Refiner Control via Quality Index for Pulp
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Solution Overview
Problem
Traditional methods for assessing pulp quality in the pulp industry are inexact, time-consuming, and sensitive to seasonal variations, leading to unreliable and delayed quality information, which hinders efficient paper manufacturing and chemical consumption optimization.
Innovation Solution
A method and system for controlling a refiner using a quality index based on on-line measurements of product and process parameters, such as the Kappa number and yield function, to generate control signals for operating parameters like specific energy consumption and Canadian Standard Freeness (CSF), enabling precise process control and real-time quality monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional quality control methods are used to measure refining results, then quality information can be obtained, but the measurement is time-consuming and provides data only months after production
Solution Approach 1:
The patent applies preliminary action by measuring and recording quality parameters (CSF, tensile strength, specific energy consumption) during the pulp production process itself, rather than waiting until months later. The refiner is equipped with sensors that continuously monitor process parameters, and quality data is stored in association with production batch identifiers, making quality information immediately available when the pulp is produced rather than delayed until later analysis.
2Measurement precision
If traditional quality assessment methods are used, then isolated analysis points are obtained, but the data does not provide representative information about the whole pulp unit
Solution Approach 1:
The patent implements continuity of useful action by using continuous online measurement of quality parameters during the entire refining process. Sensors continuously monitor CSF, tensile strength, and specific energy consumption throughout production, generating a continuous stream of quality data for each batch rather than isolated snapshot measurements. This continuous monitoring ensures representative data coverage of the entire pulp unit.
3Reliability
If traditional quality control is used, then quality information is sensitive to seasonal variations and humidity, but the information remains inexact and unreliable
Solution Approach 1:
The patent applies feedback by continuously measuring actual quality parameters (CSF, tensile strength, specific energy consumption) during production and using this real-time data to adjust and control the refining process. The measured quality information is fed back to the control system, allowing immediate correction of process deviations and compensation for environmental variations, thereby improving reliability and reducing sensitivity to seasonal and humidity effects.
4Manufacturing precision
If extensive parameter tuning is performed to achieve desired paper quality, then quality control complexity increases, but very few criteria are available for on-line control
Solution Approach 1:
The patent applies parameter changes by directly measuring and controlling key quality parameters (CSF, tensile strength, specific energy consumption) online during the refining process. Instead of using indirect or limited criteria, the system monitors actual quality-determining parameters in real-time, enabling precise control with fewer tuning steps. The control system adjusts refiner operations based on direct feedback from these critical parameter measurements, simplifying the control approach while improving precision.
Data Source
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AI summary
The present invention relates to a method and a system for controlling a refiner, grinder or the like for refining a product containing cellulose, such as pulp. A quality index specific to the product is provided and related to at least one predefined property of a slurry containing the cellulose product, or a finished product made of it. Control signals in response to the quality index is generated to achieve a desired value of the predetermined property, and at least one operating parameter of the refiner is set accordingly. The predefined property is either the tensile strength of said finished product or the Canadian Standard Freeness (CSF) of the slurry.