US3650890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuously detecting the degree of delignification of pulp
Assignee: Honshu Paper Co Ltd
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Filing: 1969-04-03
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Granted: 1972-03-21
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Expires: 1989-04-03
Abstract
Abstract A process for continuously detecting the degree of delignification of pulp in a continuous digester wherein pressure drop in a length of pipe located downstream of the digester, between a blow tank and an accumulator, is measured and used to compute the degree of delignification of the pulp. Pulp flow through the pipe and consistency of the pulp leaving the digester can also be used in obtaining a more accurate determination of the degree of delignification.
Inventors
- 👤 Shigeo Kamio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:36
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/22; D21C3/228; Y; Y10; Y10S; Y10S162/00; Y10S162/09; Y10S162/10; Y10S162/11
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
49 words
The process as claimed in claim 1 and further including modifying said values received by detecting load current and number of revolutions of an agitator located within said digester to determine the consistency of the pulp flowing out of said digester and using said consistency in said computing step.
Claim 2
Dependent Claim
41 words
The process as claimed in claim 2 and further including modifying said values received by detecting the pulp flow across the flow pipe of the digester for the cooked pulp ejected therefrom and using said pulp flow in said computing step.
Claim 3
Dependent Claim
121 words
In pulping operations at a pulp mill equipped with a continuous-type digester wherein the pulp is cooked and delignified, the process of continuously detecting the degree of delignification of the pulp being cooked in the digester which comprises measuring the pressure drop of the cooked pulp withdrawn from and flowing downstream of the digester between said blow tank unit and the overhead of said accumulator tank, and computing the degree of delignification of said pulp in accordance with the equation of K Ko + K1P wherein K is a dependent variable standing for the degree of delignification and P is an independent variable for said pressure drop and Ko and K1 are multiple regression coefficients having values 28 and -0.45 respectively.
Claim 4
Dependent Claim
169 words
In pulping operations at a pulp mill equipped with a continuous-type digester wherein the pulp is cooked and delignified, the process of continuously detecting the degree of delignification of the pulp being cooked in the digester which comprises measuring the load current of the digester agitator, measuring the number of revolutions of said agitator, measuring the pressure drop and flow of the cooked pulp withdrawn from and flowing downstream of the digester between said blow tank unit and the overhead of said accumulator tank, and computing the degree of delignification of said pulp in accordance with the equation K Ko + K1P + K2F + K3A + K4S wherein K is the degree of delignification obtained according to the invention, P is the pressure drop, S is revolutions per minute of the agitator, A is the load current of the agitator and F is the flow of cooked pulp and Ko, K1, K2, K3 and K4 are multiple regression coefficients having values 28, -0.45, 0.048, 0.31 and 2.2 respectively.
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) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |