Solidification in heat packs: I. Nucleation rate

• Published in: AIChE journal Vol. 49; no. 2; pp. 505 - 515
• Main Authors: Rogerson, Mansel A., Cardoso, Silvana S. S.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.02.2003; Wiley Subscription Services; American Institute of Chemical Engineers
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Growth from solutions; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Solid-liquid transitions; Specific phase transitions; Subcooling; Phase transformations; Solid-liquid transformations; Heat storage; Theoretical study; Crystal nucleation; Thermodynamic analysis; Kinetics; Experimental study; Hydrates; Solidification
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.690490220

The solidification of sodium acetate trihydrate in a commercial heat pack is investigated in a series of three articles. In the first work, the classic nucleation theory is used to predict the range of temperatures and pressures for which a subcooled solution of sodium acetate solidifies spontaneously. The nucleation temperature was determined experimentally and it was shown that it is insensitive to concentration, at atmospheric pressure. Using the theoretical results for high pressure and the experimental measurements at atmospheric pressure, an equation for the nucleation temperature was derived as a function of pressure. This relation takes into account heterogeneous nucleation on ever‐present impurities suspended in the solution.