Gas Detection Device with Membrane Filter for Sensor Poisoning

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Solution Overview

Problem

Existing electrochemical sensors for gaseous compounds face durability issues due to poisoning by chemical compounds, which limits their lifetime and performance, and current adsorbents provide inadequate protection and selectivity.

Innovation Solution

A gas detection device with a membrane filter, comprising molecular sieves, polymers, or their combination, is placed between the electrochemical sensor and the environment to block and exclude harmful chemical compounds, offering targeted protection and extended longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adsorbents are used to protect the sensor from poisoning compounds, then the sensor is protected from harmful chemical compounds, but the adsorbent has finite capacity requiring regeneration or replacement and increases device bulk

Engineering Contradiction:
Improvesensor protection from poisoningVSAvoidadsorbent service life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent changes the protective mechanism from adsorption (finite capacity) to membrane-based physical/chemical barrier (continuous protection). The membrane filter uses size exclusion, charge repulsion, or solubility differences to continuously block poisoning compounds without saturation, eliminating the need for regeneration or replacement.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The membrane filter acts as an intermediary barrier between the sensor and harmful compounds. It selectively allows target gas molecules to reach the sensor while blocking larger or charged poisoning compounds, providing ongoing protection without the capacity limitations of adsorbents.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If adsorbents are used in sufficient quantity to protect the sensor, then the sensor is adequately protected, but the device becomes bulky which limits placement options

Engineering Contradiction:
Improvesensor protection effectivenessVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent replaces bulky adsorbent materials with a thin membrane filter that can be disposed directly over the sensor. The membrane's selective permeability provides effective protection in a thin profile, dramatically reducing the volume required for protection compared to sufficient-quantity adsorbents.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The membrane filter may be a composite material combining multiple functional layers or properties (e.g., size exclusion pores with charge-selective surfaces) to achieve both high protection effectiveness and thin profile, eliminating the need for large quantities of single-material adsorbents.

Inventive Principle:
Principle #40Composite materials

3Duration of action of moving object

If a membrane filter is used to protect the sensor, then the sensor is protected from poisoning compounds with longer duration, but the membrane filter requires specific thickness and material properties to achieve selectivity

Engineering Contradiction:
Improveprotection durationVSAvoidmembrane thickness control
Core Design Contradiction:
Duration of action of moving objectVSManufacturing precision

Solution Approach 1:

The membrane filter uses controlled porosity (pore size, distribution, and structure) as the primary protection mechanism. The pore dimensions are engineered to physically exclude poisoning compounds while allowing target gases to pass, providing long-term protection without requiring extreme thickness precision—only that pores remain smaller than the poisoning molecules.

Inventive Principle:
Principle #31Porous materials

4Measurement precision

If the membrane filter has high selectivity for the target compound, then the detection accuracy is improved, but the membrane filter may also block some target compound reducing sensor response

Engineering Contradiction:
Improvedetection selectivityVSAvoidtarget compound reaching sensor
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The membrane filter is designed with local quality variations—different regions or layers have different properties optimized for specific functions. For example, one layer may provide size exclusion while another provides charge-based separation, allowing high selectivity for target compounds while maintaining adequate permeability through the combined effect of multiple specialized layers.

Inventive Principle:
Principle #3Local quality

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 membrane filter provides longer-lasting and more robust protection against poisoning, allowing for targeted exclusion of specific compounds and reducing aqueous solution evaporation, resulting in a smaller, more reliable gas detection device.

Implementation Method 1

The membrane filter may comprise a molecular sieve, a polymer, or a combination thereof. The molecular sieve may comprise zeolites, metal organic frameworks, engineered activated carbon, clay, and combinations thereof.

Methodology Applied
Scientific EffectMolecular sieving: Molecular Sieve

Implementation Method 2

A membrane filter, comprising molecular sieves, polymers, or their combination, is placed between the electrochemical sensor and the environment to block and exclude harmful chemical compounds

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 3

The polymer may have a selectivity greater than or equal to 25:1 for a target compound and the gas detection device may be capable of detecting the target compound.

Methodology Applied
Scientific EffectSelective permeation: Permeation

Data Source

PatentEP4009043A1Gas detection device for gaseous compound
Publication Date: 2022.06.08 CARRIER CORP
  • EP4009043A1 patent drawingFigure 1
  • EP4009043A1 patent drawingFigure 2
  • EP4009043A1 patent drawingFigure 3

AI summary

Disclosed herein is a gas detection device (10) comprising a membrane filter (100) disposed between an electrochemical sensor (12) and an environment exterior to the gas detection device (10).