Axial vs. Radial
How to transfer
Axial process to Radial
Residence time is a popular parameter in transferring processes. In fact this is only valid when the bed height of the column remains the same or very similar.
Since Radial columns offer a stable low bed-height bed at large bed volumes, with Radial one can combine increased productivity, resin cost saving and increased product yield.
Processes often run more than proportionally faster because the pressure buildup is more than proportionally less in radial columns. Therefore translate residence time into (average) LV and try running a bit faster than that.
This transfer is done by using the reference area value which is provided with each radial column.The reference area is a imaginary cylinder (blue) which represents the corrected average surface area between the outer (2) and inner (1) boundaries Proxcys indicates the reference area in the type number of Pilot and Process HP-RFC columns e.g. CA 602 = 6cm bed height with a reference surface area of 0,2m2. Hence this column will have a flow of 200L/hr at 100cm/hr.
Processing velocity expressed in LV
- Residence time / surface area
- Normalize to cm/hr
Axial LV projected on Radial reference area
- Correct for reduced pressure drop
- Correct for increased loading efficacy
Differences in favour of Radial processing
(optimizing to lower bed height)
- Pressure drop 20-50% reduced
- Loading efficacy improved
- Complex feed handling improved
- Binding kinetics (dynamic capacity)
- Process robustness (larger process tolerance window)
- Higher Throughput