The Behavior of Counter-current Packed Bed in the Proximity of the Flooding Point Under Periodic Variations of Inlet Velocities

An experimental study has been carried out of the two phase counter-current gas-liquid flow in a packed bed column operated in the proximity of the flooding point under periodic variations of inlet velocity of gas or liquid. Additional experiments have been focused on evaluating axial dispersion characteristics in the proximity of the flooding line in both liquid and gas phase using inert tracers. The transient flow experiments have revealed hysteretic behavior of liquid holdup and gas pressure in the bed. The tracer RTD experiments have shown that no deterioration of axial dispersion in both gas and liquid place takes place unless the flooding phenomenon has already prevailed. In fact, axial dispersion in the gas phase lessens with increasing gas velocity and so does axial dispersion in liquid phase at higher liquid loads