(48f) Modeling Fraction Jetting on Distillation Trays

The bi-phases on distillation trays can function in several different regimes depending on the physical properties of the system and the liquid-to-vapor ratio. Predicting the fraction of the vapor transported as jets, or fraction jetting, on a tray operating in the mixed-froth regime can bridge froth and spray regime models, explain the gradual changes in tray efficiency during the froth-spray transition, and eliminate the need to predict the froth-spray transition point when separate froth and spray regime models are used.  Fraction jetting models will also facilitate multi-regime models, such as the Syeda, Afacan, and Chuang (2007) sieve tray efficiency model, that are valid for both froth and spray regimes.  Current fraction jetting models are empirical and developed from limited data. In this paper, the factors affecting fraction jetting on a tray are discussed  and a new semi-empirical model to predict fraction jetting as an alternative to existing models is presented.