US3802964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous measurement of pulp properties
Assignee: Individual
•
Filing: 1971-11-23
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Granted: 1974-04-09
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Expires: 1991-11-23
Abstract
Abstract A method and apparatus are disclosed which permit the ''''online'''' measuring of the properties of a pulp, notably the specific surface, the weight-average fibre length and the consistency of a mechanical pulp. The pulp is passed through a conventional freeness analyzer, a conventional consistency meter and a specially devised stock fractionator and the readings or signals from these instruments are used, e.g. in a suitably programmed computing device, to obtain the values of the specific surface, the weight-average fibre length and the consistency of the pulp. The stock fractionator used is a self-cleaning screen of a suitable mesh size by means of which the pulp is split into a retained fraction and a through fraction. The weight ratio of one of the fractions to the feed is related to the L-factor of the pulp.
Inventors
- 👤 O Forgacs
- 👤 A Karnis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:14
CPC Classifications
D; D21; D21G; D21G9/00; D21G9/0009; Y; Y10; Y10S; Y10S162/00; Y10S162/09; Y10S162/10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2499; Y10T137/2506
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
An apparatus for continuous on-stream determination of the specific surface and the weight-average fibre length of a pulp which comprises a freeness analyzing means and a stock fractionating means arranged in parallel, means for feeding a sample of said pulp in suspension to each of said means, said freeness analyzing means providing a first signal, said first signal being a measure of the specific surface of the pulp and at the same time reflecting the weight average fibre length of said pulp, said stock fractionating means providing a second signal, said second signal being a measure of the weight-average fibre length of the pulp and at the same time reflecting the specific surface of said pulp, computor means, said computor means computing from said signals true values of said specific surface and said weight-average fibre length and means for feeding said first and said second signals to said means for computing thereby to obtain said true values of specific surface and weight-average fibre length of the pulp.
Claim 2
Independent Claim
167 words
An apparatus for continuous on-stream determination of the specific surface and the weight-average fibre length of a pulp which comprises a freeness analyzing means and a stock fractionating means arranged in parallel, means for feeding a sample of said pulp in suspension to each of said means, said freeness analyzing means providing a first signal, said first signal being a measure of the specific surface of the pulp and at the same time reflecting the weight average fibre length of said pulp, said stock fractionating means providing a second signal, said second signal being a measure of the weight-average fibre length of the pulp and at the same time reflecting the specific surface of said pulp, computor means, said computor means computing from said signals true values of said specific surface and said weight-average fibre length and means for feeding said first and said second signals to said means for computing thereby to obtain said true values of specific surface and weight-average fibre length of the pulp.
Claim 3
Dependent Claim
109 words
An apparatus as defined in claim 1 further comprising consistency measuring means providing a third signal, means for feeding a sample of said pulp in suspension to said consistency measuring means, said third signal being a measure of consistency and at the same time reflecting said specific surface and said weight-average fibre length of said pulp, said consistency measuriNg means being arranged in parallel with the freeness analyzing means and the stock fractionating means, means for feeding said third signal to said computor means, said computor means computing from said first, second and third signals, true values of said specific surface, said weight-average fibre length and of said consistency.
Claim 4
Dependent Claim
25 words
An apparatus as claimed in claim 2 wherein said freeness analyzing means is a continuous freeness analyzer measuring the drainage rate of said pulp suspension.
Claim 5
Dependent Claim
26 words
An apparatus as claimed in claim 2 wherein said consistency measuring means is a continuous consistency meter measuring resistance to the flow of the pulp suspension.
Claim 6
Dependent Claim
37 words
An apparatus as claimed in claim 2 wherein said stock fractionating means is a self-cleaning vibrating vertical screen of a mesh size to divide said pulp suspension fed to said stock fractionating means into substantially equal fractions.
Claim 7
Dependent Claim
25 words
An apparatus as defined in claim 5 wherein said stock fractionating means further comprises means measuring the consistency and flow of one of said fractions.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-08 | 1977-10-08 | 1978-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-08 | 1981-10-08 | 1982-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-08 | 1985-10-08 | 1986-04-09 | $7700.00 | Window Closed / Lapsed |