Leaf Filter Bag Closure System for Alumina Production

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Solution Overview

Problem

Leaf filters in alumina production plants experience leaks and labor-intensive bag replacement due to imperfect sealing and scale accumulation, leading to production losses and waste of filtration fabric.

Innovation Solution

A filter bag closure system featuring EPDM rubber snapping closures and a fabric hood with a tongue to securely seal the outlet pipe aperture, reducing scale accumulation and facilitating easy bag replacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual closing of the bag edge is used, then the bag can be sealed, but leaks occur and scale accumulates leading to production losses

Engineering Contradiction:
Improvesealing reliabilityVSAvoidproduction continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The closure system is designed to be self-sealing through the snapping action of the male and female closures that automatically engage when the bag is inserted into the frame, eliminating the need for manual sealing operations that are prone to errors and leaks

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The manual mechanical closing process is replaced with an automated snapping closure mechanism that uses elastic deformation of the rubber closure elements to create a reliable seal without human intervention

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If traditional bag closure methods are used, then bags can be sealed, but labor-intensive replacement is required due to scale accumulation

Engineering Contradiction:
Improveseal integrityVSAvoidbag replacement ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The closure system is divided into separate male and female closure components that can be independently positioned and engaged, allowing for easy disassembly and replacement of the bag without requiring removal of the entire frame structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The closure material properties are optimized with specific durometer ranges (30-70 Shore A) and elastic modulus values that allow the rubber closures to deform and snap into place easily during installation while maintaining seal integrity during operation

Inventive Principle:
Principle #35Parameter changes

3Reliability

If manual sealing is used at the outlet pipe interface, then the bag can be closed, but leaks occur and production is lost

Engineering Contradiction:
Improveoutlet pipe sealingVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The outlet pipe closure is merged with the main bag closure system, using the same male and female snapping closure mechanism to seal both the bag edge and the outlet pipe interface simultaneously in a single operation

Inventive Principle:
Principle #5Merging (Combining)

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 closure system effectively prevents leaks and reduces scale accumulation, enhancing the operational efficiency and reducing the frequency of bag replacements, thereby minimizing production losses and labor costs.

Implementation Method 1

a male snapping closure made integral to the first sheet portion along a portion of the closure edge leading to the outlet pipe aperture, and a female snapping closure made integral to the second sheet portion along the portion of the closure edge, the male snapping closure and the female snapping closure being made of EPDM rubber

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a fabric hood secured externally to both the first sheet portion and the second sheet portion along and partially around the outlet pipe aperture, and protruding from the closure edge, the fabric band being wrappable around at least a complementary portion of the outlet pipe and cooperating with the tongue when held in position to form a seal between the leaf filter bag and the outlet pipe when held

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3003525B1Closure for leaf filter in alumina production
Publication Date: 2019.09.04 SEFAR BDH
  • EP3003525B1 patent drawingFigure 1
  • EP3003525B1 patent drawingFigure 2~3
  • EP3003525B1 patent drawingFigure 4~5

AI summary

An edge closure system is presented herein wherein a portion of the closure edge of the filter bags leading to the outlet pipe aperture are provided with mating snapping closures, allowing to sealingly close the length of the edge of the fabric leading to the outlet pipe aperture simply by engaging the male and female components of the snapping closures. Moreover, an outlet pipe closure system is also presented herein using a combination of a tongue mounted internally to one of the sides of the fabric forming the bag in a manner to be wrappable around at least a corresponding portion of the outlet pipe, and a fabric hood mounted externally and overlapping both sides of the bag at the outlet pipe aperture, which cooperates with the tongue to seal the interface between the outlet pipe and the bag when held in position.