Correlation of heat transfer and gas holdup data from slurry bubble columns

✍ Scribed by S.C. Saxena; N.S. Rao; A.C. Saxena

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 357 KB
• Volume: 18
• Category: Article
• ISSN: 0735-1933
• DOI: 10.1016/0735-1933(91)90046-7

✦ Synopsis

Our recently reported gas holdup and heat transfer data for the airwater-magnetite system extending over a range of air velocities, particle diameters, and slurry concentrations have been correlated. The gas holdup correlation is based on the drift-flux theory, while the heat transfer correlation is based on an empirical modification of the Higbie's theory of unsteady-state mass transfer as applied to heat transfer and Kolmogoroff's theory of isotropic turbulence as developed by Deckwer and Deckwer et al.

Introd .uction

Recently Saxena et al. [1] reported gas holdup and heat transfer data for a 19mm diameter cylindrical surface immersed in a 0.108m internal diameter slurry bubble column at temperature 308K. The data were taken for the air-watermagnetite system as a function of air velocity for powders of different mean diameters (dp) in the range 35.7 to 137.5 ~tm and for powder concentrations (w s) up to 30 weight percent in the slurry. The gas holdup data were analyzed on the basis of correlations due to Roy et al. [2], Smith et al. [3], and Reilly et al. [4], and it was concluded that none of these correlations are adequate to represent the data. Similarly the heat transfer data could not be reproduced by the correlations due to