Criterion of homogeneous boiling-up of superheated liquids
G.V. Ermakov1, E.V. Lipnyagov2
1 Institute of Thermal Physics UB RAS, Ekaterinburg, Russia, ermakov-german@mail.ru 2 Institute of Thermal Physics UB RAS, Ekaterinburg, Russia
Keywords: waiting time for boiling-up of superheated liquid, theory of homogeneous stationary nucleation, theoretical and empirical work of critical nucleus formation
Pages: 667-675
Abstract
It is difficult to eliminate the effect of vessel walls and impurities in practical studies of boiling-up of strongly superheated liquids. Therefore, some doubts are always cast upon validity of experiments and their agreement with the classical theory of homogeneous stationary nucleation, impairing the verification of theoretical considerations. This paper reports main results of the theory of homogeneous nucleation and presents formulas for calculating the work of formation of a critical nucleus by an incline of the accessible superheating boundary on isobars and isotherms. Matching of experimental and theoretical values of the work of formation was considered as the homogeneous boiling-up criterion. Calculations by isobars and isotherms were made for some liquids. The theoretical values of the work of formation of a critical nucleus were 1.23-4.5 times higher than the corresponding empirical values for all the liquids, i.e., they were much higher than the calculation error. Thus, boiling-up of the studied liquids was not homogeneous and, hence, it did not correspond to the classical theory of nucleation.
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