Compact Target Flow Meter With Magnetic Hinge Linearization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flow sensing technologies face challenges in achieving a wide dynamic range and linearization of sensor response, especially in miniaturized applications, due to quadratic increase in flow force and variable frictional resistance from traditional hinges, which limits turndown ratio and sensitivity to flow orientation.
Innovation Solution
A flow measurement device with a hinged target and fixed magnet arrangement, utilizing a repulsive magnetic force between opposing magnets to counteract drag force, combined with sensing elements like Hall-effect sensors, capacitive, optical, or inductive methods, to linearize the force-displacement relationship and enhance turndown ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional mechanical hinge is used for the target, then the target can register deflection, but variable frictional resistance swamps the deflection force at low flow rates
Solution Approach 1:
The patent replaces the traditional mechanical hinge with a magnetic hinge system. A magnet is attached to the target and interacts with a stationary magnet assembly, creating a magnetic field that provides the restoring force. This substitution eliminates mechanical contact and friction, allowing the target to respond to very low flow forces that would be undetectable with a mechanical hinge.
2Measurement precision
If elastic materials are used for the living hinge, then frictional effects are reduced, but the modulus of elasticity is too high to deflect against small flow forces in millimetric channels
Solution Approach 1:
The patent replaces the elastic material hinge with a magnetic field-based hinge. The magnetic interaction provides a soft, adjustable restoring force that is much weaker than elastic materials, enabling deflection against small flow forces in millimetric channels while eliminating internal friction of viscoelastic materials.
3Adaptability or versatility
If the target is hinged to register deflection, then flow measurement is possible, but the force increases quadratically with flow rate, limiting the turndown ratio
Solution Approach 1:
The patent replaces the mechanical hinge with a magnetic hinge system where a magnet on the target interacts with a stationary magnet assembly. The magnetic field provides a restoring force that can be tuned to counteract the quadratic increase in drag force, extending the measurable flow range from very low to high flow rates and improving the turndown ratio.
Solution Approach 2:
The patent changes the physical state from mechanical contact to magnetic field interaction. By adjusting magnetic field strength and geometry, the restoring force characteristic can be optimized to match the quadratic drag force profile, enabling measurement across a wider dynamic range.
4Measurement precision
If thermal methods are used for flow sensing, then low-flow rates can be measured, but saturation occurs at higher rates especially in media with high thermal conductivity
Solution Approach 1:
The patent replaces thermal sensing methods with a magnetic hinge-based mechanical deflection system. This substitution avoids thermal conduction issues in high thermal conductivity media like water, allowing measurement from very low to high flow rates without saturation.
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 device provides reliable, real-time measurement of fluid volume with a wide dynamic range and fast response, suitable for channels of millimetric dimensions, and can differentiate between different media types, including gas and liquid, with improved sensitivity and accuracy.
Implementation Method 1
A flow measurement device with a hinged target and fixed magnet arrangement, utilizing a repulsive magnetic force between opposing magnets to counteract drag force
Implementation Method 2
sensing elements like Hall-effect sensors
Data Source
AI summary
A flow measurement device is provided. The flow measurement device comprising a rigid housing defining a flow channel having a channel input and a channel output, the flow channel being configured to allow a fluid medium to flow from the channel input to the channel output; a moving member hingeably mounted within the flow channel, and extending transverse to a direction of flow of the fluid medium, the moving member comprising a moving member magnet, the moving member operatively moving on exposure to a drag force resultant from fluid passing in the flow channel, where the moving member is formed from a flexible supporting structure forming a living hinge, the moving member magnet being coupled to the flexible supporting structure; a fixed magnet, provided at least proximal to a side-wall of the flow channel, the fixed magnet having like polarity with respect to moving member magnet, and being arranged to operatively exert a repulsive force on the moving member magnet thereby limiting its displacement proportionally to the magnitude of the drag force exerted by the fluid flow, so to linearise a relationship between a rate of flow of the fluid medium and moving member displacement; and a sensing element located relative to the moving member and configured to provide an output indicative movement of the moving member within the flow channel.