US3622262A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for washing preferentially cellulosic pulp
Assignee: Valmet AB
•
Filing: 1968-04-11
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Granted: 1971-11-23
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Expires: 1988-04-11
Abstract
Abstract Washing pulp is effected in apparatus wherein the washing liquid is forced through a perforate wall into and through a body of the pulp and into a collecting space for the washing liquid. To prevent clogging of the perforate wall, the influx of treatment liquid into the collecting space is interrupted at suitable intervals, the interruption being produced by pressure variations induced by a vibrator operating in the liquid.
Inventors
- 👤 Nils Gustav Leffler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:26
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
32 words
A method as claimed in claim 1 wherein the step of periodically interrupting the flow of liquid at the points of withdrawal from the suspension comprises subjecting the liquid to pressure impulses.
Claim 2
Dependent Claim
35 words
A method as claimed in claim 1 wherein the suspension of fibrous material being subjected to treatment with the treatment liquid has a concentration of from about 1 percent to about 15 percent fibrous material.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 2 wherein the pressure impulses are carried out intermittently.
Claim 4
Dependent Claim
37 words
A method as claimed in claim 2 wherein the pressure impulses are carried out intermittently and suddenly to more positively effect a removal of any fibrous material which may have tended to clog the points of withdrawal.
Claim 5
Dependent Claim
20 words
A method as claimed in claim 2 wherein the pressure impulses are carried out intermittently and at regular time intervals.
Claim 6
Dependent Claim
16 words
A method as claimed in claim 2 wherein the pressure impulses are initiated and concluded gradually.
Claim 7
Dependent Claim
20 words
A method as claimed in claim 5 and further comprising initiating the pressure impulses suddenly and concluding the impulses gradually.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |