Heat transfer coefficients for condensing vapors on a horizontal tube

Author

Maurice Edward Brown, New Jersey Institute of Technology

Document Type

Thesis

Date of Award

6-30-1955

Degree Name

Master of Science in Chemical Engineering - (M.S.)

Department

Chemical Engineering

First Advisor

George C. Keeffe

Second Advisor

Jerome J. Salamone

Third Advisor

C. L. Mantell

Abstract

Film coefficients of heat transfer for vapors condensing on a smooth horizontal tube have been experimentally determined by many investigators. The so-called Thermocouple Method and the Wilson Method, have been used and generally accepted as the two methods for determining these film coefficients. A number of different organic vapors have been studied on various condensing surfaces. Nusselt has also developed a theoretical equation,

hN = 0.725 4√k_f³ρf²λg/D_oμfΔtcf

for evaluating the film coefficients of vapors condensing on hori?zontal tubes.

The earlier investigators have shown that theoretical values, hN do not check with experimentally determined values, he, and that many discrepancies exist among different experimentally determined values. Advocates of the Wilson Method have discredited the accuracy of the Thermocouple Method and vice versa.

With these points in mind, the experimental work in this thesis was undertaken. Film coefficients of heat transfer were experimentally determined for single vapor systems of each of four alcohols condensing on a smooth horizontal tube. Both methods of evaluating the heat transfer coefficients were used. Methyl Alcohol, Isopropyl Alcohol, n-Propyl Alcohol, and n-Butyl Alcohol were studied. A single piece of equipment designed to eliminate problems noted by earlier authors of similar work was used for the entire investigation. Data was taken for both of the methods simultaneously and under identical operational conditions.

The experimental results of this investigation showed film coefficients of heat transfer by both accepted methods to be of the same order of magnitude for each particular compound. It can be concluded, therefore, that the discrepancies in earlier data are probably due to other factors and not the use of either the 'Wilson Method or the Thermocouple Method. The results also showed definite evidence that he for vapors condensing on a horizontal tube decreases for increasing molecular weight within the homologous alcohol series.

Recommended Citation

Brown, Maurice Edward, "Heat transfer coefficients for condensing vapors on a horizontal tube" (1955). Theses. 2279.
https://digitalcommons.njit.edu/theses/2279