Efficiency Comparison of Valve and Sieve Trays in Distillation Columns

Abstract

The purpose of this study was to compare Murphree efficiencies of various valve trays to those of sieve trays, for 18-in. and overall efficiency for larger diameter columns. Within the accuracy of the available basic data, effects of component surface tension differences and component molar latent heat of vaporization differences were observed. The valve tray types studied exhibited a higher average operating efficiency and greater turndown ratio than the sieve tray studied. The binary system which demonstrated a positive deviation from neutrality by both Zuiderweg's definition of surface tension effects and Todd's definition of molar latent heat of vaporization effects exhibited a higher operating efficiency than did the negative binary system. Efficiency plots determined for all the valve trays studied were quite similar. The only major difference in these plots was a slight shift in average efficiency between the different valve trays.

Predicted comparisons of the efficiency of large valve trays and large sieve trays

“…Considering the results reported by Anderson, Garrett, and van Winkle (1976) on the system benzene/propanol in a 0.46 m diameter column, very similar tray efficiencies were established for two types of valve trays and a sieve tray. Calculations based on the conditions reported in their column, with its fairly low liquid rate, indicate very similar values for the Peclet number.…”

Scale-up of plate efficiency from laboratory Oldershaw data

“…and tray spacing was 18 in. Details of the equipment are given in the theses by Anderson (1974) and Garrett (1975) and in the papers by Anderson et al (1976) and Garrett et al (1977). Total reflux efficiencies were reported.…”

Correlation of fractionation tray performance via a cross‐flow boundary‐layer model

“…sieve tray. Some of these data are discussed by Anderson et al (1976) and by Garrett et al (1977). The two binary systems (toluene-n-propanol and n-propanol-benzene) were intended to be representative of the two classes of surfacetension-active systems defined by Zuiderweg and Harmens (1958); however, calculations by the methods described in Appendix A indicate only minor variations of surface tension in these systems.…”