Considerations on the design of flow cells in by-pass systems for process analytical applications and its influence on the flow profile using NMR and CFD
Considerations on the design of flow cells in by-pass systems for process analytical applications and its influence on the flow profile using NMR and CFD
复制标题
使用 NMR 和 CFD 考虑过程分析应用旁路系统中流通池的设计及其对流量剖面的影响
DOI：
10.1016/j.ces.2012.03.042
复制
发表时间：
2012
影响因子：
4.7
通讯作者：
G. Guthausen
中科院分区：
文献类型：
--
作者：
F. Dalitz;M. Maiwald;G. Guthausen
采用1H NMR和数值模拟的方法，对低磁场下中分辨率NMR谱（MR-NMR）在线分析中常用的样品流动池的设计进行了实验和理论研究。流型的特征在于获得有关停留时间分布和混合效果的信息。使用1H NMR成像和光谱来确定流动池的特性及其对在线测量的意义，例如反应监测或联用分离光谱。研究的体积流速在0.1至10 ml/min的范围内，通常应用于上述应用中。通过各种NMR实验揭示了用于MR-NMR的流动池的特殊特性，并与CFD模拟和高场NMR中常用的流动池进行了比较。研究了进口和出口的设计对流型的影响以及单元长度的影响。为便于实际应用，给出了入流长度的数值估算。此外，还展示了极化建立实验如何揭示MR-NMR中的流动特性。
The design of sample flow cells, commonly used in on-line analytics and especially for medium resolution NMR spectroscopy (MR-NMR) in low magnetic fields, was experimentally and theoretically investigated by1H NMR and numerical simulations. The flow pattern was characterised to gain information about the residence time distribution and mixing effects. Both1H NMR imaging and spectroscopy were used to determine the characteristics of flow cells and their significance for on-line measurements such as reaction monitoring or hyphenated separation spectroscopy. The volume flow rates investigated were in the range from 0.1 to 10ml/min, typically applied in the above mentioned applications. The special characteristics of flow cells for MR-NMR were revealed by various NMR experiments and compared with CFD simulations and to flow cells commonly used in high-field NMR. The influence of the design of the inlet and outlet on the flow pattern was investigated as well as the effect of the length of the cell. For practical use, a numerical estimation of the inflow length was given. In addition, it was shown how experiments on the polarisation build-up revealed insight into the flow characteristics in MR-NMR.