The effects of the operation parameters

such as pulse amplitude

pulse frequency

fluid velocity and flow ratio

and structure parameters

such as packing free ratio and packing distance

on the hydrodynamics

including the flooding rate

flooding holdup and holdup of dispersed phase

of φ50 pulsed extraction column with discs and doughnuts were experimentally studied for the 30% trialkyl phoshine oxide (TRPO)(in kerosene)/1 mol·L-1 nitric acid/water system.Experimental results indicated that the flooding rate increased with increasing packing free ratio and decreasing pulse strength

and was independent of packing distance.Based on the results of the flooding holdup

the optimal packing free ratio of 23% was suggested.The holdup of dispersed phase is directly proportional to the velocity of continuous phase

flow ratio and pulse amplitude

but independent of pulse frequency.The wetting of packed materials led to the different effects of packing distance on the holdup of dispersed phase for 30% TRPO (in kerosene) or 1 mol·L-1nitric acid as the continuous phase.