(129d) How to Surpass Conventional and High Capacity Structured Packings with Raschig Super-Pak

Abstract

Raschig Super-Pak
is a novel development in structured packing product technology that is
fundamentally different to the well known corrugated perforated or
non-perforated, textured sheet metal structured packings.  It comprises of a
systematic sequence of smooth sinusoidal waves above and below the plain of the
metal sheet.  Tests at the Ruhr University of Bochum showed that the new open
structure resulted in very high capacities low pressure drops and excellent
mass transfer efficiencies.

Encouraged by
these early successes, total reflux distillation tests with Raschig Super-Pak
300 were conducted at the Separations Research Program, University of Texas at
Austin.  Results in terms of useful capacity, (more suitable parameter for
column design than hydraulic capacity), mass transfer efficiency, pressure drop
and pressure drop per theoretical stage are presented.   Comparisons with the
conventional and high capacity structured packings tested under identical
conditions as shown in figure 1 will be discussed in detail.

Overall Raschig
Super-Pak 300 exhibits higher useful capacities and lower pressure drops
compared not only with conventional 45^o corrugation angle 250m²/m³
specific surface area structured packings but also with the high capacity counterpart
types as well.  Remarkably these gains were achieved without any adverse
effects on mass transfer efficiency as reflected in the lower pressure drop per
theoretical stage of Raschig Super-Pak 300 compared to the 250m²/m³
specific surface area structured packings. These highly encouraging results
provide industry with an alternative choice for smaller column diameter and/or
higher capacity: the Raschig Super-Pak.

Figure
1:         Mass transfer efficiency (HETP) comparison
at total reflux.

                        SRP
test column, 0.43 m I.D., 3.124 m bed height, system: cyclohexane/n-heptane