Guo Junhui, Zhu Huacheng, Yang Yang, Guo Qinggong
College of Electronic and Information Engineering, Sichuan University, Chengdu 610065, China.
Foods. 2023 Jan 18;12(3):459. doi: 10.3390/foods12030459.
Microwave continuous-flow liquid food sterilisation, in which the liquid is mainly heated by microwaves, has the advantages of fast sterilisation speed, energy saving, comprehensive elimination, and less nutrient loss. Circular pipes are commonly used in microwave continuous-flow liquid heating processing. However, with circular pipes, which are widely used in the industry, the heating is uneven owing to the phenomenon of tube focusing when adopting external radiation. In this study, a novel microwave continuous-flow milk sterilisation system based on a coaxial slot radiator is proposed. First, the coaxial slot radiator was designed to realise efficient radiation through the establishment of multi-physics model. The structure of the system was then optimised by comparing the heating efficiency and uniformity of simulation results. The effect of microwave coaxial slot radiator rotation on heating uniformity was simulated and the results show that the heating uniformity is improved obviously. Experimental equipment was set up to verify the results of the simulation. The experimental results are consistent with the simulation results. Finally, the sensitivity analysis of the system is performed to confirm that, when the dielectric properties and types of liquid food change, the heating of the proposed microwave continuous-flow system remains efficient and uniform.
微波连续流液态食品杀菌技术主要通过微波对液体进行加热，具有杀菌速度快、节能、杀菌全面、营养成分损失少等优点。在微波连续流液体加热处理中通常使用圆形管道。然而，在工业中广泛使用的圆形管道，采用外部辐射时会因管聚焦现象导致加热不均匀。本研究提出了一种基于同轴缝隙散热器的新型微波连续流牛奶杀菌系统。首先，通过建立多物理场模型设计同轴缝隙散热器以实现高效辐射。然后通过比较模拟结果的加热效率和均匀性对系统结构进行优化。模拟了微波同轴缝隙散热器旋转对加热均匀性的影响，结果表明加热均匀性得到明显改善。搭建了实验装置来验证模拟结果。实验结果与模拟结果一致。最后，对系统进行敏感性分析以确认，当液态食品的介电特性和类型发生变化时，所提出的微波连续流系统的加热仍然高效且均匀。
