Method for determining liquid content in chemical pulps using ramen spectrometry
US6551451B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2000 |
| Grant date | Apr 22, 2003 |
| Priority date | — |
| Expiry date | Jan 6, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/65
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A rapid method is provided for the on-line spectroscopic determination of lignin content and/or kappa number in wood pulps. Unlike currently available commercial instrumentation, the method enables one to measure lignin content independently of species variations and pulp consistency. The method includes the steps of: (1) withdrawing high-consistency samples of wood pulp from a chemical pulp manufacturing process; (2) subjecting these samples to a monochromatic visible-light source; (3) recording the resulting scattered light and its Raman spectrum over a predetermined range of wave numbers so as to produce Raman-scattered light intensity measurements; (4) determining either the uncorrected, baseline-corrected and/or integrated Raman-scattered light intensity of the samples over a predetermined range of wavenumbers shown by different combinations of lignin content, cellulose content, and consistency; (5) correlating by either univariate or multivariate calibration the relationships between the Raman-scattered light intensity measurements of unknown samples and the Raman-scattered light intensity shown by known combinations of lignin content, cellulose content, and consistency so th…
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