US 12,454,796 B2Granted

Pulp quality monitoring

AssigneeKemira Oyj

InventorsMarjatta Piironen, Iiris Joensuu, Lari Vähäsalo

Life of this patent

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Abstract

A method for monitoring hydrophobic particles contained in a pulp suspension, includes obtaining a sample from a pulp suspension or a filtrate of the pulp suspension. A fluorescent dye is added to the sample to stain particles in the sample. The sample is fractionated to obtain at least a first fraction and a second fraction, wherein the second fraction is a fiber fraction. The method includes for the obtained fractions, fluorescence emitted by the particles in the fractions, calculating an integral of the fluorescence measured for the fractions excluding the fiber fraction, and correlating the calculated integral of the fluorescence to the amount of acetone soluble material in the pulp suspension, and optionally measuring light scattering signal of the particles in at least first and second fractions.

Claims8

Dependent claims

A system for monitoring hydrophobic particles in a pulp and/or paper making process, the system comprising:

a sampler configured to obtain a sample from a pulp suspension or a filtrate of a pulp suspension;
a dye injection unit configured to add a dye to the sample to stain particles in the sample, wherein the dye is a fluorescent dye;
a fractionator configured to fractionate the sample to at least a first fraction and a second fraction, wherein the first fraction is a colloid fraction and the second fraction is a fiber fraction;
an optical meter configured to measure fluorescence emitted by the particles in at least the first fraction, and a computer configured to calculate an integral of the fluorescence measured for at least the first fraction;
and wherein
the computer is configured to correlate the calculated integral of the fluorescence measured for at least the first fraction, and excluding the fiber fraction, to an amount of acetone soluble material in the pulp suspension or filtrate.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/319,521Filed 18 May 2023 · continuation
Priority: FI 2017563030 Jun 2017
Published: US 2023/0287629 A114 Sep 2023
Granted: 28 Oct 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

D21C 9/08
After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking…:…
D21H 23/78
Processes or apparatus for adding material to the pulp or to the paper: controlling or regulating not limited to any particular process or apparatus
D21H 21/02
Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised…:…
D21H 21/28
Characterised by function or properties in or on the paper: colorants ; Pigments or opacifying agents

Family

PCT/FI2018/050526Parent of this continuation · filed 2 Jul 2018
US 2023/0287629 A1Pre-grant publication · published 14 Sep 2023
Application16/627,642Parent of this continuation
US 11,692,312 B2Parent of this continuation
US 2021/0156092 A1Published application
US 12,454,796 B2This patent

From the US filing history. Foreign family members aren’t listed.