Piezoelectric Cable Bluff Body for Vortex Flowmeter Leakage

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Solution Overview

Problem

Vortex flowmeters face challenges with complex and costly sensors that require additional fasteners and a robust seal, leading to potential fluid leakage and wear due to direct contact with the process fluid, especially in high-pressure and vibrating environments.

Innovation Solution

Incorporating piezoelectric cables within the bluff body of the flowmeter, connected in parallel pairs, to detect deformations caused by vortices, eliminating the need for external sensors and reducing the risk of leakage by integrating sensors directly into the bluff body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional vortex sensors are used, then vortex detection is achieved, but device complexity and cost increase due to additional fasteners and sealing requirements

Engineering Contradiction:
Improvesealing reliabilityVSAvoidsensor structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the sensor function directly into the bluff body by embedding piezoelectric cables within holes in the bluff body structure. This integration eliminates the need for separate external sensors and their associated fasteners and sealing components, thereby reducing device complexity while maintaining detection reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the sensing function from external components and embeds it directly within the bluff body structure. The piezoelectric cables are placed inside holes in the bluff body, removing the need for separate sensor assemblies and their associated sealing requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If sensors are inserted into the flow tube, then vortex detection is enabled, but fluid leakage risk increases due to direct contact with process fluid

Engineering Contradiction:
Improvevortex detection accuracyVSAvoidfluid leakage prevention
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The sensor function is merged with the bluff body structure itself. The piezoelectric cables are embedded within holes in the bluff body, which is a permanent structural component, eliminating the need for separate inserted sensors that would require sealing and create leakage risks.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bluff body structure itself serves as the sensor housing and detection interface. The piezoelectric cables embedded in the bluff body utilize the bluff body's own structural features (holes) to provide both structural integrity and sensing capability, eliminating the need for separate sealed sensor insertions.

Inventive Principle:
Principle #25Self-service

3Productivity

If external sensors are used, then flow measurement is achieved, but maintenance requirements increase due to direct exposure to process fluid

Engineering Contradiction:
Improveflow measurement capabilityVSAvoidsensor maintenance difficulty
Core Design Contradiction:
ProductivityVSEase of repair

Solution Approach 1:

The sensing function is merged into the permanent bluff body structure. The piezoelectric cables embedded in the bluff body are protected from direct exposure to process fluid, reducing maintenance requirements and improving ease of repair compared to external sensors that would require periodic sealing maintenance.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If robust seals are used, then fluid leakage is prevented, but device complexity and cost increase

Engineering Contradiction:
Improvesealing performanceVSAvoidsealing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the sealing function from the sensor assembly by integrating sensors directly into the bluff body structure. The piezoelectric cables are embedded in holes in the bluff body, removing the need for separate sealing components and associated complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

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 configuration allows for accurate flow rate measurement without external sensors, reducing maintenance needs and preventing fluid leakage, while enabling operation in high-pressure and vibrating conditions without separate membranes or gaskets.

Implementation Method 1

The plurality of sensors comprise piezoelectric cables disposed within holes of the bluff body

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The operating principle of a vortex flowmeter is based on a phenomenon of vortex shedding known as the von Karman effect. As fluid passes a shedding bar or 'bluff body', it separates and generates small eddies or vortices that are shed alternately along and behind each side of the bluff body.

Methodology Applied
Scientific EffectVortex shedding: Kármán Vortex Street

Data Source

PatentEP3844461B1Non-invasive sensor for vortex flowmeter
Publication Date: 2023.07.19 MICRO MOTION INC
  • EP3844461B1 patent drawingFigure 1
  • EP3844461B1 patent drawingFigure 2A
  • EP3844461B1 patent drawingFigure 2B

AI summary

A vortex flowmeter includes a flow tube configured to receive a flow of process fluid in a first direction. A bluff body is disposed within the flow tube between a first end and a second end. The bluff body is configured to generate vortices in the flow of process fluid. A plurality of sensors are disposed within the bluff body configured to detect deformations within the bluff body resulting from the vortices acting on the bluff body.