Ultrafine Ceramic Fiber Filter for Virus Removal

Solution Overview

Problem

Conventional water filtration systems face challenges in achieving high filtration efficiency for ultrafine particles like viruses while maintaining low operating pressures and high flow rates, with existing filters often suffering from clogging, high pressure drops, and reduced lifespan due to material limitations and manufacturing difficulties.

Innovation Solution

A ceramic filter with a fibrous porous body composed of randomly arranged continuous ultrafine metal oxide fibers and incorporated or coated powdery nano-alumina, produced through electrospinning and sintering, which achieves a pore size of 0.05 to 2 μm and high porosity, allowing for effective filtration of ultrafine particles with low pressure drop and high flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pore size is decreased to filter ultrafine particles such as viruses, then filtration efficiency is improved, but pressure drop increases dramatically and flow rate decreases

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidpressure drop

Core Design Contradiction:

Measurement precisionVSStress or pressure

Solution Approach 1:

The filter employs a hierarchical pore structure with different pore sizes in different regions: the surface layer has small pores (0.01-0.1 μm) for high filtration efficiency, while the inner layer has larger pores (1-10 μm) for low pressure drop. This local differentiation allows the filter to achieve both high filtration efficiency and low pressure drop simultaneously

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention transitions from a uniform pore structure to a three-dimensional hierarchical pore structure with multiple pore size levels. By adding the dimension of pore size variation through depth, the filter can accommodate both small pores for filtration and large pores for flow without compromising either function

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Measurement precision

If pore size is decreased to filter ultrafine particles, then filtration efficiency is improved, but flow rate decreases sharply

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidflow rate

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The filter employs a hierarchical pore structure with different pore sizes in different regions: the surface layer has small pores (0.01-0.1 μm) for high filtration efficiency, while the inner layer has larger pores (1-10 μm) for low pressure drop. This local differentiation allows the filter to achieve both high filtration efficiency and low pressure drop simultaneously

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention transitions from a uniform pore structure to a three-dimensional hierarchical pore structure with multiple pore size levels. By adding the dimension of pore size variation through depth, the filter can accommodate both small pores for filtration and large pores for flow without compromising either function

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Stress or pressure

If fiber diameter is minimized to reduce pressure drop, then operating pressure is reduced, but filtering precision decreases due to large pores formed by larger diameter fibers

Engineering Contradiction:

Improveoperating pressureVSAvoidfiltering precision

Core Design Contradiction:

Stress or pressureVSMeasurement precision

Solution Approach 1:

The filter employs a hierarchical pore structure with different pore sizes in different regions: the surface layer has small pores (0.01-0.1 μm) for high filtration efficiency, while the inner layer has larger pores (1-10 μm) for low pressure drop. This local differentiation allows the filter to achieve both high filtration efficiency and low pressure drop simultaneously

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention transitions from a uniform pore structure to a three-dimensional hierarchical pore structure with multiple pore size levels. By adding the dimension of pore size variation through depth, the filter can accommodate both small pores for filtration and large pores for flow without compromising either function

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Measurement precision

If membrane pore size is made smaller to remove viruses, then filtration efficiency is improved, but back washing is required which causes membrane damage and increases operating costs

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidmembrane lifespan

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The filter employs a hierarchical pore structure with different pore sizes in different regions: the surface layer has small pores (0.01-0.1 μm) for high filtration efficiency, while the inner layer has larger pores (1-10 μm) for low pressure drop. This local differentiation allows the filter to achieve both high filtration efficiency and low pressure drop simultaneously

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention transitions from a uniform pore structure to a three-dimensional hierarchical pore structure with multiple pore size levels. By adding the dimension of pore size variation through depth, the filter can accommodate both small pores for filtration and large pores for flow without compromising either function

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 ceramic filter demonstrates high filtration efficiency for ultrafine particles, low pressure drop, and high permeation flow rates, along with the ability to be regenerated, resulting in a long-lasting and environmentally friendly water treatment solution.

Implementation Method 1

the ultrafine fibers being obtained by electrospinning a spinning solution comprising a metal oxide precursor sol-gel solution

Methodology Applied

Scientific EffectElectrospinning: Electrohydrodynamics

Implementation Method 2

sintering the electrospun fibers

Methodology Applied

Scientific EffectSintering: Sintering

Implementation Method 3

A ceramic filter with a fibrous porous body composed of randomly arranged continuous ultrafine metal oxide fibers and incorporated or coated powdery nano-alumina, produced through electrospinning and sintering, which achieves a pore size of 0.05 to 2 μm and high porosity, allowing for effective filtration of ultrafine particles with low pressure drop and high flow rates.

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentUS9994488B2Ultrafine continuous fibrous ceramic filter and method of manufacturing same

Publication Date: 2018.06.12 KOREA INST OF SCI & TECH

AI summary

An ultrafine continuous fibrous ceramic filter, which comprises a filtering layer of a fibrous porous body, wherein the fibrous porous body comprises continuous ultrafine fibers of metal oxide which are randomly arranged and layered, and powdery nano-alumina incorporated into the ultrafine fibers or coated thereon, the ultrafine fibers being obtained by electrospinning a spinning solution comprising a metal oxide precursor sol-gel solution, and optionally, a polymer resin, and sintering the electrospun fibers, in which the ultrafine fibers have an average diameter of 10˜500 nm, and the fibrous porous body has a pore size of maximum frequency ranging from 0.05 to 2 μm, exhibits high filtration efficiency at a high flow rate, and can be regenerated.