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...