Gas Sensor Probe with Split Sample Flow for Optical Protection
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Solution Overview
Problem
Gas sensors used in harsh environments, such as exhaust systems, face challenges in protecting delicate optical parts from damage due to exposure to particles and gases, and existing designs often fail to control gas flow conditions effectively, leading to unreliable measurements.
Innovation Solution
A probe design that splits the sample gas into multiple flows, with each flow entering the measuring region at a controlled angle and relative flow restrictions, ensuring uniform distribution and preventing purge gas interference, while using purge gas volumes to create a barrier against particles and gases, thereby protecting the optical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If purge gas is introduced to protect optical parts from particles and gases in harsh environments, then the protection of optical parts is improved, but the purge gas may interfere with the measurements in the measuring region
Solution Approach 1:
The probe internal space is segmented into distinct regions: a measuring region where sample gas flows for measurement, and protected regions where optical parts are located. Purge gas flows are introduced into protected regions to prevent particle deposition on optics, while sample gas flows are directed through the measuring region. This spatial segmentation allows simultaneous operation of both measurement and protection functions without mutual interference.
Solution Approach 2:
Different gas flow conditions are applied to different locations within the probe. The measuring region receives sample gas with controlled flow characteristics optimized for measurement (e.g., uniform distribution, specific velocity), while protected regions receive purge gas flows optimized for protection (e.g., higher velocity to prevent particle deposition). This local differentiation of gas flow properties resolves the contradiction between measurement accuracy and optical protection.
2Ease of operation
If the sample inlet is positioned to allow gas to flow directly into it from the exhaust environment, then the sampling is simplified, but the flow conditions within the measuring region cannot be controlled
Solution Approach 1:
A sample gas conduit acts as an intermediary element between the sample inlet and the measuring region. The conduit includes flow control elements (such as flow restrictors or valves) that regulate the sample gas flow before it enters the measuring region. This intermediary structure enables controlled flow conditions in the measuring region while maintaining a simple external sample inlet configuration.
Solution Approach 2:
The sample gas undergoes preliminary processing in the sample gas conduit before entering the measuring region. Flow control elements in the conduit pre-regulate the gas flow characteristics (velocity, distribution uniformity) to ensure optimal measurement conditions are established before the gas reaches the measuring region. This preliminary action enables precise flow control without complicating the sampling interface.
3Reliability
If multiple gas flows are introduced into the measuring region to ensure uniform distribution, then the measurement reliability is improved, but the device complexity increases
Solution Approach 1:
The gas flow system is segmented into multiple independent flow paths, each with its own flow control element. Sample gas is divided into multiple streams that are independently regulated and then combined to achieve uniform distribution in the measuring region. This segmentation approach enables reliable flow control through simple, modular components rather than a single complex control mechanism.
Solution Approach 2:
Multiple gas flows are introduced into the measuring region to ensure complete and uniform filling of the measurement space. By using several flow paths instead of a single flow, the system achieves better distribution uniformity and measurement reliability. The additional flows provide redundancy and ensure that all regions of the measuring volume are adequately sampled, compensating for any local flow non-uniformities.
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 design allows for controlled and uniform gas flow conditions, preventing particle contact with delicate parts and ensuring accurate measurements by maintaining the concentration of the gas to be measured, thus enhancing the reliability and longevity of the sensor in harsh environments.
Implementation Method 1
the light path passes through at least one purge gas volume, wherein a purge gas flow in the purge gas volume forms a gas barrier preventing particles in the measuring region from passing the end of the purge gas volumes
Implementation Method 2
the sample gas traverses the measuring region with an angle in the range of 45 degrees
Implementation Method 3
A probe for an IR or UV sensor comprising a light emitter and detector
Implementation Method 4
measuring the spectrum absorptions of emitted light by a gas
Data Source
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AI summary
A probe for an IR or UV sensor comprising a light emitter and detector is described comprising a lens (2). The detector detects the spectrums of the emitted light after it has passed a gas to be measured (6). The sensor of the present invention is especially suitable for such as harsh or aggressive environments measuring the exhaust gasses, for example in ships, vehicles, chimneys etc., and comprises purge gas protections for delicate optical parts to prevent particles etc. from the exhaust gas depositing on the optics. The sensor further has a flow of sample gas from the gas to be measured being adapted to prevent the purge gas (7) from interfering with the measurements where the sample gas is split into at least two flows (6a, 6b, 6c) where one (6c) is adapted for preventing the purge gas from influencing the measurement in a measuring region (5).