Flow Sensor Heated Air Collar for Condensation Control
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Solution Overview
Problem
Variable orifice flow sensors used in medical applications, such as breathing apparatuses, face issues with moisture condensation that affects the accuracy of flow rate measurements due to interference with the flapper mechanism.
Innovation Solution
A fluid flow sensor design incorporating a collar around the housing with a heating element to maintain the airspace temperature above the dew point of the moist gas, reducing condensation within the sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a variable orifice flow sensor is used to measure breathing gas flow rates, then the sensor can provide sufficient pressure difference for measurement across a broad range of flow rates, but moisture in the gas may condense and accumulate in the sensor, interfering with the flapper mechanism and reducing measurement accuracy
Solution Approach 1:
The patent applies parameter changes by heating the sensor housing to maintain its temperature above the dew point of the breathing gas. This temperature parameter change prevents moisture condensation within the sensor, thereby eliminating liquid droplet accumulation that would interfere with the flapper mechanism and compromise measurement accuracy and reliability
Solution Approach 2:
The patent converts the harmful effect of moisture condensation into a beneficial outcome by using the heating element to raise the housing temperature above the dew point. This transforms the potential harm of condensation into a benefit where the heated housing actively prevents condensation, protecting the flapper mechanism and ensuring consistent operation
2Reliability
If a heating element is added to prevent condensation, then condensation is reduced and measurement consistency is improved, but the device complexity and power consumption increase
Solution Approach 1:
The heating element is integrated into the existing sensor housing structure, allowing the housing to serve dual functions: structural containment and thermal regulation. This multi-functionality approach prevents condensation while avoiding the need for separate heating apparatus, thereby minimizing the increase in device complexity
Solution Approach 2:
The patent merges the heating function with the sensor housing by incorporating the heating element directly into the housing structure. This consolidation combines two functions (structural support and temperature control) into a single integrated component, reducing overall device complexity compared to using separate heating devices
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 solution effectively prevents condensation, ensuring consistent and accurate flow rate measurements by maintaining the fluid flow passage above the dew point, thus enhancing the reliability of the sensor.
Implementation Method 1
A heating element is disposed in the airspace and is operable to heat the air contained within the airspace to consequently heat the fluid flow passage above the dew point of the moist gas
Implementation Method 2
heat the air contained within the airspace to consequently heat the fluid flow passage
Data Source
AI summary
A collar is provided for use with a fluid flow sensor to reduce condensation of a moist gas flowing through the fluid flow sensor. The collar comprises a body defining an interior that defines an airspace between the collar and the housing of the fluid flow sensor when the collar is positioned on the fluid flow sensor. The collar also includes a heat source secured to the body and adapted to heat air contained within the airspace to consequently heat the housing of the fluid flow sensor and the interior surfaces of the sensor to reduce condensation of the moist gas.