Vibrating Meter Damping for Frequency Separation
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Solution Overview
Problem
Vibrating meters face measurement inaccuracies due to interference between conduit and case vibrational frequencies, as the case's natural modes of vibration often overlap with the drive mode frequency of the conduits, leading to erroneous readings.
Innovation Solution
Applying a damping material to the surface of the meter components, such as the case, to reduce and separate the resonant frequencies of the meter components from those of the conduits, thereby preventing the drive mode from inducing unwanted vibrations in the case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the case is made extremely stiff and/or massive to decrease vibrational frequencies away from the drive mode, then the frequency separation between case and conduit vibrations is improved, but the manufacturing complexity and cost increase significantly
Solution Approach 1:
The patent applies damping material to the case surface to change the vibrational characteristics of the case. This modifies the damping ratio and natural frequencies of the case without requiring changes to the case's mass or stiffness, thereby avoiding manufacturing complexity while achieving frequency separation and reduced vibration interference with the conduits
Solution Approach 2:
The patent uses composite structures by applying damping material (such as viscoelastic layers) to the case surface. This creates a composite system where the damping material works together with the case to reduce vibrational frequencies and separate them from the drive mode frequency, improving measurement precision without increasing manufacturing complexity
2Measurement precision
If metal weights are welded to the case to increase its mass, then the resonant frequencies of the case are reduced, but the manufacturing complexity increases and vibrational energy dissipation is insufficient
Solution Approach 1:
Instead of adding mass through welded weights, the patent changes the damping parameters of the case by applying damping material. This approach reduces resonant frequencies through increased energy dissipation rather than mass addition, avoiding welding operations and associated manufacturing complexity while achieving sufficient vibrational energy dissipation
Solution Approach 2:
The patent converts the potentially harmful vibrations of the case into beneficial frequency separation. By applying damping material, the case vibrations are reduced and shifted to frequencies below the drive mode, transforming the interference problem into a solution where the case and conduit vibrations are well-separated, improving measurement accuracy
3Measurement precision
If the shape of the case is modified to increase vibrational frequencies above the drive mode, then frequency separation is achieved, but the manufacturing cost and time increase significantly
Solution Approach 1:
The damping material is applied to the case in advance during the manufacturing process, before final assembly. This preliminary application of damping material establishes the desired vibrational characteristics early, avoiding the need for complex case shape modifications and subsequent disassembly/reassembly operations, thereby improving manufacturing ease
Solution Approach 2:
Rather than modifying the geometric parameters of the case shape, the patent changes the vibrational parameters by applying damping material. This approach achieves frequency separation through material properties rather than geometric redesign, significantly reducing manufacturing time and cost while maintaining ease of manufacture
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 damping material effectively reduces the resonant frequencies of the meter components, ensuring accurate measurements by maintaining a significant frequency separation between the drive mode and the case's vibrational modes, thus minimizing measurement errors.
Implementation Method 1
a damping material 310 applied to a surface of the meter component. The damping material 310 reduces the resonant frequencies of the meter component
Implementation Method 2
The damping material 310 reduces the resonant frequencies of the meter component so that the drive mode of the vibrating portion of the conduits does not induce a mode of vibration in the meter component
Data Source
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AI summary
A vibrating meter (5) is provided. The vibrating meter (5) includes one or more conduits (103A, 103B) including a vibrating portion (471) and a non-vibrating portion (472) and a driver (104) coupled to a conduit of the one or more conduits (103A, 103B) and configured to vibrate the vibrating portion (471) of the conduit at one or more drive frequencies. The vibrating meter (5) also includes one or more pick-offs (105, 105') coupled to a conduit of the one or more conduits (103A, 103B) and configured to detect a motion of the conduit. One or more meter components exclusive of the vibrating portion (471) of the conduits (103A, 103B), the driver (104), and the pick-offs (105, 105') is provided with a damping material (310) applied to at least a portion of a surface of a meter component of the one or more meter components that reduces one or more vibrational resonant frequencies of the meter component below the one or more drive frequencies.