US3631982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for the control of pressures for the formation of a sheet or layer by continuous filtration of particles in suspension
Assignee: Neyrpic BMB SA
•
Filing: 1970-01-12
•
Granted: 1972-01-04
•
Expires: 1990-01-12
Abstract
Abstract A sheet is formed by filtration of a suspension of particles on a moving filter. Loss of suspension where the sheet and filter leave the device is minimized by coordinate control of the absolute pressures above and below the filter to provide a desired pressure differential acting on the filter.
Inventors
- 👤 Pierre Lejeune
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:18
CPC Classifications
D; D21; D21G; D21G9/00; D21G9/0009; D21G9/0027; D21F; D21F1/00; D21F1/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
27 words
Process as described in claim 1 including the step of controlling the absolute pressure under the filter to a varying value along the length of the filter.
Claim 2
Dependent Claim
170 words
Apparatus for the continuous filtration on a moving filter of a suspension of particles comprising a feed conduit for the suspension, a chamber connected to the feed conduit, a distributor connected to said chamber, an enclosure, said distributor discharging the suspension into said enclosure with a free surface in said enclosure, lateral walls for said enclosure, an uppeR wall for said enclosure, a lower wall for said enclosure, an endless moving screen forming a part of said lower wall, means for moving said screen toward a lower part of the enclosure, means for regulating the absolute pressure in said enclosure above the free surface of the suspension therein, a tank receiving the filtrate extracted through the filter wall, mean opening into said tank for controlling the absolute pressure therein, a controlled opening for removal of the sheet formed on said screen at the lower part of said enclosure and means for automatically coordinating said means for regulating the absolute pressures whereby a predetermined differential pressure is maintained on said filter.
Claim 3
Dependent Claim
37 words
Apparatus as described in claim 3, said tank being divided into successive chambers along the length of the lower portion of said filter wall, and individual means for regulating the absolute pressure in each of said chambers.
Claim 4
Dependent Claim
39 words
Apparatus as defined in claim 4, said means for individual regulation of absolute pressure in each of said chambers being automatically controlled whereby a predetermined variation of the differential pressure is maintained along the length of said filter wall.
References Cited (Backward Citations)
US1881404A
Cited
US2851161A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |