Ind. Eng. Chem. Res. 1990,29,928
928
liquid viscosity, Paas density of liquid, kg/m3 = surface tension, N/m
pL = pL = u
Literature Cited Zou, R.; Jiang, X.; Li, B.; Zu, Y.; Zhang, L. Studies on Gas Holdup in a Bubble Column Operated a t Elevated Temperatures. Ind.
Eng. Chem. Res. 1988,27, 1910-1916. Peter M. Wilkinson, Laurent L. van Dierendonck* Department of Chemical Engineering Rijksuniversiteit Croningen Nijenborgh 16, 9747 AG Groningen, The Netherlands and DSM Research, P.O. Box 18 6160 M D Geleen, The Netherlands
Response to Comments on “Studies on Gas Holdup in a Bubble Column Operated at Elevated Temperatures” Sir: We thank Wilkinson and Dierendonck (1990) very much for their comments on our paper (Zou et al., 1988). Their comments make our field of vision wider. We discussed the effect of temperature on gas holdup from the viewpoint of application, while Wilkinson and Dierendonck do so from the viewpoint of the degree of saturation of the gas by liquid, which we considered. The conclusions reached by Wilkinson and Dierendonck and by us seem to be different. However, after serious analysis, the conclusions aren’t contradictory but are only different from the viewpoint of the discussions. The existence of the end of the column is the main cause of the resulting “end effect”. But as Qu (1981) showed, the influence of the column height, H, on this effect is negligible when H 3 1 m. Since the temperature inside the column is equal to that of the U-tube and the ratio of the column liquid to the liquid in the U-tube replaced by column liquid is very large in our experiments, the property of the liquid inside the column and the property of the liquid in the U-tube are the same, and our experiments are certainly correct. In our paper we mainly paid attention to the feed rates and the production capacity of the reactor and not to the degree of saturation of gas by liquid. We didn’t discuss the effect of the temperature on the gas holdup from the viewpoint of the degree of saturation of gas by liquid as Wilkinson and Dierendonck did. But our conclusions and the conclusions of Wilkinson and Dier-
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endonck are not contradictory. The correction in our paper indeed reflects well the relationship of gas holdup, temperature, and the physical property for the air-water and air-alcohol systems. Literature Cited Qu, Yantao. The Process and the Equipment in Basic Organic Chemical Industry; Chemical Industry Press: Beijing, 1981. Wilkinson, P. M.; Dierendonck, L. L. v. Comments on “Studies on Gas Holdup in a Bubble Column Operated a t Elevated Temperatures”. lnd. Eng. Chem. Res. 1990, preceding paper in this issue. Zou, Renjun; Jiang, Xinzhen; Li, Baozhang, Zu, Yong; Zhang, Laiqi. Studies on Gas Holdup in a Bubble Column Operated at Elevated Temperatures. Ind. Eng. Chem. Res. 1988, 27 (lo), 1910-1916.
* In accordance with the authors’ wishes, their family name is listed first. Zou Renjun*
Hebei Academy of Sciences Shijiazhuang, The People’s Republic of China
Zhang Laiqi Northwestern University Xi’an, The People’s Republic of China
0 1990 American Chemical Society
