Triangular Inlet Protrusions for Refiner Plate Feed Stability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional refiner plates, particularly in conical-disk refiners, face challenges with feed material stalling at the junction of the flat and conical zones due to insufficient mechanical centrifugal forces, leading to feed instabilities and operational difficulties, especially at higher production rates.

Innovation Solution

The design incorporates a rotor conical zone inlet with substantially triangular protrusions that extend beyond the base level, imparting a forward feeding mechanical force and promoting even distribution of feed material around the rotor conical zone, ensuring effective transition from the flat to the conical zone and operating in both directions of rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional refiner plate designs are used in conical-disk refiners, then the structure is simple, but the feed material stalls at the junction of flat and conical zones due to insufficient mechanical centrifugal forces

Engineering Contradiction:

Improvefeeding reliabilityVSAvoidinlet zone structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The inlet zone is segmented into multiple functional zones: a first inlet zone with radial bars for initial refining and a second inlet zone with triangular protrusions for forward feeding. This segmentation allows each zone to perform its specific function optimally, with the triangular protrusions providing enhanced mechanical forces to propel feed material forward from the flat zone into the conical zone, eliminating stalling while maintaining structural clarity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the inlet zone are given different local qualities and functions. The first inlet zone has radial bars for initial refining, while the second inlet zone has triangular protrusions with specific geometric characteristics (apex angle 15-75 degrees, base extending beyond plate base) designed to provide forward feeding mechanical forces. This local differentiation ensures that each area performs its specific function effectively.

Inventive Principle:

Principle #3Local quality

2Speed

If the conical zone relies primarily on forward flow of steam, then the structure remains simple, but feed material movement is insufficient and stalling occurs

Engineering Contradiction:

Improvefeed material movement speedVSAvoidmechanical feature complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The triangular protrusions in the second inlet zone perform preliminary action by providing mechanical forward feeding forces before the feed material enters the conical zone. The protrusions contact the feed material and propel it forward, ensuring adequate material movement into the conical zone before centrifugal forces take over, thereby preventing stalling at the zone junction.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The triangular protrusions act as intermediary mechanical elements between the flat zone and conical zone. They provide the transition mechanism that bridges the two zones, using their geometric shape and positioning to impart forward motion to the feed material as it moves from the flat zone into the conical zone, facilitating smooth transition without stalling.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Force

If features on conventional refiner plates throw fiber against the stator conical zone, then some feeding occurs, but insufficient mechanical forces fail to feed forward the fiber along the gap

Engineering Contradiction:

Improvemechanical feeding forceVSAvoidoperational stability

Core Design Contradiction:

ForceVSEase of operation

Solution Approach 1:

The triangular protrusions feature asymmetric geometry with specific apex angles (15-75 degrees) and base configurations that extend beyond the plate base. This asymmetric design creates directional mechanical forces that effectively propel feed material forward along the gap between rotor and stator in the conical zone, providing sufficient feeding force while maintaining operational stability through the controlled geometric interactions.

Inventive Principle:

Principle #4Asymmetry

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 design enhances the feeding and distribution of lignocellulosic material, reducing stalling issues and improving operational stability and efficiency, particularly by utilizing triangular protrusions that create a positive feeding vector to propel material forward into the conical zone, thus addressing the limitations of conventional refiner plate designs.

Implementation Method 1

The design incorporates a rotor conical zone inlet with substantially triangular protrusions that extend beyond the base level, imparting a forward feeding mechanical force

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

centrifugal forces force the feed material along the gap created between two opposing refining plates

Methodology Applied

Scientific EffectCentrifugal Force: Centrifugal Force

Data Source

PatentUS7954745B2Refiner plate segment with triangular inlet feature

Publication Date: 2011.06.07 ANDRITZ INC

AI summary

A refiner plate for refining lignocellulosic materials has an injector inlet having a substantially triangular protrusion. The substantially triangular protrusion may feed the incoming lignocellulosic material into the refining zone and may distribute the material around the refining zone.