| Abstract: | Screen trays are proprietary devices similar to sieve trays which are used in distillation and absorption applications. The pressure drop, liquid holdup and entrainment are measured for screen trays in an air/water column and compared to results obtained with sieve trays. The effciencies of both types of trays were compared in a distillation column using systems of various physical properties (methanol/water, acetic acid/water and cyclohexane/n-heptane mixtures). It was found that the screen tray has a lower dry pressure drop, higher liquid holdup, lower entrainment and weeping, and higher jet flooding capacity than the sieve tray. However, the effciencies of both trays are similar for the systems studied. A model was developed for predicting total pressure drop for screen trays using an air/water column. The model was tested using results for methanol/water, cyclohexane/n-heptane and acetic acid/water systems at total reflux. The deviations are within +/- 20% for 90% of the data points. The effect of a bed of mesh packing on the screen tray was also studied. It was found that the packing led to a higher tray effciency, but resulted in a higher tray pressure drop. |
