(183f) Mass Transfer Performance of an Annular Heat Integrated Sieve Tray

An internally heat integrated distillation column, HIDiC, offers the maximum energy saving potential for difficult and energy intensive separations, such as propylene-propane and the like, which are carried out in tray columns. Adopting the concentric distillation column design, with low pressure annular stripping section configured around a high pressure rectifying section, an annular type of HIDiC tray was developed and evaluated experimentally at the TU Delft. In order to comply with a rather large heat transfer duty requirement per stage, heat transferring panels are placed on the active area of the stripping section distillation tray. Results of total reflux experiments carried out at atmospheric pressure using cyclohexane/n-heptane system obtained in a 0.8 m diameter pilot plant were used to validate literature models for the prediction of the efficiency and pressure drop. The separation efficiency and pressure drop of this complex annular tray resemble those of a conventional cross flow sieve trays. However, the heat panels appeared to have a significant enhancing effect on tray efficiency, without affecting the pressure drop and/or capacity adversely.