NMR Probe Turbine Cooling for Low-Temperature Analysis
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Solution Overview
Problem
Current NMR devices face challenges in maintaining very low temperatures while minimizing energy consumption and reducing the size of the heat exchanger, as well as simplifying the configuration with hot compressors.
Innovation Solution
The NMR analysis device employs a closed and pressurized cold loop with a compression module that circulates motor and coolant fluids, utilizing a Brayton thermodynamic cycle to rotate the sample holder and achieve low temperatures, with a cryostat design that includes multiple heat exchangers and a cryorefrigerator to optimize temperature control and reduce heat exchanger size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thermal insulation techniques are used to maintain very low temperatures, then temperature control is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple functions into the probe structure itself: the probe housing serves as both the NMR detection chamber and the thermal insulation enclosure, while the cold finger integrates both cooling and sample holder functions. This merging reduces the number of separate insulation components needed while maintaining very low temperature control.
Solution Approach 2:
The probe design implements multi-functionality where the same structural elements perform multiple roles: the probe housing provides both NMR signal detection and thermal insulation, the cold finger serves as both the cooling element and sample holder, and the turbine assembly provides both sample rotation and additional cooling through gas expansion. This reduces overall device complexity while maintaining temperature control.
2Use of energy by moving object
If a closed pressurized cold loop with compression module is used, then energy consumption is reduced, but device complexity increases
Solution Approach 1:
The system uses the cold loop fluid to perform multiple functions simultaneously: it cools the sample holder through the cold finger, drives the turbine to rotate the sample, and absorbs excess heat from the NMR coil and electronics. This self-service approach reduces overall energy consumption while the integrated design keeps the compression module compact.
Solution Approach 2:
The patent utilizes phase transitions of the cold loop fluid (helium or nitrogen) to achieve cooling: the fluid evaporates at low temperature to absorb heat, then is compressed and condensed back to liquid form. This phase change mechanism provides efficient cooling with minimal energy input compared to continuous mechanical cooling, while the system remains relatively compact.
3Temperature
If multiple heat exchangers and cryorefrigerator are added to optimize temperature control, then temperature control is improved, but device complexity increases
Solution Approach 1:
The patent merges the heat exchanger and cryorefrigerator functions into the existing cold loop system. The cold finger acts as both the primary heat exchanger and the cryogenic cooling element, while the probe housing walls serve as additional heat exchanger surfaces. This integration achieves optimized temperature control without adding separate, complex heat exchanger assemblies.
4Use of energy by moving object
If turbine-driven sample holder rotation is used, then cooling efficiency is improved, but device complexity increases
Solution Approach 1:
The turbine assembly is designed with multi-functionality: it drives the sample holder rotation for magic-angle spinning, provides additional cooling through gas expansion and turbulence, and serves as a heat exchanger surface. This integration achieves improved cooling efficiency while avoiding the need for separate cooling mechanisms, thereby limiting the increase in device complexity.
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 efficient operation at very low temperatures with reduced energy consumption and a minimized heat exchanger size, simplifying the device configuration and enhancing temperature control within the NMR analysis device.
Implementation Method 1
utilizing a Brayton thermodynamic cycle to rotate the sample holder and achieve low temperatures
Implementation Method 2
The function of the first flow is to bring the sample to a certain temperature
Implementation Method 3
The function of the second flow is to create an aerostatic bearing making it possible to support or guide the rotor in the stator
Implementation Method 4
The function of the third flow is to rotate this sample holder, by acting on the blades or fins of a turbine
Implementation Method 5
it is known to have recourse to techniques of thermal insulation of the elements constituting such NMR devices so as to protect them from the surrounding thermal radiation and to avoid losses by convection or by radiation, or even by conduction
Data Source
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AI summary
The invention relates to an NMR analysis device, method and probe, said probe comprising: a frame; a sample holder (12) which includes a rotor (31) and can receive a sample of material (15) to be analysed; a bearing (13) for guiding the rotation of the sample holder (12) in relation to the frame. The invention is characterised in that the probe also comprises a turbine (14) kinematically linked to the rotor, said turbine having a shape that allows the isentropic expansion of a third fluid (M3) passing therethrough, and in that the probe comprises a fourth element (24, 23) for channeling a fourth gas flow (M4) of fluid downstream of the expansion turbine (14) or for channeling a sixth gas flow (M6) of fluid downstream of the rotor (31) and stator (30) of the sample holder (12).