Superconducting Magnet Baffle for Quench Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Superconducting magnet devices in MRI systems face high quench pressure risks due to rapid refrigerant vaporization during coil quench events, leading to safety and reliability concerns, with existing solutions either increasing costs or being impractical.
Innovation Solution
Incorporating a baffle with a gap between the coil and the former, made from low-thermal-conductivity materials like glass fibre reinforced plastics, and using aluminium 5083 or AC4A formers, which helps to slow down heat diffusion and reduce quench pressure without the need for costly reinforcement or high-cost alloys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the low-temperature vessel is reinforced to withstand higher quench pressure, then the safety and reliability improve, but the manufacturing cost increases due to more stainless steel or aluminium alloy material needed
Solution Approach 1:
A baffle is introduced as an intermediary component between the coil assembly and the refrigerant in the low-temperature vessel. This baffle acts as a mediator that controls the interaction during quench events, allowing the vessel to operate with standard wall thickness while still managing quench pressure effectively.
Solution Approach 2:
The internal space of the low-temperature vessel is segmented by the baffle into different zones. This segmentation allows the refrigerant to be divided into regions with different thermal and pressure characteristics during quench, enabling pressure management without reinforcing the entire vessel structure.
2Reliability
If the exhaust channel and exhaust port size are increased to discharge gas faster, then the quench pressure decreases, but the additional heat load on the low-temperature vessel increases and installation space requirements are exceeded
Solution Approach 1:
The baffle serves as an intermediary that actively manages heat and gas flow during quench events. By controlling the refrigerant's thermal response, it reduces the need for large exhaust channels while maintaining effective quench pressure control and minimizing additional heat load on the vessel.
3Reliability
If aluminium alloy with lower resistivity and thermal conductivity is used for formers to lower quench pressure, then the quench pressure decreases effectively, but the manufacturing cost increases
Solution Approach 1:
The baffle is introduced as an intermediary component that takes over the quench pressure management function, allowing the use of standard, cost-effective aluminium alloy formers without compromising quench pressure control.
Solution Approach 2:
The baffle acts as a sacrificial or replaceable component that protects the more expensive coil assembly and former structure. By absorbing or managing the quench energy, it allows the use of standard materials for permanent components while maintaining system reliability.
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
Effectively lowers quench pressure and improves the reliability of superconducting magnet devices while reducing material costs, as demonstrated by quench testing showing reduced peak pressure and slower magnetic field attenuation.
Implementation Method 1
the baffle helps to slow down the diffusion of heat from the first coil into the refrigerant
Implementation Method 2
Joule heating arising from the current in the superconducting wire
Implementation Method 3
eddy currents induced in the former and/or low-temperature vessel
Implementation Method 4
the refrigerant surrounding the superconducting coil to rapidly boil and vaporize, in which case the volume of the refrigerant expands sharply
Data Source
AI summary
A superconducting magnet device and a magnetic resonance imaging system not only avoid the need for costly aluminum alloy formers but also lower quench pressure effectively, have a baffle covering the former and the coil, with a gap between the baffle and the coil.