食品软包装机无菌气室三维流场的有限元分析

Analysis of Three-Dimensional Fluid Field in Aseptic Isolator Using Finite Element Method

分析了无菌包装气室的结构，研究了确保气室无菌的条件，并采用了有限单元法对气室中的三维流场进行了分析。建立了保证气室无菌的流场分布评价指标，分析了影响流场分布的因素，考虑到无菌气室的隔菌性与经济性，得出了进气方式１ 和方式２ 均能满足隔菌性的要求，但方式２又优于方式１。得出了无菌气室的合理结构参数。并通过实验验证了理论分析。

Sanitation is the key to preserving food and keeping food fresh. Aseptic packaging is paid more and more attention. In this paper, the structure of an aseptic packaging isolator was analyzed, and the conditions to ensure that there are no microbes in the aseptic isolator were studied. To ensure microbe obstructability of the three dimension turbulent flow field in the aseptic isolator, a new analysis method was used. Computational theory of three dimension turbulent flow field was analyzed, and then, the flow equations of the flow field were solved with Ansys Flotran Module. Through the appropriate theoretical calculation, the distribution of the flow field in the aseptic isolator was known entirely. The evaluation indexes of the microbe obstructability of the germ free isolator were established. The factors affecting these indexes were analyzed in detail. Considering microbe obstructability and economy, the reasonable structure and parameters of the germ free isolator were obtained. Mode one and mode two can meet the demand of microbe obstructability, we find that mode two is more reasonable. At the same time a vast amount of experimental data was obtained from corresponding model tests for verifying the computation, and a satisfying comparison was obtained.