metal through the porous filter member as defined by claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |