Vibrating Flowmeter Case Indentations for Resonance Separation
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Solution Overview
Problem
Vibrating meter cases with large side panels often have low resonant frequencies that overlap with the intended drive frequency of conduits, causing measurement interference and requiring costly or complex solutions like increased mass or ribs to separate frequencies.
Innovation Solution
The case design incorporates indentations extending completely between panel edges to increase resonant frequencies, dividing the panel into smaller sections and minimizing stress, thereby separating the case's vibrational modes from the conduits' modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the case has large side panels, then the case provides adequate protection and containment, but the resonant frequency of the case decreases causing measurement interference
Solution Approach 1:
The case panel is divided into multiple sections by adding reinforcing ribs, transforming a single large panel into a segmented structure. This segmentation increases the panel's stiffness and raises its resonant frequency away from the drive frequency, eliminating measurement interference while maintaining the protective function of the case
2Measurement precision
If reinforcing ribs are added to increase resonant frequency, then measurement interference is reduced, but device complexity and manufacturing cost increase
Solution Approach 1:
Reinforcing ribs are strategically positioned at specific locations on the case panel where they most effectively increase stiffness and resonant frequency. This localized reinforcement achieves the desired frequency separation with minimal additional complexity, rather than uniformly thickening the entire case structure
3Measurement precision
If case mass is increased to separate frequencies, then resonant frequency increases, but weight and manufacturing complexity increase
Solution Approach 1:
The reinforcing ribs are designed with curved profiles rather than straight lines, optimizing their structural efficiency. The curved geometry provides enhanced stiffness and resonant frequency increase per unit of material, achieving frequency separation with minimal additional weight compared to straight rib configurations
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 design effectively increases the resonant frequencies of the case, reducing measurement interference and avoiding the drawbacks of prior methods, such as increased mass or ribs, while maintaining ease of manufacturing and aesthetics.
Implementation Method 1
The one or more conduits are vibrated by at least one driver at a resonant frequency in one of these modes, hereinafter referred to as the drive mode
Implementation Method 2
The pick-off is typically a magnet/coil combination, with the magnet typically being affixed to one conduit and the coil being affixed to a mounting structure or to another conduit
Data Source
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AI summary
A case (330) for a vibrating meter (300) is provided. The case (330) includes a first panel (331a) defined by at least a first edge (333) and a second edge (334). The case (330) also includes one or more indentations (332) formed in the first panel (331a). The one or more indentations (332) include at least a portion extending from the first edge (333) to the second edge (334). The resonant frequencies of the case can be increased and separated from the intended drive frequencies of the fluid conduits (306A, 306B).