Ultrasonic Flowmeter Coupling Element Rods
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Solution Overview
Problem
Ultrasonic flowmeters face challenges in high-temperature applications due to material mismatches between transducers and measurement media, leading to signal loss and limited bandwidth, requiring additional matching layers which can further reduce signal strength.
Innovation Solution
A coupling element comprising at least three rods with varying cross-sectional areas and lengths, made of materials like steel, stainless steel, or ceramic, designed to minimize impedance mismatch and maintain acoustic signal integrity by direct or indirect contact with the transducer, allowing for efficient transmission without material transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If metallic coupling elements are used for good thermal insulation, then thermal performance is improved, but additional matching layers are required which reduce signal strength
Solution Approach 1:
The patent changes the material parameter from traditional metallic coupling elements to a composite structure with a polymer outer layer and metallic inner rods. This parameter change allows the coupling element to maintain thermal insulation properties while eliminating the need for additional matching layers, thereby preserving signal strength.
Solution Approach 2:
The patent employs a composite material structure consisting of a polymer outer layer surrounding metallic inner rods. This composite design combines the thermal insulation advantages of polymers with the acoustic properties of metals, achieving both thermal performance and signal integrity without requiring additional matching layers.
2Reliability
If additional matching layers are added to reduce impedance mismatch, then impedance matching is improved, but signal strength is reduced
Solution Approach 1:
The patent changes the structural parameter by using a multi-material composite design where the polymer outer layer and metallic inner rods are specifically dimensioned and positioned to achieve impedance matching. This eliminates the need for separate matching layers while maintaining signal strength.
Solution Approach 2:
The composite coupling element structure serves multiple functions simultaneously: thermal insulation from the polymer outer layer, acoustic signal transmission through the metallic rods, and impedance matching through the specific configuration of materials and dimensions. This multi-functionality eliminates the need for separate matching layers.
3Ease of operation
If ultrasonic transducers are attached to pipe wall with toggle fastener, then ease of installation is improved, but signal transmission is reduced compared to firm attachment
Solution Approach 1:
The patent introduces a coupling element as an intermediary between the ultrasonic transducer and the pipe wall. This coupling element with its specific composite structure and acoustic properties enables effective signal transmission while allowing for easy installation, bridging the gap between installation convenience and signal integrity.
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 solution provides a robust, high-temperature capable ultrasonic flowmeter with improved signal strength, reduced signal decay, and adapted impedance matching, enabling effective flow measurement across a wide temperature range.
Implementation Method 1
The ultrasonic transducers normally consist of an electromechanical transducer element, e.g. a piezoelectric element, also known as a piezo for short
Implementation Method 2
The ultrasonic waves are generated in the piezoelectric element and guided via the coupling layer to the pipe wall and from there into the liquid
Implementation Method 3
Since the speeds of sound in liquids and plastics are different, the ultrasonic waves are refracted when passing from one medium to the other. The angle of refraction is determined in a first approximation according to Snell's law.
Implementation Method 4
The adaptation layer assumes the function of transmitting the ultrasonic signal and at the same time reducing a reflection at boundary layers between two materials caused by different acoustic impedances.
Implementation Method 5
With the Doppler principle, ultrasonic waves with a specific frequency are coupled into the liquid and the ultrasonic waves reflected by the liquid are evaluated. The flow velocity of the liquid can also be determined from the frequency shift between the coupled and reflected waves.
Implementation Method 6
With the transit time difference principle, the different transit times of ultrasonic pulses are evaluated relative to the flow direction of the liquid.
Data Source
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AI summary
Coupling element of a sensor of an ultrasonic flow meter, comprising at least three rods, each with a first rod end and a second rod end, wherein the rods each have first end faces at their first ends, which are each acoustically coupleable with the sound-emitting and/or sound-receiving surface of an ultrasonic transducer element, wherein the first end faces of the rods together form a first coupling surface of the coupling element, and wherein the rods each have second end faces at their second ends, which form a second coupling surface of the coupling element, wherein the rods each have a first rod cross-section which differs in shape and/or size from a second rod cross-section.