Multi-layer Diaphragm Assembly for High Temperature Pressure Sensors
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Solution Overview
Problem
Existing pressure sensors are limited to measuring external processes with temperatures below 400°C due to the decomposition of commonly used measuring fluids under higher temperatures, which compromises accurate pressure measurements, and they lack durability and ease of maintenance.
Innovation Solution
A diaphragm assembly with an intermediate layer that reduces heat exchange between the outer and inner diaphragms, allowing the pressure sensor to operate up to 600-700°C while keeping the measuring fluid temperature below 400°C, featuring a multi-layer design with a permeable intermediate layer for air heat exchange and easy replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed diaphragm is used to separate the external process from the measuring fluid, then accurate pressure measurement is achieved, but the measuring fluid decomposes at temperatures above 400°C
Solution Approach 1:
A removable intermediate diaphragm is introduced between the outer diaphragm (exposed to external process) and the inner diaphragm (exposed to measuring fluid). This intermediate layer acts as a thermal barrier that blocks heat transmission from the external high-temperature process to the measuring fluid, preventing fluid decomposition while maintaining pressure measurement accuracy through mechanical coupling of all three diaphragms.
2Reliability
If the diaphragm is made impermeable to ensure sealing, then accurate pressure transmission is achieved, but heat exchange between outer and inner diaphragms occurs
Solution Approach 1:
The removable intermediate diaphragm serves as a thermal barrier layer that is impermeable to the measuring fluid but permeable to heat blockage. It maintains the sealing integrity of the pressure sensor while simultaneously preventing heat transmission from the outer diaphragm to the inner diaphragm and measuring fluid.
3Temperature
If a multi-layer diaphragm assembly is used to block heat, then temperature protection is achieved, but device complexity increases
Solution Approach 1:
The diaphragm assembly is segmented into three separate layers: an outer diaphragm exposed to the external process, a removable intermediate diaphragm for thermal protection, and an inner diaphragm in contact with the measuring fluid. This segmentation allows independent optimization of each layer's function and enables easy replacement of the intermediate layer without affecting the other components.
Solution Approach 2:
The intermediate diaphragm is designed to be removable and replaceable, transforming a previously static single-diaphragm structure into a dynamic multi-layer assembly. This allows the intermediate layer to be adjusted or replaced based on temperature conditions while maintaining the overall structural integrity of the pressure sensor.
4Ease of repair
If the intermediate layer is made removable for easy maintenance, then ease of repair is improved, but sealing reliability may be compromised
Solution Approach 1:
The intermediate diaphragm is designed as a separate, removable component that can be independently replaced without disassembling the entire pressure sensor. This segmentation enables easy maintenance while the standardized coupling interfaces ensure consistent sealing reliability when properly reassembled.
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
Enables accurate and durable pressure measurements at high temperatures, maintaining the fluid below decomposition temperature and allowing for easy maintenance, with a simple design that facilitates heat exchange through ambient air, broadening the sensor's applicability in industries like petro-chemical processing and solar energy.
Implementation Method 1
the intermediate layer has a capacity to achieve such an insulating effect by its provision between the two diaphragms
Implementation Method 2
the intermediate layer at the same time is capable of heat exchange with surrounding air
Data Source
Figure 1~2
AI summary
Diaphragm assembly for a pressure sensor, comprising a multi-layered assembly of an outer diaphragm and an inner diaphragm, and an intermediate layer between both diaphragms, the intermediate layer being made of a solid material which is permeable to air. Pressure sensor comprised of an assembly of: a diaphragm seal body, having a diaphragm side which comprises a chamber for containing a pressure measuring fluid, and a channel designed for connecting the chamber to a measuring device; a mounting body which is at an inner side designed for assembling to the diaphragm side of the diaphragm seal body, and at an outer side is designed for mounting the sensor to external equipment of which an external pressure is to be measured; a diaphragm assembly, fixed between the diaphragm side of the diaphragm seal body, and the inner side of the mounting body, and wherein the diaphragm seal body and the mounting body are assembled to each other by coupling means.