Measurements of bubbles formed in boiling Methanol

摘要: The photographic method was used to measure bubble sizes and frequencies for methanol boiling at atmospheric pressure outside a 3/8-in. O.D., steam-heated, horizontal copper tube. average temperature of the tube measured by use as resistance thermometer. For nucleate heat fluxes up 80% maximum, product diameter frequency constant 4 in./sec. In this region both Rohsenow equation Forster-Zuber gave good predictions transfer. At higher f × D increased equations were much less suitable. critical difference not single value but extending from 52° 62°F. flux nearly throughout range maximum 115,000 B.t.u./(hr.)(sq. ft.). film boiling, 11 sec.−1 Bromley's unsuitable ΔT values than 180°F., it became applicable ΔT. Nusselt's steam condensing inside found be satisfactory, proof that slight slope sufficient permit adequate condensate drainage.