Nitrogen-Containing-Gas Removing Means for Flue Gas Analyzer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Electrochemical oxygen sensors in flue gas analyzers often fail within days to months due to exposure to flue gas, particularly when combined with high water vapor concentrations, and the exact cause of failure was not well understood.

Innovation Solution

Incorporating nitrogen-containing-gas removing means, such as filters or catalysts like potassium permanganate, to remove nitrogen dioxide and its byproducts formed in high humidity, which would otherwise damage the sensors, thereby extending the operational life of the analyzers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrochemical oxygen sensors are used to measure oxygen concentration in flue gas, then oxygen measurement function is achieved, but sensor failure occurs within days to months due to exposure to flue gas containing nitrogen dioxide and water vapor

Engineering Contradiction:
Improvesensor operational lifeVSAvoiddamage from nitrogen dioxide and water vapor
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A filter element is introduced as an intermediary component between the flue gas environment and the electrochemical oxygen sensor. This filter selectively removes nitrogen dioxide and water vapor from the gas stream before it contacts the sensor, thereby protecting the sensor from harmful exposure while allowing oxygen to pass through for measurement. The filter acts as a mediator that separates the sensor from the damaging flue gas components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful components (nitrogen dioxide and water vapor) are extracted or removed from the flue gas stream before it reaches the sensor. The filter element specifically targets and removes these harmful substances, allowing only oxygen to reach the sensor. This extraction approach eliminates the harmful factors while preserving the measurement function.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If nitrogen-containing-gas removing means are added to protect the sensor, then sensor reliability is improved, but device complexity increases

Engineering Contradiction:
Improvesensor operational lifeVSAvoidstructure with filter element
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filter element serves multiple functions simultaneously: it removes nitrogen dioxide, removes water vapor, and allows oxygen to pass through for measurement. This multi-functionality reduces the need for separate components for each function, thereby limiting the increase in device complexity while achieving comprehensive protection and measurement capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 use of nitrogen-containing-gas removing means significantly extends the operational life of electrochemical oxygen sensors in flue gas analyzers, preventing damage from nitrogen dioxide and high water vapor conditions, allowing for prolonged and reliable measurement of oxygen concentrations.

Implementation Method 1

nitrogen-containing-gas removing means for removing from received gas one or more gaseous species comprising nitrogen and oxygen which are either nitrogen dioxide, or formed from nitrogen dioxide

Methodology Applied
Scientific EffectChemical absorption: Absorption (physical)

Implementation Method 2

filters or catalysts like potassium permanganate

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

Electrochemical oxygen sensors are in common use at the present time for measuring the concentration of oxygen in gas samples

Methodology Applied
Scientific EffectElectrochemical reaction: Electrolysis

Data Source

PatentEP2026064B1Usage of nitrogen-containing-gas removing means to avoid failure of an electrochemical oxygen flue-gas anlayzer
Publication Date: 2019.10.09 ALPHASENSE LTD
  • EP2026064B1 patent drawingFigure 1
  • EP2026064B1 patent drawingFigure 2
  • EP2026064B1 patent drawingFigure 3

AI summary

A flue gas analyser for measuring the concentration of oxygen in flue gas, comprising an electrochemical oxygen sensor and water vapour removing means for reducing the relative humidity of received gas and/or nitrogen-containing-gas removing means for removing from received gas one or more gaseous species comprising nitrogen and oxygen which are either nitrogen dioxide, or formed from nitrogen dioxide in the presence of sufficient water vapour, which would otherwise lead to damage of the electrochemical oxygen sensor.