Dual Impeller Toner Classification Device for Particle Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional classification devices, such as tandem toner separators, face issues with accurately classifying toner particles by size, leading to poor heat-resistant storage stability, background fouling, filming, and reduced yield due to adhesion and fusion of toner particles, especially when trying to remove particles with a diameter of 2 μm or less.
Innovation Solution
The proposed classification device features two impeller-type rotors with differently sized penetration holes at their ends, allowing for controlled centrifugal and centripetal forces to efficiently separate toner particles, reducing adhesion and improving classification accuracy and yield by maintaining a gap between the rotors and optimizing the design of the classification space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional classification devices are used to remove fine particles, then particle size classification is performed, but desired-size particles are also removed along with fine particles causing reduced yield
Solution Approach 1:
The classification device is divided into two independent classification rotors with different centrifugal forces. The first classification rotor removes fine particles (2 μm or less) while the second classification rotor removes coarse particles (4 μm or more). This segmentation allows selective removal of unwanted particles without removing desired-size particles, thereby improving both classification accuracy and toner yield.
Solution Approach 2:
Each classification rotor is designed with different local characteristics - different rotor diameters, rotation speeds, and penetration hole sizes - to create different centrifugal forces. The first rotor has higher centrifugal force for removing fine particles, while the second rotor has lower centrifugal force for removing coarse particles. This local quality differentiation enables precise particle size classification.
2Productivity
If high centrifugal force is applied to remove fine particles, then classification efficiency is improved, but adhesion and fusion of toner particles occurs
Solution Approach 1:
The harmful adhesion effect is segmented and localized to specific rotors. The first classification rotor operates at high speed to remove fine particles, while the second classification rotor operates at lower speed to remove coarse particles. By segmenting the classification process, the harmful adhesion effect is limited to the first rotor while the second rotor operates under conditions that prevent adhesion, thereby maintaining overall classification efficiency.
Solution Approach 2:
The adhesion effect, which is normally harmful, is converted into a beneficial separation mechanism. By carefully controlling the centrifugal force in the second classification rotor, toner particles that would otherwise adhere to the rotor surface are instead selectively removed as coarse particles. This converts the potential harm of adhesion into a useful particle removal mechanism.
3Manufacturing precision
If rotor speed is increased to improve classification accuracy, then particle size separation is enhanced, but energy consumption increases
Solution Approach 1:
The energy consumption is segmented across two rotors with different speed requirements. The first classification rotor operates at high speed to achieve accurate removal of fine particles, while the second classification rotor operates at lower speed for removing coarse particles. This segmentation allows the system to achieve high classification accuracy for fine particles without requiring both rotors to operate at high speed, thereby reducing overall energy consumption.
Solution Approach 2:
The system changes the operational parameters of different rotors to optimize energy consumption. By setting different rotation speeds, rotor diameters, and penetration hole sizes for the two rotors, the system achieves efficient particle size separation without requiring excessive energy. The parameter optimization allows accurate classification while minimizing energy consumption.
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 enables precise classification of toner particles, preventing the removal of desired-size particles and reducing adhesion, thereby enhancing the accuracy and efficiency of toner classification while maintaining high yield and preventing toner fouling.
Implementation Method 1
A typical TTSP performs classification by balancing centrifugal force generated from blades provided on a rotor and centripetal force generated from fan suction force of the rotor. The centrifugal force collects coarse particles, whereas the centripetal force collects fine particles from the periphery of the rotor.
Data Source
AI summary
A classification device for classifying particles by size including an upper impeller-type rotor, a first end of which is covered with a cover disc without penetration hole and a second end of which is covered with an upper cover disc with a penetration hole; and a lower impeller-type rotor, a first end of which is covered with a cover disc without penetration hole and a second end of which is covered with a lower cover disc with a penetration hole. The upper impeller-type rotor and the lower impeller-type rotor are provided so that axes thereof are coincident and the first ends face with each other forming a gap therebetween in an axial direction, and the diameters of the penetration holes of the upper cover disc and the lower cover disc are different.