ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
Rigorous mathematical modeling of the process dynamics associated with the construction and filling of density gradient columns is presented in this article. These models incorporate the hydrostatic driving forces for fluid flow, friction losses associated with this flow, and the unsteady-state behavior of the liquid levels in the filling vessels and in the column itself. Four different filling arrangements are considered, corresponding to the density order of the two fluids in the filling vessels and two methods for introducing the fluid of varying density into the column. Time requirements for filling of the column and the resulting calibration curve for liquid density versus height in the gradient column are both obtained as a result of this modeling procedure. Further, extremely important operating guidelines for the final achievement of a linear density gradient in the column, which is normally the desired objective in most laboratory applications, are derived and presented. Conversely, the causes leading to nonlinear gradients are elucidated and quantified. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1147301
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