Classifying Apparatus Rotor and Louver Angle Design

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Solution Overview

Problem

Conventional rotary mechanical classifying apparatuses face challenges in achieving uniform force balance, leading to reduced classification efficiency and accuracy in separating particles of desired sizes, with issues such as coarse powder contamination in fine powder and vice versa.

Innovation Solution

A classifying apparatus with a rotor and louver design where the angle between louver blades and the rotor's outer diameter, combined with a regenerative converter for controlling rotor speed, ensures increased centrifugal force and uniform airflow distribution, allowing efficient classification of powder into coarse and fine powders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional rotary mechanical classifying apparatuses are used, then continuous classification is possible, but classification efficiency is reduced due to non-uniform force balance on powder particles

Engineering Contradiction:
Improveclassification efficiencyVSAvoidclassification accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating different airflow conditions in different regions of the classification chamber. Specifically, the air inlet is positioned to supply air that creates a controlled airflow pattern, ensuring that powder particles experience more uniform aerodynamic forces throughout the classification process. This local optimization of airflow distribution directly addresses the non-uniform force balance problem, improving both classification efficiency and accuracy simultaneously

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If powder material is supplied to the gap between rotor and louver for centrifugal classification, then coarse and fine powder can be separated, but classification accuracy decreases due to non-uniform force distribution

Engineering Contradiction:
Improveclassification accuracyVSAvoidclassification efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the airflow parameters by controlling the air inlet position and the angle of the louver blades. These parameter adjustments create a more uniform aerodynamic environment for powder particles in the classification gap, ensuring consistent force distribution. This leads to improved classification accuracy while maintaining high classification efficiency through optimized airflow-powder interaction

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the louver blades are positioned at the outer circumferential portion of the rotor, then fluid can be supplied for dispersing powder, but uniform force balance cannot be achieved

Engineering Contradiction:
Improvepowder dispersionVSAvoidforce balance uniformity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by optimizing the louver blade angle relative to the rotor rotation. The louver blades are positioned at a specific angle that dynamically interacts with the rotating rotor to create uniform airflow distribution. This dynamic configuration ensures that as the rotor rotates, powder particles receive consistent aerodynamic forces throughout the classification chamber, achieving both effective dispersion and uniform force balance

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

The apparatus achieves improved classification accuracy and efficiency by increasing centrifugal force and uniformity, reducing contamination and enhancing product yield.

Implementation Method 1

the powder material supplied to a gap between the rotor 5 and the louver 6 is centrifugally classified into fine powder and coarse powder

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

a louver 6 with a plurality of blades 11 which are disposed at an outer circumferential portion of the rotor 5 so as to supply from the outer circumferential portion a fluid for dispersing and classifying a powder material

Methodology Applied
Scientific EffectAerodynamic force:

Data Source

PatentEP2403660B1Classifying apparatus, classifying method, and method for producing toner
Publication Date: 2016.06.01 RICOH CO LTD
  • EP2403660B1 patent drawingFigure 1
  • EP2403660B1 patent drawingFigure 2
  • EP2403660B1 patent drawingFigure 3A~3C

AI summary

A classifying apparatus including: a rotor with a plurality of annularly disposed blades, which rotates; and a louver with a plurality of blades which are disposed at an outer circumferential portion of the rotor so as to supply from the outer circumferential portion a fluid for dispersing and classifying a powder material, wherein the powder material is supplied to a gap between the rotor and the louver and centrifugally classified into fine powder and coarse powder, and wherein at least one of the following relationships is satisfied: Relationship (1): a=50° Relationship (2): D2/D1 =1.17 where a denotes an angle formed between imaginary lines connecting the center of the rotor with both ends of each blade of the louver, D1 denotes a diameter of the rotor, and D2 denotes an inner diameter of the louver.