A Basic Study on Freezing of Food (Freezing Behavior of a Saline Solution Through a Semipermeable Membrane)

众所周知，食品的新鲜度取决于冷冻食品的冷却速度。因此，为了控制食品的新鲜度，获得冷却速度对细胞内冷却和冻结行为的影响是很重要的。要做到这一点，不仅需要评估单个细胞内的流动、温度和浓度分布过程，还需要考虑细胞内外通过细胞膜的热量和质量交换。作为电池组件，为了注意具有电池组件中凝固点最高特性的游离水，使用质量浓度为5%的氯化钠水溶液(氯化钠水溶液)。此外，考虑到功能和强度，本文采用微孔膜作为细胞膜，从热…的角度研究了氯化钠水溶液通过微孔膜的冷却和冻结行为更多的是工程学。这些行为被可视化，并使用实时激光全息干涉计量术进行测量。作为对比，使用铜板和除微孔薄膜以外的其他隔板作为隔板。结果表明：在使用氯化钠水溶液的实验中，由于隔板的存在，冷却过程没有明显的差别。然而，在冻结过程中，随着凝固的进行，第一室中被固化的氯化钠通过微孔薄膜进入第二室。因此，在分析食品冷冻过程时，有必要考虑固化后膜的传质过程。在用水进行的实验中，阐明了水本身通过微孔膜。然而，在水不能完全通过的情况下，使用薄膜时的换热特性与使用铜板时的结果相差不大。较少

It is well known that the freshness of food depends on the cooling rate in freezing food. Therefore, in order to control the freshness of food, it is important to obtain the effect of cooling rate on the cooling and freezing behaviors in cells. To do it, it is necessary not only to evaluate the processcs of flow, temperature and concentration distributions in a single cell, but also to consider the exchange of heat and mass inside and outside of cells through cell membrance.This study regards food as the cell aggregation. As a cell component, paying attention on free water having the characteristics of the highest freezing point in cell components, an aqueous sodium chloride solution (NaCl aqueous solution) with a concentration of 5% by mass was used. Furthemor, a micro porous film was used as a cell membrane taking account of function and strength.This study deals with the cooling and freezing behaviors of NaCl aqueous solution through a micro porous film from the viewpoint of thermal … More engineering. These behaviors were visualized and measured using a real-time laser holographic interferometry. For comparison, a copper plate and no partitions other than a micro porous film were used as partitions. Water other than NaCl aqueous solution was also used as liquid to be cooled.As a result, following conclusions were obtained.In the experiments using NaCl aqueous solution, there is no significant difference in the cooling process due to partitions. However, in the freezing process, NaCl rejected by solidification in the first cell goes into the second cell passing through a micro porous film with the progress of solidification. Therefore, it is necessary to consider mass transfer through films after solidification in analyzing food freezing.In the experiments using water, it is clarified that water itself passes through the micro porous film. However, there is little difference in heat transfer characteristics between the results using film and those using copper plate where water cannot pass completely. Less