An Empirical Modification of Nucleation Theory and Its Application to Boiling Heat Transfer Page: 20 of 38
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According to the conclusions reached in Section 7, Eq. (21) applies
to the following cases:
(a) the entire range of vigorous boiling of saturated liquid in a pool;
(b) the entire range of vigorous boiling from rough surfaces for
saturated and subcooled liquids with and without forced
(c) the earlier part of vigorous boiling from smooth surfaces for
saturated and subcooled liquids with forced convection.
Since Avogadro's number, Planck's number and Boltzmann's constant
for a given system of units are constant numbers, they can be absorbed into
the constant in Eqs. (21). When the British units are used, as given in the
Nomenclature in this paper, Eq. (21) becomes
T. 3/ -X-m
q = Cpc 8 e-nXY (22)
8. VIGOROUS BOILING OF ORGANIC LIQUIDS
In recent years a great number of experimental investigations of the
boiling of organic liquids from various heating elements have been made.
It would be impossible to cite all of them in this paper. Therefore only
those immediately available to the author were used for comparison with
the predicted results.
To illustrate how the constant m in Eq. (21) can be determined, con-
sider the vigorous boiling of benzene. Calculated values of X and Y for
various superheats at pressures from one atmosphere to about eighty per
cent of critical point are shown in Table I in the Appendix. It is seen that
the exponential function in Eq. (15) becomes vanishingly small for all
pressures except those near the critical. This difficulty can be removed
by the use of a factor 5 x 10-6 Y-1 multiplying the activation energy. The
validity of this multiplication factor has been tested for fifteen different
organic liquids under various pressures and within the range of superheats
in nucleate boiling. Thus the general equation of heat transfer in vigorous
boiling of organic liquid is obtained from Eq. (22) by taking m = 1:
q =Cpc T3/ e .nY (23)
Test results of Cichelli and Bonilla(24) for boiling of benzene and
ethanol from a chromium plated surface are reproduced in Figs. 3 and 4.
Mesler and Banchero(25) tested the boiling of benzene, ethanol, acetone,
etc., from a well-polished stainless steel tube, and their results are
reproduced in Figs. 5, 6, and 7.
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Chang, Y. P. An Empirical Modification of Nucleation Theory and Its Application to Boiling Heat Transfer, report, February 1, 1961; United States. (https://digital.library.unt.edu/ark:/67531/metadc863296/m1/20/: accessed May 26, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.