Vibrating Screen Conveying Device for Nuclear Fuel Pellet Sorting

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Solution Overview

Problem

Existing systems for aligning and sorting nuclear fuel pellets before insertion into rods face issues with blockages and contamination due to fragments and dust, which increase downtime and reject conforming pellets, as they fail to effectively separate and align cylindrical objects in bulk storage.

Innovation Solution

A conveying device with a vibrating corridor and multiple screens, where the screens are set in motion independently to generate different speeds and are vertically and horizontally offset, allowing for the separation and alignment of cylindrical objects while collecting residues, and a method involving a dual conveying system with vibrating screens to sort and align pellets by removing shards and dust.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional conveyor belt or single-screen system is used to transport and align pellets, then the structure is simple and easy to operate, but blockages occur frequently due to fragments and dust, causing downtime and rejecting conforming pellets

Engineering Contradiction:
Improveproduction line continuityVSAvoidconveyor system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The conveying system is divided into multiple independent vibrating screens with different mesh sizes, arranged in sequence. Each screen segment handles specific size classification, with the first screen removing large fragments and subsequent screens removing smaller dust particles. This segmentation allows the system to effectively eliminate blockage causes while maintaining manageable complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-plane conveyor to a multi-dimensional screening system where vibrations are applied in vertical directions and screens are arranged at different heights and angles. This dimensional expansion enables simultaneous separation of particles by size while maintaining continuous flow, resolving the contradiction between reliability and complexity.

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

2Manufacturing precision

If pellets are transported without effective separation, then the device complexity is low, but conforming pellets are rejected due to contamination by fragments and dust

Engineering Contradiction:
Improvepellet alignment qualityVSAvoidsorting system structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Different screening surfaces with specifically designed mesh sizes are applied at different locations in the conveying path. The first screen has larger openings for fragment removal, while subsequent screens have progressively smaller openings for dust removal. This local differentiation of screening qualities ensures high precision pellet separation without requiring an overly complex unified system.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The vibrating screens perform preliminary separation of fragments and dust from pellets before the main alignment process. By removing contaminants in advance, the subsequent alignment mechanisms work only with clean pellets, ensuring high manufacturing precision while keeping the overall system complexity manageable through staged processing.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multiple vibrating screens with independent motion are used to separate pellets effectively, then the separation precision is high, but the device complexity and energy consumption increase

Engineering Contradiction:
Improveparticle size separation accuracyVSAvoidvibration system energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The vibrating screens operate with periodic motions at different frequencies and amplitudes, creating oscillating separation zones that efficiently sort particles by size. The periodic vibration allows particles to jump and reposition themselves according to their size, achieving high separation precision. Energy consumption is optimized by adjusting vibration parameters to minimum effective levels and using the natural resonance characteristics of the screening system.

Inventive Principle:
Principle #19Periodic 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

The solution effectively reduces the risk of blockages and contamination by sorting and aligning pellets efficiently, ensuring only compliant objects are processed, thereby minimizing downtime and improving the production line's efficiency.

Implementation Method 1

a conveying device with a vibrating corridor and multiple screens, where the screens are set in motion independently to generate different speeds

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

a conveying device with a vibrating corridor and multiple screens

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP1973817B1Screening and utilization of nuclear fuel pellets
Publication Date: 2009.08.19 AREVA NC
  • EP1973817B1 patent drawingFigure 1
  • EP1973817B1 patent drawingFigure 2A~2B

AI summary

In order to remove fragments and residues from nuclear fuel pellets stored loose in a container, and filling them into rods, a conveying device (10) has a series of two vibrating screens (14, 24) separated vertically by a distance (d) from each other and feeding them to a utilizing bowl. Owing to the presence of the two screens (14, 24), the pellets are separated and turned over, and the fragments are efficiently diverted into a pot (30) so that the system does not become choked.