Particle Sensor Guide Path Narrowing for Concentration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing particle sensors are ineffective in concentrating particles in the detection area, leading to measurement errors, especially when detecting gases with fewer particulates, due to the design that allows particles to bypass the measurement center.

Innovation Solution

A particle sensor configuration with a guide path that narrows from the inlet to the detection area, combined with an airflow generating device, such as a heater or fan, to effectively concentrate particles in the detection area, and an exhaust path that expels gas perpendicular to the guide path, allowing for a smaller sensor size and reduced measurement errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the space near the detection area is widened to allow unobstructed particle flow, then particle flow is improved, but particle concentration in the detection area deteriorates

Engineering Contradiction:
Improveparticle flowVSAvoidparticle concentration
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The internal space of the enclosure is segmented into distinct functional zones: a guide path section with gradually narrowing cross-section for particle concentration, and a detection area section with adequate space for measurement. This segmentation allows the gas flow path to be optimized for particle concentration while the detection area maintains proper dimensions for accurate measurement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the enclosure are given different spatial characteristics: the guide path has a gradually narrowing cross-sectional area to concentrate particles, while the detection area has a cross-sectional area that is not smaller than the guide path outlet to ensure accurate detection. This local differentiation of spatial properties resolves the contradiction between flow ease and measurement precision.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If particles are concentrated in the detection area, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveparticle detection accuracyVSAvoidenclosure structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The enclosure is divided into a guide path section and a detection area section with distinct geometric characteristics. The guide path section features gradually narrowing side walls to concentrate particles, while the detection area section maintains adequate cross-sectional area. This segmentation achieves particle concentration without requiring complex external mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The enclosure structure itself performs the particle concentration function through its geometric design. The gradually narrowing guide path section automatically concentrates particles as gas flows through it, eliminating the need for separate concentration devices or complex mechanical systems. The structure serves both as containment and as the active concentration mechanism.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If the guide path narrows from inlet to detection area, then particle concentration is improved, but gas flow resistance increases

Engineering Contradiction:
Improveparticle concentrationVSAvoidgas flow resistance
Core Design Contradiction:
Measurement precisionVSStress or pressure

Solution Approach 1:

The guide path section features gradually narrowing side walls that curve smoothly rather than abrupt transitions. This gradual curvature reduces turbulence and flow resistance while still achieving effective particle concentration. The smooth geometric transition minimizes pressure losses compared to sharp or stepped narrowing.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The cross-sectional area of the guide path is varied gradually along the flow direction rather than remaining constant or changing abruptly. This gradual parameter change in the geometric dimensions allows particle concentration while maintaining acceptable gas flow characteristics and minimizing pressure drop across the sensor.

Inventive Principle:
Principle #35Parameter changes

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 configuration ensures effective particle concentration in the detection area, reducing measurement errors and enabling accurate detection of particles even in low-particulate gases, while allowing for a compact sensor design.

Implementation Method 1

The light emitting element irradiates the aforementioned gas with light, and the light receiving element receives the resulting diffuse radiation. The diffuse radiation makes it possible to detect the presence of particles in the gas.

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

a heating apparatus provided near the entry point... The heater heats the gas entering the guide path through the entry point, facilitating intake of the gas into the guide path for measurement.

Methodology Applied
Scientific EffectThermal convection: Convection

Implementation Method 3

an intake fan provided at the entry point... The airflow generating device may also be an exhaust fan provided at the exit point to expel the gas.

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP3220124B1Particle sensor, and electronic device provided with same
Publication Date: 2020.02.12 OMRON CORP
  • EP3220124B1 patent drawingFigure 1A~1B
  • EP3220124B1 patent drawingFigure 1C
  • EP3220124B1 patent drawingFigure 2A

AI summary

To effectively concentrate particles in a detection area serving as the measurement center of a sensor. A particle sensor is provided with an enclosure; a detection area inside the enclosure, and a guide path in the enclosure, configured to guide a gas to a detection area. The cross-sectional perimeter in a direction perpendicular to the extending direction of the guide path gradually becomes smaller from an inlet to the guide path toward the detection area.