Nucleate boiling coefficient

A well-recognized and often-used equation for determining a reasonable, even if preliminary, nucleate boiling coefficient is represented by the McNelly equation for boiling outside of tubes ... 

U(j) = single tube overall heat transfer coefficient hj = nucleate boiling coefficient for single tube, outside Btu/hr (ft) (°F)... 

Figure 10-108. Uncorrected nucleate boiling coefficient. (Used by permission Chen, Ning Hsing. Chemical Engineering, V. 66, No. 5, 1959. McGraw-Hill, Inc. All rights reserved.)...

Figure 10-115—1/Xjj values for use in Figure 10-118. Figure 10-118—a for correcting the nucleate boiling coefficient.

Figure 10-118 a from Equation 10-184. d. Nucleate boiling coefficient, h, from Table 10-30 or other source. (An estimate of the film temperature drop is required.)... 

The nucleate boiling coefficient can be calculated using correlations for nucleate pool boiling modified by a factor fs to account for the fact that nucleate boiling is more difficult in a flowing liquid. 

As the heat flux is known and only a rough estimate of the coefficient is required, use Mostinski s equation to estimate the nucleate boiling coefficient Section 12.11.2. 

The equations for estimating nucleate boiling coefficients given in Section 12.11.1 can be used for close boiling mixtures, say less than 5°C, but will overestimate the coefficient if used for mixtures with a wide boiling range. Palen and Small (1964) give an empirical correction factor for mixtures which can be used to estimate the heat-transfer coefficient in the absence of experimental data ... 

Boiling Coefficients For the nucleate-boiling coefficient the Mostinski equation [Teplenergetika, 4, 66 (1963)] may be used ... 

Fouling coefficient on inside of tube Nucleate boiling-heat transfer coefficient Nucleate boiling coefficient in equation 12.67 Heat transfer coefficient outside a tube Heat transfer coefficient for cross-flow over an ideal tube bank... 

The heat-transfer coefficient for the combined nucleate-boiling and convective vaporization processes, is related to the nucleate-boiling coefficient / nb, and the convective coefficient, by... 

Of related interest are the results of Gannett and Williams [239], who found that small quantities of certain polymers dissolved in water increase nucleate boiling coefficients. As reported by Jensen et al. [240], oily contaminants generally decrease boiling coefficients however, increases are observed under certain conditions. 

Here hNB is the nucleate boiling coefficient (calculated from equations analogous to those given previously) and hFC is the forced convective component, which is related to the heat transfer coefficient h, for the liquid phase flowing alone across the tube bundle by the expression... 

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