Regenerable system and method for filtering microfibres from a waste liquid

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Solution Overview

Problem

Current methods for filtering microfibers from textile treatment devices, such as washing machines, are inefficient, requiring frequent consumable replacement and posing risks due to plastic nanofibers, and existing filters are not designed to capture microfibers effectively, leading to environmental and health concerns as microplastics end up in water and food supplies.

Innovation Solution

A system comprising a granular medium in an enclosure with a support allowing percolation of liquid effluent, equipped with means for regeneration by fluidization, which captures microfibers through depth filtration and allows for regeneration and recycling of the granular medium, reducing the need for frequent consumable replacement and minimizing environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a flexible woven filter with large pores is used to protect wastewater pipes, then the filter can be physically removed for cleaning, but it cannot retain microfibers effectively

Engineering Contradiction:
Improvefilter cleaningVSAvoidmicrofiber retention
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent uses a porous granular medium (such as sand, glass beads, or ceramic particles) with controlled pore sizes to filter microfibers. The porous structure allows liquid to pass through while trapping microfibers in the interstices, achieving both microfiber retention and maintainable flow rates without requiring fine-mesh filters that clog easily

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent replaces the mechanical woven filter structure with a granular medium filtration system. Instead of relying on fabric weave density, the system uses the natural pore structure and surface area of granular particles to capture microfibers, allowing for better flow characteristics and reduced clogging

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

2Manufacturing precision

If a woven filter plastic bag with fine perforations is used to retain microfibers, then microfiber retention is improved, but the bag clogs rapidly and requires frequent replacement

Engineering Contradiction:
Improvemicrofiber retentionVSAvoidfilter lifespan
Core Design Contradiction:
Manufacturing precisionVSDuration of action of moving object

Solution Approach 1:

The granular medium provides a three-dimensional porous network that distributes microfiber capture throughout the entire filter volume rather than concentrating it on a two-dimensional surface. This prevents rapid clogging and extends filter lifespan while maintaining effective microfiber retention

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent transitions from a two-dimensional flat filter surface to a three-dimensional granular bed structure. This adds depth to the filtration process, allowing microfibers to be captured throughout the volume of the granular medium, which significantly increases the effective filtering capacity and extends service life

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

3Manufacturing precision

If a micro-filtration membrane with small pore diameter is used to retain microfibers, then microfiber retention efficiency is improved, but the membrane clogs and requires frequent cartridge replacement

Engineering Contradiction:
Improvemicrofiber retentionVSAvoidplastic consumable consumption
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The granular medium provides a robust porous structure that is resistant to clogging compared to dense membrane structures. The interconnected pore network and larger void spaces allow sustained flow rates while maintaining microfiber capture, reducing the need for frequent cartridge replacements and plastic consumables

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent enables recovery and reuse of the granular medium through backwashing and regeneration processes. Instead of discarding clogged membranes, the system can reverse the flow to flush trapped microfibers from the granular bed, restoring filtration capacity and extending operational life significantly

Inventive Principle:
Principle #34Discarding and recovering

4Manufacturing precision

If a filter with small pore size is used to capture microfibers, then microfiber retention is improved, but the flow rate decreases and clogging occurs more rapidly

Engineering Contradiction:
Improvemicrofiber retentionVSAvoidliquid flow rate
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The granular medium provides an optimal balance between pore size and surface area. The numerous small pores within each particle and between particles create large total surface area for microfiber capture while maintaining adequate flow channels, preventing the flow rate reduction associated with dense fine-pore filters

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The system can use composite granular media combining different materials (e.g., sand with activated carbon, or glass beads with ceramic particles) to enhance both filtration performance and flow characteristics, achieving high microfiber retention without sacrificing productivity

Inventive Principle:
Principle #40Composite materials

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 system efficiently captures microfibers, extending the lifespan of the filtration medium, reducing plastic consumption, and enabling the recycling of collected microfibers, thereby addressing environmental and health concerns associated with microplastic pollution.

Implementation Method 1

captures microfibers through depth filtration

Methodology Applied
Scientific EffectDepth filtration: Filter (physical)

Implementation Method 2

means for regenerating by fluidization of the granular medium

Methodology Applied
Scientific EffectFluidization: Fluidisation

Data Source

PatentEP4127301B1Regenerable system and method for filtering microfibres from a waste liquid
Publication Date: 2024.03.20 IFP ENERGIES NOUVELLES
  • EP4127301B1 patent drawingFigure 1
  • EP4127301B1 patent drawingFigure 2a
  • EP4127301B1 patent drawingFigure 2b

AI summary

The invention relates to a regenerable system and method for filtering microfibres contained in a liquid effluent from a textile treatment device. The system comprises at least one enclosure (10) in which a granular medium (30) is arranged, means for percolating the liquid effluent through the granular medium (100), means (110) for discharging the liquid effluent under the granular medium (30), and means (120) for connection to means for regenerating the granular medium (30) by fluidisation.