Nature of Residual Liquid Holdup in Packed Beds of Spherical Particles

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• 作者：Werner van der Merwe ; Chandra Maree ; and Willie Nicol
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2004
• 出版时间：December 22, 2004
• 年：2004
• 卷：43
• 期：26
• 页码：8363 - 8368
• 全文大小：280K
• 年卷期：v.43,no.26(December 22, 2004)
• ISSN：1520-5045

文摘

The theoretical prediction of the residual liquid holdup in beds packed with nonporous sphericalparticles is tested by microscopic imaging of a bed of glass spheres wetted by water. The commonlyused Young-Laplace equation accurately predicts the meniscus shapes of the pendular rings(Saez, A. E.; Carbonell, R. G. J. Colloid Interface Sci. 1990, 140, 408). The ring sizes are measureddirectly, and the minimum internal energy (Mao et al. Chem. Eng. Sci. 1993, 48, 2697) andcritical percolation (Kramer, G. J. Chem. Eng. Sci. 1998, 53, 2985) boundary conditions proposedin the literature are shown to overpredict the average ring size. The summation of ring volumesover the bed yields a residual holdup smaller than that obtained through weighing. It is concludedthat additional liquid is trapped through capillary action at locations where two or more particlesare in close proximity. Photographic evidence of the existence of such liquid "globules" ispresented.