The forgotten effect in thermal diffusion
Article first published online: 17 JUN 2004
Copyright © 1967 American Institute of Chemical Engineers
Volume 13, Issue 2, pages 224–230, March 1967
How to Cite
Korchinsky, W. J. and Emery, A. H. (1967), The forgotten effect in thermal diffusion. AIChE J., 13: 224–230. doi: 10.1002/aic.690130208
- Issue published online: 17 JUN 2004
- Article first published online: 17 JUN 2004
- Manuscript Accepted: 19 JUL 1966
- Manuscript Received: 31 JAN 1966
The basic equations that describe the thermal diffusion column, including the forgotten effect, were solved numerically. When the density of the liquid in the column varies with concentration, the effect is important in transient batch operation of columns, increasingly so as the wall spacing decreases, but it has no influence at the steady state. Experimental work corroborated the theoretical results.
According to the theory, the instances of concentration reversal reported in the literature cannot be the result of the forgotten effect; the fluids involved could not have had the necessary properties. Attempted duplications of these instances in careful experiments yielded normal behavior. However, theoretical and experimental work on a column with a deliberately nonconstant wall spacing indicated that concentration reversals could occur in the complete absence of any forgotten effect contribution.