Study of the Influence of Inducing Nucleation on the Performance of the Freezing Temperature Plateau of Metal Fixed-Point Cells

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Study of the Influence of Inducing Nucleation on the Performance of the Freezing Temperature Plateau of Metal Fixed-Point Cells (171.94 KB)

Experimental research was carried out to investigate the influence of the technique of inducing nucleation on the performance of the temperature plateau during the realization of freezing points of metal fixed-point cells. Different induction techniques were studied in the experiments. The experimental results show that the induction methods and the induction time significantly affect the performance of the freezing temperature plateau, especially at the beginning of freez-ing. Insufficient induction removes too little of the latent heat released by the start of the freeze and causes delayed settling at the beginning of the plateau. The induction method, induction du-ration, and the furnace maintenance temperature should be carefully chosen based on the charac-teristics of the particular fixed-point cell in order to provide sufficient cooling for nucleation and obtain the ideal freezing temperature plateau. A simple theoretical analysis shows that the freez-ing plateau duration is inversely proportional to the temperature difference between the furnace maintenance temperature and the freezing-point temperature. The freezing rate along the radius direction increases linearly with the temperature, and varies during the freezing process. The analytical results agree well with the experimental results.