Monolithic Mini-Horn Array for Ultrasonic Flow Meter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ultrasonic flow meters face challenges in extreme temperature environments due to thermal expansion mismatches and chemical resistance issues with low-density epoxy matching layers, leading to transducer degradation and performance loss.
Innovation Solution
A monolithic mini-horn array made of chemically resistant materials like titanium provides acoustic impedance matching between the piezoelectric crystal and the fluid, eliminating thermal expansion mismatches and enhancing chemical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low-density epoxy matching layers are used in ultrasonic transducers, then acoustic impedance matching is achieved, but thermal expansion mismatches and chemical resistance issues occur in extreme temperature environments
Solution Approach 1:
The patent changes the material parameter from low-density epoxy to high-density polymeric foam with density between 0.05 and 0.2 times the density of the piezoelectric crystal. This parameter change provides both acoustic impedance matching and thermal expansion compatibility, resolving the contradiction between reliability in extreme temperatures and compositional stability.
Solution Approach 2:
The patent uses composite material structures including polymeric foam matched with piezoelectric crystals, and optionally titanium housing with ceramic coatings. These composite materials provide both acoustic impedance matching and resistance to thermal expansion mismatches and chemical degradation in harsh environments.
2Reliability
If conventional matching layers are used, then acoustic impedance matching is provided, but cracking and delamination occur due to thermal expansion mismatches
Solution Approach 1:
The patent changes the density parameter of the matching layer to be between 0.05 and 0.2 times the density of the piezoelectric crystal, and matches the coefficient of thermal expansion to that of the piezoelectric crystal. This resolves the contradiction by providing both acoustic impedance matching and thermal compatibility, preventing cracking and delamination while maintaining transducer durability.
Solution Approach 2:
The patent introduces a polymeric foam intermediary material between the piezoelectric crystal and the external environment. This intermediary provides acoustic impedance matching while also serving as a buffer against thermal expansion mismatches and chemical degradation, preventing direct damage to the piezoelectric crystal.
3Reliability
If epoxy matching layers are used, then acoustic coupling is achieved, but chemical resistance issues lead to performance loss
Solution Approach 1:
The patent uses chemically resistant composite materials including polymeric foam and titanium with ceramic coatings. These materials provide both acoustic impedance matching and superior chemical resistance compared to epoxy, preventing chemical degradation while maintaining reliable transducer performance in harsh chemical environments.
Solution Approach 2:
The patent changes from organic epoxy materials to inorganic or chemically resistant polymeric materials. This parameter change in material composition provides both acoustic coupling and enhanced chemical resistance, eliminating the chemical degradation issues associated with conventional epoxy matching layers.
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 ensures the ultrasonic transducers remain functional in harsh conditions, preventing cracking and delamination, thus maintaining accurate fluid flow measurements without the need for frequent replacements.
Implementation Method 1
Each of the transducers includes a piezoelectric crystal
Implementation Method 2
The matching structure includes a mini-horn array that is acoustically coupled to the piezoelectric crystal on one side, and is configured to provide acoustic impedance matching between the piezoelectric crystal and the fluid stream
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A monolithic matching structure for use in an ultrasonic transducer. The matching structure includes a mini-horn array. The mini-horn array includes a back plate, a plurality of horns, and a front plate. The plurality of horns extend from the back plate. Each of the horns includes a base and a neck. The base is adjacent the back plate. The neck extends from the base. Transverse area of the base is larger than transverse area of the neck. The front plate is adjacent the neck of each of the horns.