The packed towers have been widely used in the oil
refining, petroleum chemical industry, food, medicine and
environmental protection areas for the advantage of great
capacity, small pressure drop and flexible operation. The gas
velocity when the flooding happens in a packed tower is
called the flooding velocity (also called the flooding point
velocity). Generally, it is important to predict the flooding
velocity accurately because it is the operating limit of the
packed towers and is required for calculation of the maximum
loading capacity at a given specific liquid load [1-3].