Refiner Blade Element With Variable Groove Cross-Section

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Solution Overview

Problem

Conventional refiners for fibrous materials face challenges in efficiently refining and homogenizing lignocellulose-containing materials due to limitations in blade geometry and groove design, leading to suboptimal refining grade and fiber length.

Innovation Solution

The refiner features a blade element with refining surfaces where the cross-sectional area of blade grooves decreases from the feed edge to the discharge edge, allowing for a wider spacing on the feed side to prevent blocking and a narrower spacing on the discharge side for enhanced refining efficiency, along with adjustable groove depth and width to control material transfer and refining quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the blade spacing is narrow throughout the refining surface, then the refining efficiency is improved, but the blade system blocks on the feed side where the material's refining grade is low

Engineering Contradiction:
Improverefining efficiencyVSAvoidblade system blocking
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The blade groove width is varied along the refining surface: wider at the feed edge to prevent blocking, and narrower toward the discharge edge to enhance refining efficiency. This local variation in geometry allows each zone to perform its specific function optimally without compromising the other.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the blade groove cross-sectional area decreases from feed edge to discharge edge, then the material transfer control is improved, but the blade geometry complexity increases

Engineering Contradiction:
Improvematerial transfer controlVSAvoidblade geometry complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The cross-sectional area of the blade grooves is systematically varied along their length, with the width decreasing from the feed edge toward the discharge edge. This parameter change enables controlled material transfer and pressing into the blade gap, improving refining quality while maintaining manufacturable geometry.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2668331B1Blade element for a refiner
Publication Date: 2016.01.20 VALMET TECH INC
  • EP2668331B1 patent drawingFigure 1~4
  • EP2668331B1 patent drawingFigure 5a~7
  • EP2668331B1 patent drawingFigure 8~9

AI summary

A refiner (10, 11) for refining fibrous material comprises at least one first refining surface (1') and at least one second refining surface (2'), which refining surfaces (1', 2') are arranged opposite to one another and mobile in relation to one another. In the refiner (10, 11) either at least the first (1') or the second (2') refining surface comprises refining surface portions (15, 27) feeding material to be refined and/or refining surface portions (15, 27) discharging refined material as well as refining surface portions (16) grinding the material to be refined, on the upper surface of which there are blade bars (17) and between them blade grooves (18). In at least one refining surface (1', 2') of the refiner (10, 11) the cross-sectional area (A) of at least some blade grooves (18) is arranged to decrease from one blade groove (18) to the next from the direction of the feed edge (13) to the direction of the discharge edge (14) of the refining surface (1', 2'). Further a blade element (12) for a refiner (10, 11) intended for refining fibrous material.