American Chemical Society, Industrial & Engineering Chemistry Research, 18(49), p. 8870-8876, 2010
DOI: 10.1021/ie1012807
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The wall effect on the settling of cylindrical particles in the inertial regime is revisited. This study covers particle Reynolds number from 600 to 16 100 and particle-length-to-diameter ratios (l/d) from 4 to 21. The wall factor (Ut/Ut,∞) is found to decrease initially as the particle-to-column diameter ratio (d/D) increases. When the wall effect becomes significant, Ut/Ut,∞ starts to increase with an increase in d/D due to a change of the particle orientation during settling. After Ut/Ut,∞ reaches a maximum, it decreases to 0 when d/D increases to 1. A semiempirical model is developed to predict the wall effect of settling of cylindrical particles over the whole range of d/D. The model shows good prediction to the experimental results and matches the wall factor models developed for spherical particles when l/d approaches 1.