HYSYS Operations Guide

2-180 Column-Specific Operations
Packing Properties
(Dynamics)
Robbins Factor A packing-specific quantity used in the Robbins
correlation, which is also called the dry bed
packing factor (m -1 ). The Robbins correlation is
used to predict the column vapour pressure drop.
For the dry packed bed at atmospheric pressure, 2
the Robbins or packing factor is proportional to the
vapour pressure drop.
Static Holdup Static liquid, hst , is the m 3 liquid/ m 3 packed bed
remaining on the packing after it has been fully
wetted and left to drain. The static liquid holdup is
a constant value.
Include Loading
Regime Term
To specify Chimney and Sump tray types, the Non Uniform Tray
Data Option must be selected from the Section Properties
group. The Non Uniform Tray Data Option allows you to model a
column with high fidelity by adjusting tray rating parameters on
a tray by tray basis.
Figure 2.136
Description
Loading regime term is the second term in the
Robbins pressure drop equation, which is limited
to atmospheric pressure and under vacuum but
not at elevated pressures. When pressure is high,
(in other words, above 1 atm), inclusion of the
loading regime term may cause an unrealistically
high pressure drop prediction.
For a Trayed section of a column, you can adjust the Internal
Type of tray, Tray Spacing, Diameter, Weir Height, Weir Length,
2-180