Aerosol Particle Sensor Axial Fan Low Pressure Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current aerosol particle counter systems face high installation costs and power consumption due to the requirement for large positive displacement pumps and extensive vacuum systems, especially when multiple sensors are used, as they need to maintain high vacuum levels to detect particles effectively.
Innovation Solution
The system employs an optical particle sensor with a low pressure drop of 3 inches of water or less, utilizing an axial fan, such as a high static pressure or counter-rotating fan, and an inlet jet nozzle with a larger cross-sectional area to reduce the need for high-power pumps and minimize system pressure drops, allowing for the use of more efficient air-moving devices like radial and regenerative blowers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a critical flow orifice is used to control volumetric flow rate, then the flow rate can be maintained constant, but the required vacuum level becomes excessively high (>15 inches Hg)
Solution Approach 1:
The patent changes the flow control mechanism from a critical flow orifice to a variable geometry nozzle. This parameter change allows the system to achieve the required flow rate stability without maintaining excessively high vacuum levels, as the nozzle geometry can be adjusted to optimize flow characteristics at lower vacuum conditions.
Solution Approach 2:
The patent replaces the traditional critical flow orifice mechanical flow control system with a variable geometry nozzle system that can be actuated by a positioner. This substitution enables flow control through geometric adjustment rather than relying solely on high vacuum pressure differentials, thereby reducing the required vacuum level.
2Stress or pressure
If positive displacement pumps are used to maintain high vacuum levels, then the required vacuum can be achieved, but the system size and power consumption increase significantly
Solution Approach 1:
The patent changes the operating parameters of the vacuum system by reducing the required vacuum level from >15 inches Hg to lower levels. This parameter change enables the use of more efficient vacuum pumps with lower power consumption, as the pumps no longer need to maintain excessively high vacuum levels to achieve the required particle detection performance.
Solution Approach 2:
The patent replaces high-power positive displacement pumps with more efficient vacuum pumping systems that operate at lower power consumption levels. This substitution is made possible by the variable geometry nozzle system that achieves effective flow control without requiring the extreme vacuum levels that necessitate large, power-intensive pumps.
3Productivity
If dedicated particle counters are installed at each sample point, then real-time monitoring is achieved, but the system cost increases significantly
Solution Approach 1:
The patent creates a universal particle sensor design with variable geometry nozzle and positioner systems that can be deployed at multiple sample points. This multi-functional approach allows a single sensor type to serve multiple locations, enabling real-time monitoring across several points without requiring dedicated counters at each location, thereby significantly reducing overall system cost.
Solution Approach 2:
The patent enables segmentation of the monitoring system into multiple distributed sensor units, each capable of independent real-time operation. This segmentation allows parallel monitoring at different sample points simultaneously, achieving the productivity of dedicated counters at each location while maintaining the cost efficiency of shared sensor designs through standardized modular units.
4Adaptability or versatility
If sample tubing runs are made lengthy to route to central particle counter, then multiple sample locations can be monitored, but large particle transport loss occurs
Solution Approach 1:
The patent enables segmentation of the centralized monitoring approach into distributed sensor units at or near each sample location. This segmentation allows sample points to be monitored locally with minimal tubing length, thereby reducing large particle transport loss while still enabling multiple sample locations to be monitored through the deployment of multiple segmented sensor units.
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 significantly reduces the cost, size, and power consumption of optical particle sensors, enabling continuous monitoring across multiple locations with a simplified installation process and lower overall system costs.
Implementation Method 1
The gas flow system includes an axial fan
Implementation Method 2
an optical system directing the light through the sample chamber
Data Source
AI summary
A particle sensor for optically detecting an unconstrained particle suspended in a flowing gas includes a sample chamber having a gas inlet and a gas outlet; a gas flow system for flowing said gas from said gas inlet through said sample chamber to said gas outlet, a source of light; an optical system directing said light through said sample chamber, an optical collection system located to collect light scattered by said particles in the gas, and a detection system located to detect the collected light. The total pressure drop through said gas flow system is 3 inches of water or less. The gas flow system includes an axial fan, which may be a high static pressure fan or a counter-rotating fan. In a 1.0 CFM system, the gas inlet nozzle has an area of 25 square millimeters or more.