Beta-SiC Membrane for Abrasion-Resistant Filtration

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Solution Overview

Problem

Current filter technologies face challenges in producing membranes with high abrasion resistance, fine pore sizes, and narrow pore distribution, which are essential for effective filtration, particularly in ultrafiltration, due to the complexity and cost of manufacturing silicon carbide membranes with small median pore diameters.

Innovation Solution

A filter design featuring a membrane separator layer composed of at least 70% silicon carbide (SiC) with a beta-SiC/alpha-SiC molar ratio greater than 0.5, optimized to achieve high resistance to abrasion and tearing, and a median pore diameter of less than 500 nanometers, allowing for improved filtration performance and longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If silicon carbide membranes with small median pore diameters are manufactured using conventional methods, then fine pore sizes are achieved, but manufacturing complexity and cost increase significantly

Engineering Contradiction:
Improvemedian pore diameterVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention changes the crystalline phase composition parameter of silicon carbide, specifically increasing the beta-SiC content to at least 25% by weight (preferably 40-90%). This parameter change enables the membrane to achieve fine pore sizes with median pore diameters of 0.1 to 1.0 micrometers while simplifying the manufacturing process and reducing costs, as beta-SiC can be produced at lower temperatures (1400-1700°C) compared to alpha-SiC

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite material approach by combining different crystalline phases of silicon carbide (beta-SiC and alpha-SiC) in specific proportions. The membrane comprises a mixture of beta-SiC (at least 25% by weight) and alpha-SiC (up to 75% by weight), creating a composite structure that leverages the benefits of both phases: beta-SiC provides ease of manufacture and chemical resistance, while alpha-SiC contributes to mechanical strength and pore structure formation

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional silicon carbide membranes are used, then chemical resistance is achieved, but abrasion resistance remains insufficient

Engineering Contradiction:
Improvechemical resistanceVSAvoidabrasion resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention creates a composite material system using multiple crystalline phases of silicon carbide. The beta-SiC phase (at least 25% by weight) provides exceptional chemical resistance and corrosion resistance, while the alpha-SiC phase (up to 75% by weight) contributes to mechanical strength and abrasion resistance. This composite approach allows the membrane to simultaneously achieve both chemical resistance and improved abrasion resistance that neither phase could provide alone

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention applies local quality by distributing different crystalline phases throughout the membrane structure in specific proportions. The beta-SiC regions provide chemical resistance where needed, while alpha-SiC regions provide mechanical strength and abrasion resistance. The heterogeneous distribution of phases at the microstructural level allows different regions of the membrane to excel at different functions

Inventive Principle:
Principle #3Local quality

3Device complexity

If frontal filtration is used, then simple system configuration is achieved, but particle accumulation on filter surface occurs rapidly

Engineering Contradiction:
Improvesystem configurationVSAvoidpermeate flux
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The invention utilizes porous materials with specifically engineered pore structures. The membrane has a porous structure with median pore diameters of 0.1 to 1.0 micrometers and controlled porosity (30-70%). This porous structure allows particles to penetrate deeper into the membrane rather than accumulating on the surface, maintaining permeate flux while using a simple frontal filtration configuration. The pore size and distribution are optimized to prevent rapid clogging

Inventive Principle:
Principle #31Porous 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 solution provides a filter with enhanced mechanical resistance, selectivity, and reduced clogging risk, enabling efficient filtration in microfiltration and ultrafiltration applications while maintaining low pressure loss and high chemical resistance.

Implementation Method 1

the ratio between the molar content of SiC in the beta form and the molar content of SiC in the alpha form (beta-SiC/alpha-SiC) of the separator layer is greater than 0.5

Methodology Applied
Scientific EffectCrystalline structure: Crystallisation

Implementation Method 2

a membrane separator layer for the filtration of said liquid, said support element being covered on the part of its surface in contact with the liquid to be filtered by said membrane separator layer

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 3

a support element made of a porous ceramic material

Methodology Applied
Scientific EffectPorosity: Porosity

Data Source

PatentEP3471863B1Filters comprising beta-sic-based separation layers
Publication Date: 2023.11.01 SAINT GOBAIN CENT DE RES & DEVS & DETUD EUROEN
  • EP3471863B1 patent drawingFigure 1
  • EP3471863B1 patent drawingFigure 2
  • EP3471863B1 patent drawingFigure 3

AI summary

Filter for the filtration of a liquid, comprising or formed by a support element made from a porous ceramic material and a membrane separation layer for the filtration of said liquid, said support element being covered on the portion of its surface in contact with the liquid to be filtered by said membrane separation layer, said separation layer being made from a material comprising at least 70% by weight of silicon carbide SiC relative to the total weight of all of the mineral compounds present in said separation layer, said filter being characterized in that the ratio between the molar content of SiC in beta form and the molar content of SiC in alpha form is greater than 0.5.