Hygromorphic Humidity Detection in Compressed Air Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing humidity sensing methods in air brake systems are inadequate for determining desiccant efficacy and service life in air dryers, as they require expensive sensors that cannot withstand pressure changes and are not effectively connected for power and signal transmission.
Innovation Solution
A system using a light emitter, light sensor, and hygromorphic element exposed to compressed air, where the hygromorphic element changes shape with humidity levels, altering light transmission between the emitter and sensor, and optionally incorporating a magnet for magnetic field changes, allowing for effective humidity monitoring and desiccant life assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If discrete humidity sensors are placed directly in the air flow path, then humidity detection is achieved, but the sensors cannot withstand pressure changes during air dryer charging and purging cycles
Solution Approach 1:
The system divides the humidity detection function into two separate components: a hygromorphic element that responds to humidity changes and a light sensor that detects the physical change. This segmentation allows the detection function to be separated from the air flow path, enabling reliable operation under pressure changes while maintaining humidity detection capability.
Solution Approach 2:
The patent introduces an intermediary mechanism (hygromorphic element that changes physical properties in response to humidity) that translates humidity information into a detectable signal without requiring direct sensor exposure to harsh air flow conditions. This intermediary protects the sensing system from pressure changes while enabling indirect humidity measurement.
2Measurement precision
If humidity sensors are used in compressed air systems, then humidity levels can be detected, but expensive sensors are required and complex connections for power and signal transmission are needed
Solution Approach 1:
The patent replaces complex electronic humidity sensing systems with a simpler optical detection system. Instead of using expensive electronic humidity sensors requiring complex wiring, the system uses a hygromorphic element whose physical changes can be detected optically, eliminating the need for complex electrical connections and reducing system complexity.
Solution Approach 2:
The system utilizes optical property changes (analogous to color changes) in the hygromorphic element in response to humidity variations. This approach converts chemical/physical humidity sensing into an optical detection problem, allowing for simpler, less expensive sensing mechanisms that do not require complex electronic connections.
3Measurement precision
If desiccant based air dryers are used to adsorb water vapor, then humidity is reduced, but the desiccant material becomes fouled with oil and contaminants over time, reducing its adsorption capability
Solution Approach 1:
The system implements continuous humidity monitoring downstream of the air dryer to provide feedback on desiccant performance. By measuring humidity levels over time, the system can detect when the desiccant is no longer effectively removing moisture, indicating it needs replacement. This feedback mechanism enables proactive maintenance scheduling.
Solution Approach 2:
The humidity monitoring system provides advance warning before complete desiccant failure occurs. By detecting rising humidity trends, the system enables scheduled replacement of desiccant materials before they become completely fouled, maintaining optimal performance and preventing moisture-related damage to downstream components.
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 provides a cost-effective and reliable means to monitor humidity levels, enabling timely desiccant replacement and reducing maintenance costs by accurately determining desiccant efficacy and service life without the need for expensive sensors.
Implementation Method 1
The hygromorphic element changes shape in response to humidity levels in the compressed air
Implementation Method 2
a light emitter, a light sensor and a hygromorphic element. The hygromorphic element is exposed to a source of compressed air and positioned between the light emitter and the light sensor
Implementation Method 3
Another method of determining humidity in a compressed air system comprises exposing a hygromorphic element and magnet to an increase in humidity. A controller receives a signal indicating a change in magnetic field due to the change in shape of the hygromorphic element
Data Source
AI summary
A device for monitoring humidity in a compressed air system comprises a light emitter; a light sensor; and a hygromorphic element. The hygromorphic element is exposed to a source of compressed air and positioned between the light emitter and the light sensor. The hygromorphic element changes the amount of light passing between the light emitter and the light sensor as the humidity in the compressed air increases.