Mechanics of column beds: I. Acquisition of the relevant parameters

Abstract

The efficiency of chromatographic columns is ad®ersely affected by large-scale radial ®ariations of the packing density or ®oid ratio of the material used to prepare the bed. This heterogeneity is due to wall friction effects that take place during the preparation of the column and to seepage effects operating during the packing process and the subsequent operation of the column. The dependence of the bed's ®oid fraction on the stress applied during its consolidation was determined, as well as its permeability at ®arious stages of the consolidation process and the coefficient of friction between typical packing materials and the stainless steel wall of chromatographic columns. These results are required to de®elop and use numerical models of the ®olumetric response to axial compression of the bed and models of the coupled mechanical-seepage rheology of particulate materials.

Estimation of Chromatographic Columns Performances using Computer Tomography and CFD Simulations

“…The size of this wall region ranges from 10 to 50 particle diameter [2,20]. Yew and al. declared that the potential reward from packing perfect homogenous columns is doubling of the column efficiency at same column length [11]. To create rules for a convenient scale-up describing the transport mechanism inside a column by precise modeling is very useful, but neglecting radial non-uniformity can lead to strong discrepancies between model and experiment [21].…”

Preparation and characterization of nickel-modified carbon cryogel beads with uniform particle size

“…In various chemical processes for energy production or environmental protection, catalysts or adsorbents are often packed in a fixed-bed reactor or a column [21][22][23][24]. Monodisperse carbon gel beads are favorable as packing materials for fixed-bed reactors or fluidized-bed reactors to increase the mechanical strength and facilitate process design.…”

Advances in monolithic silica columns for high-performance liquid chromatography

“…However, at the same flow rate in 3.5 μm column provides a higher resistance system. One of the most important properties of porous beds in HPLC is the degree of radial homogeneity (Yew, Drumm, and Guiochon, 2003a;Yew, Ureta, Shalliker, Drumm, and Guiochon, 2003b). Mobile phase should percolate through the bed or it may cause a deleterious increase in bandwidth (Guiochon et al 1997).…”