(48a) On Distillation Tray Weir Loadings

Distillation tray liquid rates are usually described via a term known as ?weir loading.? A weir loading on

a tray is simply the volumetric liquid flow rate per unit length of outlet weir. The last 50 years of

distillation tray literature proposes to tray designers a very wide, and confusing, range of ?weir loading

criteria.? It is often unclear as to whether the high-end criteria are referring to the points at which

flooding occurs , or, the points at which the number of flow passes need to be increased. There are also

low-end criteria which refer to spray fluidization points or points at which picket fence weirs need to be

used. This paper explains the utility of the weir loading variable and the associated literature criteria.