Fluid Flow Measuring Device with Differential Sensing Coils
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid flow measuring devices in systems like potable water systems are prone to inaccurate measurements due to noise interference from magnetic fields generated by electrical devices, which is exacerbated by the use of separate devices rather than integral solutions within armatures.
Innovation Solution
A fluid flow measuring device with a rotatable magnetic element and a pair of sensing coils positioned around ferromagnetic cores, where the coils are connected in series and positioned at different circumferential positions to minimize noise interference, allowing for accurate and reliable flow measurement even in the presence of disturbing magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic rotatable element is used for fluid flow measurement, then the measurement can be performed, but the measurement accuracy deteriorates due to noise from electrical devices
Solution Approach 1:
The patent applies differential measurement technique where two sensing coils are used to detect the magnetic field. The signal from the rotatable magnetic element is extracted by differentiating between the two coil outputs, which allows the useful signal to be separated from the common-mode noise generated by electrical devices. This converts the harmful noise into a distinguishable background that can be mathematically eliminated.
Solution Approach 2:
The patent introduces ferromagnetic cores as intermediaries between the rotatable magnetic element and the sensing coils. These cores concentrate and guide the magnetic field lines, enhancing the coupling between the rotating element and the sensing coils. This intermediary structure amplifies the useful magnetic signal while maintaining immunity to external electromagnetic noise.
2Object-affected harmful factors
If the sensing distance between the rotatable magnetic element and the sensing coil is increased, then the magnetic field strength from electrical devices is reduced, but the signal induced in the sensing coil becomes weaker
Solution Approach 1:
Ferromagnetic cores are positioned between the rotatable magnetic element and the sensing coils to act as magnetic flux concentrators. These cores extend the magnetic field from the rotating element to the sensing coils over larger distances while maintaining strong coupling. This allows the sensing coils to be positioned farther from the rotating element, reducing exposure to external electromagnetic noise while preserving signal strength through the guided magnetic flux.
Solution Approach 2:
The patent creates localized regions of enhanced magnetic field strength at the positions of the sensing coils by using ferromagnetic cores. The magnetic flux is concentrated locally at the coil positions rather than being distributed uniformly, which maintains strong signal induction even when the overall sensing distance is increased. This local field enhancement allows the coils to operate in a low-noise environment while detecting strong localized signals.
3Measurement precision
If a separate fluid flow measuring device is used, then the measurement can be performed, but the device complexity increases and integration with armatures is lost
Solution Approach 1:
The patent combines the fluid flow measurement function with the armature structure by integrating the sensing coils and ferromagnetic cores directly into the armature housing. The rotatable magnetic element is coupled to the valve mechanism, so that flow measurement and valve operation become a unified system. This merging eliminates the need for separate external measuring devices and reduces overall system complexity.
Solution Approach 2:
The armature structure is designed to serve multiple functions: it acts as both the valve control mechanism and the housing for the fluid flow measurement system. The ferromagnetic cores and sensing coils are integrated into the armature components, allowing the same structure to perform both flow regulation and flow measurement functions simultaneously, thereby eliminating the need for separate dedicated measuring 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 enables reliable fluid flow measurement by eliminating noise interference from electrical devices, allowing for the integration of the measuring device as an integral element within armatures, providing accurate and reliable flow data.
Implementation Method 1
the rotation of the rotatable, magnetic element generates a magnetic field which is detected by a sensing coil
Implementation Method 2
The magnetic field induces an electrical current signal in the sensing coil, namely an alternate current signal, which frequency is determined
Implementation Method 3
the respective first sensing coil of the or each sensing coil pair is positioned around, namely wound around, a first ferromagnetic core that is positioned at a first circumferential position of the rotatable, magnetic element
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Fluid flow measuring device (11) for measuring a fluid flow, comprising a rotatable, magnetic element (16), wherein the rotatable, magnetic element (16) is positioned in the fluid flow, wherein the rotation of the rotatable, magnetic element (16) depends from the fluid flow, wherein the rotation of the rotatable, magnetic element (16) generates a magnetic field; further comprising at least one sensing coil pair (19) having a first sensing coil (19a) and a second sensing coil (19b), wherein the respective sensing coils (19a, 19b) of the or each sensing coil pair (19) are arranged in such a way that the magnetic field generated by the fluid flow dependent rotation of the rotatable element (16) has a first polarity and a first phase in the region of the respective first sensing coil (19a) and a second polarity and a second phase in the region of the respective second sensing coil (19b), wherein at least said polarities differ from each other. (Figure 3)