US4443296A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processes and devices for the disintegration of cellulose materials
Assignee: Kadant Lamort SAS
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Filing: 1980-08-25
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Granted: 1984-04-17
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Expires: 2000-08-25
Abstract
Abstract A process is provided for the removal from paper pulp of impurities, the pulp being contained in a pulping machine. Some of the pulp is periodically transferred into an enclosed chamber annexed to the pulping machine, the chamber having a volume which is small compared to the volume of the pulping machine. The pulp in the chamber is stirred and separated by a rotor, and fibre suspension is returned to the pulping machine, dilution water being introduced into this chamber. The chamber is emptied and impurities thereafter discharged.
Inventors
- 👤 Jean P. Lamort
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:13
CPC Classifications
D; D21; D21B; D21B1/00; D21B1/04; D21B1/12; D21B1/30; D21B1/34; D21B1/345
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
202 words
A method of intermittently processing refusals rejected by a pulp discharge sieve of a pulping machine, comprising the steps of: periodically extracting a predetermined volume of a mixture of pulp and refusals from the machine upstream of and in the vicinity of the discharge sieve; transferring the extracted volume of mixture to an enclosed chamber via a first conduit; closing the first conduit by means of a valve located in the first conduit; separating the extracted volume of mixture in the chamber into a cleansed pulp suspension and refusals by agitation of the extracted volume within the chamber with a means for stirring the volume; recharging the pulping machine with said suspension via a second conduit; introducing water into the enclosed chamber via a third conduit to dilute the suspension until the pulp content falls below a predetermined value; pressurizing said enclosed chamber with gas via means for releasably pressurizing said chamber; emptying the dilute suspension from the enclosed chamber under gas pressure through said second conduit while continuing the agitation so that the dilute suspension washes the chamber walls; and discarding the refusals from the bottom of the enclosed chamber through an outlet means for opening the bottom of the chamber.
Claim 2
Independent Claim
202 words
A method of intermittently processing refusals rejected by a pulp discharge sieve of a pulping machine, comprising the steps of: periodically extracting a predetermined volume of a mixture of pulp and refusals from the machine upstream of and in the vicinity of the discharge sieve; transferring the extracted volume of mixture to an enclosed chamber via a first conduit; closing the first conduit by means of a valve located in the first conduit; separating the extracted volume of mixture in the chamber into a cleansed pulp suspension and refusals by agitation of the extracted volume within the chamber with a means for stirring the volume; recharging the pulping machine with said suspension via a second conduit; introducing water into the enclosed chamber via a third conduit to dilute the suspension until the pulp content falls below a predetermined value; pressurizing said enclosed chamber with gas via means for releasably pressurizing said chamber; emptying the dilute suspension from the enclosed chamber under gas pressure through said second conduit while continuing the agitation so that the dilute suspension washes the chamber walls; and discarding the refusals from the bottom of the enclosed chamber through an outlet means for opening the bottom of the chamber.
Claim 3
Dependent Claim
37 words
The method of claim 1 in which the extracting step comprises charging a enclosed chamber with said mixture by permitting a predetermined amount of the mixture to flow into said chamber from the machine via the conduit.
Claim 4
Dependent Claim
26 words
The method according to claim 2, wherein the volume of the said chamber is not more than a tenth of the volume of the pulping machine.
Claim 5
Dependent Claim
89 words
The method of claim 2 in which said separating step comprises: stirring said extracted volume within the chamber with a disc-shaped agitator to cause it to circulate to separate the heavier material in the mixture from the lighter pulp material by causing the lighter pulp material to pass through a gap between the disc and a wall of the enclosed chamber without letting the refusals pass therethrough; and withdrawing the lighter pulp material in form of said cleansed suspension from said chamber after it has passed through the gap.
Claim 6
Dependent Claim
12 words
The method of claim 1 in which the steps are repeated periodically.
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) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |