Refining Disc Steam Evacuation via Asymmetric Segmentation

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Solution Overview

Problem

The existing technologies for refining fibrous materials in pulp or fiber refiners face challenges in effectively evacuating steam generated during the refining process, leading to turbulence, increased energy consumption, and non-uniform fiber quality due to irregular steam flow and back-streaming steam interfering with material flow.

Innovation Solution

A refining disc design with non-central openings and a central hole allows steam to flow from the refining space to the backside of the disc, guiding it out of the defibrator without disturbing the material flow, thereby preventing feed conflicts and improving steam evacuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If steam is evacuated from the central space between refining discs, then steam flow speed increases, but material flow stability deteriorates

Engineering Contradiction:

Improvesteam flow speedVSAvoidmaterial flow stability

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The patent divides the single central steam evacuation opening into multiple non-central openings distributed around the refining disc. This segmentation allows steam to be evacuated through multiple pathways simultaneously, reducing the velocity and turbulence of steam flow through each individual opening while maintaining effective steam removal, thereby preserving material flow stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent positions the steam evacuation openings asymmetrically away from the central axis of the refining disc. This asymmetric positioning strategically locates openings in regions where steam generation is significant but where they will not directly interfere with the central material feed path, thus evacuating steam effectively while maintaining stable material flow.

Inventive Principle:

Principle #4Asymmetry

2Productivity

If steam evacuation openings are positioned centrally, then steam removal efficiency is high, but material feed stability deteriorates

Engineering Contradiction:

Improvesteam removal efficiencyVSAvoidmaterial feed stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent deliberately positions steam evacuation openings asymmetrically away from the central axis of the refining disc. This asymmetric positioning strategically locates openings in regions where steam generation is significant but where they will not directly interfere with the central material feed path, thus evacuating steam effectively while maintaining stable material flow.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent applies different functional characteristics to different regions of the refining disc. The central region is dedicated to material feeding and processing, while non-central regions are designated for steam evacuation. This local differentiation allows each region to perform its specific function optimally without interfering with the other.

Inventive Principle:

Principle #3Local quality

3Productivity

If steam flow speed is increased for better evacuation, then steam removal efficiency improves, but energy consumption increases

Engineering Contradiction:

Improvesteam removal efficiencyVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces turbulence, energy consumption, and fiber quality issues by ensuring stable material feed and uniform fiber production, leading to longer equipment lifetimes and improved pulp quality.

Implementation Method 1

at least one non-central opening extending from a front side of the first refining disc to a backside of the first refining disc, for allowing steam developed in the refining space during refining to flow through the at least one non-central opening from the front side to the backside of the first refining disc

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS11440017B2Steam evacuation in a pulp or fiber refiner

Publication Date: 2022.09.13 VALMET AB

AI summary

A refining disc (6) in a defibrator (1) for refining fibrous material is provided with non-central openings (11) for allowing steam developed in the refining space (2) during refining to flow from the front side to the backside of the refining disc (6), where the front side is facing a second refining disc (5) and the backside is facing away from the second refining disc (5). The refining disc (6) also comprises a central hole (12) for allowing steam (8b) to flow from the backside to the front side at the rotational center of the refining disc (6), and escape from the defibrator (1) backwards through the feed screw (3a) without passing through the fibrous material (7) being refined in the refining space (2).