Continuous Kneading Device Rotor Diameter Gradient

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Solution Overview

Problem

Conventional continuous kneading devices face challenges in increasing the mesh between kneading rotors to effectively knead hard-to-knead materials due to the resulting high kneading load, which can damage the rotors and their bearings.

Innovation Solution

The continuous kneading device design features a pair of kneading rotors with a larger rotational outer diameter for the downstream kneading section and a smaller diameter for the upstream section, allowing for increased meshing while maintaining a manageable kneading load by ensuring the rotational outer diameter of the downstream section is larger than the inter-axis distance and the upstream section's diameter is smaller than or equal to the inter-axis distance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the inter-axis distance between kneading rotors is reduced to increase mesh, then the kneading ability is improved, but the kneading load increases significantly

Engineering Contradiction:
Improvekneading abilityVSAvoidkneading load
Core Design Contradiction:
Adaptability or versatilityVSForce

Solution Approach 1:

The patent applies different rotor diameters at different axial positions (upstream vs downstream) to create localized meshing characteristics. The upstream rotor has a smaller outer diameter while the downstream rotor has a larger outer diameter, allowing mesh to occur only in specific downstream sections rather than uniformly along the entire rotor length. This localized approach increases kneading ability where needed while limiting the overall kneading load.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The kneading process is segmented into multiple sections along the axial direction, with each section having different rotor diameter characteristics. This segmentation allows the mesh between rotors to be controlled in specific zones (downstream sections) rather than throughout the entire kneading chamber, thereby improving kneading ability for hard-to-knead materials while preventing excessive load buildup across the entire system.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the mesh between kneading rotors is increased to knead hard-to-knead materials, then the kneading effectiveness is improved, but the load on rotors and bearings increases adversely

Engineering Contradiction:
Improvekneading effectivenessVSAvoidrotor and bearing durability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

By making the downstream rotor's outer diameter larger than the upstream rotor's outer diameter, the patent creates localized meshing zones only in the downstream sections. This ensures high kneading effectiveness for hard-to-knead materials while limiting the duration and intensity of meshing contact, thereby protecting rotors and bearings from excessive cumulative load that would compromise reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a dynamic meshing pattern where the rotating rotors with different diameters engage and disengage periodically. As the rotors rotate, the mesh between them occurs intermittently in the downstream sections rather than continuously along the entire rotor length. This dynamic engagement reduces the average load on rotors and bearings while maintaining effective kneading when mesh does occur.

Inventive Principle:
Principle #15Dynamics

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 configuration enhances the kneading ability while suppressing the kneading load, enabling stable operation and effective kneading of hard-to-knead materials without exceeding the design load capacity of the rotors and bearings.

Implementation Method 1

a material supplied into the barrel is led to between the kneading rotors rotating in the directions different from each other and kneading screws provided in the kneading rotors apply shearing forces to the material to thereby knead the material

Methodology Applied
Scientific EffectShearing force: Shear Stress

Data Source

PatentEP3106278B1Continuous kneading device
Publication Date: 2021.02.03 KOBE STEEL LTD
  • EP3106278B1 patent drawingFigure 1
  • EP3106278B1 patent drawingFigure 2
  • EP3106278B1 patent drawingFigure 3

AI summary

A continuous kneading device (1) includes a pair of kneading rotors (3), being capable of increasing mesh between the kneading rotors (3) while suppressing a kneading load applied to the kneading rotors (3). The continuous kneading device (1) includes a barrel (2) and a pair of kneading rotors (3) housed in the barrel (2) and rotating in mesh in directions different from each other. Each kneading rotor (3) includes a plurality of kneading flights (11, 15) for kneading a material supplied into the barrel (2). The kneading flights (11, 15) and respective portions of the barrel (2) housing the kneading flights (11, 15) respectively configure a plurality of kneading sections aligned axially of the kneading rotors (3). The material is fed axially from the upstream kneading section to the downstream kneading section to be sequentially kneaded. The kneading flight (15) constituting the downstream kneading section has a rotational outer diameter (D2) larger than a rotational outer diameter (D1) of the kneading flight (11) constituting the upstream kneading section.