Multi-Pair Electrostatic Granule Separation for Single-Pass Sorting

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Solution Overview

Problem

Existing electrostatic separation devices for granular materials face inefficiencies in single-pass separation, leading to high rates of unseparated material and increased spatial footprint or time requirements when multiple passes are needed.

Innovation Solution

An electrostatic separation device with a configuration of multiple electrode pairs and a controlled electric field distribution, utilizing triboelectric charging and a divergent arrangement of electrodes to enhance single-pass separation efficiency without increasing device size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the height of the separation zone is increased to improve single-pass separation rate, then the separation efficiency is improved, but the spatial footprint of the device is greatly increased

Engineering Contradiction:
Improvesingle-pass separation rateVSAvoidspatial footprint
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent transitions from a vertical arrangement (single pair of electrodes with large height) to a horizontal arrangement (multiple pairs of electrodes arranged side by side). This dimensional change allows the separation zone to extend horizontally rather than vertically, maintaining separation efficiency while reducing the device's vertical footprint and overall spatial requirement

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The separation zone is divided into multiple independent pairs of electrodes (at least three pairs) arranged horizontally. Each pair acts as an independent separation unit, and their combined effect achieves high single-pass separation rates without requiring a tall vertical structure, thus reducing the spatial footprint

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If multiple passes are used to reduce unseparated material, then the separation purity is improved, but the hourly throughput and time efficiency are reduced

Engineering Contradiction:
Improveseparation purityVSAvoidhourly throughput
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent employs multiple pairs of electrodes (at least three) working simultaneously in a single pass, providing excessive separation action in one pass rather than partial action requiring multiple passes. This ensures that even materials requiring multiple separation opportunities are separated in the same pass, maintaining high purity while preserving throughput

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The horizontal arrangement of multiple electrode pairs creates a continuous separation zone where granules experience sequential electric fields from multiple pairs in a single continuous pass. This continuous action ensures complete separation in one pass, eliminating the need for repeated passes and maintaining both purity and throughput

Inventive Principle:
Principle #20Continuity of useful action

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

Significantly improves separation rates and reduces energy costs by optimizing the electric field distribution, allowing for efficient and continuous operation with minimal device footprint.

Implementation Method 1

the granules are charged by triboelectric effect in a vibrating or rotating device

Methodology Applied
Scientific EffectTriboelectric effect: Triboelectric Effect

Implementation Method 2

the charged granules are conveyed to an electrostatic sorting device where they are separated by an electric field

Methodology Applied
Scientific EffectElectric field: Electric Field

Implementation Method 3

Positively charged granules are attracted to the anode (the negative electrode), while negatively charged granules are attracted to the cathode (the positive electrode)

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentEP3782734B1Electrostatic separation device, associated separation method and use
Publication Date: 2025.11.05 SKYTECH
  • EP3782734B1 patent drawingFigure 1
  • EP3782734B1 patent drawingFigure 2
  • EP3782734B1 patent drawingFigure 3

AI summary

The present invention relates to an electrostatic separation device (10) for a mixture of granules of different materials, comprising: - a separation chamber (14) having an inlet (26) and delimiting an internal volume (25), - a granule collection device (18) disposed in the internal volume (25), opposite the inlet (26) in an upward direction (Z), - at least two pairs (20) of electrodes disposed successively in the upward direction in the internal volume (25), between the inlet (26) and the collection device (18), each pair (20) comprising an anode (48) and a cathode (50), disposed on either side of a central axis (A) extending in the upward direction (Z), and - at least one generation system (22), adapted to apply an electrical potential difference between the anode (48) and the cathode (50) of each pair (20).