The?rstGermanedition of thebook"Fluiddynamicsofpackedcolumns with modern
random and structured packings for gas/liquid systems" was published in
1991. It sold out within a few years. Added to this were numerous
enquiries, in particular within the industry, prompting me to publish a
second, extended edition. A packed column remains the core element of
any diffusional separation process. This underlines the need for basic
design principles for packed columns, which enhance the design process
by making it more accurate and reliable. The SBD (suspended bed of
droplets) model introduced in the ?rst German edition of the book was
well received by the experts and is now used by a large number of com-
nies in the industry, as it offers improved reliability in the ?uid
dynamic design of packed columns. For the purpose of facilitating the
design process, the SBD model was in- grated into the simulation
programme ChemCAD. The software programme FDPAK, which is available for
Windows, has certainly contributed to the widespread use of the SBD
model. The programme is very user-friendly and the calculation results
are p- sented in tabular as well as graphic form, showing ?ood load,
pressure drop and hold-up diagrams in the entire operating range.