Flue Gas Particle Sensor with Multi-Path Light and Single Sensor
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Solution Overview
Problem
Conventional particle-measuring devices in flues face inaccuracies due to contamination and temperature variations, requiring complex compensation methods, and are bulky, making maintenance and calibration challenging.
Innovation Solution
A compact measuring device with a light source emitting multiple wavelengths, guiding the light ray perpendicular through the scattering zone multiple times to measure both scattered and unscattered light using a single sensor, and using a laminar clean gas flow to prevent contamination without diluting the flue gas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser is used as a light source in a flue, then measurement of particle scattering is enabled, but the device becomes large and heavy requiring access for maintenance and cleaning
Solution Approach 1:
The device is divided into modular components: a light source unit with optical elements, a sensor unit, and a housing that can be detached. This segmentation allows the optical elements to be accessed and cleaned separately without replacing the entire device, reducing maintenance complexity while maintaining measurement precision
Solution Approach 2:
The optical elements (lens, window) are designed as removable components that can be extracted from the housing for cleaning. This extraction principle allows maintenance of critical optical surfaces without disassembling the entire measurement device, addressing the contradiction between precision measurement requirements and maintenance accessibility
2Reliability
If clean gas is blown to flow away from optical elements to prevent contamination, then optical element protection is improved, but the flue gas is diluted and unintended refractions occur
Solution Approach 1:
A physical barrier (window or lens) is introduced as an intermediary between the optical elements and the flue gas. This barrier protects the optical elements from direct contamination by particles while allowing light transmission, eliminating the need for purge gas and preventing measurement interference
Solution Approach 2:
A thin transparent window or coating is applied to the optical elements to create a protective barrier against particle contamination. This thin film approach maintains optical transparency while preventing direct contact between particles and optical surfaces, avoiding both contamination and measurement interference
3Device complexity
If a single sensor measures both scattered and unscattered light, then device complexity is reduced, but measurement separation becomes more difficult
Solution Approach 1:
The measurement is separated by spatial dimension rather than using multiple sensors. The unscattered light is directed to a different location (first position) than the scattered light (second position) through optical path design, allowing a single sensor to measure both components at different positions without cross-interference
Solution Approach 2:
The measurement process is segmented into two distinct measurement positions: one for unscattered light and one for scattered light. The single sensor is sequentially positioned or the optical system is configured to direct different light components to different measurement positions, enabling separate measurement of both light components with one sensor
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 approach allows for accurate and efficient measurement of particle properties across a wide range of concentrations, reduces the need for extensive temperature compensation, and enables easy maintenance and calibration of the device without compromising measurement accuracy.
Implementation Method 1
The properties of particles in gases and liquids are generally measured by observing the scattering of a ray of light as it travels through a medium
Implementation Method 2
A laser produces monochromatic light, the scattering angle of which depends on the wavelength of the light. The wavelength of the light produced by a laser depends on the temperature
Implementation Method 3
Attempts have been made to prevent contamination of the optical elements by guiding the ray of light to the flue gas and away from it through an opening, from which a clean gas, such as air, is blown to flow away from the optical elements
Data Source
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AI summary
The invention relates to a method for determining properties of particles in a medium by measuring scattering of a light ray guided through the medium. The light ray(2)can be led through a scattering zone(4)more than once. Both the scattered(5)and unscattered light are measured using the same sensor(6).The invention also relates to a measuring device for measuring the properties of particles in a medium, such as flue gas.