Heated Flow-Calming Chamber for Gas Sensor Protection

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Solution Overview

Problem

Existing gas sensors face challenges in maintaining measurement accuracy and longevity due to high dust and moisture levels, which often require frequent filter replacements and can lead to clogged protective devices, increased sensor inertia, or high maintenance costs.

Innovation Solution

A device with a heatable flow calming space that creates a temperature gradient to prevent moisture condensation and particle accumulation, using a hollow cylindrical housing with a heating element and impact protection to shield the gas sensor inlet, allowing unhindered gas flow while preventing dirt and moisture from reaching the sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If protective filter devices (sintered disks) are used to protect against dust and moisture, then the gas sensor is protected from particle and moisture deposits, but the filter device becomes clogged under high dust and moisture conditions requiring frequent replacement

Engineering Contradiction:
Improveprotection against particle and moisture depositsVSAvoidservice life of protective filter device
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The harmful components (moisture and particles) are extracted from the gas stream before reaching the sensor through a two-stage separation process: a coarse separator removes large particles, and a hygroscopic substance absorbs moisture, preventing both from reaching the protective filter device and extending its service life

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A hygroscopic substance acts as an intermediary between the humid gas stream and the protective filter device, absorbing moisture and preventing it from reaching the filter. This mediator protects the filter without requiring direct contact between the filter and the harmful moisture

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If filters are used to separate particles and moisture, then the gas sensor is protected, but the device becomes more complex and requires regular maintenance and replacement

Engineering Contradiction:
Improveprotection against particle and moisture depositsVSAvoidcomplexity of protective device
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protective device is segmented into functional modules: a coarse separator for particle removal, a hygroscopic substance for moisture absorption, and a fine separator for residual particles. This segmentation allows each component to perform its specific function efficiently while maintaining overall system simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hygroscopic substance automatically absorbs moisture from the gas stream without requiring external power or control systems. The device operates passively, with the hygroscopic material continuously drawing moisture from the environment, eliminating the need for active maintenance or replacement under normal operating conditions

Inventive Principle:
Principle #25Self-service

3Reliability

If protective filter devices are used, then the gas sensor is protected from deposits, but the sensor outputs signals that are too low due to clogging

Engineering Contradiction:
Improveprotection against particle and moisture depositsVSAvoidaccuracy of gas sensor output
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The hygroscopic substance serves as an intermediary that removes moisture before it can reach the protective filter device, preventing clogging that would otherwise cause signal attenuation. This ensures the filter remains permeable and the sensor maintains accurate signal output

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The coarse separator and hygroscopic substance perform preliminary separation and moisture removal actions before the gas stream reaches the protective filter device. This preliminary action prevents particles and moisture from accumulating on the filter, maintaining its filtering efficiency and the sensor's measurement accuracy over time

Inventive Principle:
Principle #10Preliminary action

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

This solution extends the service life of gas sensors, reduces maintenance needs, and ensures accurate measurements by effectively protecting against particle and moisture accumulation without the need for filters, maintaining sensor sensitivity and reducing interference.

Implementation Method 1

the flow calming space being heatable in such a way that a temperature gradient is formed between the end near the sensor and the end far from the sensor during operation of the device

Methodology Applied
Scientific EffectTemperature gradient: Temperature Gradient

Implementation Method 2

a temperature gradient is formed... to prevent moisture condensation and particle accumulation

Methodology Applied
Scientific EffectCondensation prevention through heating: Heating

Data Source

PatentEP3566049B1Device for moisture and particle separation for a gas sensor
Publication Date: 2021.02.24 DRAGERWERK AG
  • EP3566049B1 patent drawingFigure 1a~1c
  • EP3566049B1 patent drawingFigure 2a~2b
  • EP3566049B1 patent drawingFigure 3

AI summary

The invention relates to a device (10) for moisture and particle separation for a gas sensor (100). The device (10) comprises a housing (20) in which a flow-calming chamber (23) is formed, which has an end (231) close to the sensor with an outlet opening (21) and an end (232) distant from the sensor with an inlet opening (27). The flow-calming chamber (23) can be heated by a heating element (30) in such a way that a temperature gradient forms between the end (231) close to the sensor and the end (232) distant from the sensor. The device can also comprise an impact protection means (40).