Sieve Tray Stability Factor Based on Efficiency Data

Using a vast collection of experimental distillation-column data, sieve tray stability, and its influence on efficiency, are explored in terms of several physical and mechanical properties For trayed distillation columns, the concept of tray stability was introduced by the author back in 2010 [1]. The data used to determine this modified Froude number term were based on simulator data, and the tray hydraulic parameter examined was weeping. This work serves to validate this stability factor concept by demonstrating when tray efficiency data “falls off” as one turns down the capacity of a trayed distillation tower. That information is readily available for sieve trays from the publicly disclosed data that have been collected by Fractionation Research Inc. (FRI; Stillwater, Okla.; www.fri.org) over the past 70 years [2]. Table 1 shows a small selection of these data sets, which were used to generate some of the charts in this article. The FRI data sets are also used in this article to demonstrate that there is a relationship between tray stability and tray efficiency, and determine which physical properties and mechanical design features most impact that relationship. An equation is presented that defines the minimum tray stability…