Actively Controlled Heat Exchanger for NMR Sample Temperature Stability
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Solution Overview
Problem
NMR analyzers face challenges in maintaining uniform sample temperature, which affects measurement accuracy, especially in process environments with varying temperatures and compositions, such as petrochemical streams.
Innovation Solution
An actively controlled heat exchanger system, integrated with fluid handlers like stream selection, solvent recirculation, and auto-sampling units, ensures precise temperature control of samples before analysis, maintaining them within a predetermined tolerance for NMR analyzers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If NMR analyzers operate in process environments with varying temperatures, then productivity is improved, but measurement precision deteriorates due to temperature variations affecting magnetic field uniformity and spectral behavior
Solution Approach 1:
The system performs preliminary temperature control by pre-heating or pre-cooling samples in a temperature-controlled chamber before they enter the NMR analyzer. This preliminary thermal conditioning ensures that samples reach the required temperature range and stability criteria prior to analysis, allowing the analyzer to maintain precise measurements while processing continuous streams from variable-temperature process environments
Solution Approach 2:
A temperature-controlled sample handling system acts as an intermediary between the variable-temperature process stream and the temperature-sensitive NMR analyzer. This intermediary system includes thermal control chambers, heat exchangers, and flow control mechanisms that buffer and regulate temperature fluctuations, enabling continuous high-productivity operation without compromising measurement precision
2Measurement precision
If temperature control is implemented to maintain measurement precision, then measurement precision is improved, but device complexity increases due to additional temperature control systems
Solution Approach 1:
The temperature control functions are merged with the sample handling and injection systems rather than being separate independent subsystems. The same pump, valve, and flow control mechanisms that manage sample delivery also serve as part of the temperature control system, reducing overall device complexity while maintaining precise temperature regulation through integrated thermal management
3Measurement precision
If samples are held at constant temperature for analysis, then measurement precision is improved, but loss of time increases due to temperature equilibration requirements
Solution Approach 1:
The system maintains continuous temperature control during the entire sample handling process, from storage through injection into the analyzer. Rather than allowing temperature equilibration to occur only before analysis, the temperature control acts continuously throughout the sample journey, eliminating idle equilibration time and ensuring that temperature stability is maintained without delaying productive operations
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 consistently homogeneous samples, enhancing measurement accuracy and precision by maintaining samples at precise temperatures, even in complex and variable process environments, thereby improving the reliability of property models and spectral measurements.
Implementation Method 1
an actively controlled heat exchanger configured for upstream serial fluid communication with a magnetic resonance analyzer
Implementation Method 2
a sample to be analyzed is subjected to a short pulse of electromagnetic energy at a predetermined frequency that is a function of the atomic nuclei to be analyzed
Data Source
AI summary
A spectroscopic sample analysis apparatus includes an actively controlled heat exchanger in serial fluid communication with a spectroscopic analyzer, and a controller communicably coupled to the heat exchanger. The heat exchanger is disposed downstream of a fluid handler in the form of a stream selection unit (SSU), a solvent/standard recirculation unit (SRU), and/or an auto-sampling unit (ASU). The SSU selectively couples individual stream inputs to an output port. The SRU includes a solvent/standard reservoir, and selectively couples output ports to the heat exchanger, and returns the solvent/standard sample to the reservoirs. The ASU includes a sample reservoir having a sample transfer pathway with a plurality of orifices disposed at spaced locations along a length thereof. The controller selectively actuates the fluid handler, enabling sample to flow therethrough to the heat exchanger, and actuates the heat exchanger to maintain the sample at a predetermined temperature.