Experimental Study of the Flooding and Appearance of a Bubble Bed on Top of a Countercurrent Packed-Bed Column

This paper presents an experimental study of the countercurrent packed-bed column in the course of flooding and above the flooding point when the column operates as a packed bed and a bubble bed in series. Pressure-drop and liquid-holdup data are presented for the packed- and bubble-bed parts of the system. The experiments show that for the two beds in series the hydrodynamic conditions within the packed-bed part are similar for various gas−liquid velocity conditions. The pressure drop in the initial stage of flooding is essentially independent of gas−liquid velocities. The porosity of the forming bubble bed is initially high/low for high/low liquid velocities. For expanded bubble beds their porosity increases with increasing gas velocities.