The effects of processing scale on the pressure drop of compressible gel supports in liquid chromatographic columns

Experimental data are given for the solid pressure distributions in liquid chromatographic columns for two commercially available agarose-based compressible gel supports. The data show that for a given liquid velocity the pressure drop increases exponentially with height from the top surface. However, beyond a threshold liquid velocity, flow instability develops rapidly and the pressure drop rises sharply as the gel matrix compresses under the applied vertical pressures. The threshold liquid velocity at the point of criticality is examined in the light of the experimental data and the numerical simulations based on a one dimensional elemental slice force balance of the gel mass. The result of this analysis shows that matrix rigidity, column diameter and bed height significantly affect the point of criticality.