Design parameters, effects column diameter

The fractional gas holdup Cq is an important parameter to characterize gas-in-liquid dispersions. Sq depends mainly on the gas throughput, the sparger design and on physico-chemical properties. If the column diameter is large compared to the bubble diameter, say larger by a factor of about 40, the column dicuneter has no significant effect. This is commonly valid if d. >10 cm. 

Schematically, one can get a variety of band profiles from column design and bed structure parameters. On the top left of Figure 4 is one profile from a high linear velocity flow of the column. The center profile shows the effect of wall effect and point source distribution of sample and solvent at high linear velocities. If one eliminates the wall effect by utilizing very wide diameter columns and smaller particle packing, but still has a point source distribution of sample and solvent, one will get band distortion in the center of the band at higher fluid velocities.

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